[Compile] Ensure we don't access the native context during bytecode finalization.

Resets the isolate's context to nullptr in debug builds during bytecode finalization
to ensure that we don't rely on the native context during context independent
unoptimized compilation.

BUG=chromium:898076, v8:8041

Change-Id: Ifaa5006a7a3d31d7fbd535ebb63f8889c75526c4
Reviewed-on: https://chromium-review.googlesource.com/c/1297961
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56979}

src/compiler.cc

@@ -504,6 +504,9 @@ bool FinalizeUnoptimizedCode(
     UnoptimizedCompilationJobList* inner_function_jobs) {
   DCHECK(AllowCompilation::IsAllowed(isolate));
 
+  // TODO(rmcilroy): Clear native context in debug once AsmJS generates doesn't
+  // rely on accessing native context during finalization.
+
   // Allocate scope infos for the literal.
   DeclarationScope::AllocateScopeInfos(parse_info, isolate);
 

src/interpreter/bytecode-generator.cc

@@ -923,6 +923,12 @@ BytecodeGenerator::BytecodeGenerator(
 Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
     Isolate* isolate, Handle<Script> script) {
   DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
+#ifdef DEBUG
+  // Unoptimized compilation should be context-independent. Verify that we don't
+  // access the native context by nulling it out during finalization.
+  SaveContext save(isolate);
+  isolate->set_context(nullptr);
+#endif
 
   AllocateDeferredConstants(isolate, script);
 

test/cctest/profiler-extension.cc

@@ -42,15 +42,14 @@ const char* ProfilerExtension::kSource =
 
 v8::Local<v8::FunctionTemplate> ProfilerExtension::GetNativeFunctionTemplate(
     v8::Isolate* isolate, v8::Local<v8::String> name) {
-  v8::Local<v8::Context> context = isolate->GetCurrentContext();
-  if (name->Equals(context, v8_str(isolate, "startProfiling")).FromJust()) {
+  if (name->StrictEquals(v8_str(isolate, "startProfiling"))) {
     return v8::FunctionTemplate::New(isolate,
                                      ProfilerExtension::StartProfiling);
   }
-  if (name->Equals(context, v8_str(isolate, "stopProfiling")).FromJust()) {
+  if (name->StrictEquals(v8_str(isolate, "stopProfiling"))) {
     return v8::FunctionTemplate::New(isolate, ProfilerExtension::StopProfiling);
   }
-  if (name->Equals(context, v8_str(isolate, "collectSample")).FromJust()) {
+  if (name->StrictEquals(v8_str(isolate, "collectSample"))) {
     return v8::FunctionTemplate::New(isolate, ProfilerExtension::CollectSample);
   }
   UNREACHABLE();

test/cctest/test-api.cc

@@ -7728,15 +7728,13 @@ static int lookup_count = 0;
 v8::Local<v8::FunctionTemplate> FunctionExtension::GetNativeFunctionTemplate(
     v8::Isolate* isolate, v8::Local<String> name) {
   lookup_count++;
-  if (name->Equals(isolate->GetCurrentContext(), v8_str("A")).FromJust()) {
+  if (name->StrictEquals(v8_str("A"))) {
     return v8::FunctionTemplate::New(isolate, CallFun,
                                      v8::Integer::New(isolate, 8));
-  } else if (name->Equals(isolate->GetCurrentContext(), v8_str("B"))
-                 .FromJust()) {
+  } else if (name->StrictEquals(v8_str("B"))) {
     return v8::FunctionTemplate::New(isolate, CallFun,
                                      v8::Integer::New(isolate, 7));
-  } else if (name->Equals(isolate->GetCurrentContext(), v8_str("C"))
-                 .FromJust()) {
+  } else if (name->StrictEquals(v8_str("C"))) {
     return v8::FunctionTemplate::New(isolate, CallFun,
                                      v8::Integer::New(isolate, 6));
   } else {

test/cctest/trace-extension.cc

@@ -43,29 +43,24 @@ const char* TraceExtension::kSource =
 
 v8::Local<v8::FunctionTemplate> TraceExtension::GetNativeFunctionTemplate(
     v8::Isolate* isolate, v8::Local<v8::String> name) {
-  v8::Local<v8::Context> context = isolate->GetCurrentContext();
-  if (name->Equals(context, v8::String::NewFromUtf8(isolate, "trace",
-                                                    v8::NewStringType::kNormal)
-                                .ToLocalChecked())
-          .FromJust()) {
+  if (name->StrictEquals(
+          v8::String::NewFromUtf8(isolate, "trace", v8::NewStringType::kNormal)
+              .ToLocalChecked())) {
     return v8::FunctionTemplate::New(isolate, TraceExtension::Trace);
-  } else if (name->Equals(context,
-                          v8::String::NewFromUtf8(isolate, "js_trace",
-                                                  v8::NewStringType::kNormal)
-                              .ToLocalChecked())
-                 .FromJust()) {
+  } else if (name->StrictEquals(
+                 v8::String::NewFromUtf8(isolate, "js_trace",
+                                         v8::NewStringType::kNormal)
+                     .ToLocalChecked())) {
     return v8::FunctionTemplate::New(isolate, TraceExtension::JSTrace);
-  } else if (name->Equals(context,
-                          v8::String::NewFromUtf8(isolate, "js_entry_sp",
-                                                  v8::NewStringType::kNormal)
-                              .ToLocalChecked())
-                 .FromJust()) {
+  } else if (name->StrictEquals(
+                 v8::String::NewFromUtf8(isolate, "js_entry_sp",
+                                         v8::NewStringType::kNormal)
+                     .ToLocalChecked())) {
     return v8::FunctionTemplate::New(isolate, TraceExtension::JSEntrySP);
-  } else if (name->Equals(context,
-                          v8::String::NewFromUtf8(isolate, "js_entry_sp_level2",
-                                                  v8::NewStringType::kNormal)
-                              .ToLocalChecked())
-                 .FromJust()) {
+  } else if (name->StrictEquals(
+                 v8::String::NewFromUtf8(isolate, "js_entry_sp_level2",
+                                         v8::NewStringType::kNormal)
+                     .ToLocalChecked())) {
     return v8::FunctionTemplate::New(isolate, TraceExtension::JSEntrySPLevel2);
   }
   UNREACHABLE();