[wasm][asm.js] Cancel exception and rethrow on parse failure.

BUG=674089
R=marja@chromium.org

Review-Url: https://codereview.chromium.org/2614563002
Cr-Commit-Position: refs/heads/master@{#42440}

src/asmjs/asm-typer.cc

@@ -573,6 +573,8 @@ bool AsmTyper::ValidateAfterFunctionsPhase() {
 
 void AsmTyper::ClearFunctionNodeTypes() { function_node_types_.clear(); }
 
+AsmType* AsmTyper::TriggerParsingError() { FAIL(root_, "Parsing error"); }
+
 namespace {
 bool IsUseAsmDirective(Statement* first_statement) {
   ExpressionStatement* use_asm = first_statement->AsExpressionStatement();

src/asmjs/asm-typer.h

@@ -82,6 +82,8 @@ class AsmTyper final {
   Handle<JSMessageObject> error_message() const { return error_message_; }
   const MessageLocation* message_location() const { return &message_location_; }
 
+  AsmType* TriggerParsingError();
+
   AsmType* TypeOf(AstNode* node) const;
   AsmType* TypeOf(Variable* v) const;
   StandardMember VariableAsStandardMember(Variable* var);

src/asmjs/asm-wasm-builder.cc

@@ -163,6 +163,11 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
           info.zone(), decl->fun()->scope()->outer_scope(), FUNCTION_SCOPE);
       info.set_asm_function_scope(new_func_scope);
       if (!Compiler::ParseAndAnalyze(&info)) {
+        decl->fun()->scope()->outer_scope()->RemoveInnerScope(new_func_scope);
+        if (isolate_->has_pending_exception()) {
+          isolate_->clear_pending_exception();
+        }
+        typer_->TriggerParsingError();
         typer_failed_ = true;
         return;
       }

test/mjsunit/asm/regress-674089.js

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --validate-asm --ignition-staging
+
+function outer() {
+  "use asm";
+  function inner() {
+    switch (1) {
+      case 0:
+        break foo;
+    }
+  }
+}
+outer();