Enable extracting unwind table on official builds without channel

This CL enables extraction of unwind tables for chrome when
is_official_build is set to true and when android_channel is not set to
a release channel. This affects build time only on official builds.
Also, Set legacy heap profiler to use unwinder for profiling.

TBR=dpranke@chromium.org
BUG=819888

Change-Id: If9732b5ac1f9dff49c58e88e2ffb6cb387715244
Reviewed-on: https://chromium-review.googlesource.com/976944Reviewed-by: Siddhartha S <ssid@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Siddhartha S <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546425}

base/BUILD.gn

@@ -1806,6 +1806,7 @@ buildflag_header("debugging_buildflags") {
     "ENABLE_PROFILING=$enable_profiling",
     "CAN_UNWIND_WITH_FRAME_POINTERS=$can_unwind_with_frame_pointers",
     "UNSAFE_DEVELOPER_BUILD=$is_unsafe_developer_build",
+    "CAN_UNWIND_WITH_CFI_TABLE=$can_unwind_with_cfi_table",
   ]
 }
 

base/trace_event/heap_profiler_allocation_context_tracker.cc

@@ -15,6 +15,11 @@
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_local_storage.h"
 #include "base/trace_event/heap_profiler_allocation_context.h"
+#include "build/build_config.h"
+
+#if defined(OS_ANDROID) && BUILDFLAG(CAN_UNWIND_WITH_CFI_TABLE)
+#include "base/trace_event/cfi_backtrace_android.h"
+#endif
 
 #if defined(OS_LINUX) || defined(OS_ANDROID)
 #include <sys/prctl.h>
@@ -214,20 +219,26 @@ bool AllocationContextTracker::GetContextSnapshot(AllocationContext* ctx) {
 // kMaxFrameCount + 1 frames, so that we know if there are more frames
 // than our backtrace capacity.
 #if !defined(OS_NACL)  // We don't build base/debug/stack_trace.cc for NaCl.
-#if BUILDFLAG(CAN_UNWIND_WITH_FRAME_POINTERS)
+#if defined(OS_ANDROID) && BUILDFLAG(CAN_UNWIND_WITH_CFI_TABLE)
+        const void* frames[Backtrace::kMaxFrameCount + 1];
+        static_assert(arraysize(frames) >= Backtrace::kMaxFrameCount,
+                      "not requesting enough frames to fill Backtrace");
+        size_t frame_count = CFIBacktraceAndroid::GetInstance()->Unwind(
+            frames, arraysize(frames));
+#elif BUILDFLAG(CAN_UNWIND_WITH_FRAME_POINTERS)
         const void* frames[Backtrace::kMaxFrameCount + 1];
         static_assert(arraysize(frames) >= Backtrace::kMaxFrameCount,
                       "not requesting enough frames to fill Backtrace");
         size_t frame_count = debug::TraceStackFramePointers(
             frames, arraysize(frames),
             1 /* exclude this function from the trace */);
-#else   // BUILDFLAG(CAN_UNWIND_WITH_FRAME_POINTERS)
+#else
         // Fall-back to capturing the stack with base::debug::StackTrace,
         // which is likely slower, but more reliable.
         base::debug::StackTrace stack_trace(Backtrace::kMaxFrameCount + 1);
         size_t frame_count = 0u;
         const void* const* frames = stack_trace.Addresses(&frame_count);
-#endif  // BUILDFLAG(CAN_UNWIND_WITH_FRAME_POINTERS)
+#endif
 
         // If there are too many frames, keep the ones furthest from main().
         size_t backtrace_capacity = backtrace_end - backtrace;

base/trace_event/memory_dump_manager.cc

@@ -41,8 +41,13 @@
 
 #if defined(OS_ANDROID)
 #include "base/trace_event/java_heap_dump_provider_android.h"
+
+#if BUILDFLAG(CAN_UNWIND_WITH_CFI_TABLE)
+#include "base/trace_event/cfi_backtrace_android.h"
 #endif
 
