Repo created

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/address_is_readable.cc

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+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// base::AddressIsReadable() probes an address to see whether it is readable,
+// without faulting.
+
+#include "absl/debugging/internal/address_is_readable.h"
+
+#if !defined(__linux__) || defined(__ANDROID__)
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// On platforms other than Linux, just return true.
+bool AddressIsReadable(const void* /* addr */) { return true; }
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#else  // __linux__ && !__ANDROID__
+
+#include <stdint.h>
+#include <syscall.h>
+#include <unistd.h>
+
+#include "absl/base/internal/errno_saver.h"
+#include "absl/base/internal/raw_logging.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// NOTE: be extra careful about adding any interposable function calls here
+// (such as open(), read(), etc.). These symbols may be interposed and will get
+// invoked in contexts they don't expect.
+//
+// NOTE: any new system calls here may also require sandbox reconfiguration.
+//
+bool AddressIsReadable(const void *addr) {
+  // rt_sigprocmask below checks 8 contiguous bytes. If addr resides in the
+  // last 7 bytes of a page (unaligned), rt_sigprocmask would additionally
+  // check the readability of the next page, which is not desired. Align
+  // address on 8-byte boundary to check only the current page.
+  const uintptr_t u_addr = reinterpret_cast<uintptr_t>(addr) & ~uintptr_t{7};
+  addr = reinterpret_cast<const void *>(u_addr);
+
+  // rt_sigprocmask below will succeed for this input.
+  if (addr == nullptr) return false;
+
+  absl::base_internal::ErrnoSaver errno_saver;
+
+  // Here we probe with some syscall which
+  // - accepts an 8-byte region of user memory as input
+  // - tests for EFAULT before other validation
+  // - has no problematic side-effects
+  //
+  // rt_sigprocmask(2) works for this.  It copies sizeof(kernel_sigset_t)==8
+  // bytes from the address into the kernel memory before any validation.
+  //
+  // The call can never succeed, since the `how` parameter is not one of
+  // SIG_BLOCK, SIG_UNBLOCK, SIG_SETMASK.
+  //
+  // This strategy depends on Linux implementation details,
+  // so we rely on the test to alert us if it stops working.
+  //
+  // Some discarded past approaches:
+  // - msync() doesn't reject PROT_NONE regions
+  // - write() on /dev/null doesn't return EFAULT
+  // - write() on a pipe requires creating it and draining the writes
+  // - connect() works but is problematic for sandboxes and needs a valid
+  //   file descriptor
+  //
+  // This can never succeed (invalid first argument to sigprocmask).
+  ABSL_RAW_CHECK(syscall(SYS_rt_sigprocmask, ~0, addr, nullptr,
+                         /*sizeof(kernel_sigset_t)*/ 8) == -1,
+                 "unexpected success");
+  ABSL_RAW_CHECK(errno == EFAULT || errno == EINVAL, "unexpected errno");
+  return errno != EFAULT;
+}
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // __linux__ && !__ANDROID__

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/address_is_readable.h

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+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_ADDRESS_IS_READABLE_H_
+#define ABSL_DEBUGGING_INTERNAL_ADDRESS_IS_READABLE_H_
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// Return whether the byte at *addr is readable, without faulting.
+// Save and restores errno.
+bool AddressIsReadable(const void *addr);
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_ADDRESS_IS_READABLE_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/bounded_utf8_length_sequence.h

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+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_BOUNDED_UTF8_LENGTH_SEQUENCE_H_
+#define ABSL_DEBUGGING_INTERNAL_BOUNDED_UTF8_LENGTH_SEQUENCE_H_
+
+#include <cstdint>
+
+#include "absl/base/config.h"
+#include "absl/numeric/bits.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// A sequence of up to max_elements integers between 1 and 4 inclusive, whose
+// insertion operation computes the sum of all the elements before the insertion
+// point.  This is useful in decoding Punycode, where one needs to know where in
+// a UTF-8 byte stream the n-th code point begins.
+//
+// BoundedUtf8LengthSequence is async-signal-safe and suitable for use in
+// symbolizing stack traces in a signal handler, provided max_elements is not
+// improvidently large.  For inputs of lengths accepted by the Rust demangler,
+// up to a couple hundred code points, InsertAndReturnSumOfPredecessors should
+// run in a few dozen clock cycles, on par with the other arithmetic required
+// for Punycode decoding.
+template <uint32_t max_elements>
+class BoundedUtf8LengthSequence {
+ public:
+  // Constructs an empty sequence.
+  BoundedUtf8LengthSequence() = default;
+
+  // Inserts `utf_length` at position `index`, shifting any existing elements at
+  // or beyond `index` one position to the right.  If the sequence is already
+  // full, the rightmost element is discarded.
+  //
+  // Returns the sum of the elements at positions 0 to `index - 1` inclusive.
+  // If `index` is greater than the number of elements already inserted, the
+  // excess positions in the range count 1 apiece.
+  //
+  // REQUIRES: index < max_elements and 1 <= utf8_length <= 4.
+  uint32_t InsertAndReturnSumOfPredecessors(
+      uint32_t index, uint32_t utf8_length) {
+    // The caller shouldn't pass out-of-bounds inputs, but if it does happen,
+    // clamp the values and try to continue.  If we're being called from a
+    // signal handler, the last thing we want to do is crash.  Emitting
+    // malformed UTF-8 is a lesser evil.
+    if (index >= max_elements) index = max_elements - 1;
+    if (utf8_length == 0 || utf8_length > 4) utf8_length = 1;
+
+    const uint32_t word_index = index/32;
+    const uint32_t bit_index = 2 * (index % 32);
+    const uint64_t ones_bit = uint64_t{1} << bit_index;
+
+    // Compute the sum of predecessors.
+    //   - Each value from 1 to 4 is represented by a bit field with value from
+    //     0 to 3, so the desired sum is index plus the sum of the
+    //     representations actually stored.
+    //   - For each bit field, a set low bit should contribute 1 to the sum, and
+    //     a set high bit should contribute 2.
+    //   - Another way to say the same thing is that each set bit contributes 1,
+    //     and each set high bit contributes an additional 1.
+    //   - So the sum we want is index + popcount(everything) + popcount(bits in
+    //     odd positions).
+    const uint64_t odd_bits_mask = 0xaaaaaaaaaaaaaaaa;
+    const uint64_t lower_seminibbles_mask = ones_bit - 1;
+    const uint64_t higher_seminibbles_mask = ~lower_seminibbles_mask;
+    const uint64_t same_word_bits_below_insertion =
+        rep_[word_index] & lower_seminibbles_mask;
+    int full_popcount = absl::popcount(same_word_bits_below_insertion);
+    int odd_popcount =
+        absl::popcount(same_word_bits_below_insertion & odd_bits_mask);
+    for (uint32_t j = word_index; j > 0; --j) {
+      const uint64_t word_below_insertion = rep_[j - 1];
+      full_popcount += absl::popcount(word_below_insertion);
+      odd_popcount += absl::popcount(word_below_insertion & odd_bits_mask);
+    }
+    const uint32_t sum_of_predecessors =
+        index + static_cast<uint32_t>(full_popcount + odd_popcount);
+
+    // Now insert utf8_length's representation, shifting successors up one
+    // place.
+    for (uint32_t j = max_elements/32 - 1; j > word_index; --j) {
+      rep_[j] = (rep_[j] << 2) | (rep_[j - 1] >> 62);
+    }
+    rep_[word_index] =
+        (rep_[word_index] & lower_seminibbles_mask) |
+        (uint64_t{utf8_length - 1} << bit_index) |
+        ((rep_[word_index] & higher_seminibbles_mask) << 2);
+
+    return sum_of_predecessors;
+  }
+
+ private:
+  // If the (32 * i + j)-th element of the represented sequence has the value k
+  // (0 <= j < 32, 1 <= k <= 4), then bits 2 * j and 2 * j + 1 of rep_[i]
+  // contain the seminibble (k - 1).
+  //
+  // In particular, the zero-initialization of rep_ makes positions not holding
+  // any inserted element count as 1 in InsertAndReturnSumOfPredecessors.
+  //
+  // Example: rep_ = {0xb1, ... the rest zeroes ...} represents the sequence
+  // (2, 1, 4, 3, ... the rest 1's ...).  Constructing the sequence of Unicode
+  // code points "Àa🂻中" = {U+00C0, U+0061, U+1F0BB, U+4E2D} (among many
+  // other examples) would yield this value of rep_.
+  static_assert(max_elements > 0 && max_elements % 32 == 0,
+                "max_elements must be a positive multiple of 32");
+  uint64_t rep_[max_elements/32] = {};
+};
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_BOUNDED_UTF8_LENGTH_SEQUENCE_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/bounded_utf8_length_sequence_test.cc

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+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/bounded_utf8_length_sequence.h"
+
+#include <cstdint>
+
+#include "gtest/gtest.h"
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+namespace {
+
+TEST(BoundedUtf8LengthSequenceTest, RemembersAValueOfOneCorrectly) {
+  BoundedUtf8LengthSequence<32> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 1), 0);
+  EXPECT_EQ(seq.InsertAndReturnSumOfPredecessors(1, 1), 1);
+}
+
+TEST(BoundedUtf8LengthSequenceTest, RemembersAValueOfTwoCorrectly) {
+  BoundedUtf8LengthSequence<32> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 2), 0);
+  EXPECT_EQ(seq.InsertAndReturnSumOfPredecessors(1, 1), 2);
+}
+
+TEST(BoundedUtf8LengthSequenceTest, RemembersAValueOfThreeCorrectly) {
+  BoundedUtf8LengthSequence<32> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 3), 0);
+  EXPECT_EQ(seq.InsertAndReturnSumOfPredecessors(1, 1), 3);
+}
+
+TEST(BoundedUtf8LengthSequenceTest, RemembersAValueOfFourCorrectly) {
+  BoundedUtf8LengthSequence<32> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 4), 0);
+  EXPECT_EQ(seq.InsertAndReturnSumOfPredecessors(1, 1), 4);
+}
+
+TEST(BoundedUtf8LengthSequenceTest, RemembersSeveralAppendedValues) {
+  BoundedUtf8LengthSequence<32> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 1), 0);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(1, 4), 1);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(2, 2), 5);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(3, 3), 7);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(4, 1), 10);
+}
+
+TEST(BoundedUtf8LengthSequenceTest, RemembersSeveralPrependedValues) {
+  BoundedUtf8LengthSequence<32> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 4), 0);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 3), 0);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 2), 0);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 1), 0);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(4, 1), 10);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(3, 1), 6);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(2, 1), 3);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(1, 1), 1);
+}
+
+TEST(BoundedUtf8LengthSequenceTest, RepeatedInsertsShiftValuesOutTheRightEnd) {
+  BoundedUtf8LengthSequence<32> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 2), 0);
+  for (uint32_t i = 1; i < 31; ++i) {
+    ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 1), 0)
+        << "while moving the 2 into position " << i;
+    ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(31, 1), 32)
+        << "after moving the 2 into position " << i;
+  }
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 1), 0)
+      << "while moving the 2 into position 31";
+  EXPECT_EQ(seq.InsertAndReturnSumOfPredecessors(31, 1), 31)
+      << "after moving the 2 into position 31";
+}
+
+TEST(BoundedUtf8LengthSequenceTest, InsertsIntoWord1LeaveWord0Untouched) {
+  BoundedUtf8LengthSequence<64> seq;
+  for (uint32_t i = 0; i < 32; ++i) {
+    ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(i, 2), 2 * i)
+        << "at index " << i;
+  }
+  EXPECT_EQ(seq.InsertAndReturnSumOfPredecessors(32, 1), 64);
+  EXPECT_EQ(seq.InsertAndReturnSumOfPredecessors(32, 1), 64);
+}
+
+TEST(BoundedUtf8LengthSequenceTest, InsertsIntoWord0ShiftValuesIntoWord1) {
+  BoundedUtf8LengthSequence<64> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(29, 2), 29);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(30, 3), 31);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(31, 4), 34);
+
+  // Pushing two 1's on the front moves the 3 and 4 into the high word.
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 1), 0);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 1), 0);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(34, 1), 31 + 2 + 3 + 4);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(32, 1), 31 + 2);
+}
+
+TEST(BoundedUtf8LengthSequenceTest, ValuesAreShiftedCorrectlyAmongThreeWords) {
+  BoundedUtf8LengthSequence<96> seq;
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(31, 3), 31);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(63, 4), 62 + 3);
+
+  // This insertion moves both the 3 and the 4 up a word.
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(0, 1), 0);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(65, 1), 63 + 3 + 4);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(64, 1), 63 + 3);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(33, 1), 32 + 3);
+  ASSERT_EQ(seq.InsertAndReturnSumOfPredecessors(32, 1), 32);
+}
+
+}  // namespace
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/decode_rust_punycode.cc

@@ -0,0 +1,258 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/decode_rust_punycode.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+
+#include "absl/base/config.h"
+#include "absl/base/nullability.h"
+#include "absl/debugging/internal/bounded_utf8_length_sequence.h"
+#include "absl/debugging/internal/utf8_for_code_point.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+namespace {
+
+// Decoding Punycode requires repeated random-access insertion into a stream of
+// variable-length UTF-8 code-point encodings.  We need this to be tolerably
+// fast (no N^2 slowdown for unfortunate inputs), and we can't allocate any data
+// structures on the heap (async-signal-safety).
+//
+// It is pragmatic to impose a moderately low limit on the identifier length and
+// bail out if we ever hit it.  Then BoundedUtf8LengthSequence efficiently
+// determines where to insert the next code point, and memmove efficiently makes
+// room for it.
+//
+// The chosen limit is a round number several times larger than identifiers
+// expected in practice, yet still small enough that a memmove of this many
+// UTF-8 characters is not much more expensive than the division and modulus
+// operations that Punycode decoding requires.
+constexpr uint32_t kMaxChars = 256;
+
+// Constants from RFC 3492 section 5.
+constexpr uint32_t kBase = 36, kTMin = 1, kTMax = 26, kSkew = 38, kDamp = 700;
+
+constexpr uint32_t kMaxCodePoint = 0x10ffff;
+
+// Overflow threshold in DecodeRustPunycode's inner loop; see comments there.
+constexpr uint32_t kMaxI = 1 << 30;
+
+// If punycode_begin .. punycode_end begins with a prefix matching the regular
+// expression [0-9a-zA-Z_]+_, removes that prefix, copies all but the final
+// underscore into out_begin .. out_end, sets num_ascii_chars to the number of
+// bytes copied, and returns true.  (A prefix of this sort represents the
+// nonempty subsequence of ASCII characters in the corresponding plaintext.)
+//
+// If punycode_begin .. punycode_end does not contain an underscore, sets
+// num_ascii_chars to zero and returns true.  (The encoding of a plaintext
+// without any ASCII characters does not carry such a prefix.)
+//
+// Returns false and zeroes num_ascii_chars on failure (either parse error or
+// not enough space in the output buffer).
+bool ConsumeOptionalAsciiPrefix(const char*& punycode_begin,
+                                const char* const punycode_end,
+                                char* const out_begin,
+                                char* const out_end,
+                                uint32_t& num_ascii_chars) {
+  num_ascii_chars = 0;
+
+  // Remember the last underscore if any.  Also use the same string scan to
+  // reject any ASCII bytes that do not belong in an identifier, including NUL,
+  // as well as non-ASCII bytes, which should have been delta-encoded instead.
+  int last_underscore = -1;
+  for (int i = 0; i < punycode_end - punycode_begin; ++i) {
+    const char c = punycode_begin[i];
+    if (c == '_') {
+      last_underscore = i;
+      continue;
+    }
+    // We write out the meaning of absl::ascii_isalnum rather than call that
+    // function because its documentation does not promise it will remain
+    // async-signal-safe under future development.
+    if ('a' <= c && c <= 'z') continue;
+    if ('A' <= c && c <= 'Z') continue;
+    if ('0' <= c && c <= '9') continue;
+    return false;
+  }
+
+  // If there was no underscore, that means there were no ASCII characters in
+  // the plaintext, so there is no prefix to consume.  Our work is done.
+  if (last_underscore < 0) return true;
+
+  // Otherwise there will be an underscore delimiter somewhere.  It can't be
+  // initial because then there would be no ASCII characters to its left, and no
+  // delimiter would have been added in that case.
+  if (last_underscore == 0) return false;
+
+  // Any other position is reasonable.  Make sure there's room in the buffer.
+  if (last_underscore + 1 > out_end - out_begin) return false;
+
+  // Consume and write out the ASCII characters.
+  num_ascii_chars = static_cast<uint32_t>(last_underscore);
+  std::memcpy(out_begin, punycode_begin, num_ascii_chars);
+  out_begin[num_ascii_chars] = '\0';
+  punycode_begin += num_ascii_chars + 1;
+  return true;
+}
+
+// Returns the value of `c` as a base-36 digit according to RFC 3492 section 5,
+// or -1 if `c` is not such a digit.
+int DigitValue(char c) {
+  if ('0' <= c && c <= '9') return c - '0' + 26;
+  if ('a' <= c && c <= 'z') return c - 'a';
+  if ('A' <= c && c <= 'Z') return c - 'A';
+  return -1;
+}
+
+// Consumes the next delta encoding from punycode_begin .. punycode_end,
+// updating i accordingly.  Returns true on success.  Returns false on parse
+// failure or arithmetic overflow.
+bool ScanNextDelta(const char*& punycode_begin, const char* const punycode_end,
+                   uint32_t bias, uint32_t& i) {
+  uint64_t w = 1;  // 64 bits to prevent overflow in w *= kBase - t
+
+  // "for k = base to infinity in steps of base do begin ... end" in RFC 3492
+  // section 6.2.  Each loop iteration scans one digit of the delta.
+  for (uint32_t k = kBase; punycode_begin != punycode_end; k += kBase) {
+    const int digit_value = DigitValue(*punycode_begin++);
+    if (digit_value < 0) return false;
+
+    // Compute this in 64-bit arithmetic so we can check for overflow afterward.
+    const uint64_t new_i = i + static_cast<uint64_t>(digit_value) * w;
+
+    // Valid deltas are bounded by (#chars already emitted) * kMaxCodePoint, but
+    // invalid input could encode an arbitrarily large delta.  Nip that in the
+    // bud here.
+    static_assert(
+        kMaxI >= kMaxChars * kMaxCodePoint,
+        "kMaxI is too small to prevent spurious failures on good input");
+    if (new_i > kMaxI) return false;
+
+    static_assert(
+        kMaxI < (uint64_t{1} << 32),
+        "Make kMaxI smaller or i 64 bits wide to prevent silent wraparound");
+    i = static_cast<uint32_t>(new_i);
+
+    // Compute the threshold that determines whether this is the last digit and
+    // (if not) what the next digit's place value will be.  This logic from RFC
+    // 3492 section 6.2 is explained in section 3.3.
+    uint32_t t;
+    if (k <= bias + kTMin) {
+      t = kTMin;
+    } else if (k >= bias + kTMax) {
+      t = kTMax;
+    } else {
+      t = k - bias;
+    }
+    if (static_cast<uint32_t>(digit_value) < t) return true;
+
+    // If this gets too large, the range check on new_i in the next iteration
+    // will catch it.  We know this multiplication will not overwrap because w
+    // is 64 bits wide.
+    w *= kBase - t;
+  }
+  return false;
+}
+
+}  // namespace
+
+absl::Nullable<char*> DecodeRustPunycode(DecodeRustPunycodeOptions options) {
+  const char* punycode_begin = options.punycode_begin;
+  const char* const punycode_end = options.punycode_end;
+  char* const out_begin = options.out_begin;
+  char* const out_end = options.out_end;
+
+  // Write a NUL terminator first.  Later memcpy calls will keep bumping it
+  // along to its new right place.
+  const size_t out_size = static_cast<size_t>(out_end - out_begin);
+  if (out_size == 0) return nullptr;
+  *out_begin = '\0';
+
+  // RFC 3492 section 6.2 begins here.  We retain the names of integer variables
+  // appearing in that text.
+  uint32_t n = 128, i = 0, bias = 72, num_chars = 0;
+
+  // If there are any ASCII characters, consume them and their trailing
+  // underscore delimiter.
+  if (!ConsumeOptionalAsciiPrefix(punycode_begin, punycode_end,
+                                  out_begin, out_end, num_chars)) {
+    return nullptr;
+  }
+  uint32_t total_utf8_bytes = num_chars;
+
+  BoundedUtf8LengthSequence<kMaxChars> utf8_lengths;
+
+  // "while the input is not exhausted do begin ... end"
+  while (punycode_begin != punycode_end) {
+    if (num_chars >= kMaxChars) return nullptr;
+
+    const uint32_t old_i = i;
+
+    if (!ScanNextDelta(punycode_begin, punycode_end, bias, i)) return nullptr;
+
+    // Update bias as in RFC 3492 section 6.1.  (We have inlined adapt.)
+    uint32_t delta = i - old_i;
+    delta /= (old_i == 0 ? kDamp : 2);
+    delta += delta/(num_chars + 1);
+    bias = 0;
+    while (delta > ((kBase - kTMin) * kTMax)/2) {
+      delta /= kBase - kTMin;
+      bias += kBase;
+    }
+    bias += ((kBase - kTMin + 1) * delta)/(delta + kSkew);
+
+    // Back in section 6.2, compute the new code point and insertion index.
+    static_assert(
+        kMaxI + kMaxCodePoint < (uint64_t{1} << 32),
+        "Make kMaxI smaller or n 64 bits wide to prevent silent wraparound");
+    n += i/(num_chars + 1);
+    i %= num_chars + 1;
+
+    // To actually insert, we need to convert the code point n to UTF-8 and the
+    // character index i to an index into the byte stream emitted so far.  First
+    // prepare the UTF-8 encoding for n, rejecting surrogates, overlarge values,
+    // and anything that won't fit into the remaining output storage.
+    Utf8ForCodePoint utf8_for_code_point(n);
+    if (!utf8_for_code_point.ok()) return nullptr;
+    if (total_utf8_bytes + utf8_for_code_point.length + 1 > out_size) {
+      return nullptr;
+    }
+
+    // Now insert the new character into both our length map and the output.
+    uint32_t n_index =
+        utf8_lengths.InsertAndReturnSumOfPredecessors(
+            i, utf8_for_code_point.length);
+    std::memmove(
+        out_begin + n_index + utf8_for_code_point.length, out_begin + n_index,
+        total_utf8_bytes + 1 - n_index);
+    std::memcpy(out_begin + n_index, utf8_for_code_point.bytes,
+                utf8_for_code_point.length);
+    total_utf8_bytes += utf8_for_code_point.length;
+    ++num_chars;
+
+    // Finally, advance to the next state before continuing.
+    ++i;
+  }
+
+  return out_begin + total_utf8_bytes;
+}
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/decode_rust_punycode.h

@@ -0,0 +1,55 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_DECODE_RUST_PUNYCODE_H_
+#define ABSL_DEBUGGING_INTERNAL_DECODE_RUST_PUNYCODE_H_
+
+#include "absl/base/config.h"
+#include "absl/base/nullability.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+struct DecodeRustPunycodeOptions {
+  const char* punycode_begin;
+  const char* punycode_end;
+  char* out_begin;
+  char* out_end;
+};
+
+// Given Rust Punycode in `punycode_begin .. punycode_end`, writes the
+// corresponding UTF-8 plaintext into `out_begin .. out_end`, followed by a NUL
+// character, and returns a pointer to that final NUL on success.  On failure
+// returns a null pointer, and the contents of `out_begin .. out_end` are
+// unspecified.
+//
+// Failure occurs in precisely these cases:
+//   - Any input byte does not match [0-9a-zA-Z_].
+//   - The first input byte is an underscore, but no other underscore appears in
+//     the input.
+//   - The delta sequence does not represent a valid sequence of code-point
+//     insertions.
+//   - The plaintext would contain more than 256 code points.
+//
+// DecodeRustPunycode is async-signal-safe with bounded runtime and a small
+// stack footprint, making it suitable for use in demangling Rust symbol names
+// from a signal handler.
+absl::Nullable<char*> DecodeRustPunycode(DecodeRustPunycodeOptions options);
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_DECODE_RUST_PUNYCODE_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/decode_rust_punycode_test.cc

