Teach Scopes whether they will end up being lazily compiled or not

src/compiler.cc

 // Copyright 2012 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.
 
 #include "src/compiler.h"
 
 #include <algorithm>
 #include <memory>
 
 #include "src/asmjs/asm-js.h"
@@ skipping 1376 matching lines @@
     // only needs to be done when the given function has bytecode, otherwise we
     // can be sure there are no activations. Note that this only applies in case
     // the --ignition-preserve-bytecode flag is not passed.
     if (!FLAG_ignition_preserve_bytecode && shared->HasBytecodeArray()) {
       InterpreterActivationsFinder activations_finder(*shared);
       if (HasInterpreterActivations(info->isolate(), &activations_finder)) {
         return false;
       }
     }
 
+    // When we call PrepareForSerializing below, we will change the shared
+    // ParseInfo. Make sure to reset it.
+    bool old_will_serialize_value = info->parse_info()->will_serialize();
+
     // If the current code has reloc info for serialization, also include
     // reloc info for serialization for the new code, so that deopt support
     // can be added without losing IC state.
     if (shared->code()->kind() == Code::FUNCTION &&
         shared->code()->has_reloc_info_for_serialization()) {
       unoptimized.PrepareForSerializing();
     }
     EnsureFeedbackMetadata(&unoptimized);
     if (!FullCodeGenerator::MakeCode(&unoptimized)) return false;
 
+    info->parse_info()->set_will_serialize(old_will_serialize_value);
+
     // TODO(4280): For now we play it safe and remove the bytecode array when we
     // switch to baseline code. We might consider keeping around the bytecode so
     // that it can be used as the "source of truth" eventually. Note that this
     // only applies in case the --ignition-preserve-bytecode flag is not passed.
     if (!FLAG_ignition_preserve_bytecode && shared->HasBytecodeArray()) {
       shared->ClearBytecodeArray();
     }
 
     // The scope info might not have been set if a lazily compiled
     // function is inlined before being called for the first time.
@@ skipping 340 matching lines @@
 
   Zone zone(isolate->allocator());
   ParseInfo parse_info(&zone, script);
   CompilationInfo info(&parse_info, Handle<JSFunction>::null());
   parse_info.set_literal(literal);
   parse_info.set_shared_info(result);
   parse_info.set_language_mode(literal->scope()->language_mode());
   if (outer_info->will_serialize()) info.PrepareForSerializing();
   if (outer_info->is_debug()) info.MarkAsDebug();
 
-  // Determine if the function can be lazily compiled. This is necessary to
-  // allow some of our builtin JS files to be lazily compiled. These
-  // builtins cannot be handled lazily by the parser, since we have to know
-  // if a function uses the special natives syntax, which is something the
-  // parser records.
-  // If the debugger requests compilation for break points, we cannot be
-  // aggressive about lazy compilation, because it might trigger compilation
-  // of functions without an outer context when setting a breakpoint through
-  // Debug::FindSharedFunctionInfoInScript.
-  bool allow_lazy = literal->AllowsLazyCompilation() && !info.is_debug();
-  bool lazy = FLAG_lazy && allow_lazy && !literal->should_eager_compile();
-
-  // Consider compiling eagerly when targeting the code cache.
-  lazy &= !(FLAG_serialize_eager && info.will_serialize());
-
-  // Consider compiling eagerly when compiling bytecode for Ignition.
-  lazy &=
-      !(FLAG_ignition && FLAG_ignition_eager && !isolate->serializer_enabled());
-
   // Generate code
   TimerEventScope<TimerEventCompileCode> timer(isolate);
   RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::CompileCode);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileCode");
 
-  if (lazy) {
+  if (!literal->ShouldEagerCompile()) {
     info.SetCode(isolate->builtins()->CompileLazy());
     Scope* outer_scope = literal->scope()->GetOuterScopeWithContext();
     if (outer_scope) {
       result->set_outer_scope_info(*outer_scope->scope_info());
     }
   } else if (Renumber(info.parse_info()) && GenerateUnoptimizedCode(&info)) {
     // Code generation will ensure that the feedback vector is present and
     // appropriately sized.
     DCHECK(!info.code().is_null());
-    if (literal->should_eager_compile() &&
-        literal->should_be_used_once_hint()) {
+    if (literal->should_be_used_once_hint()) {
       info.code()->MarkToBeExecutedOnce(isolate);
     }
     // Update the shared function info with the scope info.
     InstallSharedScopeInfo(&info, result);
     // Install compilation result on the shared function info.
     InstallSharedCompilationResult(&info, result);
   } else {
     return Handle<SharedFunctionInfo>::null();
   }
 
@@ skipping 89 matching lines @@
     DCHECK(shared->is_compiled());
     function->set_literals(cached.literals);
   } else if (shared->is_compiled()) {
     // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
     JSFunction::EnsureLiterals(function);
   }
 }
 
 }  // namespace internal
 }  // namespace v8