+#endif  // defined(OS_ANDROID)
+
 namespace base {
 namespace trace_event {
 
@@ -273,8 +278,15 @@ bool MemoryDumpManager::EnableHeapProfiling(HeapProfilingMode profiling_mode) {
       break;
 
     case kHeapProfilingModeNative:
-      // If we don't have frame pointers then native tracing falls-back to
-      // using base::debug::StackTrace, which may be slow.
+#if defined(OS_ANDROID) && BUILDFLAG(CAN_UNWIND_WITH_CFI_TABLE)
+    {
+      bool can_unwind =
+          CFIBacktraceAndroid::GetInstance()->can_unwind_stack_frames();
+      DCHECK(can_unwind);
+    }
+#endif
+      // If we don't have frame pointers and unwind tables then native tracing
+      // falls-back to using base::debug::StackTrace, which may be slow.
       AllocationContextTracker::SetCaptureMode(
           AllocationContextTracker::CaptureMode::NATIVE_STACK);
       break;

build/config/android/extract_unwind_tables.gni

@@ -7,14 +7,20 @@ import("//build/config/android/rules.gni")
 template("unwind_table_asset") {
   _unwind_action = "${target_name}__extract"
   _asset_path = "${target_gen_dir}/${target_name}/unwind_cfi"
+
   action(_unwind_action) {
     if (defined(invoker.testonly)) {
       testonly = invoker.testonly
     }
+
     script = "//build/android/gyp/extract_unwind_tables.py"
     outputs = [
       _asset_path,
     ]
+    inputs = [
+      "$root_out_dir/lib.unstripped/$shlib_prefix${invoker.library_target}$shlib_extension",
+    ]
+
     args = [
       "--input_path",
       rebase_path(
@@ -25,11 +31,11 @@ template("unwind_table_asset") {
       "--dump_syms_path",
       rebase_path("$root_out_dir/dump_syms", root_build_dir),
     ]
-    deps = [
-      ":${invoker.library_target}",
-      "//third_party/breakpad:dump_syms",
-    ]
+
+    deps = invoker.deps
+    deps += [ "//third_party/breakpad:dump_syms" ]
   }
+
   android_assets(target_name) {
     if (defined(invoker.testonly)) {
       testonly = invoker.testonly

chrome/android/BUILD.gn

@@ -21,6 +21,7 @@ import("//tools/v8_context_snapshot/v8_context_snapshot.gni")
 import("channel.gni")
 import("java_sources.gni")
 import("static_initializers.gni")
+import("//build/config/android/extract_unwind_tables.gni")
 
 manifest_package = "org.chromium.chrome"
 
@@ -730,6 +731,22 @@ java_group("chrome_public_non_pak_assets") {
   }
 }
 
+# Enable stack unwinding only for local official builds. Enabling on all local
+# builds would increase build time for developers. Choosing a release channel
+# should be done based on the size of the unwind file and performance of
+# unwinding.
+_add_unwind_tables_in_apk = can_unwind_with_cfi_table && is_android &&
+                            is_official_build && android_channel == "default"
+
+if (_add_unwind_tables_in_apk) {
+  unwind_table_asset("chrome_public_unwind_assets") {
+    library_target = "chrome"
+    deps = [
+      ":libchrome",
+    ]
+  }
+}
+
 android_assets("chrome_public_pak_assets") {
   sources = [
     "$root_out_dir/chrome_100_percent.pak",
@@ -741,6 +758,9 @@ android_assets("chrome_public_pak_assets") {
     ":chrome_public_locale_pak_assets",
     "//chrome:packed_resources",
   ]
+  if (_add_unwind_tables_in_apk) {
+    deps += [ ":chrome_public_unwind_assets" ]
+  }
 }
 
 # This target is separate from chrome_public_pak_assets because it does not
@@ -974,6 +994,15 @@ if (current_toolchain == default_toolchain) {
     ]
   }
 
+  if (_add_unwind_tables_in_apk) {
+    unwind_table_asset("monochrome_unwind_assets") {
+      library_target = "monochrome"
+      deps = [
+        ":monochrome",
+      ]
+    }
+  }
+
   # This target explicitly includes locale paks via deps.
   android_assets("monochrome_pak_assets") {
     sources = [
@@ -987,6 +1016,9 @@ if (current_toolchain == default_toolchain) {
       ":monochrome_paks",
       "//android_webview:locale_pak_assets",
     ]
+    if (_add_unwind_tables_in_apk) {
+      deps += [ ":monochrome_unwind_assets" ]
+    }
   }
 }  # current_toolchain == host_toolchain
 

testing/test.gni

@@ -110,6 +110,9 @@ template("test") {
         unwind_table_asset(_unwind_table_asset_name) {
           testonly = true
           library_target = _library_target
+          deps = [
+            ":$_library_target",
+          ]
         }
       }