@@ -0,0 +1,606 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/decode_rust_punycode.h"
+
+#include <cstddef>
+#include <cstring>
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+namespace {
+
+using ::testing::AllOf;
+using ::testing::Eq;
+using ::testing::IsNull;
+using ::testing::Pointee;
+using ::testing::ResultOf;
+using ::testing::StrEq;
+
+class DecodeRustPunycodeTest : public ::testing::Test {
+ protected:
+  void FillBufferWithNonzeroBytes() {
+    // The choice of nonzero value to fill with is arbitrary.  The point is just
+    // to fail tests if DecodeRustPunycode forgets to write the final NUL
+    // character.
+    std::memset(buffer_storage_, 0xab, sizeof(buffer_storage_));
+  }
+
+  DecodeRustPunycodeOptions WithAmpleSpace() {
+    FillBufferWithNonzeroBytes();
+
+    DecodeRustPunycodeOptions options;
+    options.punycode_begin = punycode_.data();
+    options.punycode_end = punycode_.data() + punycode_.size();
+    options.out_begin = buffer_storage_;
+    options.out_end = buffer_storage_ + sizeof(buffer_storage_);
+    return options;
+  }
+
+  DecodeRustPunycodeOptions WithJustEnoughSpace() {
+    FillBufferWithNonzeroBytes();
+
+    const size_t begin_offset = sizeof(buffer_storage_) - plaintext_.size() - 1;
+    DecodeRustPunycodeOptions options;
+    options.punycode_begin = punycode_.data();
+    options.punycode_end = punycode_.data() + punycode_.size();
+    options.out_begin = buffer_storage_ + begin_offset;
+    options.out_end = buffer_storage_ + sizeof(buffer_storage_);
+    return options;
+  }
+
+  DecodeRustPunycodeOptions WithOneByteTooFew() {
+    FillBufferWithNonzeroBytes();
+
+    const size_t begin_offset = sizeof(buffer_storage_) - plaintext_.size();
+    DecodeRustPunycodeOptions options;
+    options.punycode_begin = punycode_.data();
+    options.punycode_end = punycode_.data() + punycode_.size();
+    options.out_begin = buffer_storage_ + begin_offset;
+    options.out_end = buffer_storage_ + sizeof(buffer_storage_);
+    return options;
+  }
+
+  // Matches a correct return value of DecodeRustPunycode when `golden` is the
+  // expected plaintext output.
+  auto PointsToTheNulAfter(const std::string& golden) {
+    const size_t golden_size = golden.size();
+    return AllOf(
+        Pointee(Eq('\0')),
+        ResultOf("preceding string body",
+                 [golden_size](const char* p) { return p - golden_size; },
+                 StrEq(golden)));
+  }
+
+  std::string punycode_;
+  std::string plaintext_;
+  char buffer_storage_[1024];
+};
+
+TEST_F(DecodeRustPunycodeTest, MapsEmptyToEmpty) {
+  punycode_ = "";
+  plaintext_ = "";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest,
+       StripsTheTrailingDelimiterFromAPureRunOfBasicChars) {
+  punycode_ = "foo_";
+  plaintext_ = "foo";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, TreatsTheLastUnderscoreAsTheDelimiter) {
+  punycode_ = "foo_bar_";
+  plaintext_ = "foo_bar";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsALeadingUnderscoreIfNotTheDelimiter) {
+  punycode_ = "_foo_";
+  plaintext_ = "_foo";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, RejectsALeadingUnderscoreDelimiter) {
+  punycode_ = "_foo";
+
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, RejectsEmbeddedNul) {
+  punycode_ = std::string("foo\0bar_", 8);
+
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, RejectsAsciiCharsOtherThanIdentifierChars) {
+  punycode_ = "foo\007_";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "foo-_";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "foo;_";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "foo\177_";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, RejectsRawNonAsciiChars) {
+  punycode_ = "\x80";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "\x80_";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "\xff";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "\xff_";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, RecognizesU0080) {
+  // a encodes 0, so the output is the smallest non-ASCII code point standing
+  // alone.  (U+0080 PAD is not an identifier character, but DecodeRustPunycode
+  // does not check whether non-ASCII characters could belong to an identifier.)
+  punycode_ = "a";
+  plaintext_ = "\xc2\x80";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, OneByteDeltaSequencesMustBeA) {
+  // Because bias = 72 for the first code point, any digit but a/A is nonfinal
+  // in one of the first two bytes of a delta sequence.
+  punycode_ = "b";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "z";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "0";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "9";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsDeltaSequenceBA) {
+  punycode_ = "ba";
+  plaintext_ = "\xc2\x81";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsOtherDeltaSequencesWithSecondByteA) {
+  punycode_ = "ca";
+  plaintext_ = "\xc2\x82";
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "za";
+  plaintext_ = "\xc2\x99";
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "0a";
+  plaintext_ = "\xc2\x9a";
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "1a";
+  plaintext_ = "\xc2\x9b";
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "9a";
+  plaintext_ = "£";  // Pound sign, U+00A3
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+}
+
+TEST_F(DecodeRustPunycodeTest, RejectsDeltaWhereTheSecondAndLastDigitIsNotA) {
+  punycode_ = "bb";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "zz";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "00";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+
+  punycode_ = "99";
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsDeltasWithSecondByteBFollowedByA) {
+  punycode_ = "bba";
+  plaintext_ = "¤";  // U+00A4
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "cba";
+  plaintext_ = "¥";  // U+00A5
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "zba";
+  plaintext_ = "¼";  // U+00BC
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "0ba";
+  plaintext_ = "½";  // U+00BD
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "1ba";
+  plaintext_ = "¾";  // U+00BE
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+
+  punycode_ = "9ba";
+  plaintext_ = "Æ";  // U+00C6
+  EXPECT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+}
+
+// Tests beyond this point use characters allowed in identifiers, so you can
+// prepend _RNvC1cu<decimal length><underscore if [0-9_] follows> to a test
+// input and run it through another Rust demangler to verify that the
+// corresponding golden output is correct.
+
+TEST_F(DecodeRustPunycodeTest, AcceptsTwoByteCharAlone) {
+  punycode_ = "0ca";
+  plaintext_ = "à";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsTwoByteCharBeforeBasicChars) {
+  punycode_ = "_la_mode_yya";
+  plaintext_ = "à_la_mode";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsTwoByteCharAmidBasicChars) {
+  punycode_ = "verre__vin_m4a";
+  plaintext_ = "verre_à_vin";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsTwoByteCharAfterBasicChars) {
+  punycode_ = "belt_3na";
+  plaintext_ = "beltà";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsRepeatedTwoByteChar) {
+  punycode_ = "0caaaa";
+  plaintext_ = "àààà";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsNearbyTwoByteCharsInOrder) {
+  punycode_ = "3camsuz";
+  plaintext_ = "ãéïôù";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsNearbyTwoByteCharsOutOfOrder) {
+  punycode_ = "3caltsx";
+  plaintext_ = "ùéôãï";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsThreeByteCharAlone) {
+  punycode_ = "fiq";
+  plaintext_ = "中";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsRepeatedThreeByteChar) {
+  punycode_ = "fiqaaaa";
+  plaintext_ = "中中中中中";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsThreeByteCharsInOrder) {
+  punycode_ = "fiq228c";
+  plaintext_ = "中文";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsNearbyThreeByteCharsOutOfOrder) {
+  punycode_ = "fiq128c";
+  plaintext_ = "文中";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsFourByteCharAlone) {
+  punycode_ = "uy7h";
+  plaintext_ = "🂻";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsFourByteCharBeforeBasicChars) {
+  punycode_ = "jack__uh63d";
+  plaintext_ = "jack_🂻";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsFourByteCharAmidBasicChars) {
+  punycode_ = "jack__of_hearts_ki37n";
+  plaintext_ = "jack_🂻_of_hearts";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsFourByteCharAfterBasicChars) {
+  punycode_ = "_of_hearts_kz45i";
+  plaintext_ = "🂻_of_hearts";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsRepeatedFourByteChar) {
+  punycode_ = "uy7haaaa";
+  plaintext_ = "🂻🂻🂻🂻🂻";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsNearbyFourByteCharsInOrder) {
+  punycode_ = "8x7hcjmf";
+  plaintext_ = "🂦🂧🂪🂭🂮";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsNearbyFourByteCharsOutOfOrder) {
+  punycode_ = "8x7hcild";
+  plaintext_ = "🂮🂦🂭🂪🂧";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, AcceptsAMixtureOfByteLengths) {
+  punycode_ = "3caltsx2079ivf8aiuy7cja3a6ak";
+  plaintext_ = "ùéôãï中文🂮🂦🂭🂪🂧";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+TEST_F(DecodeRustPunycodeTest, RejectsOverlargeDeltas) {
+  punycode_ = "123456789a";
+
+  EXPECT_THAT(DecodeRustPunycode(WithAmpleSpace()), IsNull());
+}
+
+// Finally, we test on a few prose and poetry snippets as a defense in depth.
+// If our artificial short test inputs did not exercise a bug that is tickled by
+// patterns typical of real human writing, maybe real human writing will catch
+// that.
+//
+// These test inputs are extracted from texts old enough to be out of copyright
+// that probe a variety of ranges of code-point space.  All are longer than 32
+// code points, so they exercise the carrying of seminibbles from one uint64_t
+// to the next higher one in BoundedUtf8LengthSequence.
+
+// The first three lines of the Old English epic _Beowulf_, mostly ASCII with a
+// few archaic two-byte letters interspersed.
+TEST_F(DecodeRustPunycodeTest, Beowulf) {
+  punycode_ = "hwt_we_gardena_in_geardagum_"
+              "eodcyninga_rym_gefrunon_"
+              "hu_a_elingas_ellen_fremedon_hxg9c70do9alau";
+  plaintext_ = "hwæt_we_gardena_in_geardagum_"
+               "þeodcyninga_þrym_gefrunon_"
+               "hu_ða_æþelingas_ellen_fremedon";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+// The whole of 過故人莊 by the 8th-century Chinese poet 孟浩然
+// (Meng Haoran), exercising three-byte-character processing.
+TEST_F(DecodeRustPunycodeTest, MengHaoran) {
+  punycode_ = "gmq4ss0cfvao1e2wg8mcw8b0wkl9a7tt90a8riuvbk7t8kbv9a66ogofvzlf6"
+              "3d01ybn1u28dyqi5q2cxyyxnk5d2gx1ks9ddvfm17bk6gbsd6wftrav60u4ta";
+  plaintext_ = "故人具雞黍" "邀我至田家"
+               "綠樹村邊合" "青山郭外斜"
+               "開軒面場圃" "把酒話桑麻"
+               "待到重陽日" "還來就菊花";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+// A poem of the 8th-century Japanese poet 山上憶良 (Yamanoue no Okura).
+// Japanese mixes two-byte and three-byte characters: a good workout for codecs.
+TEST_F(DecodeRustPunycodeTest, YamanoueNoOkura) {
+  punycode_ = "48jdaa3a6ccpepjrsmlb0q4bwcdtid8fg6c0cai9822utqeruk3om0u4f2wbp0"
+              "em23do0op23cc2ff70mb6tae8aq759gja";
+  plaintext_ = "瓜食めば"
+               "子ども思ほゆ"
+               "栗食めば"
+               "まして偲はゆ"
+               "何処より"
+               "来りしものそ"
+               "眼交に"
+               "もとな懸りて"
+               "安眠し寝さぬ";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+// The first two lines of the Phoenician-language inscription on the sarcophagus
+// of Eshmunazar II of Sidon, 6th century BCE.  Phoenician and many other
+// archaic scripts are allocated in the Supplemental Multilingual Plane (U+10000
+// through U+1FFFF) and thus exercise four-byte-character processing.
+TEST_F(DecodeRustPunycodeTest, EshmunazarSarcophagus) {
+  punycode_ = "wj9caaabaabbaaohcacxvhdc7bgxbccbdcjeacddcedcdlddbdbddcdbdcknfcee"
+              "ifel8del2a7inq9fhcpxikms7a4a9ac9ataaa0g";
+  plaintext_ = "𐤁𐤉𐤓𐤇𐤁𐤋𐤁𐤔𐤍𐤕𐤏𐤎𐤓"
+               "𐤅𐤀𐤓𐤁𐤏𐤗𐤖𐤖𐤖𐤖𐤋𐤌𐤋𐤊𐤉𐤌𐤋𐤊"
+               "𐤀𐤔𐤌𐤍𐤏𐤆𐤓𐤌𐤋𐤊𐤑𐤃𐤍𐤌"
+               "𐤁𐤍𐤌𐤋𐤊𐤕𐤁𐤍𐤕𐤌𐤋𐤊𐤑𐤃𐤍𐤌"
+               "𐤃𐤁𐤓𐤌𐤋𐤊𐤀𐤔𐤌𐤍𐤏𐤆𐤓𐤌𐤋𐤊"
+               "𐤑𐤃𐤍𐤌𐤋𐤀𐤌𐤓𐤍𐤂𐤆𐤋𐤕";
+
+  ASSERT_THAT(DecodeRustPunycode(WithAmpleSpace()),
+              PointsToTheNulAfter(plaintext_));
+  ASSERT_THAT(DecodeRustPunycode(WithJustEnoughSpace()),
+              PointsToTheNulAfter(plaintext_));
+  EXPECT_THAT(DecodeRustPunycode(WithOneByteTooFew()), IsNull());
+}
+
+}  // namespace
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/demangle.h

@@ -0,0 +1,76 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_DEMANGLE_H_
+#define ABSL_DEBUGGING_INTERNAL_DEMANGLE_H_
+
+#include <string>
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// Demangle `mangled`.  On success, return true and write the
+// demangled symbol name to `out`.  Otherwise, return false.
+// `out` is modified even if demangling is unsuccessful.
+//
+// This function provides an alternative to libstdc++'s abi::__cxa_demangle,
+// which is not async signal safe (it uses malloc internally).  It's intended to
+// be used in async signal handlers to symbolize stack traces.
+//
+// Note that this demangler doesn't support full demangling.  More
+// specifically, it doesn't print types of function parameters and
+// types of template arguments.  It just skips them.  However, it's
+// still very useful to extract basic information such as class,
+// function, constructor, destructor, and operator names.
+//
+// See the implementation note in demangle.cc if you are interested.
+//
+// Example:
+//
+// | Mangled Name  | Demangle    | DemangleString
+// |---------------|-------------|-----------------------
+// | _Z1fv         | f()         | f()
+// | _Z1fi         | f()         | f(int)
+// | _Z3foo3bar    | foo()       | foo(bar)
+// | _Z1fIiEvi     | f<>()       | void f<int>(int)
+// | _ZN1N1fE      | N::f        | N::f
+// | _ZN3Foo3BarEv | Foo::Bar()  | Foo::Bar()
+// | _Zrm1XS_"     | operator%() | operator%(X, X)
+// | _ZN3FooC1Ev   | Foo::Foo()  | Foo::Foo()
+// | _Z1fSs        | f()         | f(std::basic_string<char,
+// |               |             |   std::char_traits<char>,
+// |               |             |   std::allocator<char> >)
+//
+// See the unit test for more examples.
+//
+// Demangle also recognizes Rust mangled names by delegating the parsing of
+// anything that starts with _R to DemangleRustSymbolEncoding (demangle_rust.h).
+//
+// Note: we might want to write demanglers for ABIs other than Itanium
+// C++ ABI in the future.
+bool Demangle(const char* mangled, char* out, size_t out_size);
+
+// A wrapper around `abi::__cxa_demangle()`.  On success, returns the demangled
+// name.  On failure, returns the input mangled name.
+//
+// This function is not async-signal-safe.
+std::string DemangleString(const char* mangled);
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_DEMANGLE_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/demangle_rust.cc

@@ -0,0 +1,925 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/demangle_rust.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <limits>
+
+#include "absl/base/attributes.h"
+#include "absl/base/config.h"
+#include "absl/debugging/internal/decode_rust_punycode.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+namespace {
+
+// Same step limit as the C++ demangler in demangle.cc uses.
+constexpr int kMaxReturns = 1 << 17;
+
+bool IsDigit(char c) { return '0' <= c && c <= '9'; }
+bool IsLower(char c) { return 'a' <= c && c <= 'z'; }
+bool IsUpper(char c) { return 'A' <= c && c <= 'Z'; }
+bool IsAlpha(char c) { return IsLower(c) || IsUpper(c); }
+bool IsIdentifierChar(char c) { return IsAlpha(c) || IsDigit(c) || c == '_'; }
+bool IsLowerHexDigit(char c) { return IsDigit(c) || ('a' <= c && c <= 'f'); }
+
+const char* BasicTypeName(char c) {
+  switch (c) {
+    case 'a': return "i8";
+    case 'b': return "bool";
+    case 'c': return "char";
+    case 'd': return "f64";
+    case 'e': return "str";
+    case 'f': return "f32";
+    case 'h': return "u8";
+    case 'i': return "isize";
+    case 'j': return "usize";
+    case 'l': return "i32";
+    case 'm': return "u32";
+    case 'n': return "i128";
+    case 'o': return "u128";
+    case 'p': return "_";
+    case 's': return "i16";
+    case 't': return "u16";
+    case 'u': return "()";
+    case 'v': return "...";
+    case 'x': return "i64";
+    case 'y': return "u64";
+    case 'z': return "!";
+  }
+  return nullptr;
+}
+
+// Parser for Rust symbol mangling v0, whose grammar is defined here:
+//
+// https://doc.rust-lang.org/rustc/symbol-mangling/v0.html#symbol-grammar-summary
+class RustSymbolParser {
+ public:
+  // Prepares to demangle the given encoding, a Rust symbol name starting with
+  // _R, into the output buffer [out, out_end).  The caller is expected to
+  // continue by calling the new object's Parse function.
+  RustSymbolParser(const char* encoding, char* out, char* const out_end)
+      : encoding_(encoding), out_(out), out_end_(out_end) {
+    if (out_ != out_end_) *out_ = '\0';
+  }
+
+  // Parses the constructor's encoding argument, writing output into the range
+  // [out, out_end).  Returns true on success and false for input whose
+  // structure was not recognized or exceeded implementation limits, such as by
+  // nesting structures too deep.  In either case *this should not be used
+  // again.
+  ABSL_MUST_USE_RESULT bool Parse() && {
+    // Recursively parses the grammar production named by callee, then resumes
+    // execution at the next statement.
+    //
+    // Recursive-descent parsing is a beautifully readable translation of a
+    // grammar, but it risks stack overflow if implemented by naive recursion on
+    // the C++ call stack.  So we simulate recursion by goto and switch instead,
+    // keeping a bounded stack of "return addresses" in the recursion_stack_
+    // member.
+    //
+    // The callee argument is a statement label.  We goto that label after
+    // saving the "return address" on recursion_stack_.  The next continue
+    // statement in the for loop below "returns" from this "call".
+    //
+    // The caller argument names the return point.  Each value of caller must
+    // appear in only one ABSL_DEMANGLER_RECURSE call and be listed in the
+    // definition of enum ReturnAddress.  The switch implements the control
+    // transfer from the end of a "called" subroutine back to the statement
+    // after the "call".
+    //
+    // Note that not all the grammar productions have to be packed into the
+    // switch, but only those which appear in a cycle in the grammar.  Anything
+    // acyclic can be written as ordinary functions and function calls, e.g.,
+    // ParseIdentifier.
+#define ABSL_DEMANGLER_RECURSE(callee, caller) \
+    do { \
+      if (recursion_depth_ == kStackSize) return false; \
+      /* The next continue will switch on this saved value ... */ \
+      recursion_stack_[recursion_depth_++] = caller; \
+      goto callee; \
+      /* ... and will land here, resuming the suspended code. */ \
+      case caller: {} \
+    } while (0)
+
+    // Parse the encoding, counting completed recursive calls to guard against
+    // excessively complex input and infinite-loop bugs.
+    int iter = 0;
+    goto whole_encoding;
+    for (; iter < kMaxReturns && recursion_depth_ > 0; ++iter) {
+      // This switch resumes the code path most recently suspended by
+      // ABSL_DEMANGLER_RECURSE.
+      switch (recursion_stack_[--recursion_depth_]) {
+        //
+        // symbol-name ->
+        // _R decimal-number? path instantiating-crate? vendor-specific-suffix?
+        whole_encoding:
+          if (!Eat('_') || !Eat('R')) return false;
+          // decimal-number? is always empty today, so proceed to path, which
+          // can't start with a decimal digit.
+          ABSL_DEMANGLER_RECURSE(path, kInstantiatingCrate);
+          if (IsAlpha(Peek())) {
+            ++silence_depth_;  // Print nothing more from here on.
+            ABSL_DEMANGLER_RECURSE(path, kVendorSpecificSuffix);
+          }
+          switch (Take()) {
+            case '.': case '$': case '\0': return true;
+          }
+          return false;  // unexpected trailing content
+
+        // path -> crate-root | inherent-impl | trait-impl | trait-definition |
+        //         nested-path | generic-args | backref
+        //
+        // Note that ABSL_DEMANGLER_RECURSE does not work inside a nested switch
+        // (which would hide the generated case label).  Thus we jump out of the
+        // inner switch with gotos before performing any fake recursion.
+        path:
+          switch (Take()) {
+            case 'C': goto crate_root;
+            case 'M': goto inherent_impl;
+            case 'X': goto trait_impl;
+            case 'Y': goto trait_definition;
+            case 'N': goto nested_path;
+            case 'I': goto generic_args;
+            case 'B': goto path_backref;
+            default: return false;
+          }
+
+        // crate-root -> C identifier (C consumed above)
+        crate_root:
+          if (!ParseIdentifier()) return false;
+          continue;
+
+        // inherent-impl -> M impl-path type (M already consumed)
+        inherent_impl:
+          if (!Emit("<")) return false;
+          ABSL_DEMANGLER_RECURSE(impl_path, kInherentImplType);
+          ABSL_DEMANGLER_RECURSE(type, kInherentImplEnding);
+          if (!Emit(">")) return false;
+          continue;
+
+        // trait-impl -> X impl-path type path (X already consumed)
+        trait_impl:
+          if (!Emit("<")) return false;
+          ABSL_DEMANGLER_RECURSE(impl_path, kTraitImplType);
+          ABSL_DEMANGLER_RECURSE(type, kTraitImplInfix);
+          if (!Emit(" as ")) return false;
+          ABSL_DEMANGLER_RECURSE(path, kTraitImplEnding);
+          if (!Emit(">")) return false;
+          continue;
+
+        // impl-path -> disambiguator? path (but never print it!)
+        impl_path:
+          ++silence_depth_;
+          {
+            int ignored_disambiguator;
+            if (!ParseDisambiguator(ignored_disambiguator)) return false;
+          }
+          ABSL_DEMANGLER_RECURSE(path, kImplPathEnding);
+          --silence_depth_;
+          continue;
+
+        // trait-definition -> Y type path (Y already consumed)
+        trait_definition:
+          if (!Emit("<")) return false;
+          ABSL_DEMANGLER_RECURSE(type, kTraitDefinitionInfix);
+          if (!Emit(" as ")) return false;
+          ABSL_DEMANGLER_RECURSE(path, kTraitDefinitionEnding);
+          if (!Emit(">")) return false;
+          continue;
+
+        // nested-path -> N namespace path identifier (N already consumed)
+        // namespace -> lower | upper
+        nested_path:
+          // Uppercase namespaces must be saved on a stack so we can print
+          // ::{closure#0} or ::{shim:vtable#0} or ::{X:name#0} as needed.
+          if (IsUpper(Peek())) {
+            if (!PushNamespace(Take())) return false;
+            ABSL_DEMANGLER_RECURSE(path, kIdentifierInUppercaseNamespace);
+            if (!Emit("::")) return false;
+            if (!ParseIdentifier(PopNamespace())) return false;
+            continue;
+          }
+
+          // Lowercase namespaces, however, are never represented in the output;
+          // they all emit just ::name.
+          if (IsLower(Take())) {
+            ABSL_DEMANGLER_RECURSE(path, kIdentifierInLowercaseNamespace);
+            if (!Emit("::")) return false;
+            if (!ParseIdentifier()) return false;
+            continue;
+          }
+
+          // Neither upper or lower
+          return false;
+
+        // type -> basic-type | array-type | slice-type | tuple-type |
+        //         ref-type | mut-ref-type | const-ptr-type | mut-ptr-type |
+        //         fn-type | dyn-trait-type | path | backref
+        //
+        // We use ifs instead of switch (Take()) because the default case jumps
+        // to path, which will need to see the first character not yet Taken
+        // from the input.  Because we do not use a nested switch here,
+        // ABSL_DEMANGLER_RECURSE works fine in the 'S' case.
+        type:
+          if (IsLower(Peek())) {
+            const char* type_name = BasicTypeName(Take());
+            if (type_name == nullptr || !Emit(type_name)) return false;
+            continue;
+          }
+          if (Eat('A')) {
+            // array-type = A type const
+            if (!Emit("[")) return false;
+            ABSL_DEMANGLER_RECURSE(type, kArraySize);
+            if (!Emit("; ")) return false;
+            ABSL_DEMANGLER_RECURSE(constant, kFinishArray);
+            if (!Emit("]")) return false;
+            continue;
+          }
+          if (Eat('S')) {
+            if (!Emit("[")) return false;
+            ABSL_DEMANGLER_RECURSE(type, kSliceEnding);
+            if (!Emit("]")) return false;
+            continue;
+          }
+          if (Eat('T')) goto tuple_type;
+          if (Eat('R')) {
+            if (!Emit("&")) return false;
+            if (!ParseOptionalLifetime()) return false;
+            goto type;
+          }
+          if (Eat('Q')) {
+            if (!Emit("&mut ")) return false;
+            if (!ParseOptionalLifetime()) return false;
+            goto type;
+          }
+          if (Eat('P')) {
+            if (!Emit("*const ")) return false;
+            goto type;
+          }
+          if (Eat('O')) {
+            if (!Emit("*mut ")) return false;
+            goto type;
+          }
+          if (Eat('F')) goto fn_type;
+          if (Eat('D')) goto dyn_trait_type;
+          if (Eat('B')) goto type_backref;
+          goto path;
+
+        // tuple-type -> T type* E (T already consumed)
+        tuple_type:
+          if (!Emit("(")) return false;
+
+          // The toolchain should call the unit type u instead of TE, but the
+          // grammar and other demanglers also recognize TE, so we do too.
+          if (Eat('E')) {
+            if (!Emit(")")) return false;
+            continue;
+          }
+
+          // A tuple with one element is rendered (type,) instead of (type).
+          ABSL_DEMANGLER_RECURSE(type, kAfterFirstTupleElement);
+          if (Eat('E')) {
+            if (!Emit(",)")) return false;
+            continue;
+          }
+
+          // A tuple with two elements is of course (x, y).
+          if (!Emit(", ")) return false;
+          ABSL_DEMANGLER_RECURSE(type, kAfterSecondTupleElement);
+          if (Eat('E')) {
+            if (!Emit(")")) return false;
+            continue;
+          }
+
+          // And (x, y, z) for three elements.
+          if (!Emit(", ")) return false;
+          ABSL_DEMANGLER_RECURSE(type, kAfterThirdTupleElement);
+          if (Eat('E')) {
+            if (!Emit(")")) return false;
+            continue;
+          }
+
+          // For longer tuples we write (x, y, z, ...), printing none of the
+          // content of the fourth and later types.  Thus we avoid exhausting
+          // output buffers and human readers' patience when some library has a
+          // long tuple as an implementation detail, without having to
+          // completely obfuscate all tuples.
+          if (!Emit(", ...)")) return false;
+          ++silence_depth_;
+          while (!Eat('E')) {
+            ABSL_DEMANGLER_RECURSE(type, kAfterSubsequentTupleElement);
+          }
+          --silence_depth_;
+          continue;
+
+        // fn-type -> F fn-sig (F already consumed)
+        // fn-sig -> binder? U? (K abi)? type* E type
+        // abi -> C | undisambiguated-identifier
+        //
+        // We follow the C++ demangler in suppressing details of function
+        // signatures.  Every function type is rendered "fn...".
+        fn_type:
+          if (!Emit("fn...")) return false;
+          ++silence_depth_;
+          if (!ParseOptionalBinder()) return false;
+          (void)Eat('U');
+          if (Eat('K')) {
+            if (!Eat('C') && !ParseUndisambiguatedIdentifier()) return false;
+          }
+          while (!Eat('E')) {
+            ABSL_DEMANGLER_RECURSE(type, kContinueParameterList);
+          }
+          ABSL_DEMANGLER_RECURSE(type, kFinishFn);
+          --silence_depth_;
+          continue;
+
+        // dyn-trait-type -> D dyn-bounds lifetime (D already consumed)
+        // dyn-bounds -> binder? dyn-trait* E
+        //
+        // The grammar strangely allows an empty trait list, even though the
+        // compiler should never output one.  We follow existing demanglers in
+        // rendering DEL_ as "dyn ".
+        //
+        // Because auto traits lengthen a type name considerably without
+        // providing much value to a search for related source code, it would be
+        // desirable to abbreviate
+        //     dyn main::Trait + std::marker::Copy + std::marker::Send
+        // to
+        //     dyn main::Trait + ...,
+        // eliding the auto traits.  But it is difficult to do so correctly, in
+        // part because there is no guarantee that the mangling will list the
+        // main trait first.  So we just print all the traits in their order of
+        // appearance in the mangled name.
+        dyn_trait_type:
+          if (!Emit("dyn ")) return false;
+          if (!ParseOptionalBinder()) return false;
+          if (!Eat('E')) {
+            ABSL_DEMANGLER_RECURSE(dyn_trait, kBeginAutoTraits);
+            while (!Eat('E')) {
+              if (!Emit(" + ")) return false;
+              ABSL_DEMANGLER_RECURSE(dyn_trait, kContinueAutoTraits);
+            }
+          }
+          if (!ParseRequiredLifetime()) return false;
+          continue;
+
+        // dyn-trait -> path dyn-trait-assoc-binding*
+        // dyn-trait-assoc-binding -> p undisambiguated-identifier type
+        //
+        // We render nonempty binding lists as <>, omitting their contents as
+        // for generic-args.
+        dyn_trait:
+          ABSL_DEMANGLER_RECURSE(path, kContinueDynTrait);
+          if (Peek() == 'p') {
+            if (!Emit("<>")) return false;
+            ++silence_depth_;
+            while (Eat('p')) {
+              if (!ParseUndisambiguatedIdentifier()) return false;
+              ABSL_DEMANGLER_RECURSE(type, kContinueAssocBinding);
+            }
+            --silence_depth_;
+          }
+          continue;
+
+        // const -> type const-data | p | backref
+        //
+        // const is a C++ keyword, so we use the label `constant` instead.
+        constant:
+          if (Eat('B')) goto const_backref;
+          if (Eat('p')) {
+            if (!Emit("_")) return false;
+            continue;
+          }
+
+          // Scan the type without printing it.
+          //
+          // The Rust language restricts the type of a const generic argument
+          // much more than the mangling grammar does.  We do not enforce this.
+          //
+          // We also do not bother printing false, true, 'A', and '\u{abcd}' for
+          // the types bool and char.  Because we do not print generic-args
+          // contents, we expect to print constants only in array sizes, and
+          // those should not be bool or char.
+          ++silence_depth_;
+          ABSL_DEMANGLER_RECURSE(type, kConstData);
+          --silence_depth_;
+
+          // const-data -> n? hex-digit* _
+          //
+          // Although the grammar doesn't say this, existing demanglers expect
+          // that zero is 0, not an empty digit sequence, and no nonzero value
+          // may have leading zero digits.  Also n0_ is accepted and printed as
+          // -0, though a toolchain will probably never write that encoding.
+          if (Eat('n') && !EmitChar('-')) return false;
+          if (!Emit("0x")) return false;
+          if (Eat('0')) {
+            if (!EmitChar('0')) return false;
+            if (!Eat('_')) return false;
+            continue;
+          }
+          while (IsLowerHexDigit(Peek())) {
+            if (!EmitChar(Take())) return false;
+          }
+          if (!Eat('_')) return false;
+          continue;
+
+        // generic-args -> I path generic-arg* E (I already consumed)
+        //
+        // We follow the C++ demangler in omitting all the arguments from the
+        // output, printing only the list opening and closing tokens.
+        generic_args:
+          ABSL_DEMANGLER_RECURSE(path, kBeginGenericArgList);
+          if (!Emit("::<>")) return false;
+          ++silence_depth_;
+          while (!Eat('E')) {
+            ABSL_DEMANGLER_RECURSE(generic_arg, kContinueGenericArgList);
+          }
+          --silence_depth_;
+          continue;
+
+        // generic-arg -> lifetime | type | K const
+        generic_arg:
+          if (Peek() == 'L') {
+            if (!ParseOptionalLifetime()) return false;
+            continue;
+          }
+          if (Eat('K')) goto constant;
+          goto type;
+
+        // backref -> B base-62-number (B already consumed)
+        //
+        // The BeginBackref call parses and range-checks the base-62-number.  We
+        // always do that much.
+        //
+        // The recursive call parses and prints what the backref points at.  We
+        // save CPU and stack by skipping this work if the output would be
+        // suppressed anyway.
+        path_backref:
+          if (!BeginBackref()) return false;
+          if (silence_depth_ == 0) {
+            ABSL_DEMANGLER_RECURSE(path, kPathBackrefEnding);
+          }
+          EndBackref();
+          continue;
+
+        // This represents the same backref production as in path_backref but
+        // parses the target as a type instead of a path.
+        type_backref:
+          if (!BeginBackref()) return false;
+          if (silence_depth_ == 0) {
+            ABSL_DEMANGLER_RECURSE(type, kTypeBackrefEnding);
+          }
+          EndBackref();
+          continue;
+
+        const_backref:
+          if (!BeginBackref()) return false;
+          if (silence_depth_ == 0) {
+            ABSL_DEMANGLER_RECURSE(constant, kConstantBackrefEnding);
+          }
+          EndBackref();
+          continue;
+      }
+    }
+
+    return false;  // hit iteration limit or a bug in our stack handling
+  }
+
+ private:
+  // Enumerates resumption points for ABSL_DEMANGLER_RECURSE calls.
+  enum ReturnAddress : uint8_t {
+    kInstantiatingCrate,
+    kVendorSpecificSuffix,
+    kIdentifierInUppercaseNamespace,
+    kIdentifierInLowercaseNamespace,
+    kInherentImplType,
+    kInherentImplEnding,
+    kTraitImplType,
+    kTraitImplInfix,
+    kTraitImplEnding,
+    kImplPathEnding,
+    kTraitDefinitionInfix,
+    kTraitDefinitionEnding,
+    kArraySize,
+    kFinishArray,
+    kSliceEnding,
+    kAfterFirstTupleElement,
+    kAfterSecondTupleElement,
+    kAfterThirdTupleElement,
+    kAfterSubsequentTupleElement,
+    kContinueParameterList,
+    kFinishFn,
+    kBeginAutoTraits,
+    kContinueAutoTraits,
+    kContinueDynTrait,
+    kContinueAssocBinding,
+    kConstData,
+    kBeginGenericArgList,
+    kContinueGenericArgList,
+    kPathBackrefEnding,
+    kTypeBackrefEnding,
+    kConstantBackrefEnding,
+  };
+
+  // Element counts for the stack arrays.  Larger stack sizes accommodate more
+  // deeply nested names at the cost of a larger footprint on the C++ call
+  // stack.
+  enum {
+    // Maximum recursive calls outstanding at one time.
+    kStackSize = 256,
+
+    // Maximum N<uppercase> nested-paths open at once.  We do not expect
+    // closures inside closures inside closures as much as functions inside
+    // modules inside other modules, so we can use a smaller array here.
+    kNamespaceStackSize = 64,
+
+    // Maximum number of nested backrefs.  We can keep this stack pretty small
+    // because we do not follow backrefs inside generic-args or other contexts
+    // that suppress printing, so deep stacking is unlikely in practice.
+    kPositionStackSize = 16,
+  };
+
+  // Returns the next input character without consuming it.
+  char Peek() const { return encoding_[pos_]; }
+
+  // Consumes and returns the next input character.
+  char Take() { return encoding_[pos_++]; }
+
+  // If the next input character is the given character, consumes it and returns
+  // true; otherwise returns false without consuming a character.
+  ABSL_MUST_USE_RESULT bool Eat(char want) {
+    if (encoding_[pos_] != want) return false;
+    ++pos_;
+    return true;
+  }
+
+  // Provided there is enough remaining output space, appends c to the output,
+  // writing a fresh NUL terminator afterward, and returns true.  Returns false
+  // if the output buffer had less than two bytes free.
+  ABSL_MUST_USE_RESULT bool EmitChar(char c) {
+    if (silence_depth_ > 0) return true;
+    if (out_end_ - out_ < 2) return false;
+    *out_++ = c;
+    *out_ = '\0';
+    return true;
+  }
+
+  // Provided there is enough remaining output space, appends the C string token
+  // to the output, followed by a NUL character, and returns true.  Returns
+  // false if not everything fit into the output buffer.
+  ABSL_MUST_USE_RESULT bool Emit(const char* token) {
+    if (silence_depth_ > 0) return true;
+    const size_t token_length = std::strlen(token);
+    const size_t bytes_to_copy = token_length + 1;  // token and final NUL
+    if (static_cast<size_t>(out_end_ - out_) < bytes_to_copy) return false;
+    std::memcpy(out_, token, bytes_to_copy);
+    out_ += token_length;
+    return true;
+  }
+
+  // Provided there is enough remaining output space, appends the decimal form
+  // of disambiguator (if it's nonnegative) or "?" (if it's negative) to the
+  // output, followed by a NUL character, and returns true.  Returns false if
+  // not everything fit into the output buffer.
+  ABSL_MUST_USE_RESULT bool EmitDisambiguator(int disambiguator) {
+    if (disambiguator < 0) return EmitChar('?');  // parsed but too large
+    if (disambiguator == 0) return EmitChar('0');
+    // Convert disambiguator to decimal text.  Three digits per byte is enough
+    // because 999 > 256.  The bound will remain correct even if future
+    // maintenance changes the type of the disambiguator variable.
+    char digits[3 * sizeof(disambiguator)] = {};
+    size_t leading_digit_index = sizeof(digits) - 1;
+    for (; disambiguator > 0; disambiguator /= 10) {
+      digits[--leading_digit_index] =
+          static_cast<char>('0' + disambiguator % 10);
+    }
+    return Emit(digits + leading_digit_index);
+  }
+
+  // Consumes an optional disambiguator (s123_) from the input.
+  //
+  // On success returns true and fills value with the encoded value if it was
+  // not too big, otherwise with -1.  If the optional disambiguator was omitted,
+  // value is 0.  On parse failure returns false and sets value to -1.
+  ABSL_MUST_USE_RESULT bool ParseDisambiguator(int& value) {
+    value = -1;
+
+    // disambiguator = s base-62-number
+    //
+    // Disambiguators are optional.  An omitted disambiguator is zero.
+    if (!Eat('s')) {
+      value = 0;
+      return true;
+    }
+    int base_62_value = 0;
+    if (!ParseBase62Number(base_62_value)) return false;
+    value = base_62_value < 0 ? -1 : base_62_value + 1;
+    return true;
+  }
+
+  // Consumes a base-62 number like _ or 123_ from the input.
+  //
+  // On success returns true and fills value with the encoded value if it was
+  // not too big, otherwise with -1.  On parse failure returns false and sets
+  // value to -1.
+  ABSL_MUST_USE_RESULT bool ParseBase62Number(int& value) {
+    value = -1;
+
+    // base-62-number = (digit | lower | upper)* _
+    //
+    // An empty base-62 digit sequence means 0.
+    if (Eat('_')) {
+      value = 0;
+      return true;
+    }
+
+    // A nonempty digit sequence denotes its base-62 value plus 1.
+    int encoded_number = 0;
+    bool overflowed = false;
+    while (IsAlpha(Peek()) || IsDigit(Peek())) {
+      const char c = Take();
+      if (encoded_number >= std::numeric_limits<int>::max()/62) {
+        // If we are close to overflowing an int, keep parsing but stop updating
+        // encoded_number and remember to return -1 at the end.  The point is to
+        // avoid undefined behavior while parsing crate-root disambiguators,
+        // which are large in practice but not shown in demangling, while
+        // successfully computing closure and shim disambiguators, which are
+        // typically small and are printed out.
+        overflowed = true;
+      } else {
+        int digit;
+        if (IsDigit(c)) {
+          digit = c - '0';
+        } else if (IsLower(c)) {
+          digit = c - 'a' + 10;
+        } else {
+          digit = c - 'A' + 36;
+        }
+        encoded_number = 62 * encoded_number + digit;
+      }
+    }
+
+    if (!Eat('_')) return false;
+    if (!overflowed) value = encoded_number + 1;
+    return true;
+  }
+
+  // Consumes an identifier from the input, returning true on success.
+  //
+  // A nonzero uppercase_namespace specifies the character after the N in a
+  // nested-identifier, e.g., 'C' for a closure, allowing ParseIdentifier to
+  // write out the name with the conventional decoration for that namespace.
+  ABSL_MUST_USE_RESULT bool ParseIdentifier(char uppercase_namespace = '\0') {
+    // identifier -> disambiguator? undisambiguated-identifier
+    int disambiguator = 0;
+    if (!ParseDisambiguator(disambiguator)) return false;
+
+    return ParseUndisambiguatedIdentifier(uppercase_namespace, disambiguator);
+  }
+
+  // Consumes from the input an identifier with no preceding disambiguator,
+  // returning true on success.
+  //
+  // When ParseIdentifier calls this, it passes the N<namespace> character and
+  // disambiguator value so that "{closure#42}" and similar forms can be
+  // rendered correctly.
+  //
+  // At other appearances of undisambiguated-identifier in the grammar, this
+  // treatment is not applicable, and the call site omits both arguments.
+  ABSL_MUST_USE_RESULT bool ParseUndisambiguatedIdentifier(
+      char uppercase_namespace = '\0', int disambiguator = 0) {
+    // undisambiguated-identifier -> u? decimal-number _? bytes
+    const bool is_punycoded = Eat('u');
+    if (!IsDigit(Peek())) return false;
+    int num_bytes = 0;
+    if (!ParseDecimalNumber(num_bytes)) return false;
+    (void)Eat('_');  // optional separator, needed if a digit follows
+    if (is_punycoded) {
+      DecodeRustPunycodeOptions options;
+      options.punycode_begin = &encoding_[pos_];
+      options.punycode_end = &encoding_[pos_] + num_bytes;
+      options.out_begin = out_;
+      options.out_end = out_end_;
+      out_ = DecodeRustPunycode(options);
+      if (out_ == nullptr) return false;
+      pos_ += static_cast<size_t>(num_bytes);
+    }
+
+    // Emit the beginnings of braced forms like {shim:vtable#0}.
+    if (uppercase_namespace != '\0') {
+      switch (uppercase_namespace) {
+        case 'C':
+          if (!Emit("{closure")) return false;
+          break;
+        case 'S':
+          if (!Emit("{shim")) return false;
+          break;
+        default:
+          if (!EmitChar('{') || !EmitChar(uppercase_namespace)) return false;
+          break;
+      }
+      if (num_bytes > 0 && !Emit(":")) return false;
+    }
+
+    // Emit the name itself.
+    if (!is_punycoded) {
+      for (int i = 0; i < num_bytes; ++i) {
+        const char c = Take();
+        if (!IsIdentifierChar(c) &&
+            // The spec gives toolchains the choice of Punycode or raw UTF-8 for
+            // identifiers containing code points above 0x7f, so accept bytes
+            // with the high bit set.
+            (c & 0x80) == 0) {
+          return false;
+        }
+        if (!EmitChar(c)) return false;
+      }
+    }
+
+    // Emit the endings of braced forms, e.g., "#42}".
+    if (uppercase_namespace != '\0') {
+      if (!EmitChar('#')) return false;
+      if (!EmitDisambiguator(disambiguator)) return false;
+      if (!EmitChar('}')) return false;
+    }
+
+    return true;
+  }
+
+  // Consumes a decimal number like 0 or 123 from the input.  On success returns
+  // true and fills value with the encoded value.  If the encoded value is too
+  // large or otherwise unparsable, returns false and sets value to -1.
+  ABSL_MUST_USE_RESULT bool ParseDecimalNumber(int& value) {
+    value = -1;
+    if (!IsDigit(Peek())) return false;
+    int encoded_number = Take() - '0';
+    if (encoded_number == 0) {
+      // Decimal numbers are never encoded with extra leading zeroes.
+      value = 0;
+      return true;
+    }
+    while (IsDigit(Peek()) &&
+           // avoid overflow
+           encoded_number < std::numeric_limits<int>::max()/10) {
+      encoded_number = 10 * encoded_number + (Take() - '0');
+    }
+    if (IsDigit(Peek())) return false;  // too big
+    value = encoded_number;
+    return true;
+  }
+
+  // Consumes a binder of higher-ranked lifetimes if one is present.  On success
+  // returns true and discards the encoded lifetime count.  On parse failure
+  // returns false.
+  ABSL_MUST_USE_RESULT bool ParseOptionalBinder() {
+    // binder -> G base-62-number
+    if (!Eat('G')) return true;
+    int ignored_binding_count;
+    return ParseBase62Number(ignored_binding_count);
+  }
+
+  // Consumes a lifetime if one is present.
+  //
+  // On success returns true and discards the lifetime index.  We do not print
+  // or even range-check lifetimes because they are a finer detail than other
+  // things we omit from output, such as the entire contents of generic-args.
+  //
+  // On parse failure returns false.
+  ABSL_MUST_USE_RESULT bool ParseOptionalLifetime() {
+    // lifetime -> L base-62-number
+    if (!Eat('L')) return true;
+    int ignored_de_bruijn_index;
+    return ParseBase62Number(ignored_de_bruijn_index);
+  }
+
+  // Consumes a lifetime just like ParseOptionalLifetime, but returns false if
+  // there is no lifetime here.
+  ABSL_MUST_USE_RESULT bool ParseRequiredLifetime() {
+    if (Peek() != 'L') return false;
+    return ParseOptionalLifetime();
+  }
+
+  // Pushes ns onto the namespace stack and returns true if the stack is not
+  // full, else returns false.
+  ABSL_MUST_USE_RESULT bool PushNamespace(char ns) {
+    if (namespace_depth_ == kNamespaceStackSize) return false;
+    namespace_stack_[namespace_depth_++] = ns;
+    return true;
+  }
+
+  // Pops the last pushed namespace.  Requires that the namespace stack is not
+  // empty (namespace_depth_ > 0).
+  char PopNamespace() { return namespace_stack_[--namespace_depth_]; }
+
+  // Pushes position onto the position stack and returns true if the stack is
+  // not full, else returns false.
+  ABSL_MUST_USE_RESULT bool PushPosition(int position) {
+    if (position_depth_ == kPositionStackSize) return false;
+    position_stack_[position_depth_++] = position;
+    return true;
+  }
+
+  // Pops the last pushed input position.  Requires that the position stack is
+  // not empty (position_depth_ > 0).
+  int PopPosition() { return position_stack_[--position_depth_]; }
+
+  // Consumes a base-62-number denoting a backref target, pushes the current
+  // input position on the data stack, and sets the input position to the
+  // beginning of the backref target.  Returns true on success.  Returns false
+  // if parsing failed, the stack is exhausted, or the backref target position
+  // is out of range.
+  ABSL_MUST_USE_RESULT bool BeginBackref() {
+    // backref = B base-62-number (B already consumed)
+    //
+    // Reject backrefs that don't parse, overflow int, or don't point backward.
+    // If the offset looks fine, adjust it to account for the _R prefix.
+    int offset = 0;
+    const int offset_of_this_backref =
+        pos_ - 2 /* _R */ - 1 /* B already consumed */;
+    if (!ParseBase62Number(offset) || offset < 0 ||
+        offset >= offset_of_this_backref) {
+      return false;
+    }
+    offset += 2;
+
+    // Save the old position to restore later.
+    if (!PushPosition(pos_)) return false;
+
+    // Move the input position to the backref target.
+    //
+    // Note that we do not check whether the new position points to the
+    // beginning of a construct matching the context in which the backref
+    // appeared.  We just jump to it and see whether nested parsing succeeds.
+    // We therefore accept various wrong manglings, e.g., a type backref
+    // pointing to an 'l' character inside an identifier, which happens to mean
+    // i32 when parsed as a type mangling.  This saves the complexity and RAM
+    // footprint of remembering which offsets began which kinds of
+    // substructures.  Existing demanglers take similar shortcuts.
+    pos_ = offset;
+    return true;
+  }
+
+  // Cleans up after a backref production by restoring the previous input
+  // position from the data stack.
+  void EndBackref() { pos_ = PopPosition(); }
+
+  // The leftmost recursion_depth_ elements of recursion_stack_ contain the
+  // ReturnAddresses pushed by ABSL_DEMANGLER_RECURSE calls not yet completed.
+  ReturnAddress recursion_stack_[kStackSize] = {};
+  int recursion_depth_ = 0;
+
+  // The leftmost namespace_depth_ elements of namespace_stack_ contain the
+  // uppercase namespace identifiers for open nested-paths, e.g., 'C' for a
+  // closure.
+  char namespace_stack_[kNamespaceStackSize] = {};
+  int namespace_depth_ = 0;
+
+  // The leftmost position_depth_ elements of position_stack_ contain the input
+  // positions to return to after fully printing the targets of backrefs.
+  int position_stack_[kPositionStackSize] = {};
+  int position_depth_ = 0;
+
+  // Anything parsed while silence_depth_ > 0 contributes nothing to the
+  // demangled output.  For constructs omitted from the demangling, such as
+  // impl-path and the contents of generic-args, we will increment
+  // silence_depth_ on the way in and decrement silence_depth_ on the way out.
+  int silence_depth_ = 0;
+
+  // Input: encoding_ points to a Rust mangled symbol, and encoding_[pos_] is
+  // the next input character to be scanned.
+  int pos_ = 0;
+  const char* encoding_ = nullptr;
+
+  // Output: *out_ is where the next output character should be written, and
+  // out_end_ points past the last byte of available space.
+  char* out_ = nullptr;
+  char* out_end_ = nullptr;
+};
+
+}  // namespace
+
+bool DemangleRustSymbolEncoding(const char* mangled, char* out,
+                                size_t out_size) {
+  return RustSymbolParser(mangled, out, out + out_size).Parse();
+}
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/demangle_rust.h

