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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "src/v8.h"
      6 
      7 #include "src/compiler.h"
      8 
      9 #include "src/bootstrapper.h"
     10 #include "src/codegen.h"
     11 #include "src/compilation-cache.h"
     12 #include "src/compiler/pipeline.h"
     13 #include "src/cpu-profiler.h"
     14 #include "src/debug.h"
     15 #include "src/deoptimizer.h"
     16 #include "src/full-codegen.h"
     17 #include "src/gdb-jit.h"
     18 #include "src/hydrogen.h"
     19 #include "src/isolate-inl.h"
     20 #include "src/lithium.h"
     21 #include "src/liveedit.h"
     22 #include "src/parser.h"
     23 #include "src/rewriter.h"
     24 #include "src/runtime-profiler.h"
     25 #include "src/scanner-character-streams.h"
     26 #include "src/scopeinfo.h"
     27 #include "src/scopes.h"
     28 #include "src/typing.h"
     29 #include "src/vm-state-inl.h"
     30 
     31 namespace v8 {
     32 namespace internal {
     33 
     34 
     35 ScriptData::ScriptData(const byte* data, int length)
     36     : owns_data_(false), data_(data), length_(length) {
     37   if (!IsAligned(reinterpret_cast<intptr_t>(data), kPointerAlignment)) {
     38     byte* copy = NewArray<byte>(length);
     39     DCHECK(IsAligned(reinterpret_cast<intptr_t>(copy), kPointerAlignment));
     40     CopyBytes(copy, data, length);
     41     data_ = copy;
     42     AcquireDataOwnership();
     43   }
     44 }
     45 
     46 
     47 CompilationInfo::CompilationInfo(Handle<Script> script, Zone* zone)
     48     : flags_(kThisHasUses),
     49       script_(script),
     50       source_stream_(NULL),
     51       osr_ast_id_(BailoutId::None()),
     52       parameter_count_(0),
     53       optimization_id_(-1),
     54       ast_value_factory_(NULL),
     55       ast_value_factory_owned_(false),
     56       aborted_due_to_dependency_change_(false) {
     57   Initialize(script->GetIsolate(), BASE, zone);
     58 }
     59 
     60 
     61 CompilationInfo::CompilationInfo(Isolate* isolate, Zone* zone)
     62     : flags_(kThisHasUses),
     63       script_(Handle<Script>::null()),
     64       source_stream_(NULL),
     65       osr_ast_id_(BailoutId::None()),
     66       parameter_count_(0),
     67       optimization_id_(-1),
     68       ast_value_factory_(NULL),
     69       ast_value_factory_owned_(false),
     70       aborted_due_to_dependency_change_(false) {
     71   Initialize(isolate, STUB, zone);
     72 }
     73 
     74 
     75 CompilationInfo::CompilationInfo(Handle<SharedFunctionInfo> shared_info,
     76                                  Zone* zone)
     77     : flags_(kLazy | kThisHasUses),
     78       shared_info_(shared_info),
     79       script_(Handle<Script>(Script::cast(shared_info->script()))),
     80       source_stream_(NULL),
     81       osr_ast_id_(BailoutId::None()),
     82       parameter_count_(0),
     83       optimization_id_(-1),
     84       ast_value_factory_(NULL),
     85       ast_value_factory_owned_(false),
     86       aborted_due_to_dependency_change_(false) {
     87   Initialize(script_->GetIsolate(), BASE, zone);
     88 }
     89 
     90 
     91 CompilationInfo::CompilationInfo(Handle<JSFunction> closure, Zone* zone)
     92     : flags_(kLazy | kThisHasUses),
     93       closure_(closure),
     94       shared_info_(Handle<SharedFunctionInfo>(closure->shared())),
     95       script_(Handle<Script>(Script::cast(shared_info_->script()))),
     96       source_stream_(NULL),
     97       context_(closure->context()),
     98       osr_ast_id_(BailoutId::None()),
     99       parameter_count_(0),
    100       optimization_id_(-1),
    101       ast_value_factory_(NULL),
    102       ast_value_factory_owned_(false),
    103       aborted_due_to_dependency_change_(false) {
    104   Initialize(script_->GetIsolate(), BASE, zone);
    105 }
    106 
    107 
    108 CompilationInfo::CompilationInfo(HydrogenCodeStub* stub, Isolate* isolate,
    109                                  Zone* zone)
    110     : flags_(kLazy | kThisHasUses),
    111       source_stream_(NULL),
    112       osr_ast_id_(BailoutId::None()),
    113       parameter_count_(0),
    114       optimization_id_(-1),
