[wasm] disable serialization for asm-wasm

Determine if the scope of the function to be serialized includes asm-
wasm, and if so, bypass serialization, since we do not support it in
that scenario.

In this change, we do so regardless of whether the asm-wasm path was
successful. This is so we keep the design simple, since the guidance
to developers, moving forward, is to use wasm.

BUG=643595

Review-Url: https://codereview.chromium.org/2573193002
Cr-Commit-Position: refs/heads/master@{#41704}

src/compiler.cc

@@ -1345,6 +1345,26 @@ bool CodeGenerationFromStringsAllowed(Isolate* isolate,
   }
 }
 
+bool ContainsAsmModule(const Scope* scope, Zone* zone) {
+  DCHECK_NOT_NULL(scope);
+  DCHECK_NOT_NULL(zone);
+  ZoneQueue<const Scope*> worklist(zone);
+  // We assume scopes form a tree, so no need to check for cycles
+  worklist.push(scope);
+  while (!worklist.empty()) {
+    const Scope* s = worklist.front();
+    worklist.pop();
+    if (s->IsAsmModule()) {
+      return true;
+    }
+    for (const Scope* child = s->inner_scope(); child != nullptr;
+         child = child->sibling()) {
+      worklist.push(child);
+    }
+  }
+  return false;
+}
+
 }  // namespace
 
 MaybeHandle<JSFunction> Compiler::GetFunctionFromString(
@@ -1486,7 +1506,8 @@ Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForScript(
     if (extension == NULL && !result.is_null()) {
       compilation_cache->PutScript(source, context, language_mode, result);
       if (FLAG_serialize_toplevel &&
-          compile_options == ScriptCompiler::kProduceCodeCache) {
+          compile_options == ScriptCompiler::kProduceCodeCache &&
+          !ContainsAsmModule(info.scope(), &zone)) {
         HistogramTimerScope histogram_timer(
             isolate->counters()->compile_serialize());
         RuntimeCallTimerScope runtimeTimer(isolate,

test/mjsunit/regress/wasm/regression-643595.js

@@ -0,0 +1,11 @@
+// Copyright 2016 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: --cache=code --validate-asm
+
+(function f() {
+  "use asm";
+  function g() { }
+  return { g: g };
+})();