@@ -0,0 +1,42 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_DEMANGLE_RUST_H_
+#define ABSL_DEBUGGING_INTERNAL_DEMANGLE_RUST_H_
+
+#include <cstddef>
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// Demangle the Rust encoding `mangled`.  On success, return true and write the
+// demangled symbol name to `out`.  Otherwise, return false, leaving unspecified
+// contents in `out`.  For example, calling DemangleRustSymbolEncoding with
+// `mangled = "_RNvC8my_crate7my_func"` will yield `my_crate::my_func` in `out`,
+// provided `out_size` is large enough for that value and its trailing NUL.
+//
+// DemangleRustSymbolEncoding is async-signal-safe and runs in bounded C++
+// call-stack space.  It is suitable for symbolizing stack traces in a signal
+// handler.
+bool DemangleRustSymbolEncoding(const char* mangled, char* out,
+                                size_t out_size);
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_DEMANGLE_RUST_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/demangle_rust_test.cc

@@ -0,0 +1,584 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/demangle_rust.h"
+
+#include <cstddef>
+#include <string>
+
+#include "gtest/gtest.h"
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+namespace {
+
+// If DemangleRustSymbolEncoding(mangled, <buffer with room for buffer_size
+// chars>, buffer_size) returns true and seems not to have overrun its output
+// buffer, returns the string written by DemangleRustSymbolEncoding; otherwise
+// returns an error message.
+std::string ResultOfDemangling(const char* mangled, size_t buffer_size) {
+  // Fill the buffer with something other than NUL so we test whether Demangle
+  // appends trailing NUL as expected.
+  std::string buffer(buffer_size + 1, '~');
+  constexpr char kCanaryCharacter = 0x7f;  // arbitrary unlikely value
+  buffer[buffer_size] = kCanaryCharacter;
+  if (!DemangleRustSymbolEncoding(mangled, &buffer[0], buffer_size)) {
+    return "Failed parse";
+  }
+  if (buffer[buffer_size] != kCanaryCharacter) {
+    return "Buffer overrun by output: " + buffer.substr(0, buffer_size + 1)
+        + "...";
+  }
+  return buffer.data();  // Not buffer itself: this trims trailing padding.
+}
+
+// Tests that DemangleRustSymbolEncoding converts mangled into plaintext given
+// enough output buffer space but returns false and avoids overrunning a buffer
+// that is one byte too short.
+//
+// The lambda wrapping allows ASSERT_EQ to branch out the first time an
+// expectation is not satisfied, preventing redundant errors for the same bug.
+//
+// We test first with excess space so that if the algorithm just computes the
+// wrong answer, it will be clear from the error log that the bounds checks are
+// unlikely to be the code at fault.
+#define EXPECT_DEMANGLING(mangled, plaintext) \
+  do { \
+    [] { \
+      constexpr size_t plenty_of_space = sizeof(plaintext) + 128; \
+      constexpr size_t just_enough_space = sizeof(plaintext); \
+      constexpr size_t one_byte_too_few = sizeof(plaintext) - 1; \
+      const char* expected_plaintext = plaintext; \
+      const char* expected_error = "Failed parse"; \
+      ASSERT_EQ(ResultOfDemangling(mangled, plenty_of_space), \
+                expected_plaintext); \
+      ASSERT_EQ(ResultOfDemangling(mangled, just_enough_space), \
+                expected_plaintext); \
+      ASSERT_EQ(ResultOfDemangling(mangled, one_byte_too_few), \
+                expected_error); \
+    }(); \
+  } while (0)
+
+// Tests that DemangleRustSymbolEncoding rejects the given input (typically, a
+// truncation of a real Rust symbol name).
+#define EXPECT_DEMANGLING_FAILS(mangled) \
+    do { \
+      constexpr size_t plenty_of_space = 1024; \
+      const char* expected_error = "Failed parse"; \
+      EXPECT_EQ(ResultOfDemangling(mangled, plenty_of_space), expected_error); \
+    } while (0)
+
+// Piping grep -C 1 _R demangle_test.cc into your favorite c++filt
+// implementation allows you to verify that the goldens below are reasonable.
+
+TEST(DemangleRust, EmptyDemangling) {
+  EXPECT_TRUE(DemangleRustSymbolEncoding("_RC0", nullptr, 0));
+}
+
+TEST(DemangleRust, FunctionAtCrateLevel) {
+  EXPECT_DEMANGLING("_RNvC10crate_name9func_name", "crate_name::func_name");
+  EXPECT_DEMANGLING(
+      "_RNvCs09azAZ_10crate_name9func_name", "crate_name::func_name");
+}
+
+TEST(DemangleRust, TruncationsOfFunctionAtCrateLevel) {
+  EXPECT_DEMANGLING_FAILS("_R");
+  EXPECT_DEMANGLING_FAILS("_RN");
+  EXPECT_DEMANGLING_FAILS("_RNvC");
+  EXPECT_DEMANGLING_FAILS("_RNvC10");
+  EXPECT_DEMANGLING_FAILS("_RNvC10crate_nam");
+  EXPECT_DEMANGLING_FAILS("_RNvC10crate_name");
+  EXPECT_DEMANGLING_FAILS("_RNvC10crate_name9");
+  EXPECT_DEMANGLING_FAILS("_RNvC10crate_name9func_nam");
+  EXPECT_DEMANGLING_FAILS("_RNvCs");
+  EXPECT_DEMANGLING_FAILS("_RNvCs09azAZ");
+  EXPECT_DEMANGLING_FAILS("_RNvCs09azAZ_");
+}
+
+TEST(DemangleRust, VendorSuffixes) {
+  EXPECT_DEMANGLING("_RNvC10crate_name9func_name.!@#", "crate_name::func_name");
+  EXPECT_DEMANGLING("_RNvC10crate_name9func_name$!@#", "crate_name::func_name");
+}
+
+TEST(DemangleRust, UnicodeIdentifiers) {
+  EXPECT_DEMANGLING("_RNvC7ice_cap17Eyjafjallajökull",
+                    "ice_cap::Eyjafjallajökull");
+  EXPECT_DEMANGLING("_RNvC7ice_caps_u19Eyjafjallajkull_jtb",
+                    "ice_cap::Eyjafjallajökull");
+}
+
+TEST(DemangleRust, FunctionInModule) {
+  EXPECT_DEMANGLING("_RNvNtCs09azAZ_10crate_name11module_name9func_name",
+                    "crate_name::module_name::func_name");
+}
+
+TEST(DemangleRust, FunctionInFunction) {
+  EXPECT_DEMANGLING(
+      "_RNvNvCs09azAZ_10crate_name15outer_func_name15inner_func_name",
+      "crate_name::outer_func_name::inner_func_name");
+}
+
+TEST(DemangleRust, ClosureInFunction) {
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_name0",
+      "crate_name::func_name::{closure#0}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_name0Cs123_12client_crate",
+      "crate_name::func_name::{closure#0}");
+}
+
+TEST(DemangleRust, ClosureNumbering) {
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_names_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#1}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_names0_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#2}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_names9_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#11}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_namesa_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#12}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_namesz_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#37}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_namesA_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#38}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_namesZ_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#63}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_names10_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#64}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_namesg6_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#1000}");
+}
+
+TEST(DemangleRust, ClosureNumberOverflowingInt) {
+  EXPECT_DEMANGLING(
+      "_RNCNvCs09azAZ_10crate_name9func_names1234567_0Cs123_12client_crate",
+      "crate_name::func_name::{closure#?}");
+}
+
+TEST(DemangleRust, UnexpectedlyNamedClosure) {
+  EXPECT_DEMANGLING(
+      "_RNCNvCs123_10crate_name9func_name12closure_nameCs456_12client_crate",
+      "crate_name::func_name::{closure:closure_name#0}");
+  EXPECT_DEMANGLING(
+      "_RNCNvCs123_10crate_name9func_names2_12closure_nameCs456_12client_crate",
+      "crate_name::func_name::{closure:closure_name#4}");
+}
+
+TEST(DemangleRust, ItemNestedInsideClosure) {
+  EXPECT_DEMANGLING(
+      "_RNvNCNvCs123_10crate_name9func_name015inner_func_nameCs_12client_crate",
+      "crate_name::func_name::{closure#0}::inner_func_name");
+}
+
+TEST(DemangleRust, Shim) {
+  EXPECT_DEMANGLING(
+      "_RNSNvCs123_10crate_name9func_name6vtableCs456_12client_crate",
+      "crate_name::func_name::{shim:vtable#0}");
+}
+
+TEST(DemangleRust, UnknownUppercaseNamespace) {
+  EXPECT_DEMANGLING(
+      "_RNXNvCs123_10crate_name9func_name14mystery_objectCs456_12client_crate",
+      "crate_name::func_name::{X:mystery_object#0}");
+}
+
+TEST(DemangleRust, NestedUppercaseNamespaces) {
+  EXPECT_DEMANGLING(
+      "_RNCNXNYCs123_10crate_names0_1ys1_1xs2_0Cs456_12client_crate",
+      "crate_name::{Y:y#2}::{X:x#3}::{closure#4}");
+}
+
+TEST(DemangleRust, TraitDefinition) {
+  EXPECT_DEMANGLING(
+      "_RNvYNtC7crate_a9my_structNtC7crate_b8my_trait1f",
+      "<crate_a::my_struct as crate_b::my_trait>::f");
+}
+
+TEST(DemangleRust, BasicTypeNames) {
+  EXPECT_DEMANGLING("_RNvYaNtC1c1t1f", "<i8 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYbNtC1c1t1f", "<bool as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYcNtC1c1t1f", "<char as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYdNtC1c1t1f", "<f64 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYeNtC1c1t1f", "<str as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYfNtC1c1t1f", "<f32 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYhNtC1c1t1f", "<u8 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYiNtC1c1t1f", "<isize as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYjNtC1c1t1f", "<usize as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYlNtC1c1t1f", "<i32 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYmNtC1c1t1f", "<u32 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYnNtC1c1t1f", "<i128 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYoNtC1c1t1f", "<u128 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYpNtC1c1t1f", "<_ as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYsNtC1c1t1f", "<i16 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYtNtC1c1t1f", "<u16 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYuNtC1c1t1f", "<() as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYvNtC1c1t1f", "<... as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYxNtC1c1t1f", "<i64 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYyNtC1c1t1f", "<u64 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYzNtC1c1t1f", "<! as c::t>::f");
+
+  EXPECT_DEMANGLING_FAILS("_RNvYkNtC1c1t1f");
+}
+
+TEST(DemangleRust, SliceTypes) {
+  EXPECT_DEMANGLING("_RNvYSlNtC1c1t1f", "<[i32] as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYSNtC1d1sNtC1c1t1f", "<[d::s] as c::t>::f");
+}
+
+TEST(DemangleRust, ImmutableReferenceTypes) {
+  EXPECT_DEMANGLING("_RNvYRlNtC1c1t1f", "<&i32 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYRNtC1d1sNtC1c1t1f", "<&d::s as c::t>::f");
+}
+
+TEST(DemangleRust, MutableReferenceTypes) {
+  EXPECT_DEMANGLING("_RNvYQlNtC1c1t1f", "<&mut i32 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYQNtC1d1sNtC1c1t1f", "<&mut d::s as c::t>::f");
+}
+
+TEST(DemangleRust, ConstantRawPointerTypes) {
+  EXPECT_DEMANGLING("_RNvYPlNtC1c1t1f", "<*const i32 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYPNtC1d1sNtC1c1t1f", "<*const d::s as c::t>::f");
+}
+
+TEST(DemangleRust, MutableRawPointerTypes) {
+  EXPECT_DEMANGLING("_RNvYOlNtC1c1t1f", "<*mut i32 as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYONtC1d1sNtC1c1t1f", "<*mut d::s as c::t>::f");
+}
+
+TEST(DemangleRust, TupleLength0) {
+  EXPECT_DEMANGLING("_RNvYTENtC1c1t1f", "<() as c::t>::f");
+}
+
+TEST(DemangleRust, TupleLength1) {
+  EXPECT_DEMANGLING("_RNvYTlENtC1c1t1f", "<(i32,) as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYTNtC1d1sENtC1c1t1f", "<(d::s,) as c::t>::f");
+}
+
+TEST(DemangleRust, TupleLength2) {
+  EXPECT_DEMANGLING("_RNvYTlmENtC1c1t1f", "<(i32, u32) as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYTNtC1d1xNtC1e1yENtC1c1t1f",
+                    "<(d::x, e::y) as c::t>::f");
+}
+
+TEST(DemangleRust, TupleLength3) {
+  EXPECT_DEMANGLING("_RNvYTlmnENtC1c1t1f", "<(i32, u32, i128) as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYTNtC1d1xNtC1e1yNtC1f1zENtC1c1t1f",
+                    "<(d::x, e::y, f::z) as c::t>::f");
+}
+
+TEST(DemangleRust, LongerTuplesAbbreviated) {
+  EXPECT_DEMANGLING("_RNvYTlmnoENtC1c1t1f",
+                    "<(i32, u32, i128, ...) as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYTlmnNtC1d1xNtC1e1yENtC1c1t1f",
+                    "<(i32, u32, i128, ...) as c::t>::f");
+}
+
+TEST(DemangleRust, PathBackrefToCrate) {
+  EXPECT_DEMANGLING("_RNvYNtC8my_crate9my_structNtB4_8my_trait1f",
+                    "<my_crate::my_struct as my_crate::my_trait>::f");
+}
+
+TEST(DemangleRust, PathBackrefToNestedPath) {
+  EXPECT_DEMANGLING("_RNvYNtNtC1c1m1sNtB4_1t1f", "<c::m::s as c::m::t>::f");
+}
+
+TEST(DemangleRust, PathBackrefAsInstantiatingCrate) {
+  EXPECT_DEMANGLING("_RNCNvC8my_crate7my_func0B3_",
+                    "my_crate::my_func::{closure#0}");
+}
+
+TEST(DemangleRust, TypeBackrefsNestedInTuple) {
+  EXPECT_DEMANGLING("_RNvYTTRlB4_ERB3_ENtC1c1t1f",
+                    "<((&i32, &i32), &(&i32, &i32)) as c::t>::f");
+}
+
+TEST(DemangleRust, NoInfiniteLoopOnBackrefToTheWhole) {
+  EXPECT_DEMANGLING_FAILS("_RB_");
+  EXPECT_DEMANGLING_FAILS("_RNvB_1sNtC1c1t1f");
+}
+
+TEST(DemangleRust, NoCrashOnForwardBackref) {
+  EXPECT_DEMANGLING_FAILS("_RB0_");
+  EXPECT_DEMANGLING_FAILS("_RB1_");
+  EXPECT_DEMANGLING_FAILS("_RB2_");
+  EXPECT_DEMANGLING_FAILS("_RB3_");
+  EXPECT_DEMANGLING_FAILS("_RB4_");
+}
+
+TEST(DemangleRust, PathBackrefsDoNotRecurseDuringSilence) {
+  // B_ points at the value f (the whole mangling), so the cycle would lead to
+  // parse failure if the parser tried to parse what was pointed to.
+  EXPECT_DEMANGLING("_RNvYTlmnNtB_1sENtC1c1t1f",
+                    "<(i32, u32, i128, ...) as c::t>::f");
+}
+
+TEST(DemangleRust, TypeBackrefsDoNotRecurseDuringSilence) {
+  // B2_ points at the tuple type, likewise making a cycle that the parser
+  // avoids following.
+  EXPECT_DEMANGLING("_RNvYTlmnB2_ENtC1c1t1f",
+                    "<(i32, u32, i128, ...) as c::t>::f");
+}
+
+TEST(DemangleRust, ConstBackrefsDoNotRecurseDuringSilence) {
+  // B_ points at the whole I...E mangling, which does not parse as a const.
+  EXPECT_DEMANGLING("_RINvC1c1fAlB_E", "c::f::<>");
+}
+
+TEST(DemangleRust, ReturnFromBackrefToInputPosition256) {
+  // Show that we can resume at input positions that don't fit into a byte.
+  EXPECT_DEMANGLING("_RNvYNtC1c238very_long_type_"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABC"
+                    "NtB4_1t1f",
+                    "<c::very_long_type_"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABCDEFGHIJabcdefghij"
+                    "ABCDEFGHIJabcdefghijABC"
+                    " as c::t>::f");
+}
+
+TEST(DemangleRust, EmptyGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1fE", "c::f::<>");
+}
+
+TEST(DemangleRust, OneSimpleTypeInGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1flE",  // c::f::<i32>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, OneTupleInGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1fTlmEE",  // c::f::<(i32, u32)>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, OnePathInGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1fNtC1d1sE",  // c::f::<d::s>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, LongerGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1flmRNtC1d1sE",  // c::f::<i32, u32, &d::s>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, BackrefInGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1fRlB7_NtB2_1sE",  // c::f::<&i32, &i32, c::s>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, NestedGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1fINtB2_1slEmE",  // c::f::<c::s::<i32>, u32>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, MonomorphicEntityNestedInsideGeneric) {
+  EXPECT_DEMANGLING("_RNvINvC1c1fppE1g",  // c::f::<_, _>::g
+                    "c::f::<>::g");
+}
+
+TEST(DemangleRust, ArrayTypeWithSimpleElementType) {
+  EXPECT_DEMANGLING("_RNvYAlj1f_NtC1c1t1f", "<[i32; 0x1f] as c::t>::f");
+}
+
+TEST(DemangleRust, ArrayTypeWithComplexElementType) {
+  EXPECT_DEMANGLING("_RNvYAINtC1c1slEj1f_NtB6_1t1f",
+                    "<[c::s::<>; 0x1f] as c::t>::f");
+}
+
+TEST(DemangleRust, NestedArrayType) {
+  EXPECT_DEMANGLING("_RNvYAAlj1f_j2e_NtC1c1t1f",
+                    "<[[i32; 0x1f]; 0x2e] as c::t>::f");
+}
+
+TEST(DemangleRust, BackrefArraySize) {
+  EXPECT_DEMANGLING("_RNvYAAlj1f_B5_NtC1c1t1f",
+                    "<[[i32; 0x1f]; 0x1f] as c::t>::f");
+}
+
+TEST(DemangleRust, ZeroArraySize) {
+  EXPECT_DEMANGLING("_RNvYAlj0_NtC1c1t1f", "<[i32; 0x0] as c::t>::f");
+}
+
+TEST(DemangleRust, SurprisingMinusesInArraySize) {
+  // Compilers shouldn't do this stuff, but existing demanglers accept it.
+  EXPECT_DEMANGLING("_RNvYAljn0_NtC1c1t1f", "<[i32; -0x0] as c::t>::f");
+  EXPECT_DEMANGLING("_RNvYAljn42_NtC1c1t1f", "<[i32; -0x42] as c::t>::f");
+}
+
+TEST(DemangleRust, NumberAsGenericArg) {
+  EXPECT_DEMANGLING("_RINvC1c1fKl8_E",  // c::f::<0x8>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, NumberAsFirstOfTwoGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1fKl8_mE",  // c::f::<0x8, u32>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, NumberAsSecondOfTwoGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1fmKl8_E",  // c::f::<u32, 0x8>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, NumberPlaceholder) {
+  EXPECT_DEMANGLING("_RNvINvC1c1fKpE1g",  // c::f::<_>::g
+                    "c::f::<>::g");
+}
+
+TEST(DemangleRust, InherentImplWithoutDisambiguator) {
+  EXPECT_DEMANGLING("_RNvMNtC8my_crate6my_modNtB2_9my_struct7my_func",
+                    "<my_crate::my_mod::my_struct>::my_func");
+}
+
+TEST(DemangleRust, InherentImplWithDisambiguator) {
+  EXPECT_DEMANGLING("_RNvMs_NtC8my_crate6my_modNtB4_9my_struct7my_func",
+                    "<my_crate::my_mod::my_struct>::my_func");
+}
+
+TEST(DemangleRust, TraitImplWithoutDisambiguator) {
+  EXPECT_DEMANGLING("_RNvXC8my_crateNtB2_9my_structNtB2_8my_trait7my_func",
+                    "<my_crate::my_struct as my_crate::my_trait>::my_func");
+}
+
+TEST(DemangleRust, TraitImplWithDisambiguator) {
+  EXPECT_DEMANGLING("_RNvXs_C8my_crateNtB4_9my_structNtB4_8my_trait7my_func",
+                    "<my_crate::my_struct as my_crate::my_trait>::my_func");
+}
+
+TEST(DemangleRust, TraitImplWithNonpathSelfType) {
+  EXPECT_DEMANGLING("_RNvXC8my_crateRlNtB2_8my_trait7my_func",
+                    "<&i32 as my_crate::my_trait>::my_func");
+}
+
+TEST(DemangleRust, ThunkType) {
+  EXPECT_DEMANGLING("_RNvYFEuNtC1c1t1f",  // <fn() as c::t>::f
+                    "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, NontrivialFunctionReturnType) {
+  EXPECT_DEMANGLING(
+      "_RNvYFERTlmENtC1c1t1f",  // <fn() -> &(i32, u32) as c::t>::f
+      "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, OneParameterType) {
+  EXPECT_DEMANGLING("_RNvYFlEuNtC1c1t1f",  // <fn(i32) as c::t>::f
+                    "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, TwoParameterTypes) {
+  EXPECT_DEMANGLING("_RNvYFlmEuNtC1c1t1f",  // <fn(i32, u32) as c::t>::f
+                    "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, ExternC) {
+  EXPECT_DEMANGLING("_RNvYFKCEuNtC1c1t1f",  // <extern "C" fn() as c::t>>::f
+                    "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, ExternOther) {
+  EXPECT_DEMANGLING(
+      "_RNvYFK5not_CEuNtC1c1t1f",  // <extern "not-C" fn() as c::t>::f
+      "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, Unsafe) {
+  EXPECT_DEMANGLING("_RNvYFUEuNtC1c1t1f",  // <unsafe fn() as c::t>::f
+                    "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, Binder) {
+  EXPECT_DEMANGLING(
+      // <for<'a> fn(&'a i32) -> &'a i32 as c::t>::f
+      "_RNvYFG_RL0_lEB5_NtC1c1t1f",
+      "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, AllFnSigFeaturesInOrder) {
+  EXPECT_DEMANGLING(
+      // <for<'a> unsafe extern "C" fn(&'a i32) -> &'a i32 as c::t>::f
+      "_RNvYFG_UKCRL0_lEB8_NtC1c1t1f",
+      "<fn... as c::t>::f");
+}
+
+TEST(DemangleRust, LifetimeInGenericArgs) {
+  EXPECT_DEMANGLING("_RINvC1c1fINtB2_1sL_EE",  // c::f::<c::s::<'_>>
+                    "c::f::<>");
+}
+
+TEST(DemangleRust, EmptyDynTrait) {
+  // This shouldn't happen, but the grammar allows it and existing demanglers
+  // accept it.
+  EXPECT_DEMANGLING("_RNvYDEL_NtC1c1t1f",
+                    "<dyn  as c::t>::f");
+}
+
+TEST(DemangleRust, SimpleDynTrait) {
+  EXPECT_DEMANGLING("_RNvYDNtC1c1tEL_NtC1d1u1f",
+                    "<dyn c::t as d::u>::f");
+}
+
+TEST(DemangleRust, DynTraitWithOneAssociatedType) {
+  EXPECT_DEMANGLING(
+      "_RNvYDNtC1c1tp1xlEL_NtC1d1u1f",  // <dyn c::t<x = i32> as d::u>::f
+      "<dyn c::t<> as d::u>::f");
+}
+
+TEST(DemangleRust, DynTraitWithTwoAssociatedTypes) {
+  EXPECT_DEMANGLING(
+      // <dyn c::t<x = i32, y = u32> as d::u>::f
+      "_RNvYDNtC1c1tp1xlp1ymEL_NtC1d1u1f",
+      "<dyn c::t<> as d::u>::f");
+}
+
+TEST(DemangleRust, DynTraitPlusAutoTrait) {
+  EXPECT_DEMANGLING(
+      "_RNvYDNtC1c1tNtNtC3std6marker4SendEL_NtC1d1u1f",
+      "<dyn c::t + std::marker::Send as d::u>::f");
+}
+
+TEST(DemangleRust, DynTraitPlusTwoAutoTraits) {
+  EXPECT_DEMANGLING(
+      "_RNvYDNtC1c1tNtNtC3std6marker4CopyNtBc_4SyncEL_NtC1d1u1f",
+      "<dyn c::t + std::marker::Copy + std::marker::Sync as d::u>::f");
+}
+
+TEST(DemangleRust, HigherRankedDynTrait) {
+  EXPECT_DEMANGLING(
+      // <dyn for<'a> c::t::<&'a i32> as d::u>::f
+      "_RNvYDG_INtC1c1tRL0_lEEL_NtC1d1u1f",
+      "<dyn c::t::<> as d::u>::f");
+}
+
+}  // namespace
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/elf_mem_image.cc

