Fix build with gcc12

- A number of erroneous flags have been added to BUILD.gn
- wasm-init-expr.cc is creating an 8 byte buffer witch may be
  much smaller than max size_t output. We also need to make room
  for the `f` character and the terminating null character
- inspector_protocol currently generates the following error
   ```
   error: loop variable ‘json_in’ of type ‘const std::string&’ {aka
   ‘const std::__cxx11::basic_string<char>&’} binds to a temporary
   constructed from type ‘const char* const’
   ```

Change-Id: I1139899b2664e47d01ebc44f2e972fc4c0ec212d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5331756
Reviewed-by: Matthias Liedtke <mliedtke@chromium.org>
Commit-Queue: Milad Farazmand <mfarazma@redhat.com>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/main@{#92615}

BUILD.gn

@@ -1699,6 +1699,20 @@ config("toolchain") {
       # Fix build with older versions of GCC
       # Ported from v8 bazel: https://crrev.com/c/3368869
       "-Wno-stringop-overflow",
+
+      # Fix a number of bogus errors with gcc12
+      # TODO(miladfarca): re-evaluate for future gcc upgrades
+      # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111499
+      "-Wno-stringop-overread",
+
+      # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104336
+      "-Wno-restrict",
+
+      # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105523
+      "-Wno-array-bounds",
+
+      # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108517
+      "-Wno-nonnull",
     ]
   }
 

src/d8/d8.cc

@@ -3972,7 +3972,9 @@ V8_NOINLINE void FuzzerMonitor::UseAfterFree() {
   // Use-after-free caught by ASAN.
   std::vector<bool>* storage = new std::vector<bool>(3);
   delete storage;
+#if defined(__clang__)
   USE(storage->at(1));
+#endif
 }
 
 V8_NOINLINE void FuzzerMonitor::UseOfUninitializedValue() {

src/wasm/function-compiler.cc

@@ -115,7 +115,7 @@ WasmCompilationResult WasmCompilationUnit::ExecuteFunctionCompilation(
     case ExecutionTier::kNone:
       UNREACHABLE();
 
-    case ExecutionTier::kLiftoff:
+    case ExecutionTier::kLiftoff: {
       // The --wasm-tier-mask-for-testing flag can force functions to be
       // compiled with TurboFan, and the --wasm-debug-mask-for-testing can force
       // them to be compiled for debugging, see documentation.
@@ -150,8 +150,8 @@ WasmCompilationResult WasmCompilationUnit::ExecuteFunctionCompilation(
       // TODO(wasm): We could actually stop or remove the tiering unit for this
       // function to avoid compiling it twice with TurboFan.
       V8_FALLTHROUGH;
-
-    case ExecutionTier::kTurbofan:
+    }
+    case ExecutionTier::kTurbofan: {
       compiler::WasmCompilationData data(func_body);
       data.func_index = func_index_;
       data.wire_bytes_storage = wire_bytes_storage;
@@ -171,6 +171,9 @@ WasmCompilationResult WasmCompilationUnit::ExecuteFunctionCompilation(
                                                         detected);
       result.for_debugging = for_debugging_;
       break;
+    }
+    default:
+      UNREACHABLE();
   }
 
   DCHECK(result.succeeded());

test/fuzzer/wasm-init-expr.cc

@@ -118,7 +118,7 @@ void FuzzIt(base::Vector<const uint8_t> data) {
            module_object->native_module()->module()->num_declared_functions);
 
   for (size_t i = 0; i < expression_count; ++i) {
-    char buffer[8];
+    char buffer[22];
     snprintf(buffer, sizeof buffer, "f%zu", i);
     // Execute corresponding function.
     auto function = Handle<WasmExportedFunction>::cast(

test/unittests/compiler/turboshaft/control-flow-unittest.cc

@@ -120,7 +120,6 @@ TEST_F(ControlFlowTest, LoopPeelingSingleInputPhi) {
   auto test = CreateFromGraph(1, [](auto& Asm) {
     Block* loop = __ NewLoopHeader();
     Block *loop_body = __ NewBlock(), *outside = __ NewBlock();
-    OpIndex cond = Asm.GetParameter(0);
     __ Goto(loop);
     __ Bind(loop);
     OpIndex cst = __ Word32Constant(42);

third_party/inspector_protocol/crdtp/dispatch_test.cc

@@ -169,10 +169,11 @@ TEST(DispatchableTest, MessageWithUnknownProperty) {
 }
 
 TEST(DispatchableTest, DuplicateMapKey) {
-  for (const std::string& json :
-       {"{\"id\":42,\"id\":42}", "{\"params\":null,\"params\":null}",
-        "{\"method\":\"foo\",\"method\":\"foo\"}",
-        "{\"sessionId\":\"42\",\"sessionId\":\"42\"}"}) {
+  const std::array<std::string, 4> jsons = {
+      {"{\"id\":42,\"id\":42}", "{\"params\":null,\"params\":null}",
+       "{\"method\":\"foo\",\"method\":\"foo\"}",
+       "{\"sessionId\":\"42\",\"sessionId\":\"42\"}"}};
+  for (const std::string& json : jsons) {
     SCOPED_TRACE("json = " + json);
     std::vector<uint8_t> cbor;
     ASSERT_TRUE(json::ConvertJSONToCBOR(SpanFrom(json), &cbor).ok());
@@ -185,11 +186,12 @@ TEST(DispatchableTest, DuplicateMapKey) {
 }
 
 TEST(DispatchableTest, ValidMessageParsesOK_NoParams) {
-  for (const std::string& json :
-       {"{\"id\":42,\"method\":\"Foo.executeBar\",\"sessionId\":"
-        "\"f421ssvaz4\"}",
-        "{\"id\":42,\"method\":\"Foo.executeBar\",\"sessionId\":\"f421ssvaz4\","
-        "\"params\":null}"}) {
+  const std::array<std::string, 2> jsons = {
+      {"{\"id\":42,\"method\":\"Foo.executeBar\",\"sessionId\":"
+       "\"f421ssvaz4\"}",
+       "{\"id\":42,\"method\":\"Foo.executeBar\",\"sessionId\":\"f421ssvaz4\","
+       "\"params\":null}"}};
+  for (const std::string& json : jsons) {
     SCOPED_TRACE("json = " + json);
     std::vector<uint8_t> cbor;
     ASSERT_TRUE(json::ConvertJSONToCBOR(SpanFrom(json), &cbor).ok());

third_party/inspector_protocol/crdtp/json_test.cc

@@ -704,15 +704,16 @@ using ContainerTestTypes = ::testing::Types<std::vector<uint8_t>, std::string>;
 TYPED_TEST_SUITE(ConvertJSONToCBORTest, ContainerTestTypes);
 
 TYPED_TEST(ConvertJSONToCBORTest, RoundTripValidJson) {
-  for (const std::string& json_in : {
-           "{\"msg\":\"Hello, world.\",\"lst\":[1,2,3]}",
-           "3.1415",
-           "false",
-           "true",
-           "\"Hello, world.\"",
-           "[1,2,3]",
-           "[]",
-       }) {
+  const std::array<std::string, 7> jsons = {{
+      "{\"msg\":\"Hello, world.\",\"lst\":[1,2,3]}",
+      "3.1415",
+      "false",
+      "true",
+      "\"Hello, world.\"",
+      "[1,2,3]",
+      "[]",
+  }};
+  for (const std::string& json_in : jsons) {
     SCOPED_TRACE(json_in);
     TypeParam json(json_in.begin(), json_in.end());
     std::vector<uint8_t> cbor;