GN win: prep_libc and fix tcmalloc linkage

On top of https://codereview.chromium.org/290633012/

R=brettw@chromium.org

Review URL: https://codereview.chromium.org/290713002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272249 0039d316-1c4b-4281-b951-d872f2087c98

base/allocator/BUILD.gn

@@ -14,6 +14,29 @@ group("allocator") {
   }
 }
 
+# This config and libc modification are only used on Windows.
+if (is_win) {
+  import("//build/config/win/visual_studio_version.gni")
+
+  config("nocmt") {
+    ldflags = [
+      "/NODEFAULTLIB:libcmt",
+      "/NODEFAULTLIB:libcmtd",
+    ]
+    libs = [ rebase_path("$target_gen_dir/allocator/libcmt.lib") ]
+  }
+
+  action("prep_libc") {
+    script = "prep_libc.py"
+    outputs = [ "$target_gen_dir/allocator/libcmt.lib" ]
+    args = [
+      visual_studio_path + "/vc/lib",
+      rebase_path("$target_gen_dir/allocator"),
+      cpu_arch,
+    ]
+  }
+}
+
 if (!is_android) {
   # tcmalloc currently won't compile on Android.
   source_set("tcmalloc") {
@@ -125,6 +148,8 @@ if (!is_android) {
     configs -= [ "//build/config/compiler:chromium_code" ]
     configs += [ "//build/config/compiler:no_chromium_code" ]
 
+    deps = []
+
     if (is_win) {
       sources -= [
         "$tcmalloc_dir/src/base/elf_mem_image.cc",
@@ -152,7 +177,14 @@ if (!is_android) {
         "$tcmalloc_dir/src/profiler.cc",
       ]
       defines += [ "PERFTOOLS_DLL_DECL=" ]
+
+      direct_dependent_configs = [ ":nocmt" ]
+
+      deps += [
+        ":prep_libc",
+      ]
     }
+
     if (is_linux || is_android) {
       sources -= [
         "$tcmalloc_dir/src/system-alloc.h",
@@ -191,7 +223,7 @@ if (!is_android) {
       configs += [ "//build/config/compiler:optimize_max" ]
     }
 
-    deps = [
+    deps += [
       "//base/third_party/dynamic_annotations",
     ]
 

base/allocator/prep_libc.py

@@ -12,7 +12,7 @@
 # VCLibDir is the path where VC is installed, something like:
 #    C:\Program Files\Microsoft Visual Studio 8\VC\lib
 # OutputDir is the directory where the modified libcmt file should be stored.
-# arch is either 'ia32' or 'x64'
+# arch is one of: 'ia32', 'x86' or 'x64'. ia32 and x86 are synonyms.
 
 import os
 import shutil

build/config/win/visual_studio_version.gni

@@ -19,4 +19,3 @@ if (visual_studio_path == "") {
   visual_studio_path = toolchain_data[0]
   windows_sdk_path = toolchain_data[1]
 }
-