Repo created

TMessagesProj/jni/voip/webrtc/base/android/bundle_utils.cc

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+// Copyright 2019 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/android/bundle_utils.h"
+
+#include <android/dlext.h>
+#include <dlfcn.h>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "base/base_jni_headers/BundleUtils_jni.h"
+#include "base/files/file_path.h"
+#include "base/logging.h"
+
+// These symbols are added by the lld linker when creating a partitioned shared
+// library. The symbols live in the base library, and are used to properly load
+// the other partitions (feature libraries) when needed.
+struct PartitionIndexEntry {
+  int32_t name_relptr;
+  int32_t addr_relptr;
+  uint32_t size;
+};
+static_assert(sizeof(PartitionIndexEntry) == 12U,
+              "Unexpected PartitionIndexEntry size");
+
+// Marked as weak_import because these symbols are lld-specific. The method that
+// uses them will only be invoked in builds that have lld-generated partitions.
+extern PartitionIndexEntry __part_index_begin[] __attribute__((weak_import));
+extern PartitionIndexEntry __part_index_end[] __attribute__((weak_import));
+
+extern "C" {
+// Marked as weak_import because this symbol is either supplied by the system
+// (on Android N+), or by Crazy Linker (Android M and prior).
+extern void* android_dlopen_ext(const char* __filename,
+                                int __flags,
+                                const android_dlextinfo* __info)
+    __attribute__((weak_import));
+}  // extern "C"
+
+namespace base {
+namespace android {
+
+namespace {
+
+const void* ReadRelPtr(const int32_t* relptr) {
+  return reinterpret_cast<const char*>(relptr) + *relptr;
+}
+
+}  // namespace
+
+// static
+std::string BundleUtils::ResolveLibraryPath(const std::string& library_name) {
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jstring> java_path = Java_BundleUtils_getNativeLibraryPath(
+      env, base::android::ConvertUTF8ToJavaString(env, library_name));
+  // TODO(https://crbug.com/1019853): Remove this tolerance.
+  if (!java_path) {
+    return std::string();
+  }
+  return base::android::ConvertJavaStringToUTF8(env, java_path);
+}
+
+// static
+bool BundleUtils::IsBundle() {
+  return Java_BundleUtils_isBundleForNative(
+      base::android::AttachCurrentThread());
+}
+
+// static
+void* BundleUtils::DlOpenModuleLibraryPartition(const std::string& library_name,
+                                                const std::string& partition) {
+  // TODO(https://crbug.com/1019853): Remove this tolerance.
+  std::string library_path = ResolveLibraryPath(library_name);
+  if (library_path.empty()) {
+    return nullptr;
+  }
+
+  // Linear search is required here because the partition descriptors are not
+  // ordered. If a large number of partitions come into existence, lld could be
+  // modified to sort the partitions.
+  DCHECK(__part_index_begin != nullptr);
+  DCHECK(__part_index_end != nullptr);
+  for (const PartitionIndexEntry* part = __part_index_begin;
+       part != __part_index_end; ++part) {
+    std::string name(
+        reinterpret_cast<const char*>(ReadRelPtr(&part->name_relptr)));
+    if (name == partition) {
+      android_dlextinfo info = {};
+      info.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
+      info.reserved_addr = const_cast<void*>(ReadRelPtr(&part->addr_relptr));
+      info.reserved_size = part->size;
+
+      DCHECK(android_dlopen_ext != nullptr);
+      return android_dlopen_ext(library_path.c_str(), RTLD_LOCAL, &info);
+    }
+  }
+
+  NOTREACHED();
+  return nullptr;
+}
+
+}  // namespace android
+}  // namespace base