@@ -0,0 +1,413 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Allow dynamic symbol lookup in an in-memory Elf image.
+//
+
+#include "absl/debugging/internal/elf_mem_image.h"
+
+#ifdef ABSL_HAVE_ELF_MEM_IMAGE  // defined in elf_mem_image.h
+
+#include <string.h>
+
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+
+#include "absl/base/config.h"
+#include "absl/base/internal/raw_logging.h"
+
+// From binutils/include/elf/common.h (this doesn't appear to be documented
+// anywhere else).
+//
+//   /* This flag appears in a Versym structure.  It means that the symbol
+//      is hidden, and is only visible with an explicit version number.
+//      This is a GNU extension.  */
+//   #define VERSYM_HIDDEN           0x8000
+//
+//   /* This is the mask for the rest of the Versym information.  */
+//   #define VERSYM_VERSION          0x7fff
+
+#define VERSYM_VERSION 0x7fff
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+namespace {
+
+#if __SIZEOF_POINTER__ == 4
+const int kElfClass = ELFCLASS32;
+int ElfBind(const ElfW(Sym) *symbol) { return ELF32_ST_BIND(symbol->st_info); }
+int ElfType(const ElfW(Sym) *symbol) { return ELF32_ST_TYPE(symbol->st_info); }
+#elif __SIZEOF_POINTER__ == 8
+const int kElfClass = ELFCLASS64;
+int ElfBind(const ElfW(Sym) *symbol) { return ELF64_ST_BIND(symbol->st_info); }
+int ElfType(const ElfW(Sym) *symbol) { return ELF64_ST_TYPE(symbol->st_info); }
+#else
+const int kElfClass = -1;
+int ElfBind(const ElfW(Sym) *) {
+  ABSL_RAW_LOG(FATAL, "Unexpected word size");
+  return 0;
+}
+int ElfType(const ElfW(Sym) *) {
+  ABSL_RAW_LOG(FATAL, "Unexpected word size");
+  return 0;
+}
+#endif
+
+// Extract an element from one of the ELF tables, cast it to desired type.
+// This is just a simple arithmetic and a glorified cast.
+// Callers are responsible for bounds checking.
+template <typename T>
+const T *GetTableElement(const ElfW(Ehdr) * ehdr, ElfW(Off) table_offset,
+                         ElfW(Word) element_size, size_t index) {
+  return reinterpret_cast<const T*>(reinterpret_cast<const char *>(ehdr)
+                                    + table_offset
+                                    + index * element_size);
+}
+
+}  // namespace
+
+// The value of this variable doesn't matter; it's used only for its
+// unique address.
+const int ElfMemImage::kInvalidBaseSentinel = 0;
+
+ElfMemImage::ElfMemImage(const void *base) {
+  ABSL_RAW_CHECK(base != kInvalidBase, "bad pointer");
+  Init(base);
+}
+
+uint32_t ElfMemImage::GetNumSymbols() const { return num_syms_; }
+
+const ElfW(Sym) * ElfMemImage::GetDynsym(uint32_t index) const {
+  ABSL_RAW_CHECK(index < GetNumSymbols(), "index out of range");
+  return dynsym_ + index;
+}
+
+const ElfW(Versym) *ElfMemImage::GetVersym(uint32_t index) const {
+  ABSL_RAW_CHECK(index < GetNumSymbols(), "index out of range");
+  return versym_ + index;
+}
+
+const ElfW(Phdr) *ElfMemImage::GetPhdr(int index) const {
+  ABSL_RAW_CHECK(index >= 0 && index < ehdr_->e_phnum, "index out of range");
+  return GetTableElement<ElfW(Phdr)>(ehdr_, ehdr_->e_phoff, ehdr_->e_phentsize,
+                                     static_cast<size_t>(index));
+}
+
+const char *ElfMemImage::GetDynstr(ElfW(Word) offset) const {
+  ABSL_RAW_CHECK(offset < strsize_, "offset out of range");
+  return dynstr_ + offset;
+}
+
+const void *ElfMemImage::GetSymAddr(const ElfW(Sym) *sym) const {
+  if (sym->st_shndx == SHN_UNDEF || sym->st_shndx >= SHN_LORESERVE) {
+    // Symbol corresponds to "special" (e.g. SHN_ABS) section.
+    return reinterpret_cast<const void *>(sym->st_value);
+  }
+  ABSL_RAW_CHECK(link_base_ < sym->st_value, "symbol out of range");
+  return GetTableElement<char>(ehdr_, 0, 1, sym->st_value - link_base_);
+}
+
+const ElfW(Verdef) *ElfMemImage::GetVerdef(int index) const {
+  ABSL_RAW_CHECK(0 <= index && static_cast<size_t>(index) <= verdefnum_,
+                 "index out of range");
+  const ElfW(Verdef) *version_definition = verdef_;
+  while (version_definition->vd_ndx < index && version_definition->vd_next) {
+    const char *const version_definition_as_char =
+        reinterpret_cast<const char *>(version_definition);
+    version_definition =
+        reinterpret_cast<const ElfW(Verdef) *>(version_definition_as_char +
+                                               version_definition->vd_next);
+  }
+  return version_definition->vd_ndx == index ? version_definition : nullptr;
+}
+
+const ElfW(Verdaux) *ElfMemImage::GetVerdefAux(
+    const ElfW(Verdef) *verdef) const {
+  return reinterpret_cast<const ElfW(Verdaux) *>(verdef+1);
+}
+
+const char *ElfMemImage::GetVerstr(ElfW(Word) offset) const {
+  ABSL_RAW_CHECK(offset < strsize_, "offset out of range");
+  return dynstr_ + offset;
+}
+
+void ElfMemImage::Init(const void *base) {
+  ehdr_      = nullptr;
+  dynsym_    = nullptr;
+  dynstr_    = nullptr;
+  versym_    = nullptr;
+  verdef_    = nullptr;
+  num_syms_ = 0;
+  strsize_   = 0;
+  verdefnum_ = 0;
+  // Sentinel: PT_LOAD .p_vaddr can't possibly be this.
+  link_base_ = ~ElfW(Addr){0};  // NOLINT(readability/braces)
+  if (!base) {
+    return;
+  }
+  const char *const base_as_char = reinterpret_cast<const char *>(base);
+  if (base_as_char[EI_MAG0] != ELFMAG0 || base_as_char[EI_MAG1] != ELFMAG1 ||
+      base_as_char[EI_MAG2] != ELFMAG2 || base_as_char[EI_MAG3] != ELFMAG3) {
+    assert(false);
+    return;
+  }
+  int elf_class = base_as_char[EI_CLASS];
+  if (elf_class != kElfClass) {
+    assert(false);
+    return;
+  }
+  switch (base_as_char[EI_DATA]) {
+    case ELFDATA2LSB: {
+#ifndef ABSL_IS_LITTLE_ENDIAN
+      assert(false);
+      return;
+#endif
+      break;
+    }
+    case ELFDATA2MSB: {
+#ifndef ABSL_IS_BIG_ENDIAN
+      assert(false);
+      return;
+#endif
+      break;
+    }
+    default: {
+      assert(false);
+      return;
+    }
+  }
+
+  ehdr_ = reinterpret_cast<const ElfW(Ehdr) *>(base);
+  const ElfW(Phdr) *dynamic_program_header = nullptr;
+  for (int i = 0; i < ehdr_->e_phnum; ++i) {
+    const ElfW(Phdr) *const program_header = GetPhdr(i);
+    switch (program_header->p_type) {
+      case PT_LOAD:
+        if (!~link_base_) {
+          link_base_ = program_header->p_vaddr;
+        }
+        break;
+      case PT_DYNAMIC:
+        dynamic_program_header = program_header;
+        break;
+    }
+  }
+  if (!~link_base_ || !dynamic_program_header) {
+    assert(false);
+    // Mark this image as not present. Can not recur infinitely.
+    Init(nullptr);
+    return;
+  }
+  ptrdiff_t relocation =
+      base_as_char - reinterpret_cast<const char *>(link_base_);
+  ElfW(Dyn)* dynamic_entry = reinterpret_cast<ElfW(Dyn)*>(
+      static_cast<intptr_t>(dynamic_program_header->p_vaddr) + relocation);
+  uint32_t *sysv_hash = nullptr;
+  uint32_t *gnu_hash = nullptr;
+  for (; dynamic_entry->d_tag != DT_NULL; ++dynamic_entry) {
+    const auto value =
+        static_cast<intptr_t>(dynamic_entry->d_un.d_val) + relocation;
+    switch (dynamic_entry->d_tag) {
+      case DT_HASH:
+        sysv_hash = reinterpret_cast<uint32_t *>(value);
+        break;
+      case DT_GNU_HASH:
+        gnu_hash = reinterpret_cast<uint32_t *>(value);
+        break;
+      case DT_SYMTAB:
+        dynsym_ = reinterpret_cast<ElfW(Sym) *>(value);
+        break;
+      case DT_STRTAB:
+        dynstr_ = reinterpret_cast<const char *>(value);
+        break;
+      case DT_VERSYM:
+        versym_ = reinterpret_cast<ElfW(Versym) *>(value);
+        break;
+      case DT_VERDEF:
+        verdef_ = reinterpret_cast<ElfW(Verdef) *>(value);
+        break;
+      case DT_VERDEFNUM:
+        verdefnum_ = static_cast<size_t>(dynamic_entry->d_un.d_val);
+        break;
+      case DT_STRSZ:
+        strsize_ = static_cast<size_t>(dynamic_entry->d_un.d_val);
+        break;
+      default:
+        // Unrecognized entries explicitly ignored.
+        break;
+    }
+  }
+  if ((!sysv_hash && !gnu_hash) || !dynsym_ || !dynstr_ || !versym_ ||
+      !verdef_ || !verdefnum_ || !strsize_) {
+    assert(false);  // invalid VDSO
+    // Mark this image as not present. Can not recur infinitely.
+    Init(nullptr);
+    return;
+  }
+  if (sysv_hash) {
+    num_syms_ = sysv_hash[1];
+  } else {
+    assert(gnu_hash);
+    // Compute the number of symbols for DT_GNU_HASH, which is specified by
+    // https://sourceware.org/gnu-gabi/program-loading-and-dynamic-linking.txt
+    uint32_t nbuckets = gnu_hash[0];
+    // The buckets array is located after the header (4 uint32) and the bloom
+    // filter (size_t array of gnu_hash[2] elements).
+    uint32_t *buckets = gnu_hash + 4 + sizeof(size_t) / 4 * gnu_hash[2];
+    // Find the chain of the last non-empty bucket.
+    uint32_t idx = 0;
+    for (uint32_t i = nbuckets; i > 0;) {
+      idx = buckets[--i];
+      if (idx != 0) break;
+    }
+    if (idx != 0) {
+      // Find the last element of the chain, which has an odd value.
+      // Add one to get the number of symbols.
+      uint32_t *chain = buckets + nbuckets - gnu_hash[1];
+      while (chain[idx++] % 2 == 0) {
+      }
+    }
+    num_syms_ = idx;
+  }
+}
+
+bool ElfMemImage::LookupSymbol(const char *name,
+                               const char *version,
+                               int type,
+                               SymbolInfo *info_out) const {
+  for (const SymbolInfo& info : *this) {
+    if (strcmp(info.name, name) == 0 && strcmp(info.version, version) == 0 &&
+        ElfType(info.symbol) == type) {
+      if (info_out) {
+        *info_out = info;
+      }
+      return true;
+    }
+  }
+  return false;
+}
+
+bool ElfMemImage::LookupSymbolByAddress(const void *address,
+                                        SymbolInfo *info_out) const {
+  for (const SymbolInfo& info : *this) {
+    const char *const symbol_start =
+        reinterpret_cast<const char *>(info.address);
+    const char *const symbol_end = symbol_start + info.symbol->st_size;
+    if (symbol_start <= address && address < symbol_end) {
+      if (info_out) {
+        // Client wants to know details for that symbol (the usual case).
+        if (ElfBind(info.symbol) == STB_GLOBAL) {
+          // Strong symbol; just return it.
+          *info_out = info;
+          return true;
+        } else {
+          // Weak or local. Record it, but keep looking for a strong one.
+          *info_out = info;
+        }
+      } else {
+        // Client only cares if there is an overlapping symbol.
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+ElfMemImage::SymbolIterator::SymbolIterator(const void *const image,
+                                            uint32_t index)
+    : index_(index), image_(image) {}
+
+const ElfMemImage::SymbolInfo *ElfMemImage::SymbolIterator::operator->() const {
+  return &info_;
+}
+
+const ElfMemImage::SymbolInfo& ElfMemImage::SymbolIterator::operator*() const {
+  return info_;
+}
+
+bool ElfMemImage::SymbolIterator::operator==(const SymbolIterator &rhs) const {
+  return this->image_ == rhs.image_ && this->index_ == rhs.index_;
+}
+
+bool ElfMemImage::SymbolIterator::operator!=(const SymbolIterator &rhs) const {
+  return !(*this == rhs);
+}
+
+ElfMemImage::SymbolIterator &ElfMemImage::SymbolIterator::operator++() {
+  this->Update(1);
+  return *this;
+}
+
+ElfMemImage::SymbolIterator ElfMemImage::begin() const {
+  SymbolIterator it(this, 0);
+  it.Update(0);
+  return it;
+}
+
+ElfMemImage::SymbolIterator ElfMemImage::end() const {
+  return SymbolIterator(this, GetNumSymbols());
+}
+
+void ElfMemImage::SymbolIterator::Update(uint32_t increment) {
+  const ElfMemImage *image = reinterpret_cast<const ElfMemImage *>(image_);
+  ABSL_RAW_CHECK(image->IsPresent() || increment == 0, "");
+  if (!image->IsPresent()) {
+    return;
+  }
+  index_ += increment;
+  if (index_ >= image->GetNumSymbols()) {
+    index_ = image->GetNumSymbols();
+    return;
+  }
+  const ElfW(Sym)    *symbol = image->GetDynsym(index_);
+  const ElfW(Versym) *version_symbol = image->GetVersym(index_);
+  ABSL_RAW_CHECK(symbol && version_symbol, "");
+  const char *const symbol_name = image->GetDynstr(symbol->st_name);
+#if defined(__NetBSD__)
+  const int version_index = version_symbol->vs_vers & VERSYM_VERSION;
+#else
+  const ElfW(Versym) version_index = version_symbol[0] & VERSYM_VERSION;
+#endif
+  const ElfW(Verdef) *version_definition = nullptr;
+  const char *version_name = "";
+  if (symbol->st_shndx == SHN_UNDEF) {
+    // Undefined symbols reference DT_VERNEED, not DT_VERDEF, and
+    // version_index could well be greater than verdefnum_, so calling
+    // GetVerdef(version_index) may trigger assertion.
+  } else {
+    version_definition = image->GetVerdef(version_index);
+  }
+  if (version_definition) {
+    // I am expecting 1 or 2 auxiliary entries: 1 for the version itself,
+    // optional 2nd if the version has a parent.
+    ABSL_RAW_CHECK(
+        version_definition->vd_cnt == 1 || version_definition->vd_cnt == 2,
+        "wrong number of entries");
+    const ElfW(Verdaux) *version_aux = image->GetVerdefAux(version_definition);
+    version_name = image->GetVerstr(version_aux->vda_name);
+  }
+  info_.name    = symbol_name;
+  info_.version = version_name;
+  info_.address = image->GetSymAddr(symbol);
+  info_.symbol  = symbol;
+}
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_HAVE_ELF_MEM_IMAGE

