rename the v8 context snapshot on arm64 macOS builds

This is done so that the arm64 and x64 v8 context snapshots can
live side by side in a universal app build of a Chromium based
application.  All other files can be Mach-O universal binaries
generated using "lipo" but these snapshot files have to be uniquely
named so that both can exist in the Resources folder at the same time
and the correct one is chosen at runtime.

Bug: 1142017
Change-Id: I8449b72ba3a36e7ce69b9d9ec7768bd80ecc3e3a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2490980Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Mark Mentovai <mark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821439}

android_webview/BUILD.gn

@@ -802,7 +802,7 @@ if (android_64bit_target_cpu) {
            "32-bit targets shouldn't have secondary abi")
     arch_suffix = "32"
     if (use_v8_context_snapshot) {
-      renaming_sources = [ "$_secondary_abi_out_dir/v8_context_snapshot.bin" ]
+      renaming_sources = [ "$_secondary_abi_out_dir/$v8_context_snapshot_filename" ]
       renaming_destinations = [ "v8_context_snapshot_$arch_suffix.bin" ]
     } else {
       renaming_sources = [ "$_secondary_abi_out_dir/snapshot_blob.bin" ]

chrome/BUILD.gn

@@ -774,7 +774,7 @@ if (is_win) {
     if (v8_use_external_startup_data) {
       public_deps += [ "//v8" ]
       if (use_v8_context_snapshot) {
-        sources += [ "$root_out_dir/v8_context_snapshot.bin" ]
+        sources += [ "$root_out_dir/$v8_context_snapshot_filename" ]
         public_deps += [ "//tools/v8_context_snapshot" ]
       } else {
         sources += [ "$root_out_dir/snapshot_blob.bin" ]

chrome/installer/mini_installer/BUILD.gn

@@ -228,7 +228,7 @@ template("generate_mini_installer") {
     if (v8_use_external_startup_data) {
       deps += [ "//v8" ]
       if (use_v8_context_snapshot) {
-        inputs += [ "$root_out_dir/v8_context_snapshot.bin" ]
+        inputs += [ "$root_out_dir/$v8_context_snapshot_filename" ]
         deps += [ "//tools/v8_context_snapshot" ]
       } else {
         inputs += [ "$root_out_dir/snapshot_blob.bin" ]

content/browser/BUILD.gn

@@ -36,6 +36,7 @@ source_set("browser") {
   configs += [
     "//build/config:precompiled_headers",
     "//content:content_implementation",
+    "//tools/v8_context_snapshot:use_v8_context_snapshot",
     "//v8:external_startup_data",
   ]
   defines = []

content/browser/v8_snapshot_files.cc

@@ -13,7 +13,7 @@ std::map<std::string, base::FilePath> GetV8SnapshotFilesToPreload() {
 #if defined(OS_LINUX) || defined(OS_CHROMEOS)
 #if defined(USE_V8_CONTEXT_SNAPSHOT)
   return {{kV8ContextSnapshotDataDescriptor,
-           base::FilePath(FILE_PATH_LITERAL("v8_context_snapshot.bin"))}};
+           base::FilePath(FILE_PATH_LITERAL(V8_CONTEXT_SNAPSHOT_FILENAME))}};
 #else
   return {{kV8SnapshotDataDescriptor,
            base::FilePath(FILE_PATH_LITERAL("snapshot_blob.bin"))}};

content/shell/BUILD.gn

@@ -562,7 +562,7 @@ if (is_mac) {
     if (v8_use_external_startup_data) {
       public_deps += [ "//v8" ]
       if (use_v8_context_snapshot) {
-        sources += [ "$root_out_dir/v8_context_snapshot.bin" ]
+        sources += [ "$root_out_dir/$v8_context_snapshot_filename" ]
         public_deps += [ "//tools/v8_context_snapshot" ]
       } else {
         sources += [ "$root_out_dir/snapshot_blob.bin" ]

gin/BUILD.gn

@@ -85,7 +85,10 @@ component("gin") {
     frameworks = [ "CoreFoundation.framework" ]
   }
 
-  configs += [ "//v8:external_startup_data" ]
+  configs += [
+    "//tools/v8_context_snapshot:use_v8_context_snapshot",
+    "//v8:external_startup_data",
+  ]
 }
 
 executable("gin_shell") {

gin/v8_initializer.cc

@@ -76,7 +76,9 @@ const char kSnapshotFileName32[] = "snapshot_blob_32.bin";
 #endif
 
