Reland 2 "Keep a canonical list of shared function infos."

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 "src/ast-numbering.h"
 #include "src/bootstrapper.h"
@@ skipping 101 matching lines @@
   // with deoptimization support.
   if (isolate_->serializer_enabled()) EnableDeoptimizationSupport();
 
   if (isolate_->debug()->is_active()) MarkAsDebug();
   if (FLAG_context_specialization) MarkAsContextSpecializing();
   if (FLAG_turbo_inlining) MarkAsInliningEnabled();
   if (FLAG_turbo_source_positions) MarkAsSourcePositionsEnabled();
   if (FLAG_turbo_splitting) MarkAsSplittingEnabled();
   if (FLAG_turbo_types) MarkAsTypingEnabled();
 
-  if (has_shared_info() && shared_info()->is_compiled()) {
-    // We should initialize the CompilationInfo feedback vector from the
-    // passed in shared info, rather than creating a new one.
-    feedback_vector_ = Handle<TypeFeedbackVector>(
-        shared_info()->feedback_vector(), parse_info->isolate());
+  if (has_shared_info()) {
+    if (shared_info()->is_compiled()) {
+      // We should initialize the CompilationInfo feedback vector from the
+      // passed in shared info, rather than creating a new one.
+      feedback_vector_ = Handle<TypeFeedbackVector>(
+          shared_info()->feedback_vector(), parse_info->isolate());
+    }
+    if (shared_info()->never_compiled()) MarkAsFirstCompile();
   }
 }
 
 
 CompilationInfo::CompilationInfo(CodeStub* stub, Isolate* isolate, Zone* zone)
     : CompilationInfo(nullptr, stub, STUB, isolate, zone) {}
 
 
 CompilationInfo::CompilationInfo(ParseInfo* parse_info, CodeStub* code_stub,
                                  Mode mode, Isolate* isolate, Zone* zone)
@@ skipping 860 matching lines @@
 
 
 void Compiler::CompileForLiveEdit(Handle<Script> script) {
   // TODO(635): support extensions.
   Zone zone;
   ParseInfo parse_info(&zone, script);
   CompilationInfo info(&parse_info);
   PostponeInterruptsScope postpone(info.isolate());
   VMState<COMPILER> state(info.isolate());
 
+  // Get rid of old list of shared function infos.
+  script->set_shared_function_infos(Smi::FromInt(0));
+
   info.parse_info()->set_global();
   if (!Parser::ParseStatic(info.parse_info())) return;
 
   LiveEditFunctionTracker tracker(info.isolate(), info.function());
   if (!CompileUnoptimizedCode(&info)) return;
   if (info.has_shared_info()) {
     Handle<ScopeInfo> scope_info =
         ScopeInfo::Create(info.isolate(), info.zone(), info.scope());
     info.shared_info()->set_scope_info(*scope_info);
   }
@@ skipping 40 matching lines @@
         // Eager parsing cannot benefit from cached data, and producing cached
         // data while parsing eagerly is not implemented.
         parse_info->set_cached_data(nullptr);
         parse_info->set_compile_options(ScriptCompiler::kNoCompileOptions);
       }
       if (!Parser::ParseStatic(parse_info)) {
         return Handle<SharedFunctionInfo>::null();
       }
     }
 
+    info->MarkAsFirstCompile();
+
     FunctionLiteral* lit = info->function();
     LiveEditFunctionTracker live_edit_tracker(isolate, lit);
 
     // Measure how long it takes to do the compilation; only take the
     // rest of the function into account to avoid overlap with the
     // parsing statistics.
     HistogramTimer* rate = info->is_eval()
           ? info->isolate()->counters()->compile_eval()
           : info->isolate()->counters()->compile();
     HistogramTimerScope timer(rate);
 
     // Compile the code.
     if (!CompileUnoptimizedCode(info)) {
       return Handle<SharedFunctionInfo>::null();
     }
 
     // Allocate function.
     DCHECK(!info->code().is_null());
     result = isolate->factory()->NewSharedFunctionInfo(
         lit->name(), lit->materialized_literal_count(), lit->kind(),
         info->code(),
         ScopeInfo::Create(info->isolate(), info->zone(), info->scope()),
         info->feedback_vector());
 
     DCHECK_EQ(RelocInfo::kNoPosition, lit->function_token_position());
     SharedFunctionInfo::InitFromFunctionLiteral(result, lit);
-    result->set_script(*script);
+    SharedFunctionInfo::SetScript(result, script);
     result->set_is_toplevel(true);
 
     Handle<String> script_name = script->name()->IsString()
         ? Handle<String>(String::cast(script->name()))
         : isolate->factory()->empty_string();
     Logger::LogEventsAndTags log_tag = info->is_eval()
         ? Logger::EVAL_TAG
         : Logger::ToNativeByScript(Logger::SCRIPT_TAG, *script);
 
     PROFILE(isolate, CodeCreateEvent(
@@ skipping 209 matching lines @@
   parse_info->set_language_mode(
       static_cast<LanguageMode>(parse_info->language_mode() | language_mode));
 
