[wasm] Throw real Error on wasm trap

Before, just a string was thrown, so no stack trace was attached there.
Generated code from wasm does not grow by this change, we just pass a
message id to the respective (new) runtime function.

R=mstarzinger@chromium.org, titzer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1874383002

Cr-Commit-Position: refs/heads/master@{#35664}

src/compiler/wasm-compiler.cc

@@ -193,12 +193,13 @@ class WasmTrapHelper : public ZoneObject {
   }
 
   void BuildTrapCode(wasm::TrapReason reason) {
-    Node* exception =
-        builder_->String(wasm::WasmOpcodes::TrapReasonMessage(reason));
+    Node* message_id = builder_->NumberConstant(
+        wasm::WasmOpcodes::TrapReasonToMessageId(reason));
     Node* end;
     Node** control_ptr = builder_->control_;
     Node** effect_ptr = builder_->effect_;
     wasm::ModuleEnv* module = builder_->module_;
+    DCHECK(traps_[reason] == NULL);
     *control_ptr = traps_[reason] =
         graph()->NewNode(common()->Merge(1), *control_ptr);
     *effect_ptr = effects_[reason] =
@@ -206,14 +207,14 @@ class WasmTrapHelper : public ZoneObject {
 
     if (module && !module->instance->context.is_null()) {
       // Use the module context to call the runtime to throw an exception.
-      Runtime::FunctionId f = Runtime::kThrow;
+      Runtime::FunctionId f = Runtime::kThrowWasmError;
       const Runtime::Function* fun = Runtime::FunctionForId(f);
       CallDescriptor* desc = Linkage::GetRuntimeCallDescriptor(
           jsgraph()->zone(), f, fun->nargs, Operator::kNoProperties,
           CallDescriptor::kNoFlags);
       Node* inputs[] = {
           jsgraph()->CEntryStubConstant(fun->result_size),  // C entry
-          exception,                                        // exception
+          message_id,                                       // message id
           jsgraph()->ExternalConstant(
               ExternalReference(f, jsgraph()->isolate())),  // ref
           jsgraph()->Int32Constant(fun->nargs),             // arity
@@ -344,6 +345,9 @@ Node* WasmGraphBuilder::EffectPhi(unsigned count, Node** effects,
                           buf);
 }
 
+Node* WasmGraphBuilder::NumberConstant(int32_t value) {
+  return jsgraph()->Constant(value);
+}
 
 Node* WasmGraphBuilder::Int32Constant(int32_t value) {
   return jsgraph()->Int32Constant(value);

src/compiler/wasm-compiler.h

@@ -79,6 +79,7 @@ class WasmGraphBuilder {
   Node* Merge(unsigned count, Node** controls);
   Node* Phi(wasm::LocalType type, unsigned count, Node** vals, Node* control);
   Node* EffectPhi(unsigned count, Node** effects, Node* control);
+  Node* NumberConstant(int32_t value);
   Node* Int32Constant(int32_t value);
   Node* Int64Constant(int64_t value);
   Node* Float32Constant(float value);

src/runtime/runtime-internal.cc

@@ -96,6 +96,13 @@ RUNTIME_FUNCTION(Runtime_ThrowStackOverflow) {
   return isolate->StackOverflow();
 }
 
+RUNTIME_FUNCTION(Runtime_ThrowWasmError) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_SMI_ARG_CHECKED(message_id, 0);
+  THROW_NEW_ERROR_RETURN_FAILURE(
+      isolate, NewError(static_cast<MessageTemplate::Template>(message_id)));
+}
 
 RUNTIME_FUNCTION(Runtime_UnwindAndFindExceptionHandler) {
   SealHandleScope shs(isolate);

src/runtime/runtime.h

@@ -290,6 +290,7 @@ namespace internal {
   F(ThrowIteratorResultNotAnObject, 1, 1)           \
   F(ThrowGeneratorRunning, 0, 1)                    \
   F(ThrowStackOverflow, 0, 1)                       \
+  F(ThrowWasmError, 1, 1)                           \
   F(PromiseRejectEvent, 3, 1)                       \
   F(PromiseRevokeReject, 1, 1)                      \
   F(StackGuard, 0, 1)                               \

test/mjsunit/wasm/unreachable.js

@@ -23,4 +23,4 @@ try {
     print("correctly caught: " + e);
     exception = e;
 }
-assertEquals("unreachable", exception);
+assertEquals("unreachable", exception.message);

test/mjsunit/wasm/wasm-constants.js

@@ -290,8 +290,8 @@ function assertTraps(trap, code) {
       }
       threwException = false;
     } catch (e) {
-      assertEquals("string", typeof e);
-      assertEquals(kTrapMsgs[trap], e);
+      assertEquals("object", typeof e);
+      assertEquals(kTrapMsgs[trap], e.message);
       // Success.
       return;
     }