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/elf_mem_image.h

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2017 The Abseil Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Allow dynamic symbol lookup for in-memory Elf images.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_ELF_MEM_IMAGE_H_
+#define ABSL_DEBUGGING_INTERNAL_ELF_MEM_IMAGE_H_
+
+// Including this will define the __GLIBC__ macro if glibc is being
+// used.
+#include <climits>
+#include <cstdint>
+
+#include "absl/base/config.h"
+
+// Maybe one day we can rewrite this file not to require the elf
+// symbol extensions in glibc, but for right now we need them.
+#ifdef ABSL_HAVE_ELF_MEM_IMAGE
+#error ABSL_HAVE_ELF_MEM_IMAGE cannot be directly set
+#endif
+
+#if defined(__ELF__) && !defined(__OpenBSD__) && !defined(__QNX__) && \
+    !defined(__native_client__) && !defined(__asmjs__) &&             \
+    !defined(__wasm__) && !defined(__HAIKU__) && !defined(__sun) &&   \
+    !defined(__VXWORKS__) && !defined(__hexagon__) && !defined(__XTENSA__)
+#define ABSL_HAVE_ELF_MEM_IMAGE 1
+#endif
+
+#ifdef ABSL_HAVE_ELF_MEM_IMAGE
+
+#include <link.h>  // for ElfW
+
+#if defined(__FreeBSD__) && !defined(ElfW)
+#define ElfW(x) __ElfN(x)
+#endif
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// An in-memory ELF image (may not exist on disk).
+class ElfMemImage {
+ private:
+  // Sentinel: there could never be an elf image at &kInvalidBaseSentinel.
+  static const int kInvalidBaseSentinel;
+
+ public:
+  // Sentinel: there could never be an elf image at this address.
+  static constexpr const void *const kInvalidBase =
+    static_cast<const void*>(&kInvalidBaseSentinel);
+
+  // Information about a single vdso symbol.
+  // All pointers are into .dynsym, .dynstr, or .text of the VDSO.
+  // Do not free() them or modify through them.
+  struct SymbolInfo {
+    const char      *name;      // E.g. "__vdso_getcpu"
+    const char      *version;   // E.g. "LINUX_2.6", could be ""
+                                // for unversioned symbol.
+    const void      *address;   // Relocated symbol address.
+    const ElfW(Sym) *symbol;    // Symbol in the dynamic symbol table.
+  };
+
+  // Supports iteration over all dynamic symbols.
+  class SymbolIterator {
+   public:
+    friend class ElfMemImage;
+    const SymbolInfo *operator->() const;
+    const SymbolInfo &operator*() const;
+    SymbolIterator& operator++();
+    bool operator!=(const SymbolIterator &rhs) const;
+    bool operator==(const SymbolIterator &rhs) const;
+   private:
+    SymbolIterator(const void *const image, uint32_t index);
+    void Update(uint32_t incr);
+    SymbolInfo info_;
+    uint32_t index_;
+    const void *const image_;
+  };
+
+
+  explicit ElfMemImage(const void *base);
+  void                 Init(const void *base);
+  bool                 IsPresent() const { return ehdr_ != nullptr; }
+  const ElfW(Phdr)*    GetPhdr(int index) const;
+  const ElfW(Sym) * GetDynsym(uint32_t index) const;
+  const ElfW(Versym)*  GetVersym(uint32_t index) const;
+  const ElfW(Verdef)*  GetVerdef(int index) const;
+  const ElfW(Verdaux)* GetVerdefAux(const ElfW(Verdef) *verdef) const;
+  const char*          GetDynstr(ElfW(Word) offset) const;
+  const void*          GetSymAddr(const ElfW(Sym) *sym) const;
+  const char*          GetVerstr(ElfW(Word) offset) const;
+  uint32_t GetNumSymbols() const;
+
+  SymbolIterator begin() const;
+  SymbolIterator end() const;
+
+  // Look up versioned dynamic symbol in the image.
+  // Returns false if image is not present, or doesn't contain given
+  // symbol/version/type combination.
+  // If info_out is non-null, additional details are filled in.
+  bool LookupSymbol(const char *name, const char *version,
+                    int symbol_type, SymbolInfo *info_out) const;
+
+  // Find info about symbol (if any) which overlaps given address.
+  // Returns true if symbol was found; false if image isn't present
+  // or doesn't have a symbol overlapping given address.
+  // If info_out is non-null, additional details are filled in.
+  bool LookupSymbolByAddress(const void *address, SymbolInfo *info_out) const;
+
+ private:
+  const ElfW(Ehdr) *ehdr_;
+  const ElfW(Sym) *dynsym_;
+  const ElfW(Versym) *versym_;
+  const ElfW(Verdef) *verdef_;
+  const char *dynstr_;
+  uint32_t num_syms_;
+  size_t strsize_;
+  size_t verdefnum_;
+  ElfW(Addr) link_base_;     // Link-time base (p_vaddr of first PT_LOAD).
+};
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_HAVE_ELF_MEM_IMAGE
+
+#endif  // ABSL_DEBUGGING_INTERNAL_ELF_MEM_IMAGE_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/examine_stack.cc

@@ -0,0 +1,320 @@
+//
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include "absl/debugging/internal/examine_stack.h"
+
+#ifndef _WIN32
+#include <unistd.h>
+#endif
+
+#include "absl/base/config.h"
+
+#ifdef ABSL_HAVE_MMAP
+#include <sys/mman.h>
+#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+#endif
+
+#if defined(__linux__) || defined(__APPLE__)
+#include <sys/ucontext.h>
+#endif
+
+#include <csignal>
+#include <cstdio>
+
+#include "absl/base/attributes.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/base/macros.h"
+#include "absl/debugging/stacktrace.h"
+#include "absl/debugging/symbolize.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+namespace {
+constexpr int kDefaultDumpStackFramesLimit = 64;
+// The %p field width for printf() functions is two characters per byte,
+// and two extra for the leading "0x".
+constexpr int kPrintfPointerFieldWidth = 2 + 2 * sizeof(void*);
+
+ABSL_CONST_INIT SymbolizeUrlEmitter debug_stack_trace_hook = nullptr;
+
+// Async-signal safe mmap allocator.
+void* Allocate(size_t num_bytes) {
+#ifdef ABSL_HAVE_MMAP
+  void* p = ::mmap(nullptr, num_bytes, PROT_READ | PROT_WRITE,
+                   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  return p == MAP_FAILED ? nullptr : p;
+#else
+  (void)num_bytes;
+  return nullptr;
+#endif  // ABSL_HAVE_MMAP
+}
+
+void Deallocate(void* p, size_t size) {
+#ifdef ABSL_HAVE_MMAP
+  ::munmap(p, size);
+#else
+  (void)p;
+  (void)size;
+#endif  // ABSL_HAVE_MMAP
+}
+
+// Print a program counter only.
+void DumpPC(OutputWriter* writer, void* writer_arg, void* const pc,
+            const char* const prefix) {
+  char buf[100];
+  snprintf(buf, sizeof(buf), "%s@ %*p\n", prefix, kPrintfPointerFieldWidth, pc);
+  writer(buf, writer_arg);
+}
+
+// Print a program counter and the corresponding stack frame size.
+void DumpPCAndFrameSize(OutputWriter* writer, void* writer_arg, void* const pc,
+                        int framesize, const char* const prefix) {
+  char buf[100];
+  if (framesize <= 0) {
+    snprintf(buf, sizeof(buf), "%s@ %*p  (unknown)\n", prefix,
+             kPrintfPointerFieldWidth, pc);
+  } else {
+    snprintf(buf, sizeof(buf), "%s@ %*p  %9d\n", prefix,
+             kPrintfPointerFieldWidth, pc, framesize);
+  }
+  writer(buf, writer_arg);
+}
+
+// Print a program counter and the corresponding symbol.
+void DumpPCAndSymbol(OutputWriter* writer, void* writer_arg, void* const pc,
+                     const char* const prefix) {
+  char tmp[1024];
+  const char* symbol = "(unknown)";
+  // Symbolizes the previous address of pc because pc may be in the
+  // next function.  The overrun happens when the function ends with
+  // a call to a function annotated noreturn (e.g. CHECK).
+  // If symbolization of pc-1 fails, also try pc on the off-chance
+  // that we crashed on the first instruction of a function (that
+  // actually happens very often for e.g. __restore_rt).
+  const uintptr_t prev_pc = reinterpret_cast<uintptr_t>(pc) - 1;
+  if (absl::Symbolize(reinterpret_cast<const char*>(prev_pc), tmp,
+                      sizeof(tmp)) ||
+      absl::Symbolize(pc, tmp, sizeof(tmp))) {
+    symbol = tmp;
+  }
+  char buf[1024];
+  snprintf(buf, sizeof(buf), "%s@ %*p  %s\n", prefix, kPrintfPointerFieldWidth,
+           pc, symbol);
+  writer(buf, writer_arg);
+}
+
+// Print a program counter, its stack frame size, and its symbol name.
+// Note that there is a separate symbolize_pc argument. Return addresses may be
+// at the end of the function, and this allows the caller to back up from pc if
+// appropriate.
+void DumpPCAndFrameSizeAndSymbol(OutputWriter* writer, void* writer_arg,
+                                 void* const pc, void* const symbolize_pc,
+                                 int framesize, const char* const prefix) {
+  char tmp[1024];
+  const char* symbol = "(unknown)";
+  if (absl::Symbolize(symbolize_pc, tmp, sizeof(tmp))) {
+    symbol = tmp;
+  }
+  char buf[1024];
+  if (framesize <= 0) {
+    snprintf(buf, sizeof(buf), "%s@ %*p  (unknown)  %s\n", prefix,
+             kPrintfPointerFieldWidth, pc, symbol);
+  } else {
+    snprintf(buf, sizeof(buf), "%s@ %*p  %9d  %s\n", prefix,
+             kPrintfPointerFieldWidth, pc, framesize, symbol);
+  }
+  writer(buf, writer_arg);
+}
+
+}  // namespace
+
+void RegisterDebugStackTraceHook(SymbolizeUrlEmitter hook) {
+  debug_stack_trace_hook = hook;
+}
+
+SymbolizeUrlEmitter GetDebugStackTraceHook() { return debug_stack_trace_hook; }
+
+// Returns the program counter from signal context, nullptr if
+// unknown. vuc is a ucontext_t*. We use void* to avoid the use of
+// ucontext_t on non-POSIX systems.
+void* GetProgramCounter(void* const vuc) {
+#ifdef __linux__
+  if (vuc != nullptr) {
+    ucontext_t* context = reinterpret_cast<ucontext_t*>(vuc);
+#if defined(__aarch64__)
+    return reinterpret_cast<void*>(context->uc_mcontext.pc);
+#elif defined(__alpha__)
+    return reinterpret_cast<void*>(context->uc_mcontext.sc_pc);
+#elif defined(__arm__)
+    return reinterpret_cast<void*>(context->uc_mcontext.arm_pc);
+#elif defined(__hppa__)
+    return reinterpret_cast<void*>(context->uc_mcontext.sc_iaoq[0]);
+#elif defined(__i386__)
+    if (14 < ABSL_ARRAYSIZE(context->uc_mcontext.gregs))
+      return reinterpret_cast<void*>(context->uc_mcontext.gregs[14]);
+#elif defined(__ia64__)
+    return reinterpret_cast<void*>(context->uc_mcontext.sc_ip);
+#elif defined(__m68k__)
+    return reinterpret_cast<void*>(context->uc_mcontext.gregs[16]);
+#elif defined(__mips__)
+    return reinterpret_cast<void*>(context->uc_mcontext.pc);
+#elif defined(__powerpc64__)
+    return reinterpret_cast<void*>(context->uc_mcontext.gp_regs[32]);
+#elif defined(__powerpc__)
+    return reinterpret_cast<void*>(context->uc_mcontext.uc_regs->gregs[32]);
+#elif defined(__riscv)
+    return reinterpret_cast<void*>(context->uc_mcontext.__gregs[REG_PC]);
+#elif defined(__s390__) && !defined(__s390x__)
+    return reinterpret_cast<void*>(context->uc_mcontext.psw.addr & 0x7fffffff);
+#elif defined(__s390__) && defined(__s390x__)
+    return reinterpret_cast<void*>(context->uc_mcontext.psw.addr);
+#elif defined(__sh__)
+    return reinterpret_cast<void*>(context->uc_mcontext.pc);
+#elif defined(__sparc__) && !defined(__arch64__)
+    return reinterpret_cast<void*>(context->uc_mcontext.gregs[19]);
+#elif defined(__sparc__) && defined(__arch64__)
+    return reinterpret_cast<void*>(context->uc_mcontext.mc_gregs[19]);
+#elif defined(__x86_64__)
+    if (16 < ABSL_ARRAYSIZE(context->uc_mcontext.gregs))
+      return reinterpret_cast<void*>(context->uc_mcontext.gregs[16]);
+#elif defined(__e2k__)
+    return reinterpret_cast<void*>(context->uc_mcontext.cr0_hi);
+#elif defined(__loongarch__)
+    return reinterpret_cast<void*>(context->uc_mcontext.__pc);
+#else
+#error "Undefined Architecture."
+#endif
+  }
+#elif defined(__APPLE__)
+  if (vuc != nullptr) {
+    ucontext_t* signal_ucontext = reinterpret_cast<ucontext_t*>(vuc);
+#if defined(__aarch64__)
+    return reinterpret_cast<void*>(
+        __darwin_arm_thread_state64_get_pc(signal_ucontext->uc_mcontext->__ss));
+#elif defined(__arm__)
+#if __DARWIN_UNIX03
+    return reinterpret_cast<void*>(signal_ucontext->uc_mcontext->__ss.__pc);
+#else
+    return reinterpret_cast<void*>(signal_ucontext->uc_mcontext->ss.pc);
+#endif
+#elif defined(__i386__)
+#if __DARWIN_UNIX03
+    return reinterpret_cast<void*>(signal_ucontext->uc_mcontext->__ss.__eip);
+#else
+    return reinterpret_cast<void*>(signal_ucontext->uc_mcontext->ss.eip);
+#endif
+#elif defined(__x86_64__)
+#if __DARWIN_UNIX03
+    return reinterpret_cast<void*>(signal_ucontext->uc_mcontext->__ss.__rip);
+#else
+    return reinterpret_cast<void*>(signal_ucontext->uc_mcontext->ss.rip);
+#endif
+#endif
+  }
+#elif defined(__akaros__)
+  auto* ctx = reinterpret_cast<struct user_context*>(vuc);
+  return reinterpret_cast<void*>(get_user_ctx_pc(ctx));
+#endif
+  static_cast<void>(vuc);
+  return nullptr;
+}
+
+void DumpPCAndFrameSizesAndStackTrace(void* const pc, void* const stack[],
+                                      int frame_sizes[], int depth,
+                                      int min_dropped_frames,
+                                      bool symbolize_stacktrace,
+                                      OutputWriter* writer, void* writer_arg) {
+  if (pc != nullptr) {
+    // We don't know the stack frame size for PC, use 0.
+    if (symbolize_stacktrace) {
+      DumpPCAndFrameSizeAndSymbol(writer, writer_arg, pc, pc, 0, "PC: ");
+    } else {
+      DumpPCAndFrameSize(writer, writer_arg, pc, 0, "PC: ");
+    }
+  }
+  for (int i = 0; i < depth; i++) {
+    if (symbolize_stacktrace) {
+      // Pass the previous address of pc as the symbol address because pc is a
+      // return address, and an overrun may occur when the function ends with a
+      // call to a function annotated noreturn (e.g. CHECK). Note that we don't
+      // do this for pc above, as the adjustment is only correct for return
+      // addresses.
+      DumpPCAndFrameSizeAndSymbol(writer, writer_arg, stack[i],
+                                  reinterpret_cast<char*>(stack[i]) - 1,
+                                  frame_sizes[i], "    ");
+    } else {
+      DumpPCAndFrameSize(writer, writer_arg, stack[i], frame_sizes[i], "    ");
+    }
+  }
+  if (min_dropped_frames > 0) {
+    char buf[100];
+    snprintf(buf, sizeof(buf), "    @ ... and at least %d more frames\n",
+             min_dropped_frames);
+    writer(buf, writer_arg);
+  }
+}
+
+// Dump current stack trace as directed by writer.
+// Make sure this function is not inlined to avoid skipping too many top frames.
+ABSL_ATTRIBUTE_NOINLINE
+void DumpStackTrace(int min_dropped_frames, int max_num_frames,
+                    bool symbolize_stacktrace, OutputWriter* writer,
+                    void* writer_arg) {
+  // Print stack trace
+  void* stack_buf[kDefaultDumpStackFramesLimit];
+  void** stack = stack_buf;
+  int num_stack = kDefaultDumpStackFramesLimit;
+  size_t allocated_bytes = 0;
+
+  if (num_stack >= max_num_frames) {
+    // User requested fewer frames than we already have space for.
+    num_stack = max_num_frames;
+  } else {
+    const size_t needed_bytes =
+        static_cast<size_t>(max_num_frames) * sizeof(stack[0]);
+    void* p = Allocate(needed_bytes);
+    if (p != nullptr) {  // We got the space.
+      num_stack = max_num_frames;
+      stack = reinterpret_cast<void**>(p);
+      allocated_bytes = needed_bytes;
+    }
+  }
+
+  int depth = absl::GetStackTrace(stack, num_stack, min_dropped_frames + 1);
+  for (int i = 0; i < depth; i++) {
+    if (symbolize_stacktrace) {
+      DumpPCAndSymbol(writer, writer_arg, stack[static_cast<size_t>(i)],
+                      "    ");
+    } else {
+      DumpPC(writer, writer_arg, stack[static_cast<size_t>(i)], "    ");
+    }
+  }
+
+  auto hook = GetDebugStackTraceHook();
+  if (hook != nullptr) {
+    (*hook)(stack, depth, writer, writer_arg);
+  }
+
+  if (allocated_bytes != 0) Deallocate(stack, allocated_bytes);
+}
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/examine_stack.h

@@ -0,0 +1,64 @@
+//
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef ABSL_DEBUGGING_INTERNAL_EXAMINE_STACK_H_
+#define ABSL_DEBUGGING_INTERNAL_EXAMINE_STACK_H_
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// Type of function used for printing in stack trace dumping, etc.
+// We avoid closures to keep things simple.
+typedef void OutputWriter(const char*, void*);
+
+// RegisterDebugStackTraceHook() allows to register a single routine
+// `hook` that is called each time DumpStackTrace() is called.
+// `hook` may be called from a signal handler.
+typedef void (*SymbolizeUrlEmitter)(void* const stack[], int depth,
+                                    OutputWriter* writer, void* writer_arg);
+
+// Registration of SymbolizeUrlEmitter for use inside of a signal handler.
+// This is inherently unsafe and must be signal safe code.
+void RegisterDebugStackTraceHook(SymbolizeUrlEmitter hook);
+SymbolizeUrlEmitter GetDebugStackTraceHook();
+
+// Returns the program counter from signal context, or nullptr if
+// unknown. `vuc` is a ucontext_t*. We use void* to avoid the use of
+// ucontext_t on non-POSIX systems.
+void* GetProgramCounter(void* const vuc);
+
+// Uses `writer` to dump the program counter, stack trace, and stack
+// frame sizes.
+void DumpPCAndFrameSizesAndStackTrace(void* const pc, void* const stack[],
+                                      int frame_sizes[], int depth,
+                                      int min_dropped_frames,
+                                      bool symbolize_stacktrace,
+                                      OutputWriter* writer, void* writer_arg);
+
+// Dump current stack trace omitting the topmost `min_dropped_frames` stack
+// frames.
+void DumpStackTrace(int min_dropped_frames, int max_num_frames,
+                    bool symbolize_stacktrace, OutputWriter* writer,
+                    void* writer_arg);
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_EXAMINE_STACK_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stack_consumption.cc

@@ -0,0 +1,206 @@
+//
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/stack_consumption.h"
+
+#ifdef ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION
+
+#include <signal.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "absl/base/attributes.h"
+#include "absl/base/internal/raw_logging.h"
+
+#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+namespace {
+
+// This code requires that we know the direction in which the stack
+// grows. It is commonly believed that this can be detected by putting
+// a variable on the stack and then passing its address to a function
+// that compares the address of this variable to the address of a
+// variable on the function's own stack. However, this is unspecified
+// behavior in C++: If two pointers p and q of the same type point to
+// different objects that are not members of the same object or
+// elements of the same array or to different functions, or if only
+// one of them is null, the results of p<q, p>q, p<=q, and p>=q are
+// unspecified. Therefore, instead we hardcode the direction of the
+// stack on platforms we know about.
+#if defined(__i386__) || defined(__x86_64__) || defined(__ppc__) || \
+    defined(__aarch64__) || defined(__riscv)
+constexpr bool kStackGrowsDown = true;
+#else
+#error Need to define kStackGrowsDown
+#endif
+
+// To measure the stack footprint of some code, we create a signal handler
+// (for SIGUSR2 say) that exercises this code on an alternate stack. This
+// alternate stack is initialized to some known pattern (0x55, 0x55, 0x55,
+// ...). We then self-send this signal, and after the signal handler returns,
+// look at the alternate stack buffer to see what portion has been touched.
+//
+// This trick gives us the the stack footprint of the signal handler.  But the
+// signal handler, even before the code for it is exercised, consumes some
+// stack already. We however only want the stack usage of the code inside the
+// signal handler. To measure this accurately, we install two signal handlers:
+// one that does nothing and just returns, and the user-provided signal
+// handler. The difference between the stack consumption of these two signals
+// handlers should give us the stack foorprint of interest.
+
+void EmptySignalHandler(int) {}
+
+// This is arbitrary value, and could be increase further, at the cost of
+// memset()ting it all to known sentinel value.
+constexpr int kAlternateStackSize = 64 << 10;  // 64KiB
+
+constexpr int kSafetyMargin = 32;
+constexpr char kAlternateStackFillValue = 0x55;
+
+// These helper functions look at the alternate stack buffer, and figure
+// out what portion of this buffer has been touched - this is the stack
+// consumption of the signal handler running on this alternate stack.
+// This function will return -1 if the alternate stack buffer has not been
+// touched. It will abort the program if the buffer has overflowed or is about
+// to overflow.
+int GetStackConsumption(const void* const altstack) {
+  const char* begin;
+  int increment;
+  if (kStackGrowsDown) {
+    begin = reinterpret_cast<const char*>(altstack);
+    increment = 1;
+  } else {
+    begin = reinterpret_cast<const char*>(altstack) + kAlternateStackSize - 1;
+    increment = -1;
+  }
+
+  for (int usage_count = kAlternateStackSize; usage_count > 0; --usage_count) {
+    if (*begin != kAlternateStackFillValue) {
+      ABSL_RAW_CHECK(usage_count <= kAlternateStackSize - kSafetyMargin,
+                     "Buffer has overflowed or is about to overflow");
+      return usage_count;
+    }
+    begin += increment;
+  }
+
+  ABSL_RAW_LOG(FATAL, "Unreachable code");
+  return -1;
+}
+
+}  // namespace
+
+int GetSignalHandlerStackConsumption(void (*signal_handler)(int)) {
+  // The alt-signal-stack cannot be heap allocated because there is a
+  // bug in glibc-2.2 where some signal handler setup code looks at the
+  // current stack pointer to figure out what thread is currently running.
+  // Therefore, the alternate stack must be allocated from the main stack
+  // itself.
+  void* altstack = mmap(nullptr, kAlternateStackSize, PROT_READ | PROT_WRITE,
+                        MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  ABSL_RAW_CHECK(altstack != MAP_FAILED, "mmap() failed");
+
+  // Set up the alt-signal-stack (and save the older one).
+  stack_t sigstk;
+  memset(&sigstk, 0, sizeof(sigstk));
+  sigstk.ss_sp = altstack;
+  sigstk.ss_size = kAlternateStackSize;
+  sigstk.ss_flags = 0;
+  stack_t old_sigstk;
+  memset(&old_sigstk, 0, sizeof(old_sigstk));
+  ABSL_RAW_CHECK(sigaltstack(&sigstk, &old_sigstk) == 0,
+                 "sigaltstack() failed");
+
+  // Set up SIGUSR1 and SIGUSR2 signal handlers (and save the older ones).
+  struct sigaction sa;
+  memset(&sa, 0, sizeof(sa));
+  struct sigaction old_sa1, old_sa2;
+  sigemptyset(&sa.sa_mask);
+  sa.sa_flags = SA_ONSTACK;
+
+  // SIGUSR1 maps to EmptySignalHandler.
+  sa.sa_handler = EmptySignalHandler;
+  ABSL_RAW_CHECK(sigaction(SIGUSR1, &sa, &old_sa1) == 0, "sigaction() failed");
+
+  // SIGUSR2 maps to signal_handler.
+  sa.sa_handler = signal_handler;
+  ABSL_RAW_CHECK(sigaction(SIGUSR2, &sa, &old_sa2) == 0, "sigaction() failed");
+
+  // Send SIGUSR1 signal and measure the stack consumption of the empty
+  // signal handler.
+  // The first signal might use more stack space. Run once and ignore the
+  // results to get that out of the way.
+  ABSL_RAW_CHECK(kill(getpid(), SIGUSR1) == 0, "kill() failed");
+
+  memset(altstack, kAlternateStackFillValue, kAlternateStackSize);
+  ABSL_RAW_CHECK(kill(getpid(), SIGUSR1) == 0, "kill() failed");
+  int base_stack_consumption = GetStackConsumption(altstack);
+
+  // Send SIGUSR2 signal and measure the stack consumption of signal_handler.
+  ABSL_RAW_CHECK(kill(getpid(), SIGUSR2) == 0, "kill() failed");
+  int signal_handler_stack_consumption = GetStackConsumption(altstack);
+
+  // Now restore the old alt-signal-stack and signal handlers.
+  if (old_sigstk.ss_sp == nullptr && old_sigstk.ss_size == 0 &&
+      (old_sigstk.ss_flags & SS_DISABLE)) {
+    // https://git.musl-libc.org/cgit/musl/commit/src/signal/sigaltstack.c?id=7829f42a2c8944555439380498ab8b924d0f2070
+    // The original stack has ss_size==0 and ss_flags==SS_DISABLE, but some
+    // versions of musl have a bug that rejects ss_size==0. Work around this by
+    // setting ss_size to MINSIGSTKSZ, which should be ignored by the kernel
+    // when SS_DISABLE is set.
+    old_sigstk.ss_size = static_cast<size_t>(MINSIGSTKSZ);
+  }
+  ABSL_RAW_CHECK(sigaltstack(&old_sigstk, nullptr) == 0,
+                 "sigaltstack() failed");
+  ABSL_RAW_CHECK(sigaction(SIGUSR1, &old_sa1, nullptr) == 0,
+                 "sigaction() failed");
+  ABSL_RAW_CHECK(sigaction(SIGUSR2, &old_sa2, nullptr) == 0,
+                 "sigaction() failed");
+
+  ABSL_RAW_CHECK(munmap(altstack, kAlternateStackSize) == 0, "munmap() failed");
+  if (signal_handler_stack_consumption != -1 && base_stack_consumption != -1) {
+    return signal_handler_stack_consumption - base_stack_consumption;
+  }
+  return -1;
+}
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#else
+
+// https://github.com/abseil/abseil-cpp/issues/1465
+// CMake builds on Apple platforms error when libraries are empty.
+// Our CMake configuration can avoid this error on header-only libraries,
+// but since this library is conditionally empty, including a single
+// variable is an easy workaround.
+#ifdef __APPLE__
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+extern const char kAvoidEmptyStackConsumptionLibraryWarning;
+const char kAvoidEmptyStackConsumptionLibraryWarning = 0;
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+#endif  // __APPLE__
+
+#endif  // ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stack_consumption.h

@@ -0,0 +1,50 @@
+//
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Helper function for measuring stack consumption of signal handlers.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACK_CONSUMPTION_H_
+#define ABSL_DEBUGGING_INTERNAL_STACK_CONSUMPTION_H_
+
+#include "absl/base/config.h"
+
+// The code in this module is not portable.
+// Use this feature test macro to detect its availability.
+#ifdef ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION
+#error ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION cannot be set directly
+#elif !defined(__APPLE__) && !defined(_WIN32) && !defined(__Fuchsia__) && \
+    (defined(__i386__) || defined(__x86_64__) || defined(__ppc__) || \
+     defined(__aarch64__) || defined(__riscv))
+#define ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION 1
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// Returns the stack consumption in bytes for the code exercised by
+// signal_handler.  To measure stack consumption, signal_handler is registered
+// as a signal handler, so the code that it exercises must be async-signal
+// safe.  The argument of signal_handler is an implementation detail of signal
+// handlers and should ignored by the code for signal_handler.  Use global
+// variables to pass information between your test code and signal_handler.
+int GetSignalHandlerStackConsumption(void (*signal_handler)(int));
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACK_CONSUMPTION_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stack_consumption_test.cc

@@ -0,0 +1,50 @@
+//
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/stack_consumption.h"
+
+#ifdef ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION
+
+#include <string.h>
+
+#include "gtest/gtest.h"
+#include "absl/log/log.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+namespace {
+
+static void SimpleSignalHandler(int signo) {
+  char buf[100];
+  memset(buf, 'a', sizeof(buf));
+
+  // Never true, but prevents compiler from optimizing buf out.
+  if (signo == 0) {
+    LOG(INFO) << static_cast<void*>(buf);
+  }
+}
+
+TEST(SignalHandlerStackConsumptionTest, MeasuresStackConsumption) {
+  // Our handler should consume reasonable number of bytes.
+  EXPECT_GE(GetSignalHandlerStackConsumption(SimpleSignalHandler), 100);
+}
+
+}  // namespace
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_aarch64-inl.inc

