Snap for 8189365 from d768fc0756bd942df7d4cbe72c8cec3c8bb3b67e to tm-frc-neuralnetworks-release

Change-Id: I621de762d84ec0aafe9f3c0ff3e0370bf1e830a9

1 files changed, 35 insertions, 18 deletions

diff --git a/third_party/libprotobuf-mutator/BUILD.gn b/third_party/libprotobuf-mutator/BUILD.gn
index cc8c6a01..cc3eeaeb 100644
--- a/third_party/libprotobuf-mutator/BUILD.gn
+++ b/third_party/libprotobuf-mutator/BUILD.gn
@@ -1,4 +1,4 @@
-# Copyright 2017 The Chromium Authors. All rights reserved.
+# Copyright 2020 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -7,17 +7,14 @@ import("//testing/libfuzzer/fuzzer_test.gni")
 import("//third_party/libprotobuf-mutator/fuzzable_proto_library.gni")
 
 config("include_config") {
-  include_dirs = [
-    "src/",
-    "//",
-  ]
-  cflags_cc = [ "-Wno-exit-time-destructors" ]
+  include_dirs = [ "src/" ]
 }
 
 source_set("libprotobuf-mutator") {
   testonly = true
 
   configs += [ ":include_config" ]
+
   public_configs = [ ":include_config" ]
   sources = [
     "src/src/binary_format.cc",
@@ -33,28 +30,49 @@ source_set("libprotobuf-mutator") {
   public_deps = [ "//third_party/protobuf:protobuf_full" ]
 }
 
+# This protoc plugin, like the compiler, should only be built for the host
+# architecture.
+if (current_toolchain == host_toolchain) {
+  # This plugin will be needed to fuzz most protobuf code in Chromium. That's
+  # because production protobuf code must contain the line:
+  # "option optimize_for = LITE_RUNTIME", which instructs the proto compiler not
+  # to compile the proto using the full protobuf runtime. This allows Chromium
+  # not to depend on the full protobuf library, but prevents
+  # libprotobuf-mutator from fuzzing because the lite runtime lacks needed
+  # features (such as reflection).  The plugin simply compiles a proto library
+  # as normal but ensures that is compiled with the full protobuf runtime.
+  executable("override_lite_runtime_plugin") {
+    sources = [ "protoc_plugin/protoc_plugin.cc" ]
+    deps = [ "//third_party/protobuf:protoc_lib" ]
+    public_configs = [ "//third_party/protobuf:protobuf_config" ]
+  }
+  # To use the plugin in a proto_library you want to fuzz, change the build
+  # target to fuzzable_proto_library (defined in
+  # //third_party/libprotobuf-mutator/fuzzable_proto_library.gni)
+}
+
 # The CQ will try building this target without "use_libfuzzer" if it is defined.
 # That will cause the build to fail, so don't define it when "use_libfuzzer" is
 # is false.
 if (use_libfuzzer) {
-  # Test that fuzzable_proto_library works. This target contains files that are
-  # optimized for LITE_RUNTIME and which import other files that are also
-  # optimized for LITE_RUNTIME.
-  openscreen_fuzzer_test("lpm_test_fuzzer") {
-    sources = [ "test_fuzzer/test_fuzzer.cc" ]
+  # Test that override_lite_runtime_plugin is working when built. This target
+  # contains files that are optimized for LITE_RUNTIME and which import other
+  # files that are also optimized for LITE_RUNTIME.
+  openscreen_fuzzer_test("override_lite_runtime_plugin_test_fuzzer") {
+    sources = [ "protoc_plugin/test_fuzzer.cc" ]
     deps = [
       ":libprotobuf-mutator",
-      ":lpm_test_fuzzer_proto",
+      ":override_lite_runtime_plugin_test_fuzzer_proto",
     ]
   }
 }
 
-# Proto library for lpm_test_fuzzer
-fuzzable_proto_library("lpm_test_fuzzer_proto") {
+# Proto library for override_lite_runtime_plugin_test_fuzzer
+fuzzable_proto_library("override_lite_runtime_plugin_test_fuzzer_proto") {
   sources = [
-    "test_fuzzer/imported.proto",
-    "test_fuzzer/imported_publicly.proto",
-    "test_fuzzer/test_fuzzer_input.proto",
+    "protoc_plugin/imported.proto",
+    "protoc_plugin/imported_publicly.proto",
+    "protoc_plugin/test_fuzzer_input.proto",
   ]
 }
 
@@ -65,6 +83,5 @@ if (use_libfuzzer) {
   # Component that can provide protobuf_full to non-testonly targets
   static_library("protobuf_full") {
     public_deps = [ "//third_party/protobuf:protobuf_full" ]
-    sources = [ "dummy.cc" ]
   }
 }