    115       ast_value_factory_(NULL),
    116       ast_value_factory_owned_(false),
    117       aborted_due_to_dependency_change_(false) {
    118   Initialize(isolate, STUB, zone);
    119   code_stub_ = stub;
    120 }
    121 
    122 
    123 CompilationInfo::CompilationInfo(
    124     ScriptCompiler::ExternalSourceStream* stream,
    125     ScriptCompiler::StreamedSource::Encoding encoding, Isolate* isolate,
    126     Zone* zone)
    127     : flags_(kThisHasUses),
    128       source_stream_(stream),
    129       source_stream_encoding_(encoding),
    130       osr_ast_id_(BailoutId::None()),
    131       parameter_count_(0),
    132       optimization_id_(-1),
    133       ast_value_factory_(NULL),
    134       ast_value_factory_owned_(false),
    135       aborted_due_to_dependency_change_(false) {
    136   Initialize(isolate, BASE, zone);
    137 }
    138 
    139 
    140 void CompilationInfo::Initialize(Isolate* isolate,
    141                                  Mode mode,
    142                                  Zone* zone) {
    143   isolate_ = isolate;
    144   function_ = NULL;
    145   scope_ = NULL;
    146   global_scope_ = NULL;
    147   extension_ = NULL;
    148   cached_data_ = NULL;
    149   compile_options_ = ScriptCompiler::kNoCompileOptions;
    150   zone_ = zone;
    151   deferred_handles_ = NULL;
    152   code_stub_ = NULL;
    153   prologue_offset_ = Code::kPrologueOffsetNotSet;
    154   opt_count_ = shared_info().is_null() ? 0 : shared_info()->opt_count();
    155   no_frame_ranges_ = isolate->cpu_profiler()->is_profiling()
    156                    ? new List<OffsetRange>(2) : NULL;
    157   for (int i = 0; i < DependentCode::kGroupCount; i++) {
    158     dependencies_[i] = NULL;
    159   }
    160   if (mode == STUB) {
    161     mode_ = STUB;
    162     return;
    163   }
    164   mode_ = mode;
    165   if (!script_.is_null() && script_->type()->value() == Script::TYPE_NATIVE) {
    166     MarkAsNative();
    167   }
    168   if (isolate_->debug()->is_active()) MarkAsDebug();
    169   if (FLAG_context_specialization) MarkAsContextSpecializing();
    170   if (FLAG_turbo_inlining) MarkAsInliningEnabled();
    171   if (FLAG_turbo_types) MarkAsTypingEnabled();
    172 
    173   if (!shared_info_.is_null()) {
    174     DCHECK(strict_mode() == SLOPPY);
    175     SetStrictMode(shared_info_->strict_mode());
    176   }
    177   bailout_reason_ = kUnknown;
    178 
    179   if (!shared_info().is_null() && shared_info()->is_compiled()) {
    180     // We should initialize the CompilationInfo feedback vector from the
    181     // passed in shared info, rather than creating a new one.
    182     feedback_vector_ =
    183         Handle<TypeFeedbackVector>(shared_info()->feedback_vector(), isolate);
    184   }
    185 }
    186 
    187 
    188 CompilationInfo::~CompilationInfo() {
    189   if (GetFlag(kDisableFutureOptimization)) {
    190     shared_info()->DisableOptimization(bailout_reason());
    191   }
    192   delete deferred_handles_;
    193   delete no_frame_ranges_;
    194   if (ast_value_factory_owned_) delete ast_value_factory_;
    195 #ifdef DEBUG
    196   // Check that no dependent maps have been added or added dependent maps have
    197   // been rolled back or committed.
    198   for (int i = 0; i < DependentCode::kGroupCount; i++) {
    199     DCHECK_EQ(NULL, dependencies_[i]);
    200   }
    201 #endif  // DEBUG
    202 }
    203 
    204 
    205 void CompilationInfo::CommitDependencies(Handle<Code> code) {
    206   for (int i = 0; i < DependentCode::kGroupCount; i++) {
    207     ZoneList<Handle<HeapObject> >* group_objects = dependencies_[i];
    208     if (group_objects == NULL) continue;
    209     DCHECK(!object_wrapper_.is_null());
    210     for (int j = 0; j < group_objects->length(); j++) {
    211       DependentCode::DependencyGroup group =
    212           static_cast<DependentCode::DependencyGroup>(i);
    213       DependentCode* dependent_code =
    214           DependentCode::ForObject(group_objects->at(j), group);
    215       dependent_code->UpdateToFinishedCode(group, this, *code);
    216     }
    217     dependencies_[i] = NULL;  // Zone-allocated, no need to delete.
