Reland: [Compiler] Ensure unoptimized code generation is context independent.

Now that Asm.js code is also context independent, move code to ensure context independence
from BytecodeGenerator to FinalizeUnoptimizedCode.

Reland of CL: https://chromium-review.googlesource.com/c/v8/v8/+/1349236

Change-Id: I718090850870c61733e0719d4091ec60bc080ebb
Reviewed-on: https://chromium-review.googlesource.com/c/1396201
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58558}

src/compiler.cc

@@ -569,31 +569,38 @@ 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);
-
-  // Finalize the outer-most function's compilation job.
-  if (FinalizeUnoptimizedCompilationJob(outer_function_job, shared_info,
-                                        isolate) != CompilationJob::SUCCEEDED) {
-    return false;
-  }
-
-  // Finalize the inner functions' compilation jobs.
-  for (auto&& inner_job : *inner_function_jobs) {
-    Handle<SharedFunctionInfo> inner_shared_info =
-        Compiler::GetSharedFunctionInfo(
-            inner_job->compilation_info()->literal(), parse_info->script(),
-            isolate);
-    // The inner function might be compiled already if compiling for debug.
-    if (inner_shared_info->is_compiled()) continue;
-    if (FinalizeUnoptimizedCompilationJob(inner_job.get(), inner_shared_info,
+  {
+#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(Context());
+#endif
+
+    // Allocate scope infos for the literal.
+    DeclarationScope::AllocateScopeInfos(parse_info, isolate);
+
+    // Finalize the outer-most function's compilation job.
+    if (FinalizeUnoptimizedCompilationJob(outer_function_job, shared_info,
                                           isolate) !=
         CompilationJob::SUCCEEDED) {
       return false;
     }
+
+    // Finalize the inner functions' compilation jobs.
+    for (auto&& inner_job : *inner_function_jobs) {
+      Handle<SharedFunctionInfo> inner_shared_info =
+          Compiler::GetSharedFunctionInfo(
+              inner_job->compilation_info()->literal(), parse_info->script(),
+              isolate);
+      // The inner function might be compiled already if compiling for debug.
+      if (inner_shared_info->is_compiled()) continue;
+      if (FinalizeUnoptimizedCompilationJob(inner_job.get(), inner_shared_info,
+                                            isolate) !=
+          CompilationJob::SUCCEEDED) {
+        return false;
+      }
+    }
   }
 
   // Report any warnings generated during compilation.

src/interpreter/bytecode-generator.cc

@@ -928,13 +928,6 @@ 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(Context());
-#endif
-
   AllocateDeferredConstants(isolate, script);
 
   if (block_coverage_builder_) {