@@ -0,0 +1,285 @@
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_AARCH64_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_AARCH64_INL_H_
+
+// Generate stack tracer for aarch64
+
+#if defined(__linux__)
+#include <signal.h>
+#include <sys/mman.h>
+#include <ucontext.h>
+#include <unistd.h>
+#endif
+
+#include <atomic>
+#include <cassert>
+#include <cstdint>
+#include <iostream>
+#include <limits>
+
+#include "absl/base/attributes.h"
+#include "absl/debugging/internal/address_is_readable.h"
+#include "absl/debugging/internal/vdso_support.h"  // a no-op on non-elf or non-glibc systems
+#include "absl/debugging/stacktrace.h"
+
+static const size_t kUnknownFrameSize = 0;
+// Stack end to use when we don't know the actual stack end
+// (effectively just the end of address space).
+constexpr uintptr_t kUnknownStackEnd =
+    std::numeric_limits<size_t>::max() - sizeof(void *);
+
+#if defined(__linux__)
+// Returns the address of the VDSO __kernel_rt_sigreturn function, if present.
+static const unsigned char* GetKernelRtSigreturnAddress() {
+  constexpr uintptr_t kImpossibleAddress = 1;
+  ABSL_CONST_INIT static std::atomic<uintptr_t> memoized{kImpossibleAddress};
+  uintptr_t address = memoized.load(std::memory_order_relaxed);
+  if (address != kImpossibleAddress) {
+    return reinterpret_cast<const unsigned char*>(address);
+  }
+
+  address = reinterpret_cast<uintptr_t>(nullptr);
+
+#ifdef ABSL_HAVE_VDSO_SUPPORT
+  absl::debugging_internal::VDSOSupport vdso;
+  if (vdso.IsPresent()) {
+    absl::debugging_internal::VDSOSupport::SymbolInfo symbol_info;
+    auto lookup = [&](int type) {
+      return vdso.LookupSymbol("__kernel_rt_sigreturn", "LINUX_2.6.39", type,
+                               &symbol_info);
+    };
+    if ((!lookup(STT_FUNC) && !lookup(STT_NOTYPE)) ||
+        symbol_info.address == nullptr) {
+      // Unexpected: VDSO is present, yet the expected symbol is missing
+      // or null.
+      assert(false && "VDSO is present, but doesn't have expected symbol");
+    } else {
+      if (reinterpret_cast<uintptr_t>(symbol_info.address) !=
+          kImpossibleAddress) {
+        address = reinterpret_cast<uintptr_t>(symbol_info.address);
+      } else {
+        assert(false && "VDSO returned invalid address");
+      }
+    }
+  }
+#endif
+
+  memoized.store(address, std::memory_order_relaxed);
+  return reinterpret_cast<const unsigned char*>(address);
+}
+#endif  // __linux__
+
+// Compute the size of a stack frame in [low..high).  We assume that
+// low < high.  Return size of kUnknownFrameSize.
+template<typename T>
+static size_t ComputeStackFrameSize(const T* low,
+                                           const T* high) {
+  const char* low_char_ptr = reinterpret_cast<const char *>(low);
+  const char* high_char_ptr = reinterpret_cast<const char *>(high);
+  return low < high ? static_cast<size_t>(high_char_ptr - low_char_ptr)
+                    : kUnknownFrameSize;
+}
+
+// Saves stack info that is expensive to calculate to avoid recalculating per frame.
+struct StackInfo {
+  uintptr_t stack_low;
+  uintptr_t stack_high;
+  uintptr_t sig_stack_low;
+  uintptr_t sig_stack_high;
+};
+
+static bool InsideSignalStack(void** ptr, const StackInfo* stack_info) {
+  uintptr_t comparable_ptr = reinterpret_cast<uintptr_t>(ptr);
+  if (stack_info->sig_stack_high == kUnknownStackEnd)
+    return false;
+  return (comparable_ptr >= stack_info->sig_stack_low &&
+          comparable_ptr < stack_info->sig_stack_high);
+}
+
+// Given a pointer to a stack frame, locate and return the calling
+// stackframe, or return null if no stackframe can be found. Perform sanity
+// checks (the strictness of which is controlled by the boolean parameter
+// "STRICT_UNWINDING") to reduce the chance that a bad pointer is returned.
+template<bool STRICT_UNWINDING, bool WITH_CONTEXT>
+ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY  // May read random elements from stack.
+static void **NextStackFrame(void **old_frame_pointer, const void *uc,
+                             const StackInfo *stack_info) {
+  void **new_frame_pointer = reinterpret_cast<void**>(*old_frame_pointer);
+
+#if defined(__linux__)
+  if (WITH_CONTEXT && uc != nullptr) {
+    // Check to see if next frame's return address is __kernel_rt_sigreturn.
+    if (old_frame_pointer[1] == GetKernelRtSigreturnAddress()) {
+      const ucontext_t *ucv = static_cast<const ucontext_t *>(uc);
+      // old_frame_pointer[0] is not suitable for unwinding, look at
+      // ucontext to discover frame pointer before signal.
+      void **const pre_signal_frame_pointer =
+          reinterpret_cast<void **>(ucv->uc_mcontext.regs[29]);
+
+      // The most recent signal always needs special handling to find the frame
+      // pointer, but a nested signal does not.  If pre_signal_frame_pointer is
+      // earlier in the stack than the old_frame_pointer, then use it. If it is
+      // later, then we have already unwound through it and it needs no special
+      // handling.
+      if (pre_signal_frame_pointer >= old_frame_pointer) {
+        new_frame_pointer = pre_signal_frame_pointer;
+      }
+  }
+#endif
+
+  // The frame pointer should be 8-byte aligned.
+  if ((reinterpret_cast<uintptr_t>(new_frame_pointer) & 7) != 0)
+    return nullptr;
+
+  // Check that alleged frame pointer is actually readable. This is to
+  // prevent "double fault" in case we hit the first fault due to e.g.
+  // stack corruption.
+  if (!absl::debugging_internal::AddressIsReadable(
+          new_frame_pointer))
+    return nullptr;
+  }
+
+  // Only check the size if both frames are in the same stack.
+  if (InsideSignalStack(new_frame_pointer, stack_info) ==
+      InsideSignalStack(old_frame_pointer, stack_info)) {
+    // Check frame size.  In strict mode, we assume frames to be under
+    // 100,000 bytes.  In non-strict mode, we relax the limit to 1MB.
+    const size_t max_size = STRICT_UNWINDING ? 100000 : 1000000;
+    const size_t frame_size =
+        ComputeStackFrameSize(old_frame_pointer, new_frame_pointer);
+    if (frame_size == kUnknownFrameSize)
+       return nullptr;
+    // A very large frame may mean corrupt memory or an erroneous frame
+    // pointer. But also maybe just a plain-old large frame.  Assume that if the
+    // frame is within a known stack, then it is valid.
+    if (frame_size > max_size) {
+      size_t stack_low = stack_info->stack_low;
+      size_t stack_high = stack_info->stack_high;
+      if (InsideSignalStack(new_frame_pointer, stack_info)) {
+        stack_low = stack_info->sig_stack_low;
+        stack_high = stack_info->sig_stack_high;
+      }
+      if (stack_high < kUnknownStackEnd &&
+          static_cast<size_t>(getpagesize()) < stack_low) {
+        const uintptr_t new_fp_u =
+            reinterpret_cast<uintptr_t>(new_frame_pointer);
+        // Stack bounds are known.
+        if (!(stack_low < new_fp_u && new_fp_u <= stack_high)) {
+          // new_frame_pointer is not within a known stack.
+          return nullptr;
+        }
+      } else {
+        // Stack bounds are unknown, prefer truncated stack to possible crash.
+        return nullptr;
+      }
+    }
+  }
+
+  return new_frame_pointer;
+}
+
+// When PAC-RET (-mbranch-protection=pac-ret) is enabled, return addresses
+// stored on the stack will be signed, which means that pointer bits outside of
+// the VA range are potentially set. Since the stacktrace code is expected to
+// return normal code pointers, this function clears those bits.
+inline void* ClearPacBits(void* ptr) {
+  register void* x30 __asm__("x30") = ptr;
+  // The normal instruction for clearing PAC bits is XPACI, but for
+  // compatibility with ARM platforms that do not support pointer
+  // authentication, we use the hint space instruction XPACLRI instead. Hint
+  // space instructions behave as NOPs on unsupported platforms.
+#define ABSL_XPACLRI_HINT "hint #0x7;"
+  asm(ABSL_XPACLRI_HINT : "+r"(x30));  // asm("xpaclri" : "+r"(x30));
+#undef ABSL_XPACLRI_HINT
+  return x30;
+}
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+// We count on the bottom frame being this one. See the comment
+// at prev_return_address
+ABSL_ATTRIBUTE_NOINLINE
+ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
+static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count,
+                      const void *ucp, int *min_dropped_frames) {
+#ifdef __GNUC__
+  void **frame_pointer = reinterpret_cast<void**>(__builtin_frame_address(0));
+#else
+# error reading stack point not yet supported on this platform.
+#endif
+  skip_count++;    // Skip the frame for this function.
+  int n = 0;
+
+  // Assume that the first page is not stack.
+  StackInfo stack_info;
+  stack_info.stack_low = static_cast<uintptr_t>(getpagesize());
+  stack_info.stack_high = kUnknownStackEnd;
+  stack_info.sig_stack_low = stack_info.stack_low;
+  stack_info.sig_stack_high = kUnknownStackEnd;
+
+  // The frame pointer points to low address of a frame.  The first 64-bit
+  // word of a frame points to the next frame up the call chain, which normally
+  // is just after the high address of the current frame.  The second word of
+  // a frame contains return address of to the caller.   To find a pc value
+  // associated with the current frame, we need to go down a level in the call
+  // chain.  So we remember return the address of the last frame seen.  This
+  // does not work for the first stack frame, which belongs to UnwindImp() but
+  // we skip the frame for UnwindImp() anyway.
+  void* prev_return_address = nullptr;
+  // The nth frame size is the difference between the nth frame pointer and the
+  // the frame pointer below it in the call chain. There is no frame below the
+  // leaf frame, but this function is the leaf anyway, and we skip it.
+  void** prev_frame_pointer = nullptr;
+
+   while (frame_pointer && n < max_depth) {
+    if (skip_count > 0) {
+      skip_count--;
+    } else {
+      result[n] = ClearPacBits(prev_return_address);
+      if (IS_STACK_FRAMES) {
+        sizes[n] = static_cast<int>(
+            ComputeStackFrameSize(prev_frame_pointer, frame_pointer));
+      }
+      n++;
+    }
+    prev_return_address = frame_pointer[1];
+    prev_frame_pointer = frame_pointer;
+    // The absl::GetStackFrames routine is called when we are in some
+    // informational context (the failure signal handler for example).
+    // Use the non-strict unwinding rules to produce a stack trace
+    // that is as complete as possible (even if it contains a few bogus
+    // entries in some rare cases).
+    frame_pointer = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(
+        frame_pointer, ucp, &stack_info);
+  }
+
+  if (min_dropped_frames != nullptr) {
+    // Implementation detail: we clamp the max of frames we are willing to
+    // count, so as not to spend too much time in the loop below.
+    const int kMaxUnwind = 200;
+    int num_dropped_frames = 0;
+    for (int j = 0; frame_pointer != nullptr && j < kMaxUnwind; j++) {
+      if (skip_count > 0) {
+        skip_count--;
+      } else {
+        num_dropped_frames++;
+      }
+      frame_pointer = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(
+          frame_pointer, ucp, &stack_info);
+    }
+    *min_dropped_frames = num_dropped_frames;
+  }
+  return n;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() {
+  return true;
+}
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_AARCH64_INL_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_arm-inl.inc

@@ -0,0 +1,139 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// This is inspired by Craig Silverstein's PowerPC stacktrace code.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_ARM_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_ARM_INL_H_
+
+#include <cstdint>
+
+#include "absl/debugging/stacktrace.h"
+
+// WARNING:
+// This only works if all your code is in either ARM or THUMB mode.  With
+// interworking, the frame pointer of the caller can either be in r11 (ARM
+// mode) or r7 (THUMB mode).  A callee only saves the frame pointer of its
+// mode in a fixed location on its stack frame.  If the caller is a different
+// mode, there is no easy way to find the frame pointer.  It can either be
+// still in the designated register or saved on stack along with other callee
+// saved registers.
+
+// Given a pointer to a stack frame, locate and return the calling
+// stackframe, or return nullptr if no stackframe can be found. Perform sanity
+// checks (the strictness of which is controlled by the boolean parameter
+// "STRICT_UNWINDING") to reduce the chance that a bad pointer is returned.
+template<bool STRICT_UNWINDING>
+static void **NextStackFrame(void **old_sp) {
+  void **new_sp = (void**) old_sp[-1];
+
+  // Check that the transition from frame pointer old_sp to frame
+  // pointer new_sp isn't clearly bogus
+  if (STRICT_UNWINDING) {
+    // With the stack growing downwards, older stack frame must be
+    // at a greater address that the current one.
+    if (new_sp <= old_sp) return nullptr;
+    // Assume stack frames larger than 100,000 bytes are bogus.
+    if ((uintptr_t)new_sp - (uintptr_t)old_sp > 100000) return nullptr;
+  } else {
+    // In the non-strict mode, allow discontiguous stack frames.
+    // (alternate-signal-stacks for example).
+    if (new_sp == old_sp) return nullptr;
+    // And allow frames upto about 1MB.
+    if ((new_sp > old_sp)
+        && ((uintptr_t)new_sp - (uintptr_t)old_sp > 1000000)) return nullptr;
+  }
+  if ((uintptr_t)new_sp & (sizeof(void *) - 1)) return nullptr;
+  return new_sp;
+}
+
+// This ensures that absl::GetStackTrace sets up the Link Register properly.
+#ifdef __GNUC__
+void StacktraceArmDummyFunction() __attribute__((noinline));
+void StacktraceArmDummyFunction() { __asm__ volatile(""); }
+#else
+# error StacktraceArmDummyFunction() needs to be ported to this platform.
+#endif
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count,
+                      const void * /* ucp */, int *min_dropped_frames) {
+#ifdef __GNUC__
+  void **sp = reinterpret_cast<void**>(__builtin_frame_address(0));
+#else
+# error reading stack point not yet supported on this platform.
+#endif
+
+  // On ARM, the return address is stored in the link register (r14).
+  // This is not saved on the stack frame of a leaf function.  To
+  // simplify code that reads return addresses, we call a dummy
+  // function so that the return address of this function is also
+  // stored in the stack frame.  This works at least for gcc.
+  StacktraceArmDummyFunction();
+
+  int n = 0;
+  while (sp && n < max_depth) {
+    // The absl::GetStackFrames routine is called when we are in some
+    // informational context (the failure signal handler for example).
+    // Use the non-strict unwinding rules to produce a stack trace
+    // that is as complete as possible (even if it contains a few bogus
+    // entries in some rare cases).
+    void **next_sp = NextStackFrame<!IS_STACK_FRAMES>(sp);
+
+    if (skip_count > 0) {
+      skip_count--;
+    } else {
+      result[n] = *sp;
+
+      if (IS_STACK_FRAMES) {
+        if (next_sp > sp) {
+          sizes[n] = (uintptr_t)next_sp - (uintptr_t)sp;
+        } else {
+          // A frame-size of 0 is used to indicate unknown frame size.
+          sizes[n] = 0;
+        }
+      }
+      n++;
+    }
+    sp = next_sp;
+  }
+  if (min_dropped_frames != nullptr) {
+    // Implementation detail: we clamp the max of frames we are willing to
+    // count, so as not to spend too much time in the loop below.
+    const int kMaxUnwind = 200;
+    int num_dropped_frames = 0;
+    for (int j = 0; sp != nullptr && j < kMaxUnwind; j++) {
+      if (skip_count > 0) {
+        skip_count--;
+      } else {
+        num_dropped_frames++;
+      }
+      sp = NextStackFrame<!IS_STACK_FRAMES>(sp);
+    }
+    *min_dropped_frames = num_dropped_frames;
+  }
+  return n;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() {
+  return false;
+}
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_ARM_INL_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_config.h

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2017 The Abseil Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+
+ * Defines ABSL_STACKTRACE_INL_HEADER to the *-inl.h containing
+ * actual unwinder implementation.
+ * This header is "private" to stacktrace.cc.
+ * DO NOT include it into any other files.
+*/
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_CONFIG_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_CONFIG_H_
+
+#include "absl/base/config.h"
+
+#if defined(ABSL_STACKTRACE_INL_HEADER)
+#error ABSL_STACKTRACE_INL_HEADER cannot be directly set
+
+#elif defined(_WIN32)
+#define ABSL_STACKTRACE_INL_HEADER \
+    "absl/debugging/internal/stacktrace_win32-inl.inc"
+
+#elif defined(__APPLE__)
+#ifdef ABSL_HAVE_THREAD_LOCAL
+// Thread local support required for UnwindImpl.
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_generic-inl.inc"
+#endif  // defined(ABSL_HAVE_THREAD_LOCAL)
+
+// Emscripten stacktraces rely on JS. Do not use them in standalone mode.
+#elif defined(__EMSCRIPTEN__) && !defined(STANDALONE_WASM)
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_emscripten-inl.inc"
+
+#elif defined(__ANDROID__) && __ANDROID_API__ >= 33
+
+// Use the generic implementation for Android 33+ (Android T+). This is the
+// first version of Android for which <execinfo.h> implements backtrace().
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_generic-inl.inc"
+
+#elif defined(__linux__) && !defined(__ANDROID__)
+
+#if defined(NO_FRAME_POINTER) && \
+    (defined(__i386__) || defined(__x86_64__) || defined(__aarch64__))
+// Note: The libunwind-based implementation is not available to open-source
+// users.
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_libunwind-inl.inc"
+#define STACKTRACE_USES_LIBUNWIND 1
+#elif defined(NO_FRAME_POINTER) && defined(__has_include)
+#if __has_include(<execinfo.h>)
+// Note: When using glibc this may require -funwind-tables to function properly.
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_generic-inl.inc"
+#endif  // __has_include(<execinfo.h>)
+#elif defined(__i386__) || defined(__x86_64__)
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_x86-inl.inc"
+#elif defined(__ppc__) || defined(__PPC__)
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_powerpc-inl.inc"
+#elif defined(__aarch64__)
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_aarch64-inl.inc"
+#elif defined(__riscv)
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_riscv-inl.inc"
+#elif defined(__has_include)
+#if __has_include(<execinfo.h>)
+// Note: When using glibc this may require -funwind-tables to function properly.
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_generic-inl.inc"
+#endif  // __has_include(<execinfo.h>)
+#endif  // defined(__has_include)
+
+#endif  // defined(__linux__) && !defined(__ANDROID__)
+
+// Fallback to the empty implementation.
+#if !defined(ABSL_STACKTRACE_INL_HEADER)
+#define ABSL_STACKTRACE_INL_HEADER \
+  "absl/debugging/internal/stacktrace_unimplemented-inl.inc"
+#endif
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_CONFIG_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_emscripten-inl.inc

@@ -0,0 +1,110 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Portable implementation - just use glibc
+//
+// Note:  The glibc implementation may cause a call to malloc.
+// This can cause a deadlock in HeapProfiler.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_EMSCRIPTEN_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_EMSCRIPTEN_INL_H_
+
+#include <emscripten.h>
+
+#include <atomic>
+#include <cstring>
+
+#include "absl/base/attributes.h"
+#include "absl/debugging/stacktrace.h"
+
+extern "C" {
+uintptr_t emscripten_stack_snapshot();
+uint32_t emscripten_stack_unwind_buffer(uintptr_t pc, void *buffer,
+                                        uint32_t depth);
+}
+
+// Sometimes, we can try to get a stack trace from within a stack
+// trace, which can cause a self-deadlock.
+// Protect against such reentrant call by failing to get a stack trace.
+//
+// We use __thread here because the code here is extremely low level -- it is
+// called while collecting stack traces from within malloc and mmap, and thus
+// can not call anything which might call malloc or mmap itself.
+static __thread int recursive = 0;
+
+// The stack trace function might be invoked very early in the program's
+// execution (e.g. from the very first malloc).
+// As such, we suppress usage of backtrace during this early stage of execution.
+static std::atomic<bool> disable_stacktraces(true);  // Disabled until healthy.
+// Waiting until static initializers run seems to be late enough.
+// This file is included into stacktrace.cc so this will only run once.
+ABSL_ATTRIBUTE_UNUSED static int stacktraces_enabler = []() {
+  // Check if we can even create stacktraces. If not, bail early and leave
+  // disable_stacktraces set as-is.
+  // clang-format off
+  if (!EM_ASM_INT({ return (typeof wasmOffsetConverter !== 'undefined'); })) {
+    return 0;
+  }
+  // clang-format on
+  disable_stacktraces.store(false, std::memory_order_relaxed);
+  return 0;
+}();
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+static int UnwindImpl(void **result, int *sizes, int max_depth, int skip_count,
+                      const void *ucp, int *min_dropped_frames) {
+  if (recursive || disable_stacktraces.load(std::memory_order_relaxed)) {
+    return 0;
+  }
+  ++recursive;
+
+  static_cast<void>(ucp);  // Unused.
+  constexpr int kStackLength = 64;
+  void *stack[kStackLength];
+
+  int size;
+  uintptr_t pc = emscripten_stack_snapshot();
+  size = emscripten_stack_unwind_buffer(pc, stack, kStackLength);
+
+  int result_count = size - skip_count;
+  if (result_count < 0) result_count = 0;
+  if (result_count > max_depth) result_count = max_depth;
+  for (int i = 0; i < result_count; i++) result[i] = stack[i + skip_count];
+
+  if (IS_STACK_FRAMES) {
+    // No implementation for finding out the stack frame sizes yet.
+    memset(sizes, 0, sizeof(*sizes) * result_count);
+  }
+  if (min_dropped_frames != nullptr) {
+    if (size - skip_count - max_depth > 0) {
+      *min_dropped_frames = size - skip_count - max_depth;
+    } else {
+      *min_dropped_frames = 0;
+    }
+  }
+
+  --recursive;
+
+  return result_count;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() { return true; }
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_EMSCRIPTEN_INL_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_generic-inl.inc

@@ -0,0 +1,108 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Portable implementation - just use glibc
+//
+// Note:  The glibc implementation may cause a call to malloc.
+// This can cause a deadlock in HeapProfiler.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_GENERIC_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_GENERIC_INL_H_
+
+#include <execinfo.h>
+#include <atomic>
+#include <cstring>
+
+#include "absl/debugging/stacktrace.h"
+#include "absl/base/attributes.h"
+
+// Sometimes, we can try to get a stack trace from within a stack
+// trace, because we don't block signals inside this code (which would be too
+// expensive: the two extra system calls per stack trace do matter here).
+// That can cause a self-deadlock.
+// Protect against such reentrant call by failing to get a stack trace.
+//
+// We use __thread here because the code here is extremely low level -- it is
+// called while collecting stack traces from within malloc and mmap, and thus
+// can not call anything which might call malloc or mmap itself.
+static __thread int recursive = 0;
+
+// The stack trace function might be invoked very early in the program's
+// execution (e.g. from the very first malloc if using tcmalloc). Also, the
+// glibc implementation itself will trigger malloc the first time it is called.
+// As such, we suppress usage of backtrace during this early stage of execution.
+static std::atomic<bool> disable_stacktraces(true);  // Disabled until healthy.
+// Waiting until static initializers run seems to be late enough.
+// This file is included into stacktrace.cc so this will only run once.
+ABSL_ATTRIBUTE_UNUSED static int stacktraces_enabler = []() {
+  void* unused_stack[1];
+  // Force the first backtrace to happen early to get the one-time shared lib
+  // loading (allocation) out of the way. After the first call it is much safer
+  // to use backtrace from a signal handler if we crash somewhere later.
+  backtrace(unused_stack, 1);
+  disable_stacktraces.store(false, std::memory_order_relaxed);
+  return 0;
+}();
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count,
+                      const void *ucp, int *min_dropped_frames) {
+  if (recursive || disable_stacktraces.load(std::memory_order_relaxed)) {
+    return 0;
+  }
+  ++recursive;
+
+  static_cast<void>(ucp);  // Unused.
+  static const int kStackLength = 64;
+  void * stack[kStackLength];
+  int size;
+
+  size = backtrace(stack, kStackLength);
+  skip_count++;  // we want to skip the current frame as well
+  int result_count = size - skip_count;
+  if (result_count < 0)
+    result_count = 0;
+  if (result_count > max_depth)
+    result_count = max_depth;
+  for (int i = 0; i < result_count; i++)
+    result[i] = stack[i + skip_count];
+
+  if (IS_STACK_FRAMES) {
+    // No implementation for finding out the stack frame sizes yet.
+    memset(sizes, 0, sizeof(*sizes) * static_cast<size_t>(result_count));
+  }
+  if (min_dropped_frames != nullptr) {
+    if (size - skip_count - max_depth > 0) {
+      *min_dropped_frames = size - skip_count - max_depth;
+    } else {
+      *min_dropped_frames = 0;
+    }
+  }
+
+  --recursive;
+
+  return result_count;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() {
+  return true;
+}
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_GENERIC_INL_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_powerpc-inl.inc

@@ -0,0 +1,258 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Produce stack trace.  I'm guessing (hoping!) the code is much like
+// for x86.  For apple machines, at least, it seems to be; see
+//    https://developer.apple.com/documentation/mac/runtimehtml/RTArch-59.html
+//    https://www.linux-foundation.org/spec/ELF/ppc64/PPC-elf64abi-1.9.html#STACK
+// Linux has similar code: http://patchwork.ozlabs.org/linuxppc/patch?id=8882
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_POWERPC_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_POWERPC_INL_H_
+
+#if defined(__linux__)
+#include <asm/ptrace.h>   // for PT_NIP.
+#include <ucontext.h>     // for ucontext_t
+#endif
+
+#include <unistd.h>
+#include <cassert>
+#include <cstdint>
+#include <cstdio>
+
+#include "absl/base/attributes.h"
+#include "absl/base/optimization.h"
+#include "absl/base/port.h"
+#include "absl/debugging/stacktrace.h"
+#include "absl/debugging/internal/address_is_readable.h"
+#include "absl/debugging/internal/vdso_support.h"  // a no-op on non-elf or non-glibc systems
+
+// Given a stack pointer, return the saved link register value.
+// Note that this is the link register for a callee.
+static inline void *StacktracePowerPCGetLR(void **sp) {
+  // PowerPC has 3 main ABIs, which say where in the stack the
+  // Link Register is.  For DARWIN and AIX (used by apple and
+  // linux ppc64), it's in sp[2].  For SYSV (used by linux ppc),
+  // it's in sp[1].
+#if defined(_CALL_AIX) || defined(_CALL_DARWIN)
+  return *(sp+2);
+#elif defined(_CALL_SYSV)
+  return *(sp+1);
+#elif defined(__APPLE__) || defined(__FreeBSD__) || \
+    (defined(__linux__) && defined(__PPC64__))
+  // This check is in case the compiler doesn't define _CALL_AIX/etc.
+  return *(sp+2);
+#elif defined(__linux)
+  // This check is in case the compiler doesn't define _CALL_SYSV.
+  return *(sp+1);
+#else
+#error Need to specify the PPC ABI for your architecture.
+#endif
+}
+
+// Given a pointer to a stack frame, locate and return the calling
+// stackframe, or return null if no stackframe can be found. Perform sanity
+// checks (the strictness of which is controlled by the boolean parameter
+// "STRICT_UNWINDING") to reduce the chance that a bad pointer is returned.
+template<bool STRICT_UNWINDING, bool IS_WITH_CONTEXT>
+ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
+static void **NextStackFrame(void **old_sp, const void *uc) {
+  void **new_sp = (void **) *old_sp;
+  enum { kStackAlignment = 16 };
+
+  // Check that the transition from frame pointer old_sp to frame
+  // pointer new_sp isn't clearly bogus
+  if (STRICT_UNWINDING) {
+    // With the stack growing downwards, older stack frame must be
+    // at a greater address that the current one.
+    if (new_sp <= old_sp) return nullptr;
+    // Assume stack frames larger than 100,000 bytes are bogus.
+    if ((uintptr_t)new_sp - (uintptr_t)old_sp > 100000) return nullptr;
+  } else {
+    // In the non-strict mode, allow discontiguous stack frames.
+    // (alternate-signal-stacks for example).
+    if (new_sp == old_sp) return nullptr;
+    // And allow frames upto about 1MB.
+    if ((new_sp > old_sp)
+        && ((uintptr_t)new_sp - (uintptr_t)old_sp > 1000000)) return nullptr;
+  }
+  if ((uintptr_t)new_sp % kStackAlignment != 0) return nullptr;
+
+#if defined(__linux__)
+  enum StackTraceKernelSymbolStatus {
+      kNotInitialized = 0, kAddressValid, kAddressInvalid };
+
+  if (IS_WITH_CONTEXT && uc != nullptr) {
+    static StackTraceKernelSymbolStatus kernel_symbol_status =
+        kNotInitialized;  // Sentinel: not computed yet.
+    // Initialize with sentinel value: __kernel_rt_sigtramp_rt64 can not
+    // possibly be there.
+    static const unsigned char *kernel_sigtramp_rt64_address = nullptr;
+    if (kernel_symbol_status == kNotInitialized) {
+      absl::debugging_internal::VDSOSupport vdso;
+      if (vdso.IsPresent()) {
+        absl::debugging_internal::VDSOSupport::SymbolInfo
+            sigtramp_rt64_symbol_info;
+        if (!vdso.LookupSymbol(
+                "__kernel_sigtramp_rt64", "LINUX_2.6.15",
+                absl::debugging_internal::VDSOSupport::kVDSOSymbolType,
+                &sigtramp_rt64_symbol_info) ||
+            sigtramp_rt64_symbol_info.address == nullptr) {
+          // Unexpected: VDSO is present, yet the expected symbol is missing
+          // or null.
+          assert(false && "VDSO is present, but doesn't have expected symbol");
+          kernel_symbol_status = kAddressInvalid;
+        } else {
+          kernel_sigtramp_rt64_address =
+              reinterpret_cast<const unsigned char *>(
+                  sigtramp_rt64_symbol_info.address);
+          kernel_symbol_status = kAddressValid;
+        }
+      } else {
+        kernel_symbol_status = kAddressInvalid;
+      }
+    }
+
+    if (new_sp != nullptr &&
+        kernel_symbol_status == kAddressValid &&
+        StacktracePowerPCGetLR(new_sp) == kernel_sigtramp_rt64_address) {
+      const ucontext_t* signal_context =
+          reinterpret_cast<const ucontext_t*>(uc);
+      void **const sp_before_signal =
+#if defined(__PPC64__)
+          reinterpret_cast<void **>(signal_context->uc_mcontext.gp_regs[PT_R1]);
+#else
+          reinterpret_cast<void **>(
+              signal_context->uc_mcontext.uc_regs->gregs[PT_R1]);
+#endif
+      // Check that alleged sp before signal is nonnull and is reasonably
+      // aligned.
+      if (sp_before_signal != nullptr &&
+          ((uintptr_t)sp_before_signal % kStackAlignment) == 0) {
+        // Check that alleged stack pointer is actually readable. This is to
+        // prevent a "double fault" in case we hit the first fault due to e.g.
+        // a stack corruption.
+        if (absl::debugging_internal::AddressIsReadable(sp_before_signal)) {
+          // Alleged stack pointer is readable, use it for further unwinding.
+          new_sp = sp_before_signal;
+        }
+      }
+    }
+  }
+#endif
+
+  return new_sp;
+}
+
+// This ensures that absl::GetStackTrace sets up the Link Register properly.
+ABSL_ATTRIBUTE_NOINLINE static void AbslStacktracePowerPCDummyFunction() {
+  ABSL_BLOCK_TAIL_CALL_OPTIMIZATION();
+}
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
+static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count,
+                      const void *ucp, int *min_dropped_frames) {
+  void **sp;
+  // Apple macOS uses an old version of gnu as -- both Darwin 7.9.0 (Panther)
+  // and Darwin 8.8.1 (Tiger) use as 1.38.  This means we have to use a
+  // different asm syntax.  I don't know quite the best way to discriminate
+  // systems using the old as from the new one; I've gone with __APPLE__.
+#ifdef __APPLE__
+  __asm__ volatile ("mr %0,r1" : "=r" (sp));
+#else
+  __asm__ volatile ("mr %0,1" : "=r" (sp));
+#endif
+
+  // On PowerPC, the "Link Register" or "Link Record" (LR), is a stack
+  // entry that holds the return address of the subroutine call (what
+  // instruction we run after our function finishes).  This is the
+  // same as the stack-pointer of our parent routine, which is what we
+  // want here.  While the compiler will always(?) set up LR for
+  // subroutine calls, it may not for leaf functions (such as this one).
+  // This routine forces the compiler (at least gcc) to push it anyway.
+  AbslStacktracePowerPCDummyFunction();
+
+  // The LR save area is used by the callee, so the top entry is bogus.
+  skip_count++;
+
+  int n = 0;
+
+  // Unlike ABIs of X86 and ARM, PowerPC ABIs say that return address (in
+  // the link register) of a function call is stored in the caller's stack
+  // frame instead of the callee's.  When we look for the return address
+  // associated with a stack frame, we need to make sure that there is a
+  // caller frame before it.  So we call NextStackFrame before entering the
+  // loop below and check next_sp instead of sp for loop termination.
+  // The outermost frame is set up by runtimes and it does not have a
+  // caller frame, so it is skipped.
+
+  // The absl::GetStackFrames routine is called when we are in some
+  // informational context (the failure signal handler for example).
+  // Use the non-strict unwinding rules to produce a stack trace
+  // that is as complete as possible (even if it contains a few
+  // bogus entries in some rare cases).
+  void **next_sp = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(sp, ucp);
+
+  while (next_sp && n < max_depth) {
+    if (skip_count > 0) {
+      skip_count--;
+    } else {
+      result[n] = StacktracePowerPCGetLR(sp);
+      if (IS_STACK_FRAMES) {
+        if (next_sp > sp) {
+          sizes[n] = (uintptr_t)next_sp - (uintptr_t)sp;
+        } else {
+          // A frame-size of 0 is used to indicate unknown frame size.
+          sizes[n] = 0;
+        }
+      }
+      n++;
+    }
+
+    sp = next_sp;
+    next_sp = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(sp, ucp);
+  }
+
+  if (min_dropped_frames != nullptr) {
+    // Implementation detail: we clamp the max of frames we are willing to
+    // count, so as not to spend too much time in the loop below.
+    const int kMaxUnwind = 1000;
+    int num_dropped_frames = 0;
+    for (int j = 0; next_sp != nullptr && j < kMaxUnwind; j++) {
+      if (skip_count > 0) {
+        skip_count--;
+      } else {
+        num_dropped_frames++;
+      }
+      next_sp = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(next_sp, ucp);
+    }
+    *min_dropped_frames = num_dropped_frames;
+  }
+  return n;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() {
+  return true;
+}
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_POWERPC_INL_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_riscv-inl.inc