    218   }
    219 }
    220 
    221 
    222 void CompilationInfo::RollbackDependencies() {
    223   // Unregister from all dependent maps if not yet committed.
    224   for (int i = 0; i < DependentCode::kGroupCount; i++) {
    225     ZoneList<Handle<HeapObject> >* group_objects = dependencies_[i];
    226     if (group_objects == NULL) continue;
    227     for (int j = 0; j < group_objects->length(); j++) {
    228       DependentCode::DependencyGroup group =
    229           static_cast<DependentCode::DependencyGroup>(i);
    230       DependentCode* dependent_code =
    231           DependentCode::ForObject(group_objects->at(j), group);
    232       dependent_code->RemoveCompilationInfo(group, this);
    233     }
    234     dependencies_[i] = NULL;  // Zone-allocated, no need to delete.
    235   }
    236 }
    237 
    238 
    239 int CompilationInfo::num_parameters() const {
    240   if (IsStub()) {
    241     DCHECK(parameter_count_ > 0);
    242     return parameter_count_;
    243   } else {
    244     return scope()->num_parameters();
    245   }
    246 }
    247 
    248 
    249 int CompilationInfo::num_heap_slots() const {
    250   if (IsStub()) {
    251     return 0;
    252   } else {
    253     return scope()->num_heap_slots();
    254   }
    255 }
    256 
    257 
    258 Code::Flags CompilationInfo::flags() const {
    259   if (IsStub()) {
    260     return Code::ComputeFlags(code_stub()->GetCodeKind(),
    261                               code_stub()->GetICState(),
    262                               code_stub()->GetExtraICState(),
    263                               code_stub()->GetStubType());
    264   } else {
    265     return Code::ComputeFlags(Code::OPTIMIZED_FUNCTION);
    266   }
    267 }
    268 
    269 
    270 // Primitive functions are unlikely to be picked up by the stack-walking
    271 // profiler, so they trigger their own optimization when they're called
    272 // for the SharedFunctionInfo::kCallsUntilPrimitiveOptimization-th time.
    273 bool CompilationInfo::ShouldSelfOptimize() {
    274   return FLAG_crankshaft &&
    275       !function()->flags()->Contains(kDontSelfOptimize) &&
    276       !function()->dont_optimize() &&
    277       function()->scope()->AllowsLazyCompilation() &&
    278       (shared_info().is_null() || !shared_info()->optimization_disabled());
    279 }
    280 
    281 
    282 void CompilationInfo::PrepareForCompilation(Scope* scope) {
    283   DCHECK(scope_ == NULL);
    284   scope_ = scope;
    285 
    286   int length = function()->slot_count();
    287   if (feedback_vector_.is_null()) {
    288     // Allocate the feedback vector too.
    289     feedback_vector_ = isolate()->factory()->NewTypeFeedbackVector(length);
    290   }
    291   DCHECK(feedback_vector_->length() == length);
    292 }
    293 
    294 
    295 class HOptimizedGraphBuilderWithPositions: public HOptimizedGraphBuilder {
    296  public:
    297   explicit HOptimizedGraphBuilderWithPositions(CompilationInfo* info)
    298       : HOptimizedGraphBuilder(info) {
    299   }
    300 
    301 #define DEF_VISIT(type)                                 \
    302   virtual void Visit##type(type* node) OVERRIDE {    \
    303     if (node->position() != RelocInfo::kNoPosition) {   \
    304       SetSourcePosition(node->position());              \
    305     }                                                   \
    306     HOptimizedGraphBuilder::Visit##type(node);          \
    307   }
    308   EXPRESSION_NODE_LIST(DEF_VISIT)
    309 #undef DEF_VISIT
    310 
    311 #define DEF_VISIT(type)                                          \
    312   virtual void Visit##type(type* node) OVERRIDE {             \
    313     if (node->position() != RelocInfo::kNoPosition) {            \
    314       SetSourcePosition(node->position());                       \
    315     }                                                            \
    316     HOptimizedGraphBuilder::Visit##type(node);                   \
    317   }
    318   STATEMENT_NODE_LIST(DEF_VISIT)
    319 #undef DEF_VISIT
    320 
    321 #define DEF_VISIT(type)                                            \
    322   virtual void Visit##type(type* node) OVERRIDE {               \
    323     HOptimizedGraphBuilder::Visit##type(node);                     \
    324   }
    325   MODULE_NODE_LIST(DEF_VISIT)
    326   DECLARATION_NODE_LIST(DEF_VISIT)
    327 #undef DEF_VISIT
    328 };
    329 
    330 
    331 OptimizedCompileJob::Status OptimizedCompileJob::CreateGraph() {
    332   DCHECK(isolate()->use_crankshaft());
    333   DCHECK(info()->IsOptimizing());
    334   DCHECK(!info()->IsCompilingForDebugging());
    335 
    336   // We should never arrive here if optimization has been disabled on the
    337   // shared function info.
