Repo created

TMessagesProj/jni/voip/webrtc/base/profiler/module_cache_mac.cc

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+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/profiler/module_cache.h"
+
+#include <dlfcn.h>
+#include <mach-o/getsect.h>
+#include <uuid/uuid.h>
+
+#include "base/strings/string_number_conversions.h"
+
+namespace base {
+
+namespace {
+
+// Returns the unique build ID for a module loaded at |module_addr|. Returns the
+// empty string if the function fails to get the build ID.
+//
+// Build IDs are created by the concatenation of the module's GUID (Windows) /
+// UUID (Mac) and an "age" field that indicates how many times that GUID/UUID
+// has been reused. In Windows binaries, the "age" field is present in the
+// module header, but on the Mac, UUIDs are never reused and so the "age" value
+// appended to the UUID is always 0.
+std::string GetUniqueId(const void* module_addr) {
+  const mach_header_64* mach_header =
+      reinterpret_cast<const mach_header_64*>(module_addr);
+  DCHECK_EQ(MH_MAGIC_64, mach_header->magic);
+
+  size_t offset = sizeof(mach_header_64);
+  size_t offset_limit = sizeof(mach_header_64) + mach_header->sizeofcmds;
+
+  for (uint32_t i = 0; i < mach_header->ncmds; ++i) {
+    if (offset + sizeof(load_command) >= offset_limit)
+      return std::string();
+
+    const load_command* current_cmd = reinterpret_cast<const load_command*>(
+        reinterpret_cast<const uint8_t*>(mach_header) + offset);
+
+    if (offset + current_cmd->cmdsize > offset_limit) {
+      // This command runs off the end of the command list. This is malformed.
+      return std::string();
+    }
+
+    if (current_cmd->cmd == LC_UUID) {
+      if (current_cmd->cmdsize < sizeof(uuid_command)) {
+        // This "UUID command" is too small. This is malformed.
+        return std::string();
+      }
+
+      const uuid_command* uuid_cmd =
+          reinterpret_cast<const uuid_command*>(current_cmd);
+      static_assert(sizeof(uuid_cmd->uuid) == sizeof(uuid_t),
+                    "UUID field of UUID command should be 16 bytes.");
+      // The ID is comprised of the UUID concatenated with the Mac's "age" value
+      // which is always 0.
+      return HexEncode(&uuid_cmd->uuid, sizeof(uuid_cmd->uuid)) + "0";
+    }
+    offset += current_cmd->cmdsize;
+  }
+  return std::string();
+}
+
+// Returns the size of the _TEXT segment of the module loaded at |module_addr|.
+size_t GetModuleTextSize(const void* module_addr) {
+  const mach_header_64* mach_header =
+      reinterpret_cast<const mach_header_64*>(module_addr);
+  DCHECK_EQ(MH_MAGIC_64, mach_header->magic);
+  unsigned long module_size;
+  getsegmentdata(mach_header, SEG_TEXT, &module_size);
+  return module_size;
+}
+
+}  // namespace
+
+class MacModule : public ModuleCache::Module {
+ public:
+  MacModule(const Dl_info& dl_info)
+      : base_address_(reinterpret_cast<uintptr_t>(dl_info.dli_fbase)),
+        id_(GetUniqueId(dl_info.dli_fbase)),
+        debug_basename_(FilePath(dl_info.dli_fname).BaseName()),
+        size_(GetModuleTextSize(dl_info.dli_fbase)) {}
+
+  MacModule(const MacModule&) = delete;
+  MacModule& operator=(const MacModule&) = delete;
+
+  // ModuleCache::Module
+  uintptr_t GetBaseAddress() const override { return base_address_; }
+  std::string GetId() const override { return id_; }
+  FilePath GetDebugBasename() const override { return debug_basename_; }
+  size_t GetSize() const override { return size_; }
+  bool IsNative() const override { return true; }
+
+ private:
+  uintptr_t base_address_;
+  std::string id_;
+  FilePath debug_basename_;
+  size_t size_;
+};
+
+// static
+std::unique_ptr<const ModuleCache::Module> ModuleCache::CreateModuleForAddress(
+    uintptr_t address) {
+  Dl_info info;
+  if (!dladdr(reinterpret_cast<const void*>(address), &info))
+    return nullptr;
+  return std::make_unique<MacModule>(info);
+}
+
+}  // namespace base