   CompilationInfo compile_info(parse_info);
   // TODO(marja): FLAG_serialize_toplevel is not honoured and won't be; when the
   // real code caching lands, streaming needs to be adapted to use it.
   return CompileToplevel(&compile_info);
 }
 
 
-Handle<SharedFunctionInfo> Compiler::BuildFunctionInfo(
+Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
     FunctionLiteral* literal, Handle<Script> script,
     CompilationInfo* outer_info) {
   // Precondition: code has been parsed and scopes have been analyzed.
+  MaybeHandle<SharedFunctionInfo> maybe_existing;
+  if (outer_info->is_first_compile()) {
+    // On the first compile, there are no existing shared function info for
+    // inner functions yet, so do not try to find them.
+    DCHECK(script->FindSharedFunctionInfo(literal).is_null());
+  } else {
+    maybe_existing = script->FindSharedFunctionInfo(literal);
+  }
+  // We found an existing shared function info. If it's already compiled,
+  // don't worry about compiling it, and simply return it. If it's not yet
+  // compiled, continue to decide whether to eagerly compile.
+  Handle<SharedFunctionInfo> existing;
+  if (maybe_existing.ToHandle(&existing) && existing->is_compiled()) {
+    return existing;
+  }
+
   Zone zone;
   ParseInfo parse_info(&zone, script);
   CompilationInfo info(&parse_info);
   parse_info.set_literal(literal);
   parse_info.set_scope(literal->scope());
   parse_info.set_language_mode(literal->scope()->language_mode());
   if (outer_info->will_serialize()) info.PrepareForSerializing();
+  if (outer_info->is_first_compile()) info.MarkAsFirstCompile();
 
   Isolate* isolate = info.isolate();
   Factory* factory = isolate->factory();
   LiveEditFunctionTracker live_edit_tracker(isolate, literal);
   // 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_without_ctx = literal->AllowsLazyCompilationWithoutContext();
   bool allow_lazy =
       literal->AllowsLazyCompilation() &&
       !DebuggerWantsEagerCompilation(isolate, allow_lazy_without_ctx);
 
   if (outer_info->parse_info()->is_toplevel() && outer_info->will_serialize()) {
     // Make sure that if the toplevel code (possibly to be serialized),
     // the inner function must be allowed to be compiled lazily.
     // This is necessary to serialize toplevel code without inner functions.
     DCHECK(allow_lazy);
   }
 
+  bool lazy = FLAG_lazy && allow_lazy && !literal->should_eager_compile();
+
   // Generate code
   Handle<ScopeInfo> scope_info;
-  if (FLAG_lazy && allow_lazy && !literal->should_eager_compile()) {
+  if (lazy) {
     Handle<Code> code = isolate->builtins()->CompileLazy();
     info.SetCode(code);
     // There's no need in theory for a lazy-compiled function to have a type
     // feedback vector, but some parts of the system expect all
     // SharedFunctionInfo instances to have one.  The size of the vector depends
     // on how many feedback-needing nodes are in the tree, and when lazily
     // parsing we might not know that, if this function was never parsed before.
     // In that case the vector will be replaced the next time MakeCode is
     // called.
     info.EnsureFeedbackVector();
     scope_info = Handle<ScopeInfo>(ScopeInfo::Empty(isolate));
   } else if (Renumber(info.parse_info()) &&
              FullCodeGenerator::MakeCode(&info)) {
     // MakeCode will ensure that the feedback vector is present and
     // appropriately sized.
     DCHECK(!info.code().is_null());
     scope_info = ScopeInfo::Create(info.isolate(), info.zone(), info.scope());
     if (literal->should_eager_compile() &&
         literal->should_be_used_once_hint()) {
       info.code()->MarkToBeExecutedOnce(isolate);
     }
   } else {
     return Handle<SharedFunctionInfo>::null();
   }
 
-  // Create a shared function info object.
-  Handle<SharedFunctionInfo> result = factory->NewSharedFunctionInfo(
-      literal->name(), literal->materialized_literal_count(), literal->kind(),
-      info.code(), scope_info, info.feedback_vector());
+  if (maybe_existing.is_null()) {
+    // Create a shared function info object.
+    Handle<SharedFunctionInfo> result = factory->NewSharedFunctionInfo(
+        literal->name(), literal->materialized_literal_count(), literal->kind(),
+        info.code(), scope_info, info.feedback_vector());
 
-  SharedFunctionInfo::InitFromFunctionLiteral(result, literal);
-  result->set_script(*script);
-  result->set_is_toplevel(false);
+    SharedFunctionInfo::InitFromFunctionLiteral(result, literal);
+    SharedFunctionInfo::SetScript(result, script);
+    result->set_is_toplevel(false);
+    // If the outer function has been compiled before, we cannot be sure that
+    // shared function info for this function literal has been created for the
+    // first time. It may have already been compiled previously.
+    result->set_never_compiled(outer_info->is_first_compile() && lazy);
 