    338   DCHECK(!info()->shared_info()->optimization_disabled());
    339 
    340   // Do not use crankshaft if we need to be able to set break points.
    341   if (isolate()->DebuggerHasBreakPoints()) {
    342     return RetryOptimization(kDebuggerHasBreakPoints);
    343   }
    344 
    345   // Limit the number of times we re-compile a functions with
    346   // the optimizing compiler.
    347   const int kMaxOptCount =
    348       FLAG_deopt_every_n_times == 0 ? FLAG_max_opt_count : 1000;
    349   if (info()->opt_count() > kMaxOptCount) {
    350     return AbortOptimization(kOptimizedTooManyTimes);
    351   }
    352 
    353   // Due to an encoding limit on LUnallocated operands in the Lithium
    354   // language, we cannot optimize functions with too many formal parameters
    355   // or perform on-stack replacement for function with too many
    356   // stack-allocated local variables.
    357   //
    358   // The encoding is as a signed value, with parameters and receiver using
    359   // the negative indices and locals the non-negative ones.
    360   const int parameter_limit = -LUnallocated::kMinFixedSlotIndex;
    361   Scope* scope = info()->scope();
    362   if ((scope->num_parameters() + 1) > parameter_limit) {
    363     return AbortOptimization(kTooManyParameters);
    364   }
    365 
    366   const int locals_limit = LUnallocated::kMaxFixedSlotIndex;
    367   if (info()->is_osr() &&
    368       scope->num_parameters() + 1 + scope->num_stack_slots() > locals_limit) {
    369     return AbortOptimization(kTooManyParametersLocals);
    370   }
    371 
    372   if (scope->HasIllegalRedeclaration()) {
    373     return AbortOptimization(kFunctionWithIllegalRedeclaration);
    374   }
    375 
    376   // Check the whitelist for Crankshaft.
    377   if (!info()->closure()->PassesFilter(FLAG_hydrogen_filter)) {
    378     return AbortOptimization(kHydrogenFilter);
    379   }
    380 
    381   // Crankshaft requires a version of fullcode with deoptimization support.
    382   // Recompile the unoptimized version of the code if the current version
    383   // doesn't have deoptimization support already.
    384   // Otherwise, if we are gathering compilation time and space statistics
    385   // for hydrogen, gather baseline statistics for a fullcode compilation.
    386   bool should_recompile = !info()->shared_info()->has_deoptimization_support();
    387   if (should_recompile || FLAG_hydrogen_stats) {
    388     base::ElapsedTimer timer;
    389     if (FLAG_hydrogen_stats) {
    390       timer.Start();
    391     }
    392     if (!Compiler::EnsureDeoptimizationSupport(info())) {
    393       return SetLastStatus(FAILED);
    394     }
    395     if (FLAG_hydrogen_stats) {
    396       isolate()->GetHStatistics()->IncrementFullCodeGen(timer.Elapsed());
    397     }
    398   }
    399 
    400   DCHECK(info()->shared_info()->has_deoptimization_support());
    401 
    402   // Check the whitelist for TurboFan.
    403   if ((FLAG_turbo_asm && info()->shared_info()->asm_function()) ||
    404       info()->closure()->PassesFilter(FLAG_turbo_filter)) {
    405     compiler::Pipeline pipeline(info());
    406     pipeline.GenerateCode();
    407     if (!info()->code().is_null()) {
    408       if (FLAG_turbo_deoptimization) {
    409         info()->context()->native_context()->AddOptimizedCode(*info()->code());
    410       }
    411       return SetLastStatus(SUCCEEDED);
    412     }
    413   }
    414 
    415   if (FLAG_trace_hydrogen) {
    416     Handle<String> name = info()->function()->debug_name();
    417     PrintF("-----------------------------------------------------------\n");
    418     PrintF("Compiling method %s using hydrogen\n", name->ToCString().get());
    419     isolate()->GetHTracer()->TraceCompilation(info());
    420   }
    421 
    422   // Type-check the function.