@@ -0,0 +1,194 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_RISCV_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_RISCV_INL_H_
+
+// Generate stack trace for riscv
+
+#include <sys/ucontext.h>
+
+#include "absl/base/config.h"
+#if defined(__linux__)
+#include <sys/mman.h>
+#include <ucontext.h>
+#include <unistd.h>
+#endif
+
+#include <atomic>
+#include <cassert>
+#include <cstdint>
+#include <iostream>
+#include <limits>
+#include <utility>
+
+#include "absl/base/attributes.h"
+#include "absl/debugging/stacktrace.h"
+
+static constexpr ptrdiff_t kUnknownFrameSize = 0;
+
+// Compute the size of a stack frame in [low..high).  We assume that low < high.
+// Return size of kUnknownFrameSize.
+template <typename T>
+static inline ptrdiff_t ComputeStackFrameSize(const T *low, const T *high) {
+  const char *low_char_ptr = reinterpret_cast<const char *>(low);
+  const char *high_char_ptr = reinterpret_cast<const char *>(high);
+  return low < high ? static_cast<ptrdiff_t>(high_char_ptr - low_char_ptr)
+                    : kUnknownFrameSize;
+}
+
+// Given a pointer to a stack frame, locate and return the calling stackframe,
+// or return null if no stackframe can be found. Perform sanity checks (the
+// strictness of which is controlled by the boolean parameter
+// "STRICT_UNWINDING") to reduce the chance that a bad pointer is returned.
+template <bool STRICT_UNWINDING, bool WITH_CONTEXT>
+ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
+static void ** NextStackFrame(void **old_frame_pointer, const void *uc,
+                              const std::pair<size_t, size_t> range) {
+  //               .
+  //               .
+  //               .
+  //   +-> +----------------+
+  //   |   | return address |
+  //   |   |   previous fp  |
+  //   |   |      ...       |
+  //   |   +----------------+ <-+
+  //   |   | return address |   |
+  //   +---|-  previous fp  |   |
+  //       |      ...       |   |
+  // $fp ->|----------------+   |
+  //       | return address |   |
+  //       |   previous fp -|---+
+  // $sp ->|      ...       |
+  //       +----------------+
+  void **new_frame_pointer = reinterpret_cast<void **>(old_frame_pointer[-2]);
+  uintptr_t frame_pointer = reinterpret_cast<uintptr_t>(new_frame_pointer);
+
+  // The RISCV ELF psABI mandates that the stack pointer is always 16-byte
+  // aligned.
+  // TODO(#1236) this doesn't hold for ILP32E which only mandates a 4-byte
+  // alignment.
+  if (frame_pointer & 15)
+    return nullptr;
+
+  // If the new frame pointer matches the signal context, avoid terminating
+  // early to deal with alternate signal stacks.
+  if (WITH_CONTEXT)
+    if (const ucontext_t *ucv = static_cast<const ucontext_t *>(uc))
+      // RISCV ELF psABI has the frame pointer at x8/fp/s0.
+      // -- RISCV psABI Table 18.2
+      if (ucv->uc_mcontext.__gregs[8] == frame_pointer)
+        return new_frame_pointer;
+
+  // Check frame size.  In strict mode, we assume frames to be under 100,000
+  // bytes.  In non-strict mode, we relax the limit to 1MB.
+  const ptrdiff_t max_size = STRICT_UNWINDING ? 100000 : 1000000;
+  const ptrdiff_t frame_size =
+      ComputeStackFrameSize(old_frame_pointer, new_frame_pointer);
+  if (frame_size == kUnknownFrameSize) {
+    if (STRICT_UNWINDING)
+      return nullptr;
+
+    // In non-strict mode permit non-contiguous stacks (e.g. alternate signal
+    // frame handling).
+    if (reinterpret_cast<uintptr_t>(new_frame_pointer) < range.first ||
+        reinterpret_cast<uintptr_t>(new_frame_pointer) > range.second)
+      return nullptr;
+  }
+
+  if (frame_size > max_size)
+    return nullptr;
+
+  return new_frame_pointer;
+}
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
+static int UnwindImpl(void **result, int *sizes, int max_depth, int skip_count,
+                      const void *ucp, int *min_dropped_frames) {
+  // The `frame_pointer` that is computed here points to the top of the frame.
+  // The two words preceding the address are the return address and the previous
+  // frame pointer.
+#if defined(__GNUC__)
+  void **frame_pointer = reinterpret_cast<void **>(__builtin_frame_address(0));
+#else
+#error reading stack pointer not yet supported on this platform
+#endif
+
+  std::pair<size_t, size_t> stack = {
+      // assume that the first page is not the stack.
+      static_cast<size_t>(sysconf(_SC_PAGESIZE)),
+      std::numeric_limits<size_t>::max() - sizeof(void *)
+  };
+
+  int n = 0;
+  void *return_address = nullptr;
+  while (frame_pointer && n < max_depth) {
+    return_address = frame_pointer[-1];
+
+    // The absl::GetStackFrames routine is called when we are in some
+    // informational context (the failure signal handler for example).  Use the
+    // non-strict unwinding rules to produce a stack trace that is as complete
+    // as possible (even if it contains a few bogus entries in some rare cases).
+    void **next_frame_pointer =
+        NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(frame_pointer, ucp,
+                                                          stack);
+
+    if (skip_count > 0) {
+      skip_count--;
+    } else {
+      result[n] = return_address;
+      if (IS_STACK_FRAMES) {
+        // NextStackFrame() has already checked that frame size fits to int
+        sizes[n] = static_cast<int>(ComputeStackFrameSize(frame_pointer,
+                                                          next_frame_pointer));
+      }
+      n++;
+    }
+
+    frame_pointer = next_frame_pointer;
+  }
+
+  if (min_dropped_frames != nullptr) {
+    // Implementation detail: we clamp the max of frames we are willing to
+    // count, so as not to spend too much time in the loop below.
+    const int kMaxUnwind = 200;
+    int num_dropped_frames = 0;
+    for (int j = 0; frame_pointer != nullptr && j < kMaxUnwind; j++) {
+      if (skip_count > 0) {
+        skip_count--;
+      } else {
+        num_dropped_frames++;
+      }
+      frame_pointer =
+          NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(frame_pointer, ucp,
+                                                            stack);
+    }
+    *min_dropped_frames = num_dropped_frames;
+  }
+
+  return n;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() { return true; }
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_unimplemented-inl.inc

@@ -0,0 +1,24 @@
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_UNIMPLEMENTED_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_UNIMPLEMENTED_INL_H_
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+static int UnwindImpl(void** /* result */, int* /* sizes */,
+                      int /* max_depth */, int /* skip_count */,
+                      const void* /* ucp */, int *min_dropped_frames) {
+  if (min_dropped_frames != nullptr) {
+    *min_dropped_frames = 0;
+  }
+  return 0;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() {
+  return false;
+}
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_UNIMPLEMENTED_INL_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_win32-inl.inc

@@ -0,0 +1,94 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Produces a stack trace for Windows.  Normally, one could use
+// stacktrace_x86-inl.h or stacktrace_x86_64-inl.h -- and indeed, that
+// should work for binaries compiled using MSVC in "debug" mode.
+// However, in "release" mode, Windows uses frame-pointer
+// optimization, which makes getting a stack trace very difficult.
+//
+// There are several approaches one can take.  One is to use Windows
+// intrinsics like StackWalk64.  These can work, but have restrictions
+// on how successful they can be.  Another attempt is to write a
+// version of stacktrace_x86-inl.h that has heuristic support for
+// dealing with FPO, similar to what WinDbg does (see
+// http://www.nynaeve.net/?p=97).  There are (non-working) examples of
+// these approaches, complete with TODOs, in stacktrace_win32-inl.h#1
+//
+// The solution we've ended up doing is to call the undocumented
+// windows function RtlCaptureStackBackTrace, which probably doesn't
+// work with FPO but at least is fast, and doesn't require a symbol
+// server.
+//
+// This code is inspired by a patch from David Vitek:
+//   https://code.google.com/p/google-perftools/issues/detail?id=83
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_
+
+#include <windows.h>    // for GetProcAddress and GetModuleHandle
+#include <cassert>
+
+typedef USHORT NTAPI RtlCaptureStackBackTrace_Function(
+    IN ULONG frames_to_skip,
+    IN ULONG frames_to_capture,
+    OUT PVOID *backtrace,
+    OUT PULONG backtrace_hash);
+
+// It is not possible to load RtlCaptureStackBackTrace at static init time in
+// UWP. CaptureStackBackTrace is the public version of RtlCaptureStackBackTrace
+#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) && \
+    !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
+static RtlCaptureStackBackTrace_Function* const RtlCaptureStackBackTrace_fn =
+    &::CaptureStackBackTrace;
+#else
+// Load the function we need at static init time, where we don't have
+// to worry about someone else holding the loader's lock.
+static RtlCaptureStackBackTrace_Function* const RtlCaptureStackBackTrace_fn =
+    (RtlCaptureStackBackTrace_Function*)GetProcAddress(
+        GetModuleHandleA("ntdll.dll"), "RtlCaptureStackBackTrace");
+#endif  // WINAPI_PARTITION_APP && !WINAPI_PARTITION_DESKTOP
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count,
+                      const void*, int* min_dropped_frames) {
+  USHORT n = 0;
+  if (!RtlCaptureStackBackTrace_fn || skip_count < 0 || max_depth < 0) {
+    // can't get a stacktrace with no function/invalid args
+  } else {
+    n = RtlCaptureStackBackTrace_fn(static_cast<ULONG>(skip_count) + 2,
+                                    static_cast<ULONG>(max_depth), result, 0);
+  }
+  if (IS_STACK_FRAMES) {
+    // No implementation for finding out the stack frame sizes yet.
+    memset(sizes, 0, sizeof(*sizes) * n);
+  }
+  if (min_dropped_frames != nullptr) {
+    // Not implemented.
+    *min_dropped_frames = 0;
+  }
+  return n;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() {
+  return false;
+}
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_WIN32_INL_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/stacktrace_x86-inl.inc

@@ -0,0 +1,394 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Produce stack trace
+
+#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_X86_INL_INC_
+#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_X86_INL_INC_
+
+#if defined(__linux__) && (defined(__i386__) || defined(__x86_64__))
+#include <ucontext.h>  // for ucontext_t
+#endif
+
+#if !defined(_WIN32)
+#include <unistd.h>
+#endif
+
+#include <cassert>
+#include <cstdint>
+#include <limits>
+
+#include "absl/base/attributes.h"
+#include "absl/base/macros.h"
+#include "absl/base/port.h"
+#include "absl/debugging/internal/address_is_readable.h"
+#include "absl/debugging/internal/vdso_support.h"  // a no-op on non-elf or non-glibc systems
+#include "absl/debugging/stacktrace.h"
+
+using absl::debugging_internal::AddressIsReadable;
+
+#if defined(__linux__) && defined(__i386__)
+// Count "push %reg" instructions in VDSO __kernel_vsyscall(),
+// preceding "syscall" or "sysenter".
+// If __kernel_vsyscall uses frame pointer, answer 0.
+//
+// kMaxBytes tells how many instruction bytes of __kernel_vsyscall
+// to analyze before giving up. Up to kMaxBytes+1 bytes of
+// instructions could be accessed.
+//
+// Here are known __kernel_vsyscall instruction sequences:
+//
+// SYSENTER (linux-2.6.26/arch/x86/vdso/vdso32/sysenter.S).
+// Used on Intel.
+//  0xffffe400 <__kernel_vsyscall+0>:       push   %ecx
+//  0xffffe401 <__kernel_vsyscall+1>:       push   %edx
+//  0xffffe402 <__kernel_vsyscall+2>:       push   %ebp
+//  0xffffe403 <__kernel_vsyscall+3>:       mov    %esp,%ebp
+//  0xffffe405 <__kernel_vsyscall+5>:       sysenter
+//
+// SYSCALL (see linux-2.6.26/arch/x86/vdso/vdso32/syscall.S).
+// Used on AMD.
+//  0xffffe400 <__kernel_vsyscall+0>:       push   %ebp
+//  0xffffe401 <__kernel_vsyscall+1>:       mov    %ecx,%ebp
+//  0xffffe403 <__kernel_vsyscall+3>:       syscall
+//
+
+// The sequence below isn't actually expected in Google fleet,
+// here only for completeness. Remove this comment from OSS release.
+
+// i386 (see linux-2.6.26/arch/x86/vdso/vdso32/int80.S)
+//  0xffffe400 <__kernel_vsyscall+0>:       int $0x80
+//  0xffffe401 <__kernel_vsyscall+1>:       ret
+//
+static const int kMaxBytes = 10;
+
+// We use assert()s instead of DCHECK()s -- this is too low level
+// for DCHECK().
+
+static int CountPushInstructions(const unsigned char *const addr) {
+  int result = 0;
+  for (int i = 0; i < kMaxBytes; ++i) {
+    if (addr[i] == 0x89) {
+      // "mov reg,reg"
+      if (addr[i + 1] == 0xE5) {
+        // Found "mov %esp,%ebp".
+        return 0;
+      }
+      ++i;  // Skip register encoding byte.
+    } else if (addr[i] == 0x0F &&
+               (addr[i + 1] == 0x34 || addr[i + 1] == 0x05)) {
+      // Found "sysenter" or "syscall".
+      return result;
+    } else if ((addr[i] & 0xF0) == 0x50) {
+      // Found "push %reg".
+      ++result;
+    } else if (addr[i] == 0xCD && addr[i + 1] == 0x80) {
+      // Found "int $0x80"
+      assert(result == 0);
+      return 0;
+    } else {
+      // Unexpected instruction.
+      assert(false && "unexpected instruction in __kernel_vsyscall");
+      return 0;
+    }
+  }
+  // Unexpected: didn't find SYSENTER or SYSCALL in
+  // [__kernel_vsyscall, __kernel_vsyscall + kMaxBytes) interval.
+  assert(false && "did not find SYSENTER or SYSCALL in __kernel_vsyscall");
+  return 0;
+}
+#endif
+
+// Assume stack frames larger than 100,000 bytes are bogus.
+static const int kMaxFrameBytes = 100000;
+// Stack end to use when we don't know the actual stack end
+// (effectively just the end of address space).
+constexpr uintptr_t kUnknownStackEnd =
+    std::numeric_limits<size_t>::max() - sizeof(void *);
+
+// Returns the stack frame pointer from signal context, 0 if unknown.
+// vuc is a ucontext_t *.  We use void* to avoid the use
+// of ucontext_t on non-POSIX systems.
+static uintptr_t GetFP(const void *vuc) {
+#if !defined(__linux__)
+  static_cast<void>(vuc);  // Avoid an unused argument compiler warning.
+#else
+  if (vuc != nullptr) {
+    auto *uc = reinterpret_cast<const ucontext_t *>(vuc);
+#if defined(__i386__)
+    const auto bp = uc->uc_mcontext.gregs[REG_EBP];
+    const auto sp = uc->uc_mcontext.gregs[REG_ESP];
+#elif defined(__x86_64__)
+    const auto bp = uc->uc_mcontext.gregs[REG_RBP];
+    const auto sp = uc->uc_mcontext.gregs[REG_RSP];
+#else
+    const uintptr_t bp = 0;
+    const uintptr_t sp = 0;
+#endif
+    // Sanity-check that the base pointer is valid. It's possible that some
+    // code in the process is compiled with --copt=-fomit-frame-pointer or
+    // --copt=-momit-leaf-frame-pointer.
+    //
+    // TODO(bcmills): -momit-leaf-frame-pointer is currently the default
+    // behavior when building with clang.  Talk to the C++ toolchain team about
+    // fixing that.
+    if (bp >= sp && bp - sp <= kMaxFrameBytes)
+      return static_cast<uintptr_t>(bp);
+
+    // If bp isn't a plausible frame pointer, return the stack pointer instead.
+    // If we're lucky, it points to the start of a stack frame; otherwise, we'll
+    // get one frame of garbage in the stack trace and fail the sanity check on
+    // the next iteration.
+    return static_cast<uintptr_t>(sp);
+  }
+#endif
+  return 0;
+}
+
+// Given a pointer to a stack frame, locate and return the calling
+// stackframe, or return null if no stackframe can be found. Perform sanity
+// checks (the strictness of which is controlled by the boolean parameter
+// "STRICT_UNWINDING") to reduce the chance that a bad pointer is returned.
+template <bool STRICT_UNWINDING, bool WITH_CONTEXT>
+ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
+static void **NextStackFrame(void **old_fp, const void *uc,
+                             size_t stack_low, size_t stack_high) {
+  void **new_fp = (void **)*old_fp;
+
+#if defined(__linux__) && defined(__i386__)
+  if (WITH_CONTEXT && uc != nullptr) {
+    // How many "push %reg" instructions are there at __kernel_vsyscall?
+    // This is constant for a given kernel and processor, so compute
+    // it only once.
+    static int num_push_instructions = -1;  // Sentinel: not computed yet.
+    // Initialize with sentinel value: __kernel_rt_sigreturn can not possibly
+    // be there.
+    static const unsigned char *kernel_rt_sigreturn_address = nullptr;
+    static const unsigned char *kernel_vsyscall_address = nullptr;
+    if (num_push_instructions == -1) {
+#ifdef ABSL_HAVE_VDSO_SUPPORT
+      absl::debugging_internal::VDSOSupport vdso;
+      if (vdso.IsPresent()) {
+        absl::debugging_internal::VDSOSupport::SymbolInfo
+            rt_sigreturn_symbol_info;
+        absl::debugging_internal::VDSOSupport::SymbolInfo vsyscall_symbol_info;
+        if (!vdso.LookupSymbol("__kernel_rt_sigreturn", "LINUX_2.5", STT_FUNC,
+                               &rt_sigreturn_symbol_info) ||
+            !vdso.LookupSymbol("__kernel_vsyscall", "LINUX_2.5", STT_FUNC,
+                               &vsyscall_symbol_info) ||
+            rt_sigreturn_symbol_info.address == nullptr ||
+            vsyscall_symbol_info.address == nullptr) {
+          // Unexpected: 32-bit VDSO is present, yet one of the expected
+          // symbols is missing or null.
+          assert(false && "VDSO is present, but doesn't have expected symbols");
+          num_push_instructions = 0;
+        } else {
+          kernel_rt_sigreturn_address =
+              reinterpret_cast<const unsigned char *>(
+                  rt_sigreturn_symbol_info.address);
+          kernel_vsyscall_address =
+              reinterpret_cast<const unsigned char *>(
+                  vsyscall_symbol_info.address);
+          num_push_instructions =
+              CountPushInstructions(kernel_vsyscall_address);
+        }
+      } else {
+        num_push_instructions = 0;
+      }
+#else  // ABSL_HAVE_VDSO_SUPPORT
+      num_push_instructions = 0;
+#endif  // ABSL_HAVE_VDSO_SUPPORT
+    }
+    if (num_push_instructions != 0 && kernel_rt_sigreturn_address != nullptr &&
+        old_fp[1] == kernel_rt_sigreturn_address) {
+      const ucontext_t *ucv = static_cast<const ucontext_t *>(uc);
+      // This kernel does not use frame pointer in its VDSO code,
+      // and so %ebp is not suitable for unwinding.
+      void **const reg_ebp =
+          reinterpret_cast<void **>(ucv->uc_mcontext.gregs[REG_EBP]);
+      const unsigned char *const reg_eip =
+          reinterpret_cast<unsigned char *>(ucv->uc_mcontext.gregs[REG_EIP]);
+      if (new_fp == reg_ebp && kernel_vsyscall_address <= reg_eip &&
+          reg_eip - kernel_vsyscall_address < kMaxBytes) {
+        // We "stepped up" to __kernel_vsyscall, but %ebp is not usable.
+        // Restore from 'ucv' instead.
+        void **const reg_esp =
+            reinterpret_cast<void **>(ucv->uc_mcontext.gregs[REG_ESP]);
+        // Check that alleged %esp is not null and is reasonably aligned.
+        if (reg_esp &&
+            ((uintptr_t)reg_esp & (sizeof(reg_esp) - 1)) == 0) {
+          // Check that alleged %esp is actually readable. This is to prevent
+          // "double fault" in case we hit the first fault due to e.g. stack
+          // corruption.
+          void *const reg_esp2 = reg_esp[num_push_instructions - 1];
+          if (AddressIsReadable(reg_esp2)) {
+            // Alleged %esp is readable, use it for further unwinding.
+            new_fp = reinterpret_cast<void **>(reg_esp2);
+          }
+        }
+      }
+    }
+  }
+#endif
+
+  const uintptr_t old_fp_u = reinterpret_cast<uintptr_t>(old_fp);
+  const uintptr_t new_fp_u = reinterpret_cast<uintptr_t>(new_fp);
+
+  // Check that the transition from frame pointer old_fp to frame
+  // pointer new_fp isn't clearly bogus.  Skip the checks if new_fp
+  // matches the signal context, so that we don't skip out early when
+  // using an alternate signal stack.
+  //
+  // TODO(bcmills): The GetFP call should be completely unnecessary when
+  // ENABLE_COMBINED_UNWINDER is set (because we should be back in the thread's
+  // stack by this point), but it is empirically still needed (e.g. when the
+  // stack includes a call to abort).  unw_get_reg returns UNW_EBADREG for some
+  // frames.  Figure out why GetValidFrameAddr and/or libunwind isn't doing what
+  // it's supposed to.
+  if (STRICT_UNWINDING &&
+      (!WITH_CONTEXT || uc == nullptr || new_fp_u != GetFP(uc))) {
+    // With the stack growing downwards, older stack frame must be
+    // at a greater address that the current one.
+    if (new_fp_u <= old_fp_u) return nullptr;
+
+    // If we get a very large frame size, it may be an indication that we
+    // guessed frame pointers incorrectly and now risk a paging fault
+    // dereferencing a wrong frame pointer. Or maybe not because large frames
+    // are possible as well. The main stack is assumed to be readable,
+    // so we assume the large frame is legit if we know the real stack bounds
+    // and are within the stack.
+    if (new_fp_u - old_fp_u > kMaxFrameBytes) {
+      if (stack_high < kUnknownStackEnd &&
+          static_cast<size_t>(getpagesize()) < stack_low) {
+        // Stack bounds are known.
+        if (!(stack_low < new_fp_u && new_fp_u <= stack_high)) {
+          // new_fp_u is not within the known stack.
+          return nullptr;
+        }
+      } else {
+        // Stack bounds are unknown, prefer truncated stack to possible crash.
+        return nullptr;
+      }
+    }
+    if (stack_low < old_fp_u && old_fp_u <= stack_high) {
+      // Old BP was in the expected stack region...
+      if (!(stack_low < new_fp_u && new_fp_u <= stack_high)) {
+        // ... but new BP is outside of expected stack region.
+        // It is most likely bogus.
+        return nullptr;
+      }
+    } else {
+      // We may be here if we are executing in a co-routine with a
+      // separate stack. We can't do safety checks in this case.
+    }
+  } else {
+    if (new_fp == nullptr) return nullptr;  // skip AddressIsReadable() below
+    // In the non-strict mode, allow discontiguous stack frames.
+    // (alternate-signal-stacks for example).
+    if (new_fp == old_fp) return nullptr;
+  }
+
+  if (new_fp_u & (sizeof(void *) - 1)) return nullptr;
+#ifdef __i386__
+  // On 32-bit machines, the stack pointer can be very close to
+  // 0xffffffff, so we explicitly check for a pointer into the
+  // last two pages in the address space
+  if (new_fp_u >= 0xffffe000) return nullptr;
+#endif
+#if !defined(_WIN32)
+  if (!STRICT_UNWINDING) {
+    // Lax sanity checks cause a crash in 32-bit tcmalloc/crash_reason_test
+    // on AMD-based machines with VDSO-enabled kernels.
+    // Make an extra sanity check to insure new_fp is readable.
+    // Note: NextStackFrame<false>() is only called while the program
+    //       is already on its last leg, so it's ok to be slow here.
+
+    if (!AddressIsReadable(new_fp)) {
+      return nullptr;
+    }
+  }
+#endif
+  return new_fp;
+}
+
+template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
+ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
+ABSL_ATTRIBUTE_NOINLINE
+static int UnwindImpl(void **result, int *sizes, int max_depth, int skip_count,
+                      const void *ucp, int *min_dropped_frames) {
+  int n = 0;
+  void **fp = reinterpret_cast<void **>(__builtin_frame_address(0));
+
+  // Assume that the first page is not stack.
+  size_t stack_low = static_cast<size_t>(getpagesize());
+  size_t stack_high = kUnknownStackEnd;
+
+  while (fp && n < max_depth) {
+    if (*(fp + 1) == reinterpret_cast<void *>(0)) {
+      // In 64-bit code, we often see a frame that
+      // points to itself and has a return address of 0.
+      break;
+    }
+    void **next_fp = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(
+        fp, ucp, stack_low, stack_high);
+    if (skip_count > 0) {
+      skip_count--;
+    } else {
+      result[n] = *(fp + 1);
+      if (IS_STACK_FRAMES) {
+        if (next_fp > fp) {
+          sizes[n] = static_cast<int>(
+              reinterpret_cast<uintptr_t>(next_fp) -
+              reinterpret_cast<uintptr_t>(fp));
+        } else {
+          // A frame-size of 0 is used to indicate unknown frame size.
+          sizes[n] = 0;
+        }
+      }
+      n++;
+    }
+    fp = next_fp;
+  }
+  if (min_dropped_frames != nullptr) {
+    // Implementation detail: we clamp the max of frames we are willing to
+    // count, so as not to spend too much time in the loop below.
+    const int kMaxUnwind = 1000;
+    int num_dropped_frames = 0;
+    for (int j = 0; fp != nullptr && j < kMaxUnwind; j++) {
+      if (skip_count > 0) {
+        skip_count--;
+      } else {
+        num_dropped_frames++;
+      }
+      fp = NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(fp, ucp, stack_low,
+                                                             stack_high);
+    }
+    *min_dropped_frames = num_dropped_frames;
+  }
+  return n;
+}
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+bool StackTraceWorksForTest() {
+  return true;
+}
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_X86_INL_INC_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/symbolize.h

