[wasm] Implement {Compile,Runtime}Error; fix traps from start function

src/wasm/wasm-js.cc

Index: src/wasm/wasm-js.cc
diff --git a/src/wasm/wasm-js.cc b/src/wasm/wasm-js.cc
index 36f286f73cffcd58a940d74e7d06442ed8fe1f92..e79a9db20c2bdfb095d2455ae3be05b45f4f5c9d 100644
--- a/src/wasm/wasm-js.cc
+++ b/src/wasm/wasm-js.cc
@@ -57,7 +57,7 @@ RawBuffer GetRawBufferSource(
     end = start + contents.ByteLength();
 
     if (start == nullptr || end == start) {
-      thrower->Error("ArrayBuffer argument is empty");
+      thrower->CompileError("ArrayBuffer argument is empty");
     }
   } else if (source->IsTypedArray()) {
     // A TypedArray was passed.
@@ -71,10 +71,10 @@ RawBuffer GetRawBufferSource(
     end = start + array->ByteLength();
 
     if (start == nullptr || end == start) {
-      thrower->Error("ArrayBuffer argument is empty");
+      thrower->TypeError("ArrayBuffer argument is empty");
     }
   } else {
-    thrower->Error("Argument 0 must be an ArrayBuffer or Uint8Array");
+    thrower->TypeError("Argument 0 must be an ArrayBuffer or Uint8Array");
   }
 
   return {start, end};
@@ -98,7 +98,7 @@ void VerifyModule(const v8::FunctionCallbackInfo<v8::Value>& args) {
                                        true, internal::wasm::kWasmOrigin);
 
   if (result.failed()) {
-    thrower.Failed("", result);
+    thrower.CompileFailed("", result);
   }
 
   if (result.val) delete result.val;
@@ -126,7 +126,7 @@ void VerifyFunction(const v8::FunctionCallbackInfo<v8::Value>& args) {
   }
 
   if (result.failed()) {
-    thrower.Failed("", result);
+    thrower.CompileFailed("", result);
   }
 
   if (result.val) delete result.val;
@@ -334,9 +334,10 @@ void WebAssemblyInstance(const v8::FunctionCallbackInfo<v8::Value>& args) {
   i::MaybeHandle<i::JSObject> instance = i::wasm::WasmModule::Instantiate(
       i_isolate, &thrower, module_obj, ffi, memory);
   if (instance.is_null()) {
-    if (!thrower.error()) thrower.Error("Could not instantiate module");
+    if (!thrower.error()) thrower.RuntimeError("Could not instantiate module");
     return;
   }
+  DCHECK(!i_isolate->has_pending_exception());
   v8::ReturnValue<v8::Value> return_value = args.GetReturnValue();
   return_value.Set(Utils::ToLocal(instance.ToHandleChecked()));
 }
@@ -444,7 +445,7 @@ void WebAssemblyMemory(const v8::FunctionCallbackInfo<v8::Value>& args) {
   ErrorThrower thrower(reinterpret_cast<i::Isolate*>(isolate),
                        "WebAssembly.Module()");
   if (args.Length() < 1 || !args[0]->IsObject()) {
-    thrower.TypeError("Argument 0 must be a table descriptor");
+    thrower.TypeError("Argument 0 must be a memory descriptor");
     return;
   }
   Local<Context> context = isolate->GetCurrentContext();
@@ -664,6 +665,17 @@ void WasmJs::InstallWasmConstructors(Isolate* isolate,
                         memory_constructor, DONT_ENUM);
   InstallFunc(isolate, memory_proto, "grow", WebAssemblyMemoryGrow);
   InstallGetter(isolate, memory_proto, "buffer", WebAssemblyMemoryGetBuffer);
+
+  // Setup errors
+  attributes = static_cast<PropertyAttributes>(DONT_DELETE | READ_ONLY);
+  Handle<JSFunction> compile_error(
+      isolate->native_context()->wasm_compile_error_function());
+  JSObject::AddProperty(wasm_object, isolate->factory()->CompileError_string(),
+                        compile_error, attributes);
+  Handle<JSFunction> runtime_error(
+      isolate->native_context()->wasm_runtime_error_function());
+  JSObject::AddProperty(wasm_object, isolate->factory()->RuntimeError_string(),
+                        runtime_error, attributes);
 }
 
 void WasmJs::Install(Isolate* isolate, Handle<JSGlobalObject> global) {