    423   AstTyper::Run(info());
    424 
    425   graph_builder_ = (FLAG_hydrogen_track_positions || FLAG_trace_ic)
    426       ? new(info()->zone()) HOptimizedGraphBuilderWithPositions(info())
    427       : new(info()->zone()) HOptimizedGraphBuilder(info());
    428 
    429   Timer t(this, &time_taken_to_create_graph_);
    430   info()->set_this_has_uses(false);
    431   graph_ = graph_builder_->CreateGraph();
    432 
    433   if (isolate()->has_pending_exception()) {
    434     return SetLastStatus(FAILED);
    435   }
    436 
    437   if (graph_ == NULL) return SetLastStatus(BAILED_OUT);
    438 
    439   if (info()->HasAbortedDueToDependencyChange()) {
    440     // Dependency has changed during graph creation. Let's try again later.
    441     return RetryOptimization(kBailedOutDueToDependencyChange);
    442   }
    443 
    444   return SetLastStatus(SUCCEEDED);
    445 }
    446 
    447 
    448 OptimizedCompileJob::Status OptimizedCompileJob::OptimizeGraph() {
    449   DisallowHeapAllocation no_allocation;
    450   DisallowHandleAllocation no_handles;
    451   DisallowHandleDereference no_deref;
    452   DisallowCodeDependencyChange no_dependency_change;
    453 
    454   DCHECK(last_status() == SUCCEEDED);
    455   // TODO(turbofan): Currently everything is done in the first phase.
    456   if (!info()->code().is_null()) {
    457     return last_status();
    458   }
    459 
    460   Timer t(this, &time_taken_to_optimize_);
    461   DCHECK(graph_ != NULL);
    462   BailoutReason bailout_reason = kNoReason;
    463 
    464   if (graph_->Optimize(&bailout_reason)) {
    465     chunk_ = LChunk::NewChunk(graph_);
    466     if (chunk_ != NULL) return SetLastStatus(SUCCEEDED);
    467   } else if (bailout_reason != kNoReason) {
    468     graph_builder_->Bailout(bailout_reason);
    469   }
    470 
    471   return SetLastStatus(BAILED_OUT);
    472 }
    473 
    474 
    475 OptimizedCompileJob::Status OptimizedCompileJob::GenerateCode() {
    476   DCHECK(last_status() == SUCCEEDED);
    477   // TODO(turbofan): Currently everything is done in the first phase.
    478   if (!info()->code().is_null()) {
    479     RecordOptimizationStats();
    480     return last_status();
    481   }
    482 
    483   DCHECK(!info()->HasAbortedDueToDependencyChange());
    484   DisallowCodeDependencyChange no_dependency_change;
    485   DisallowJavascriptExecution no_js(isolate());
    486   {  // Scope for timer.
    487     Timer timer(this, &time_taken_to_codegen_);
    488     DCHECK(chunk_ != NULL);
    489     DCHECK(graph_ != NULL);
    490     // Deferred handles reference objects that were accessible during
    491     // graph creation.  To make sure that we don't encounter inconsistencies
    492     // between graph creation and code generation, we disallow accessing
    493     // objects through deferred handles during the latter, with exceptions.
    494     DisallowDeferredHandleDereference no_deferred_handle_deref;
    495     Handle<Code> optimized_code = chunk_->Codegen();
    496     if (optimized_code.is_null()) {
    497       if (info()->bailout_reason() == kNoReason) {
    498         return AbortOptimization(kCodeGenerationFailed);
    499       }
    500       return SetLastStatus(BAILED_OUT);
    501     }
    502     info()->SetCode(optimized_code);
    503   }
    504   RecordOptimizationStats();
    505   // Add to the weak list of optimized code objects.
    506   info()->context()->native_context()->AddOptimizedCode(*info()->code());
    507   return SetLastStatus(SUCCEEDED);
    508 }
    509 
    510 
    511 void OptimizedCompileJob::RecordOptimizationStats() {
    512   Handle<JSFunction> function = info()->closure();
    513   if (!function->IsOptimized()) {
    514     // Concurrent recompilation and OSR may race.  Increment only once.
