[wasm] Do not expose ModuleResult in wasm-engine

Instead, pass a return parameter to store the error message, if any.

Change-Id: Ie71910149271a4268799ee41a8873df51812c505
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3218989
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77375}

src/wasm/wasm-engine.cc

@@ -461,23 +461,23 @@ WasmEngine::~WasmEngine() {
 }
 
 bool WasmEngine::SyncValidate(Isolate* isolate, const WasmFeatures& enabled,
-                              const ModuleWireBytes& bytes) {
-  return SyncValidateResult(isolate, enabled, bytes).ok();
-}
-
-ModuleResult WasmEngine::SyncValidateResult(Isolate* isolate,
-                                            const WasmFeatures& enabled,
-                                            const ModuleWireBytes& bytes) {
+                              const ModuleWireBytes& bytes,
+                              std::string* error_message) {
   TRACE_EVENT0("v8.wasm", "wasm.SyncValidate");
   // TODO(titzer): remove dependency on the isolate.
   if (bytes.start() == nullptr || bytes.length() == 0) {
-    return ModuleResult(WasmError(0, "empty module wire bytes"));
+    if (error_message) *error_message = "empty module wire bytes";
+    return false;
   }
-  return DecodeWasmModule(
+  auto result = DecodeWasmModule(
       enabled, bytes.start(), bytes.end(), true, kWasmOrigin,
       isolate->counters(), isolate->metrics_recorder(),
       isolate->GetOrRegisterRecorderContextId(isolate->native_context()),
       DecodingMethod::kSync, allocator());
+  if (result.failed() && error_message) {
+    *error_message = result.error().message();
+  }
+  return result.ok();
 }
 
 MaybeHandle<AsmWasmData> WasmEngine::SyncCompileTranslatedAsmJs(

src/wasm/wasm-engine.h

@@ -45,11 +45,8 @@ class GdbServer;
 class AsyncCompileJob;
 class ErrorThrower;
 struct ModuleWireBytes;
-template <typename T>
-class Result;
 class StreamingDecoder;
 class WasmFeatures;
-using ModuleResult = Result<std::shared_ptr<WasmModule>>;
 
 class V8_EXPORT_PRIVATE CompilationResultResolver {
  public:
@@ -151,13 +148,11 @@ class V8_EXPORT_PRIVATE WasmEngine {
   ~WasmEngine();
 
   // Synchronously validates the given bytes that represent an encoded Wasm
-  // module.
+  // module. If validation fails and {error_msg} is present, it is set to the
+  // validation error.
   bool SyncValidate(Isolate* isolate, const WasmFeatures& enabled,
-                    const ModuleWireBytes& bytes);
-  // Synchronously validates the given bytes that represent an encoded Wasm
-  // module.
-  ModuleResult SyncValidateResult(Isolate* isolate, const WasmFeatures& enabled,
-                                  const ModuleWireBytes& bytes);
+                    const ModuleWireBytes& bytes,
+                    std::string* error_message = nullptr);
 
   // Synchronously compiles the given bytes that represent a translated
   // asm.js module.

test/fuzzer/wasm-fuzzer-common.cc

@@ -627,14 +627,14 @@ void WasmExecutionFuzzer::FuzzWasmModule(base::Vector<const uint8_t> data,
     GenerateTestCase(i_isolate, wire_bytes, compiles);
   }
 
-  ModuleResult result = GetWasmEngine()->SyncValidateResult(
-      i_isolate, enabled_features, wire_bytes);
+  std::string error_message;
+  bool result = GetWasmEngine()->SyncValidate(i_isolate, enabled_features,
+                                              wire_bytes, &error_message);
 
-  CHECK_EQ(compiles, result.ok());
+  CHECK_EQ(compiles, result);
   CHECK_WITH_MSG(
-      !require_valid || result.ok(),
-      ("Generated module should validate, but got: " + result.error().message())
-          .c_str());
+      !require_valid || result,
+      ("Generated module should validate, but got: " + error_message).c_str());
 
   if (!compiles) return;