@@ -0,0 +1,153 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file contains internal parts of the Abseil symbolizer.
+// Do not depend on the anything in this file, it may change at anytime.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
+#define ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
+
+#ifdef __cplusplus
+
+#include <cstddef>
+#include <cstdint>
+
+#include "absl/base/config.h"
+#include "absl/strings/string_view.h"
+
+#ifdef ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
+#error ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE cannot be directly set
+#elif defined(__ELF__) && defined(__GLIBC__) && !defined(__native_client__) \
+      && !defined(__asmjs__) && !defined(__wasm__)
+#define ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE 1
+
+#include <elf.h>
+#include <link.h>  // For ElfW() macro.
+#include <functional>
+#include <string>
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// Iterates over all sections, invoking callback on each with the section name
+// and the section header.
+//
+// Returns true on success; otherwise returns false in case of errors.
+//
+// This is not async-signal-safe.
+bool ForEachSection(int fd,
+                    const std::function<bool(absl::string_view name,
+                                             const ElfW(Shdr) &)>& callback);
+
+// Gets the section header for the given name, if it exists. Returns true on
+// success. Otherwise, returns false.
+bool GetSectionHeaderByName(int fd, const char *name, size_t name_len,
+                            ElfW(Shdr) *out);
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
+
+#ifdef ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE
+#error ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE cannot be directly set
+#elif defined(__APPLE__)
+#define ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE 1
+#endif
+
+#ifdef ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE
+#error ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE cannot be directly set
+#elif defined(__EMSCRIPTEN__)
+#define ABSL_INTERNAL_HAVE_EMSCRIPTEN_SYMBOLIZE 1
+#endif
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+struct SymbolDecoratorArgs {
+  // The program counter we are getting symbolic name for.
+  const void *pc;
+  // 0 for main executable, load address for shared libraries.
+  ptrdiff_t relocation;
+  // Read-only file descriptor for ELF image covering "pc",
+  // or -1 if no such ELF image exists in /proc/self/maps.
+  int fd;
+  // Output buffer, size.
+  // Note: the buffer may not be empty -- default symbolizer may have already
+  // produced some output, and earlier decorators may have adorned it in
+  // some way. You are free to replace or augment the contents (within the
+  // symbol_buf_size limit).
+  char *const symbol_buf;
+  size_t symbol_buf_size;
+  // Temporary scratch space, size.
+  // Use that space in preference to allocating your own stack buffer to
+  // conserve stack.
+  char *const tmp_buf;
+  size_t tmp_buf_size;
+  // User-provided argument
+  void* arg;
+};
+using SymbolDecorator = void (*)(const SymbolDecoratorArgs *);
+
+// Installs a function-pointer as a decorator. Returns a value less than zero
+// if the system cannot install the decorator. Otherwise, returns a unique
+// identifier corresponding to the decorator. This identifier can be used to
+// uninstall the decorator - See RemoveSymbolDecorator() below.
+int InstallSymbolDecorator(SymbolDecorator decorator, void* arg);
+
+// Removes a previously installed function-pointer decorator. Parameter "ticket"
+// is the return-value from calling InstallSymbolDecorator().
+bool RemoveSymbolDecorator(int ticket);
+
+// Remove all installed decorators.  Returns true if successful, false if
+// symbolization is currently in progress.
+bool RemoveAllSymbolDecorators();
+
+// Registers an address range to a file mapping.
+//
+// Preconditions:
+//   start <= end
+//   filename != nullptr
+//
+// Returns true if the file was successfully registered.
+bool RegisterFileMappingHint(const void* start, const void* end,
+                             uint64_t offset, const char* filename);
+
+// Looks up the file mapping registered by RegisterFileMappingHint for an
+// address range. If there is one, the file name is stored in *filename and
+// *start and *end are modified to reflect the registered mapping. Returns
+// whether any hint was found.
+bool GetFileMappingHint(const void** start, const void** end, uint64_t* offset,
+                        const char** filename);
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // __cplusplus
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C"
+#endif  // __cplusplus
+
+    bool
+    AbslInternalGetFileMappingHint(const void** start, const void** end,
+                                   uint64_t* offset, const char** filename);
+
+#endif  // ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/utf8_for_code_point.cc

@@ -0,0 +1,70 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/utf8_for_code_point.h"
+
+#include <cstdint>
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+namespace {
+
+// UTF-8 encoding bounds.
+constexpr uint32_t kMinSurrogate = 0xd800, kMaxSurrogate = 0xdfff;
+constexpr uint32_t kMax1ByteCodePoint = 0x7f;
+constexpr uint32_t kMax2ByteCodePoint = 0x7ff;
+constexpr uint32_t kMax3ByteCodePoint = 0xffff;
+constexpr uint32_t kMaxCodePoint = 0x10ffff;
+
+}  // namespace
+
+Utf8ForCodePoint::Utf8ForCodePoint(uint64_t code_point) {
+  if (code_point <= kMax1ByteCodePoint) {
+    length = 1;
+    bytes[0] = static_cast<char>(code_point);
+    return;
+  }
+
+  if (code_point <= kMax2ByteCodePoint) {
+    length = 2;
+    bytes[0] = static_cast<char>(0xc0 | (code_point >> 6));
+    bytes[1] = static_cast<char>(0x80 | (code_point & 0x3f));
+    return;
+  }
+
+  if (kMinSurrogate <= code_point && code_point <= kMaxSurrogate) return;
+
+  if (code_point <= kMax3ByteCodePoint) {
+    length = 3;
+    bytes[0] = static_cast<char>(0xe0 | (code_point >> 12));
+    bytes[1] = static_cast<char>(0x80 | ((code_point >> 6) & 0x3f));
+    bytes[2] = static_cast<char>(0x80 | (code_point & 0x3f));
+    return;
+  }
+
+  if (code_point > kMaxCodePoint) return;
+
+  length = 4;
+  bytes[0] = static_cast<char>(0xf0 | (code_point >> 18));
+  bytes[1] = static_cast<char>(0x80 | ((code_point >> 12) & 0x3f));
+  bytes[2] = static_cast<char>(0x80 | ((code_point >> 6) & 0x3f));
+  bytes[3] = static_cast<char>(0x80 | (code_point & 0x3f));
+}
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/utf8_for_code_point.h

@@ -0,0 +1,47 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_UTF8_FOR_CODE_POINT_H_
+#define ABSL_DEBUGGING_INTERNAL_UTF8_FOR_CODE_POINT_H_
+
+#include <cstdint>
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+struct Utf8ForCodePoint {
+  // Converts a Unicode code point to the corresponding UTF-8 byte sequence.
+  // Async-signal-safe to support use in symbolizing stack traces from a signal
+  // handler.
+  explicit Utf8ForCodePoint(uint64_t code_point);
+
+  // Returns true if the constructor's code_point argument was valid.
+  bool ok() const { return length != 0; }
+
+  // If code_point was in range, then 1 <= length <= 4, and the UTF-8 encoding
+  // is found in bytes[0 .. (length - 1)].  If code_point was invalid, then
+  // length == 0.  In either case, the contents of bytes[length .. 3] are
+  // unspecified.
+  char bytes[4] = {};
+  uint32_t length = 0;
+};
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_UTF8_FOR_CODE_POINT_H_

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/utf8_for_code_point_test.cc

@@ -0,0 +1,175 @@
+// Copyright 2024 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/internal/utf8_for_code_point.h"
+
+#include <cstdint>
+
+#include "gtest/gtest.h"
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+namespace {
+
+TEST(Utf8ForCodePointTest, RecognizesTheSmallestCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0});
+  ASSERT_EQ(utf8.length, 1);
+  EXPECT_EQ(utf8.bytes[0], '\0');
+}
+
+TEST(Utf8ForCodePointTest, RecognizesAsciiSmallA) {
+  Utf8ForCodePoint utf8(uint64_t{'a'});
+  ASSERT_EQ(utf8.length, 1);
+  EXPECT_EQ(utf8.bytes[0], 'a');
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheLargestOneByteCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0x7f});
+  ASSERT_EQ(utf8.length, 1);
+  EXPECT_EQ(utf8.bytes[0], '\x7f');
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheSmallestTwoByteCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0x80});
+  ASSERT_EQ(utf8.length, 2);
+  EXPECT_EQ(utf8.bytes[0], static_cast<char>(0xc2));
+  EXPECT_EQ(utf8.bytes[1], static_cast<char>(0x80));
+}
+
+TEST(Utf8ForCodePointTest, RecognizesSmallNWithTilde) {
+  Utf8ForCodePoint utf8(uint64_t{0xf1});
+  ASSERT_EQ(utf8.length, 2);
+  const char* want = "ñ";
+  EXPECT_EQ(utf8.bytes[0], want[0]);
+  EXPECT_EQ(utf8.bytes[1], want[1]);
+}
+
+TEST(Utf8ForCodePointTest, RecognizesCapitalPi) {
+  Utf8ForCodePoint utf8(uint64_t{0x3a0});
+  ASSERT_EQ(utf8.length, 2);
+  const char* want = "Π";
+  EXPECT_EQ(utf8.bytes[0], want[0]);
+  EXPECT_EQ(utf8.bytes[1], want[1]);
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheLargestTwoByteCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0x7ff});
+  ASSERT_EQ(utf8.length, 2);
+  EXPECT_EQ(utf8.bytes[0], static_cast<char>(0xdf));
+  EXPECT_EQ(utf8.bytes[1], static_cast<char>(0xbf));
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheSmallestThreeByteCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0x800});
+  ASSERT_EQ(utf8.length, 3);
+  EXPECT_EQ(utf8.bytes[0], static_cast<char>(0xe0));
+  EXPECT_EQ(utf8.bytes[1], static_cast<char>(0xa0));
+  EXPECT_EQ(utf8.bytes[2], static_cast<char>(0x80));
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheChineseCharacterZhong1AsInZhong1Wen2) {
+  Utf8ForCodePoint utf8(uint64_t{0x4e2d});
+  ASSERT_EQ(utf8.length, 3);
+  const char* want = "中";
+  EXPECT_EQ(utf8.bytes[0], want[0]);
+  EXPECT_EQ(utf8.bytes[1], want[1]);
+  EXPECT_EQ(utf8.bytes[2], want[2]);
+}
+
+TEST(Utf8ForCodePointTest, RecognizesOneBeforeTheSmallestSurrogate) {
+  Utf8ForCodePoint utf8(uint64_t{0xd7ff});
+  ASSERT_EQ(utf8.length, 3);
+  EXPECT_EQ(utf8.bytes[0], static_cast<char>(0xed));
+  EXPECT_EQ(utf8.bytes[1], static_cast<char>(0x9f));
+  EXPECT_EQ(utf8.bytes[2], static_cast<char>(0xbf));
+}
+
+TEST(Utf8ForCodePointTest, RejectsTheSmallestSurrogate) {
+  Utf8ForCodePoint utf8(uint64_t{0xd800});
+  EXPECT_EQ(utf8.length, 0);
+}
+
+TEST(Utf8ForCodePointTest, RejectsTheLargestSurrogate) {
+  Utf8ForCodePoint utf8(uint64_t{0xdfff});
+  EXPECT_EQ(utf8.length, 0);
+}
+
+TEST(Utf8ForCodePointTest, RecognizesOnePastTheLargestSurrogate) {
+  Utf8ForCodePoint utf8(uint64_t{0xe000});
+  ASSERT_EQ(utf8.length, 3);
+  EXPECT_EQ(utf8.bytes[0], static_cast<char>(0xee));
+  EXPECT_EQ(utf8.bytes[1], static_cast<char>(0x80));
+  EXPECT_EQ(utf8.bytes[2], static_cast<char>(0x80));
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheLargestThreeByteCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0xffff});
+  ASSERT_EQ(utf8.length, 3);
+  EXPECT_EQ(utf8.bytes[0], static_cast<char>(0xef));
+  EXPECT_EQ(utf8.bytes[1], static_cast<char>(0xbf));
+  EXPECT_EQ(utf8.bytes[2], static_cast<char>(0xbf));
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheSmallestFourByteCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0x10000});
+  ASSERT_EQ(utf8.length, 4);
+  EXPECT_EQ(utf8.bytes[0], static_cast<char>(0xf0));
+  EXPECT_EQ(utf8.bytes[1], static_cast<char>(0x90));
+  EXPECT_EQ(utf8.bytes[2], static_cast<char>(0x80));
+  EXPECT_EQ(utf8.bytes[3], static_cast<char>(0x80));
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheJackOfHearts) {
+  Utf8ForCodePoint utf8(uint64_t{0x1f0bb});
+  ASSERT_EQ(utf8.length, 4);
+  const char* want = "🂻";
+  EXPECT_EQ(utf8.bytes[0], want[0]);
+  EXPECT_EQ(utf8.bytes[1], want[1]);
+  EXPECT_EQ(utf8.bytes[2], want[2]);
+  EXPECT_EQ(utf8.bytes[3], want[3]);
+}
+
+TEST(Utf8ForCodePointTest, RecognizesTheLargestFourByteCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0x10ffff});
+  ASSERT_EQ(utf8.length, 4);
+  EXPECT_EQ(utf8.bytes[0], static_cast<char>(0xf4));
+  EXPECT_EQ(utf8.bytes[1], static_cast<char>(0x8f));
+  EXPECT_EQ(utf8.bytes[2], static_cast<char>(0xbf));
+  EXPECT_EQ(utf8.bytes[3], static_cast<char>(0xbf));
+}
+
+TEST(Utf8ForCodePointTest, RejectsTheSmallestOverlargeCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0x110000});
+  EXPECT_EQ(utf8.length, 0);
+}
+
+TEST(Utf8ForCodePointTest, RejectsAThroughlyOverlargeCodePoint) {
+  Utf8ForCodePoint utf8(uint64_t{0xffffffff00000000});
+  EXPECT_EQ(utf8.length, 0);
+}
+
+TEST(Utf8ForCodePointTest, OkReturnsTrueForAValidCodePoint) {
+  EXPECT_TRUE(Utf8ForCodePoint(uint64_t{0}).ok());
+}
+
+TEST(Utf8ForCodePointTest, OkReturnsFalseForAnInvalidCodePoint) {
+  EXPECT_FALSE(Utf8ForCodePoint(uint64_t{0xffffffff00000000}).ok());
+}
+
+}  // namespace
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/vdso_support.cc

@@ -0,0 +1,205 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Allow dynamic symbol lookup in the kernel VDSO page.
+//
+// VDSOSupport -- a class representing kernel VDSO (if present).
+
+#include "absl/debugging/internal/vdso_support.h"
+
+#ifdef ABSL_HAVE_VDSO_SUPPORT     // defined in vdso_support.h
+
+#if !defined(__has_include)
+#define __has_include(header) 0
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#if __has_include(<syscall.h>)
+#include <syscall.h>
+#elif __has_include(<sys/syscall.h>)
+#include <sys/syscall.h>
+#endif
+#include <unistd.h>
+
+#if !defined(__UCLIBC__) && defined(__GLIBC__) && \
+    (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 16))
+#define ABSL_HAVE_GETAUXVAL
+#endif
+
+#ifdef ABSL_HAVE_GETAUXVAL
+#include <sys/auxv.h>
+#endif
+
+#include "absl/base/dynamic_annotations.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/base/port.h"
+
+#ifndef AT_SYSINFO_EHDR
+#define AT_SYSINFO_EHDR 33  // for crosstoolv10
+#endif
+
+#if defined(__NetBSD__)
+using Elf32_auxv_t = Aux32Info;
+using Elf64_auxv_t = Aux64Info;
+#endif
+#if defined(__FreeBSD__)
+#if defined(__ELF_WORD_SIZE) && __ELF_WORD_SIZE == 64
+using Elf64_auxv_t = Elf64_Auxinfo;
+#endif
+using Elf32_auxv_t = Elf32_Auxinfo;
+#endif
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+ABSL_CONST_INIT
+std::atomic<const void *> VDSOSupport::vdso_base_(
+    debugging_internal::ElfMemImage::kInvalidBase);
+
+ABSL_CONST_INIT std::atomic<VDSOSupport::GetCpuFn> VDSOSupport::getcpu_fn_(
+    &InitAndGetCPU);
+
+VDSOSupport::VDSOSupport()
+    // If vdso_base_ is still set to kInvalidBase, we got here
+    // before VDSOSupport::Init has been called. Call it now.
+    : image_(vdso_base_.load(std::memory_order_relaxed) ==
+                     debugging_internal::ElfMemImage::kInvalidBase
+                 ? Init()
+                 : vdso_base_.load(std::memory_order_relaxed)) {}
+
+// NOTE: we can't use GoogleOnceInit() below, because we can be
+// called by tcmalloc, and none of the *once* stuff may be functional yet.
+//
+// In addition, we hope that the VDSOSupportHelper constructor
+// causes this code to run before there are any threads, and before
+// InitGoogle() has executed any chroot or setuid calls.
+//
+// Finally, even if there is a race here, it is harmless, because
+// the operation should be idempotent.
+const void *VDSOSupport::Init() {
+  const auto kInvalidBase = debugging_internal::ElfMemImage::kInvalidBase;
+#ifdef ABSL_HAVE_GETAUXVAL
+  if (vdso_base_.load(std::memory_order_relaxed) == kInvalidBase) {
+    errno = 0;
+    const void *const sysinfo_ehdr =
+        reinterpret_cast<const void *>(getauxval(AT_SYSINFO_EHDR));
+    if (errno == 0) {
+      vdso_base_.store(sysinfo_ehdr, std::memory_order_relaxed);
+    }
+  }
+#endif  // ABSL_HAVE_GETAUXVAL
+  if (vdso_base_.load(std::memory_order_relaxed) == kInvalidBase) {
+    int fd = open("/proc/self/auxv", O_RDONLY);
+    if (fd == -1) {
+      // Kernel too old to have a VDSO.
+      vdso_base_.store(nullptr, std::memory_order_relaxed);
+      getcpu_fn_.store(&GetCPUViaSyscall, std::memory_order_relaxed);
+      return nullptr;
+    }
+    ElfW(auxv_t) aux;
+    while (read(fd, &aux, sizeof(aux)) == sizeof(aux)) {
+      if (aux.a_type == AT_SYSINFO_EHDR) {
+#if defined(__NetBSD__)
+        vdso_base_.store(reinterpret_cast<void *>(aux.a_v),
+                         std::memory_order_relaxed);
+#else
+        vdso_base_.store(reinterpret_cast<void *>(aux.a_un.a_val),
+                         std::memory_order_relaxed);
+#endif
+        break;
+      }
+    }
+    close(fd);
+    if (vdso_base_.load(std::memory_order_relaxed) == kInvalidBase) {
+      // Didn't find AT_SYSINFO_EHDR in auxv[].
+      vdso_base_.store(nullptr, std::memory_order_relaxed);
+    }
+  }
+  GetCpuFn fn = &GetCPUViaSyscall;  // default if VDSO not present.
+  if (vdso_base_.load(std::memory_order_relaxed)) {
+    VDSOSupport vdso;
+    SymbolInfo info;
+    if (vdso.LookupSymbol("__vdso_getcpu", "LINUX_2.6", STT_FUNC, &info)) {
+      fn = reinterpret_cast<GetCpuFn>(const_cast<void *>(info.address));
+    }
+  }
+  // Subtle: this code runs outside of any locks; prevent compiler
+  // from assigning to getcpu_fn_ more than once.
+  getcpu_fn_.store(fn, std::memory_order_relaxed);
+  return vdso_base_.load(std::memory_order_relaxed);
+}
+
+const void *VDSOSupport::SetBase(const void *base) {
+  ABSL_RAW_CHECK(base != debugging_internal::ElfMemImage::kInvalidBase,
+                 "internal error");
+  const void *old_base = vdso_base_.load(std::memory_order_relaxed);
+  vdso_base_.store(base, std::memory_order_relaxed);
+  image_.Init(base);
+  // Also reset getcpu_fn_, so GetCPU could be tested with simulated VDSO.
+  getcpu_fn_.store(&InitAndGetCPU, std::memory_order_relaxed);
+  return old_base;
+}
+
+bool VDSOSupport::LookupSymbol(const char *name,
+                               const char *version,
+                               int type,
+                               SymbolInfo *info) const {
+  return image_.LookupSymbol(name, version, type, info);
+}
+
+bool VDSOSupport::LookupSymbolByAddress(const void *address,
+                                        SymbolInfo *info_out) const {
+  return image_.LookupSymbolByAddress(address, info_out);
+}
+
+// NOLINT on 'long' because this routine mimics kernel api.
+long VDSOSupport::GetCPUViaSyscall(unsigned *cpu,  // NOLINT(runtime/int)
+                                   void *, void *) {
+#ifdef SYS_getcpu
+  return syscall(SYS_getcpu, cpu, nullptr, nullptr);
+#else
+  // x86_64 never implemented sys_getcpu(), except as a VDSO call.
+  static_cast<void>(cpu);  // Avoid an unused argument compiler warning.
+  errno = ENOSYS;
+  return -1;
+#endif
+}
+
+// Use fast __vdso_getcpu if available.
+long VDSOSupport::InitAndGetCPU(unsigned *cpu,  // NOLINT(runtime/int)
+                                void *x, void *y) {
+  Init();
+  GetCpuFn fn = getcpu_fn_.load(std::memory_order_relaxed);
+  ABSL_RAW_CHECK(fn != &InitAndGetCPU, "Init() did not set getcpu_fn_");
+  return (*fn)(cpu, x, y);
+}
+
+// This function must be very fast, and may be called from very
+// low level (e.g. tcmalloc). Hence I avoid things like
+// GoogleOnceInit() and ::operator new.
+ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY
+int GetCPU() {
+  unsigned cpu;
+  long ret_code =  // NOLINT(runtime/int)
+      (*VDSOSupport::getcpu_fn_)(&cpu, nullptr, nullptr);
+  return ret_code == 0 ? static_cast<int>(cpu) : static_cast<int>(ret_code);
+}
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_HAVE_VDSO_SUPPORT

TMessagesProj/jni/voip/webrtc/absl/debugging/internal/vdso_support.h

@@ -0,0 +1,158 @@
+//
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// Allow dynamic symbol lookup in the kernel VDSO page.
+//
+// VDSO stands for "Virtual Dynamic Shared Object" -- a page of
+// executable code, which looks like a shared library, but doesn't
+// necessarily exist anywhere on disk, and which gets mmap()ed into
+// every process by kernels which support VDSO, such as 2.6.x for 32-bit
+// executables, and 2.6.24 and above for 64-bit executables.
+//
+// More details could be found here:
+// http://www.trilithium.com/johan/2005/08/linux-gate/
+//
+// VDSOSupport -- a class representing kernel VDSO (if present).
+//
+// Example usage:
+//  VDSOSupport vdso;
+//  VDSOSupport::SymbolInfo info;
+//  typedef (*FN)(unsigned *, void *, void *);
+//  FN fn = nullptr;
+//  if (vdso.LookupSymbol("__vdso_getcpu", "LINUX_2.6", STT_FUNC, &info)) {
+//     fn = reinterpret_cast<FN>(info.address);
+//  }
+
+#ifndef ABSL_DEBUGGING_INTERNAL_VDSO_SUPPORT_H_
+#define ABSL_DEBUGGING_INTERNAL_VDSO_SUPPORT_H_
+
+#include <atomic>
+
+#include "absl/base/attributes.h"
+#include "absl/debugging/internal/elf_mem_image.h"
+
+#ifdef ABSL_HAVE_ELF_MEM_IMAGE
+
+#ifdef ABSL_HAVE_VDSO_SUPPORT
+#error ABSL_HAVE_VDSO_SUPPORT cannot be directly set
+#else
+#define ABSL_HAVE_VDSO_SUPPORT 1
+#endif
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace debugging_internal {
+
+// NOTE: this class may be used from within tcmalloc, and can not
+// use any memory allocation routines.
+class VDSOSupport {
+ public:
+  VDSOSupport();
+
+  typedef ElfMemImage::SymbolInfo SymbolInfo;
+  typedef ElfMemImage::SymbolIterator SymbolIterator;
+
+  // On PowerPC64 VDSO symbols can either be of type STT_FUNC or STT_NOTYPE
+  // depending on how the kernel is built.  The kernel is normally built with
+  // STT_NOTYPE type VDSO symbols.  Let's make things simpler first by using a
+  // compile-time constant.
+#ifdef __powerpc64__
+  enum { kVDSOSymbolType = STT_NOTYPE };
+#else
+  enum { kVDSOSymbolType = STT_FUNC };
+#endif
+
+  // Answers whether we have a vdso at all.
+  bool IsPresent() const { return image_.IsPresent(); }
+
+  // Allow to iterate over all VDSO symbols.
+  SymbolIterator begin() const { return image_.begin(); }
+  SymbolIterator end() const { return image_.end(); }
+
+  // Look up versioned dynamic symbol in the kernel VDSO.
+  // Returns false if VDSO is not present, or doesn't contain given
+  // symbol/version/type combination.
+  // If info_out != nullptr, additional details are filled in.
+  bool LookupSymbol(const char *name, const char *version,
+                    int symbol_type, SymbolInfo *info_out) const;
+
+  // Find info about symbol (if any) which overlaps given address.
+  // Returns true if symbol was found; false if VDSO isn't present
+  // or doesn't have a symbol overlapping given address.
+  // If info_out != nullptr, additional details are filled in.
+  bool LookupSymbolByAddress(const void *address, SymbolInfo *info_out) const;
+
+  // Used only for testing. Replace real VDSO base with a mock.
+  // Returns previous value of vdso_base_. After you are done testing,
+  // you are expected to call SetBase() with previous value, in order to
+  // reset state to the way it was.
+  const void *SetBase(const void *s);
+
+  // Computes vdso_base_ and returns it. Should be called as early as
+  // possible; before any thread creation, chroot or setuid.
+  static const void *Init();
+
+ private:
+  // image_ represents VDSO ELF image in memory.
+  // image_.ehdr_ == nullptr implies there is no VDSO.
+  ElfMemImage image_;
+
+  // Cached value of auxv AT_SYSINFO_EHDR, computed once.
+  // This is a tri-state:
+  //   kInvalidBase   => value hasn't been determined yet.
+  //              0   => there is no VDSO.
+  //           else   => vma of VDSO Elf{32,64}_Ehdr.
+  //
+  // When testing with mock VDSO, low bit is set.
+  // The low bit is always available because vdso_base_ is
+  // page-aligned.
+  static std::atomic<const void *> vdso_base_;
+
+  // NOLINT on 'long' because these routines mimic kernel api.
+  // The 'cache' parameter may be used by some versions of the kernel,
+  // and should be nullptr or point to a static buffer containing at
+  // least two 'long's.
+  static long InitAndGetCPU(unsigned *cpu, void *cache,     // NOLINT 'long'.
+                            void *unused);
+  static long GetCPUViaSyscall(unsigned *cpu, void *cache,  // NOLINT 'long'.
+                               void *unused);
+  typedef long (*GetCpuFn)(unsigned *cpu, void *cache,      // NOLINT 'long'.
+                           void *unused);
+
+  // This function pointer may point to InitAndGetCPU,
+  // GetCPUViaSyscall, or __vdso_getcpu at different stages of initialization.
+  ABSL_CONST_INIT static std::atomic<GetCpuFn> getcpu_fn_;
+
+  friend int GetCPU(void);  // Needs access to getcpu_fn_.
+
+  VDSOSupport(const VDSOSupport&) = delete;
+  VDSOSupport& operator=(const VDSOSupport&) = delete;
+};
+
+// Same as sched_getcpu() on later glibc versions.
+// Return current CPU, using (fast) __vdso_getcpu@LINUX_2.6 if present,
+// otherwise use syscall(SYS_getcpu,...).
+// May return -1 with errno == ENOSYS if the kernel doesn't
+// support SYS_getcpu.
+int GetCPU();
+
+}  // namespace debugging_internal
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_HAVE_ELF_MEM_IMAGE
+
+#endif  // ABSL_DEBUGGING_INTERNAL_VDSO_SUPPORT_H_