-  RecordFunctionCompilation(Logger::FUNCTION_TAG, &info, result);
-  result->set_allows_lazy_compilation(literal->AllowsLazyCompilation());
-  result->set_allows_lazy_compilation_without_context(allow_lazy_without_ctx);
+    RecordFunctionCompilation(Logger::FUNCTION_TAG, &info, result);
+    result->set_allows_lazy_compilation(literal->AllowsLazyCompilation());
+    result->set_allows_lazy_compilation_without_context(allow_lazy_without_ctx);
 
-  // Set the expected number of properties for instances and return
-  // the resulting function.
-  SetExpectedNofPropertiesFromEstimate(result,
-                                       literal->expected_property_count());
-  live_edit_tracker.RecordFunctionInfo(result, literal, info.zone());
-  return result;
+    // Set the expected number of properties for instances and return
+    // the resulting function.
+    SetExpectedNofPropertiesFromEstimate(result,
+                                         literal->expected_property_count());
+    live_edit_tracker.RecordFunctionInfo(result, literal, info.zone());
+    return result;
+  } else {
+    // We may have additional data from compilation now.
+    DCHECK(!existing->is_compiled());
+    existing->ReplaceCode(*info.code());
+    existing->set_scope_info(*scope_info);
+    existing->set_feedback_vector(*info.feedback_vector());
+    return existing;
+  }
 }
 
 
 MaybeHandle<Code> Compiler::GetOptimizedCode(Handle<JSFunction> function,
                                              Handle<Code> current_code,
                                              ConcurrencyMode mode,
                                              BailoutId osr_ast_id) {
   Handle<Code> cached_code;
   if (GetCodeFromOptimizedCodeMap(
           function, osr_ast_id).ToHandle(&cached_code)) {
     if (FLAG_trace_opt) {
       PrintF("[found optimized code for ");
       function->ShortPrint();
       if (!osr_ast_id.IsNone()) {
         PrintF(" at OSR AST id %d", osr_ast_id.ToInt());
       }
       PrintF("]\n");
     }
     return cached_code;
   }
 
-  SmartPointer<CompilationInfo> info(new CompilationInfoWithZone(function));
-  Isolate* isolate = info->isolate();
+  Isolate* isolate = function->GetIsolate();
   DCHECK(AllowCompilation::IsAllowed(isolate));
-  VMState<COMPILER> state(isolate);
-  DCHECK(!isolate->has_pending_exception());
-  PostponeInterruptsScope postpone(isolate);
 
-  Handle<SharedFunctionInfo> shared = info->shared_info();
-  if (shared->code()->kind() != Code::FUNCTION ||
-      ScopeInfo::Empty(isolate) == shared->scope_info()) {
+  Handle<SharedFunctionInfo> shared(function->shared(), isolate);
+  if (!shared->is_compiled() ||
+      shared->scope_info() == ScopeInfo::Empty(isolate)) {
     // The function was never compiled. Compile it unoptimized first.
     // TODO(titzer): reuse the AST and scope info from this compile.
-    CompilationInfoWithZone nested(function);
-    nested.EnableDeoptimizationSupport();
-    if (!GetUnoptimizedCodeCommon(&nested).ToHandle(&current_code)) {
+    CompilationInfoWithZone unoptimized(function);
+    unoptimized.EnableDeoptimizationSupport();
+    if (!GetUnoptimizedCodeCommon(&unoptimized).ToHandle(&current_code)) {
       return MaybeHandle<Code>();
     }
     shared->ReplaceCode(*current_code);
   }
+
   current_code->set_profiler_ticks(0);
 
   // TODO(mstarzinger): We cannot properly deserialize a scope chain containing
   // an eval scope and hence would fail at parsing the eval source again.
   if (shared->disable_optimization_reason() == kEval) {
     return MaybeHandle<Code>();
   }
 
   // TODO(mstarzinger): We cannot properly deserialize a scope chain for the
   // builtin context, hence Genesis::InstallExperimentalNatives would fail.
   if (shared->is_toplevel() && isolate->bootstrapper()->IsActive()) {
     return MaybeHandle<Code>();
   }
 
+  SmartPointer<CompilationInfo> info(new CompilationInfoWithZone(function));
+  VMState<COMPILER> state(isolate);
+  DCHECK(!isolate->has_pending_exception());
+  PostponeInterruptsScope postpone(isolate);
+
   info->SetOptimizing(osr_ast_id, current_code);
 
   if (mode == CONCURRENT) {
     if (GetOptimizedCodeLater(info.get())) {
       info.Detach();  // The background recompile job owns this now.
       return isolate->builtins()->InOptimizationQueue();
     }
   } else {
     if (GetOptimizedCodeNow(info.get())) return info->code();
   }
@@ skipping 94 matching lines @@
 
 
 #if DEBUG
 void CompilationInfo::PrintAstForTesting() {
   PrintF("--- Source from AST ---\n%s\n",
          PrettyPrinter(isolate(), zone()).PrintProgram(function()));
 }
 #endif
 }  // namespace internal
 }  // namespace v8