Reland "Add a flag for building HWASAN splits."

This is a reland of 27453d76

Split out the is_a_target_toolchain change to another change.

Original change's description:
> Add a flag for building HWASAN splits.
>
> The new build_hwasan_splits flag causes HWASAN splits to be created for
> the Monochrome6432 and TrichromeChrome6432 bundles, as well as any of its
> DFMs that contain native code. The intent is that this flag will eventually
> default to true in official builds.
>
> The library is deliberately installed in TrichromeChrome6432 rather than
> TrichromeLibrary6432 (where the regular native library lives) because the
> Android platform does not support splits for the library containing the
> WebView implementation. This means that only Chrome will use the HWASANified
> native library, and WebView will use the regular native library.
>
> Bug: 916828
> Change-Id: Ie92bb36e83df245ab431b0123a44b0f0a3182100
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1769731
> Commit-Queue: Peter Collingbourne <pcc@chromium.org>
> Reviewed-by: Andrew Grieve <agrieve@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#729945}

Bug: 916828
Change-Id: I2c64720b72572a1c718cbd44d79d3fb2a44afcac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1994671Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Peter Collingbourne <pcc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732689}

build/android/gyp/apkbuilder.py

@@ -238,7 +238,11 @@ def _AddNativeLibraries(out_apk, native_libs, android_abi, uncompress,
         if has_crazy_linker and not has_monochrome:
           basename = 'crazy.' + basename
 
-    apk_path = 'lib/%s/%s' % (android_abi, basename)
+    lib_android_abi = android_abi
+    if path.startswith('android_clang_arm64_hwasan/'):
+      lib_android_abi = 'arm64-v8a-hwasan'
+
+    apk_path = 'lib/%s/%s' % (lib_android_abi, basename)
     zipalign.AddToZipHermetic(
         out_apk,
         apk_path,

build/android/gyp/write_build_config.py

@@ -789,7 +789,8 @@ def _CreateJavaLibrariesList(library_paths):
   """Returns a java literal array with the "base" library names:
   e.g. libfoo.so -> foo
   """
-  return ('{%s}' % ','.join(['"%s"' % s[3:-3] for s in library_paths]))
+  names = ['"%s"' % os.path.basename(s)[3:-3] for s in library_paths]
+  return ('{%s}' % ','.join(sorted(set(names))))
 
 
 def _CreateJavaLocaleListFromAssets(assets, locale_paks):

build/config/android/abi.gni

@@ -26,6 +26,9 @@ declare_args() {
   # Only effective if use_order_profiling = true. When this is true the call
   # graph based instrumentation is used.
   use_call_graph = false
+
+  # Build additional browser splits with HWASAN instrumentation enabled.
+  build_hwasan_splits = false
 }
 
 assert(!devtools_instrumentation_dumping || use_order_profiling,

build/config/sanitizers/BUILD.gn

@@ -253,7 +253,11 @@ config("common_sanitizer_flags") {
 
   if (using_sanitizer) {
     assert(is_clang, "sanitizers only supported with clang")
-    assert(!is_official_build, "sanitizers not supported in official builds")
+
+    # Allow non-default toolchains to enable sanitizers in toolchain_args even
+    # in official builds.
+    assert(current_toolchain != default_toolchain || !is_official_build,
+           "sanitizers not supported in official builds")
 
     cflags += [
       # Column info in debug data confuses Visual Studio's debugger, so don't

build/config/sanitizers/sanitizers.gni

@@ -113,8 +113,8 @@ declare_args() {
   archive_seed_corpus = true
 }
 
-# Disable sanitizers for non-default toolchains.
-if (current_toolchain != default_toolchain) {
+# Disable sanitizers for non-target toolchains.
+if (!is_a_target_toolchain) {
   is_asan = false
   is_cfi = false
   is_hwasan = false

build/toolchain/android/BUILD.gn

@@ -99,6 +99,15 @@ android_clang_toolchain("android_clang_arm64") {
   }
 }
 
+android_clang_toolchain("android_clang_arm64_hwasan") {
+  binary_prefix = "aarch64-linux-android"
+  toolchain_args = {
+    current_cpu = "arm64"
+    is_hwasan = true
+    android64_ndk_api_level = 29
+  }
+}
+
 android_clang_toolchain("android_clang_mips64el") {
   binary_prefix = "mips64el-linux-android"
   toolchain_args = {

chrome/android/chrome_public_apk_tmpl.gni

@@ -332,6 +332,7 @@ template("monochrome_public_common_apk_or_module_tmpl") {
         defined(invoker.use_trichrome_library) && invoker.use_trichrome_library
     is_monochrome = !is_trichrome
 
+    shared_libraries = []
     loadable_modules = []
     secondary_abi_loadable_modules = []
 
@@ -444,6 +445,18 @@ template("monochrome_public_common_apk_or_module_tmpl") {
     use_chromium_linker = is_trichrome && chromium_linker_supported
     use_modern_linker = use_chromium_linker
 
+    if (build_hwasan_splits && android_64bit_target_cpu &&
+        invoker.is_64_bit_browser) {
+      _hwasan_toolchain = "//build/toolchain/android:android_clang_arm64_hwasan"
+      shared_libraries +=
+          [ "//chrome/android:libmonochrome_64($_hwasan_toolchain)" ]
+
+      if (use_chromium_linker) {
+        shared_libraries +=
+            [ "//base/android/linker:chromium_android_linker($_hwasan_toolchain)" ]
+      }
+    }
+
     # Resources config for blocklisting resource names from obfuscation
     resources_config_path = "//android_webview/aapt2.config"
 

chrome/android/modules/chrome_feature_module_tmpl.gni

@@ -54,6 +54,12 @@ template("chrome_feature_module") {
     _shared_libraries += [
       "//chrome/android:${_base_target_name}_${_module_desc.name}${_toolchain}",
     ]
+
+    if (android_64bit_target_cpu && _is_monochrome_or_trichrome &&
+        invoker.is_64_bit_browser && build_hwasan_splits) {
+      _hwasan_toolchain = "//build/toolchain/android:android_clang_arm64_hwasan"
+      _shared_libraries += [ "//chrome/android:${_base_target_name}_${_module_desc.name}($_hwasan_toolchain)" ]
+    }
   } else {
     not_needed([ "_is_monochrome_or_trichrome" ])
   }