    515     int opt_count = function->shared()->opt_count();
    516     function->shared()->set_opt_count(opt_count + 1);
    517   }
    518   double ms_creategraph = time_taken_to_create_graph_.InMillisecondsF();
    519   double ms_optimize = time_taken_to_optimize_.InMillisecondsF();
    520   double ms_codegen = time_taken_to_codegen_.InMillisecondsF();
    521   if (FLAG_trace_opt) {
    522     PrintF("[optimizing ");
    523     function->ShortPrint();
    524     PrintF(" - took %0.3f, %0.3f, %0.3f ms]\n", ms_creategraph, ms_optimize,
    525            ms_codegen);
    526   }
    527   if (FLAG_trace_opt_stats) {
    528     static double compilation_time = 0.0;
    529     static int compiled_functions = 0;
    530     static int code_size = 0;
    531 
    532     compilation_time += (ms_creategraph + ms_optimize + ms_codegen);
    533     compiled_functions++;
    534     code_size += function->shared()->SourceSize();
    535     PrintF("Compiled: %d functions with %d byte source size in %fms.\n",
    536            compiled_functions,
    537            code_size,
    538            compilation_time);
    539   }
    540   if (FLAG_hydrogen_stats) {
    541     isolate()->GetHStatistics()->IncrementSubtotals(time_taken_to_create_graph_,
    542                                                     time_taken_to_optimize_,
    543                                                     time_taken_to_codegen_);
    544   }
    545 }
    546 
    547 
    548 // Sets the expected number of properties based on estimate from compiler.
    549 void SetExpectedNofPropertiesFromEstimate(Handle<SharedFunctionInfo> shared,
    550                                           int estimate) {
    551   // If no properties are added in the constructor, they are more likely
    552   // to be added later.
    553   if (estimate == 0) estimate = 2;
    554 
    555   // TODO(yangguo): check whether those heuristics are still up-to-date.
    556   // We do not shrink objects that go into a snapshot (yet), so we adjust
    557   // the estimate conservatively.
    558   if (shared->GetIsolate()->serializer_enabled()) {
    559     estimate += 2;
    560   } else if (FLAG_clever_optimizations) {
    561     // Inobject slack tracking will reclaim redundant inobject space later,
    562     // so we can afford to adjust the estimate generously.
    563     estimate += 8;
    564   } else {
    565     estimate += 3;
    566   }
    567 
    568   shared->set_expected_nof_properties(estimate);
    569 }
    570 
    571 
    572 // Sets the function info on a function.
    573 // The start_position points to the first '(' character after the function name
    574 // in the full script source. When counting characters in the script source the
    575 // the first character is number 0 (not 1).
    576 static void SetFunctionInfo(Handle<SharedFunctionInfo> function_info,
    577                             FunctionLiteral* lit,
    578                             bool is_toplevel,
    579                             Handle<Script> script) {
    580   function_info->set_length(lit->parameter_count());
    581   function_info->set_formal_parameter_count(lit->parameter_count());
    582   function_info->set_script(*script);
    583   function_info->set_function_token_position(lit->function_token_position());
    584   function_info->set_start_position(lit->start_position());
    585   function_info->set_end_position(lit->end_position());
    586   function_info->set_is_expression(lit->is_expression());
    587   function_info->set_is_anonymous(lit->is_anonymous());
    588   function_info->set_is_toplevel(is_toplevel);
    589   function_info->set_inferred_name(*lit->inferred_name());
    590   function_info->set_allows_lazy_compilation(lit->AllowsLazyCompilation());
    591   function_info->set_allows_lazy_compilation_without_context(
    592       lit->AllowsLazyCompilationWithoutContext());
    593   function_info->set_strict_mode(lit->strict_mode());
    594   function_info->set_uses_arguments(lit->scope()->arguments() != NULL);
    595   function_info->set_has_duplicate_parameters(lit->has_duplicate_parameters());
    596   function_info->set_ast_node_count(lit->ast_node_count());
    597   function_info->set_is_function(lit->is_function());
    598   function_info->set_bailout_reason(lit->dont_optimize_reason());
    599   function_info->set_dont_cache(lit->flags()->Contains(kDontCache));
    600   function_info->set_kind(lit->kind());
    601   function_info->set_asm_function(lit->scope()->asm_function());
    602 }
    603 
    604 
    605 static void RecordFunctionCompilation(Logger::LogEventsAndTags tag,
    606                                       CompilationInfo* info,
    607                                       Handle<SharedFunctionInfo> shared) {
    608   // SharedFunctionInfo is passed separately, because if CompilationInfo
    609   // was created using Script object, it will not have it.
    610 
    611   // Log the code generation. If source information is available include
    612   // script name and line number. Check explicitly whether logging is
    613   // enabled as finding the line number is not free.