 #else  // defined(OS_ANDROID)
-const char kV8ContextSnapshotFileName[] = "v8_context_snapshot.bin";
+#if defined(USE_V8_CONTEXT_SNAPSHOT)
+const char kV8ContextSnapshotFileName[] = V8_CONTEXT_SNAPSHOT_FILENAME;
+#endif
 const char kSnapshotFileName[] = "snapshot_blob.bin";
 #endif  // defined(OS_ANDROID)
 
@@ -86,7 +88,12 @@ const char* GetSnapshotFileName(
     case V8Initializer::V8SnapshotFileType::kDefault:
       return kSnapshotFileName;
     case V8Initializer::V8SnapshotFileType::kWithAdditionalContext:
+#if defined(USE_V8_CONTEXT_SNAPSHOT)
       return kV8ContextSnapshotFileName;
+#else
+      NOTREACHED();
+      return nullptr;
+#endif
   }
   NOTREACHED();
   return nullptr;

headless/BUILD.gn

@@ -475,7 +475,7 @@ component("headless_non_renderer") {
     if (v8_use_external_startup_data) {
       public_deps += [ "//v8" ]
       if (use_v8_context_snapshot) {
-        data += [ "$root_out_dir/v8_context_snapshot.bin" ]
+        data += [ "$root_out_dir/$v8_context_snapshot_filename" ]
         data_deps += [ "//tools/v8_context_snapshot" ]
       } else {
         data += [ "$root_out_dir/snapshot_blob.bin" ]

tools/v8_context_snapshot/BUILD.gn

@@ -21,14 +21,17 @@ group("v8_context_snapshot") {
   if (use_v8_context_snapshot) {
     public_deps = [ ":generate_v8_context_snapshot" ]
     if (!is_android) {
-      data = [ "$root_out_dir/v8_context_snapshot.bin" ]
+      data = [ "$root_out_dir/$v8_context_snapshot_filename" ]
     }
   }
 }
 
 config("use_v8_context_snapshot") {
   if (use_v8_context_snapshot) {
-    defines = [ "USE_V8_CONTEXT_SNAPSHOT" ]
+    defines = [
+      "USE_V8_CONTEXT_SNAPSHOT",
+      "V8_CONTEXT_SNAPSHOT_FILENAME=\"$v8_context_snapshot_filename\"",
+    ]
   }
 }
 
@@ -36,7 +39,7 @@ if (use_v8_context_snapshot) {
   if (is_android && enable_java_templates) {
     android_assets("v8_context_snapshot_assets") {
       deps = [ ":v8_context_snapshot" ]
-      renaming_sources = [ "$root_out_dir/v8_context_snapshot.bin" ]
+      renaming_sources = [ "$root_out_dir/$v8_context_snapshot_filename" ]
       if (current_cpu == "arm" || current_cpu == "x86" ||
           current_cpu == "mipsel") {
         renaming_destinations = [ "v8_context_snapshot_32.bin" ]
@@ -49,7 +52,7 @@ if (use_v8_context_snapshot) {
 
   action("generate_v8_context_snapshot") {
     script = "//build/gn_run_binary.py"
-    output_file = "$root_out_dir/v8_context_snapshot.bin"
+    output_file = "$root_out_dir/$v8_context_snapshot_filename"
     output_path = rebase_path(output_file, root_build_dir)
 
     args = [

tools/v8_context_snapshot/v8_context_snapshot.gni

@@ -18,6 +18,18 @@ declare_args() {
       !is_chromeos && !is_android && !is_chromecast && !is_fuchsia &&
       !(host_os == "mac" && current_cpu == "x86") &&
       (v8_target_cpu == target_cpu || is_msan) && !(is_win && host_os != "win")
+
+  # We use a different filename for arm64 macOS builds so that the arm64 and
+  # x64 snapshots can live side-by-side in a universal macOS app.
+  if (is_mac) {
+    if (v8_target_cpu == "x64") {
+      v8_context_snapshot_filename = "v8_context_snapshot.x86_64.bin"
+    } else if (v8_target_cpu == "arm64") {
+      v8_context_snapshot_filename = "v8_context_snapshot.arm64.bin"
+    }
+  } else {
+    v8_context_snapshot_filename = "v8_context_snapshot.bin"
+  }
 }
 
 # We cannot use V8 context snapshot, if V8 doesn't use snapshot files.