tcmalloc: Add build flag to select new tcmalloc version

We are trying to uprev the tcmalloc version used in Chromium.
As part of the transition to a new tcmalloc, we plan to run experiments
with the new tcmalloc on a small number of boards before we enable the
new version globally.

This CL adds a build flag to select between the two tcmalloc versions at
build time. By default, the old tcmalloc version is used.

BUG=724399,b:70905156

Change-Id: I6839bba721b0d2a5f3515e7346bff418b0155221
Reviewed-on: https://chromium-review.googlesource.com/1130672Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Albert J. Wong <ajwong@chromium.org>
Reviewed-by: Will Harris <wfh@chromium.org>
Commit-Queue: Gabriel Marin <gmx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577320}

base/allocator/BUILD.gn

@@ -74,7 +74,11 @@ config("tcmalloc_flags") {
 if (use_allocator == "tcmalloc") {
   # tcmalloc currently won't compile on Android.
   source_set("tcmalloc") {
-    tcmalloc_dir = "//third_party/tcmalloc/gperftools-2.0/chromium"
+    if (use_new_tcmalloc) {
+      tcmalloc_dir = "//third_party/tcmalloc/chromium"
+    } else {
+      tcmalloc_dir = "//third_party/tcmalloc/gperftools-2.0/chromium"
+    }
 
     # Don't check tcmalloc's includes. These files include various files like
     # base/foo.h and they actually refer to tcmalloc's forked copy of base
@@ -214,7 +218,9 @@ if (use_allocator == "tcmalloc") {
       configs -= [ "//build/config/compiler:afdo" ]
     }
 
-    deps = []
+    deps = [
+      ":buildflags",
+    ]
 
     if (enable_profiling) {
       sources += [
@@ -272,7 +278,10 @@ if (use_allocator == "tcmalloc") {
 
 buildflag_header("buildflags") {
   header = "buildflags.h"
-  flags = [ "USE_ALLOCATOR_SHIM=$use_allocator_shim" ]
+  flags = [
+    "USE_ALLOCATOR_SHIM=$use_allocator_shim",
+    "USE_NEW_TCMALLOC=$use_new_tcmalloc",
+  ]
 }
 
 # Used to shim malloc symbols on Android. see //base/allocator/README.md.

base/allocator/allocator_extension.cc

@@ -3,14 +3,20 @@
 // found in the LICENSE file.
 
 #include "base/allocator/allocator_extension.h"
-
+#include "base/allocator/buildflags.h"
 #include "base/logging.h"
 
 #if defined(USE_TCMALLOC)
+#if BUILDFLAG(USE_NEW_TCMALLOC)
+#include "third_party/tcmalloc/chromium/src/gperftools/heap-profiler.h"
+#include "third_party/tcmalloc/chromium/src/gperftools/malloc_extension.h"
+#include "third_party/tcmalloc/chromium/src/gperftools/malloc_hook.h"
+#else
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/gperftools/heap-profiler.h"
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/gperftools/malloc_extension.h"
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/gperftools/malloc_hook.h"
 #endif
+#endif
 
 namespace base {
 namespace allocator {

base/allocator/allocator_shim_default_dispatch_to_tcmalloc.cc

@@ -4,8 +4,15 @@
 
 #include "base/allocator/allocator_shim.h"
 #include "base/allocator/allocator_shim_internals.h"
+#include "base/allocator/buildflags.h"
+
+#if BUILDFLAG(USE_NEW_TCMALLOC)
+#include "third_party/tcmalloc/chromium/src/config.h"
+#include "third_party/tcmalloc/chromium/src/gperftools/tcmalloc.h"
+#else
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/config.h"
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/gperftools/tcmalloc.h"
+#endif
 
 namespace {
 

base/allocator/debugallocation_shim.cc

@@ -13,8 +13,22 @@
 #pragma GCC optimize ("no-auto-profile")
 #endif
 
+#include "base/allocator/buildflags.h"
+
+#if BUILDFLAG(USE_NEW_TCMALLOC)
+
+#if defined(TCMALLOC_FOR_DEBUGALLOCATION)
+#include "third_party/tcmalloc/chromium/src/debugallocation.cc"
+#else
+#include "third_party/tcmalloc/chromium/src/tcmalloc.cc"
+#endif
+
+#else
+
 #if defined(TCMALLOC_FOR_DEBUGALLOCATION)
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/debugallocation.cc"
 #else
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/tcmalloc.cc"
 #endif
+
+#endif

base/debug/profiler.cc

@@ -6,6 +6,7 @@
 
 #include <string>
 
+#include "base/allocator/buildflags.h"
 #include "base/debug/debugging_buildflags.h"
 #include "base/process/process_handle.h"
 #include "base/strings/string_number_conversions.h"
@@ -19,9 +20,15 @@
 
 // TODO(peria): Enable profiling on Windows.
 #if BUILDFLAG(ENABLE_PROFILING) && !defined(NO_TCMALLOC) && !defined(OS_WIN)
+
+#if BUILDFLAG(USE_NEW_TCMALLOC)
+#include "third_party/tcmalloc/chromium/src/gperftools/profiler.h"
+#else
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/gperftools/profiler.h"
 #endif
 
+#endif
+
 namespace base {
 namespace debug {
 

base/process/memory_linux.cc

@@ -18,9 +18,14 @@
 #include "build/build_config.h"
 
 #if defined(USE_TCMALLOC)
+#if BUILDFLAG(USE_NEW_TCMALLOC)
+#include "third_party/tcmalloc/chromium/src/config.h"
+#include "third_party/tcmalloc/chromium/src/gperftools/tcmalloc.h"
+#else
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/config.h"
 #include "third_party/tcmalloc/gperftools-2.0/chromium/src/gperftools/tcmalloc.h"
 #endif
+#endif
 
 namespace base {
 

build/config/allocator.gni

@@ -32,6 +32,9 @@ declare_args() {
 
   # Partition alloc is included by default except iOS.
   use_partition_alloc = !is_ios
+
+  # Use the new tcmalloc. It's relevant only when use_allocator == "tcmalloc".
+  use_new_tcmalloc = false
 }
 
 if (is_nacl) {

third_party/tcmalloc/BUILD.gn

@@ -2,12 +2,19 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/allocator.gni")
 import("//build/config/compiler/compiler.gni")
 
 executable("addr2line-pdb") {
-  sources = [
-    "gperftools-2.0/chromium/src/windows/addr2line-pdb.c",
-  ]
+  if (use_new_tcmalloc) {
+    sources = [
+      "chromium/src/windows/addr2line-pdb.c",
+    ]
+  } else {
+    sources = [
+      "gperftools-2.0/chromium/src/windows/addr2line-pdb.c",
+    ]
+  }
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]