    614   if (info->isolate()->logger()->is_logging_code_events() ||
    615       info->isolate()->cpu_profiler()->is_profiling()) {
    616     Handle<Script> script = info->script();
    617     Handle<Code> code = info->code();
    618     if (code.is_identical_to(info->isolate()->builtins()->CompileLazy())) {
    619       return;
    620     }
    621     int line_num = Script::GetLineNumber(script, shared->start_position()) + 1;
    622     int column_num =
    623         Script::GetColumnNumber(script, shared->start_position()) + 1;
    624     String* script_name = script->name()->IsString()
    625                               ? String::cast(script->name())
    626                               : info->isolate()->heap()->empty_string();
    627     Logger::LogEventsAndTags log_tag = Logger::ToNativeByScript(tag, *script);
    628     PROFILE(info->isolate(),
    629             CodeCreateEvent(log_tag, *code, *shared, info, script_name,
    630                             line_num, column_num));
    631   }
    632 
    633   GDBJIT(AddCode(Handle<String>(shared->DebugName()),
    634                  Handle<Script>(info->script()), Handle<Code>(info->code()),
    635                  info));
    636 }
    637 
    638 
    639 static bool CompileUnoptimizedCode(CompilationInfo* info) {
    640   DCHECK(AllowCompilation::IsAllowed(info->isolate()));
    641   DCHECK(info->function() != NULL);
    642   if (!Rewriter::Rewrite(info)) return false;
    643   if (!Scope::Analyze(info)) return false;
    644   DCHECK(info->scope() != NULL);
    645 
    646   if (!FullCodeGenerator::MakeCode(info)) {
    647     Isolate* isolate = info->isolate();
    648     if (!isolate->has_pending_exception()) isolate->StackOverflow();
    649     return false;
    650   }
    651   return true;
    652 }
    653 
    654 
    655 MUST_USE_RESULT static MaybeHandle<Code> GetUnoptimizedCodeCommon(
    656     CompilationInfo* info) {
    657   VMState<COMPILER> state(info->isolate());
    658   PostponeInterruptsScope postpone(info->isolate());
    659 
    660   // Parse and update CompilationInfo with the results.
    661   if (!Parser::Parse(info)) return MaybeHandle<Code>();
    662   Handle<SharedFunctionInfo> shared = info->shared_info();
    663   FunctionLiteral* lit = info->function();
    664   shared->set_strict_mode(lit->strict_mode());
    665   SetExpectedNofPropertiesFromEstimate(shared, lit->expected_property_count());
    666   shared->set_bailout_reason(lit->dont_optimize_reason());
    667   shared->set_ast_node_count(lit->ast_node_count());
    668 
    669   // Compile unoptimized code.
    670   if (!CompileUnoptimizedCode(info)) return MaybeHandle<Code>();
    671 
    672   CHECK_EQ(Code::FUNCTION, info->code()->kind());
    673   RecordFunctionCompilation(Logger::LAZY_COMPILE_TAG, info, shared);
    674 
    675   // Update the shared function info with the scope info. Allocating the
    676   // ScopeInfo object may cause a GC.
    677   Handle<ScopeInfo> scope_info = ScopeInfo::Create(info->scope(), info->zone());
    678   shared->set_scope_info(*scope_info);
    679 
    680   // Update the code and feedback vector for the shared function info.
    681   shared->ReplaceCode(*info->code());
    682   if (shared->optimization_disabled()) info->code()->set_optimizable(false);
    683   shared->set_feedback_vector(*info->feedback_vector());
    684 
    685   return info->code();
    686 }
    687 
    688 
    689 MUST_USE_RESULT static MaybeHandle<Code> GetCodeFromOptimizedCodeMap(
    690     Handle<JSFunction> function, BailoutId osr_ast_id) {
    691   if (FLAG_cache_optimized_code) {
    692     Handle<SharedFunctionInfo> shared(function->shared());
    693     // Bound functions are not cached.
    694     if (shared->bound()) return MaybeHandle<Code>();
    695     DisallowHeapAllocation no_gc;
    696     int index = shared->SearchOptimizedCodeMap(
    697         function->context()->native_context(), osr_ast_id);
    698     if (index > 0) {
    699       if (FLAG_trace_opt) {
    700         PrintF("[found optimized code for ");
    701         function->ShortPrint();
    702         if (!osr_ast_id.IsNone()) {
    703           PrintF(" at OSR AST id %d", osr_ast_id.ToInt());
    704         }
    705         PrintF("]\n");
    706       }
    707       FixedArray* literals = shared->GetLiteralsFromOptimizedCodeMap(index);
    708       if (literals != NULL) function->set_literals(literals);
    709       return Handle<Code>(shared->GetCodeFromOptimizedCodeMap(index));
    710     }
    711   }
    712   return MaybeHandle<Code>();
    713 }
    714 
    715 
    716 static void InsertCodeIntoOptimizedCodeMap(CompilationInfo* info) {
    717   Handle<Code> code = info->code();
    718   if (code->kind() != Code::OPTIMIZED_FUNCTION) return;  // Nothing to do.
    719 
    720   // Context specialization folds-in the context, so no sharing can occur.
    721   if (code->is_turbofanned() && info->is_context_specializing()) return;
    722 
    723   // Cache optimized code.
    724   if (FLAG_cache_optimized_code) {
    725     Handle<JSFunction> function = info->closure();
    726     Handle<SharedFunctionInfo> shared(function->shared());
    727     // Do not cache bound functions.
    728     if (shared->bound()) return;
    729     Handle<FixedArray> literals(function->literals());
    730     Handle<Context> native_context(function->context()->native_context());
    731     SharedFunctionInfo::AddToOptimizedCodeMap(shared, native_context, code,
    732                                               literals, info->osr_ast_id());
    733   }
    734 }
    735 
    736 
    737 static bool CompileOptimizedPrologue(CompilationInfo* info) {
    738   if (!Parser::Parse(info)) return false;
    739   if (!Rewriter::Rewrite(info)) return false;
    740   if (!Scope::Analyze(info)) return false;
    741   DCHECK(info->scope() != NULL);
    742   return true;
    743 }
    744 
    745 
    746 static bool GetOptimizedCodeNow(CompilationInfo* info) {
    747   if (!CompileOptimizedPrologue(info)) return false;
    748 
    749   TimerEventScope<TimerEventRecompileSynchronous> timer(info->isolate());
    750 
    751   OptimizedCompileJob job(info);
    752   if (job.CreateGraph() != OptimizedCompileJob::SUCCEEDED ||
    753       job.OptimizeGraph() != OptimizedCompileJob::SUCCEEDED ||
    754       job.GenerateCode() != OptimizedCompileJob::SUCCEEDED) {
    755     if (FLAG_trace_opt) {
    756       PrintF("[aborted optimizing ");
    757       info->closure()->ShortPrint();
    758       PrintF(" because: %s]\n", GetBailoutReason(info->bailout_reason()));
    759     }
    760     return false;
    761   }
    762 
    763   // Success!
    764   DCHECK(!info->isolate()->has_pending_exception());
    765   InsertCodeIntoOptimizedCodeMap(info);
    766   RecordFunctionCompilation(Logger::LAZY_COMPILE_TAG, info,
    767                             info->shared_info());
    768   if (FLAG_trace_opt) {
    769     PrintF("[completed optimizing ");
    770     info->closure()->ShortPrint();
    771     PrintF("]\n");
    772   }
    773   return true;
    774 }
    775 
    776 
    777 static bool GetOptimizedCodeLater(CompilationInfo* info) {
    778   Isolate* isolate = info->isolate();
    779   if (!isolate->optimizing_compiler_thread()->IsQueueAvailable()) {
    780     if (FLAG_trace_concurrent_recompilation) {
    781       PrintF("  ** Compilation queue full, will retry optimizing ");
    782       info->closure()->ShortPrint();
    783       PrintF(" later.\n");
    784     }
    785     return false;
    786   }
    787 
    788   CompilationHandleScope handle_scope(info);
    789   if (!CompileOptimizedPrologue(info)) return false;
    790   info->SaveHandles();  // Copy handles to the compilation handle scope.
    791 
    792   TimerEventScope<TimerEventRecompileSynchronous> timer(info->isolate());
    793 
    794   OptimizedCompileJob* job = new (info->zone()) OptimizedCompileJob(info);
    795   OptimizedCompileJob::Status status = job->CreateGraph();
    796   if (status != OptimizedCompileJob::SUCCEEDED) return false;
    797   isolate->optimizing_compiler_thread()->QueueForOptimization(job);
    798 
    799   if (FLAG_trace_concurrent_recompilation) {
    800     PrintF("  ** Queued ");
    801     info->closure()->ShortPrint();
    802     if (info->is_osr()) {
    803       PrintF(" for concurrent OSR at %d.\n", info->osr_ast_id().ToInt());
    804     } else {
    805       PrintF(" for concurrent optimization.\n");
    806     }
    807   }
    808   return true;
    809 }
    810 
    811 
    812 MaybeHandle<Code> Compiler::GetUnoptimizedCode(Handle<JSFunction> function) {
    813   DCHECK(!function->GetIsolate()->has_pending_exception());
    814   DCHECK(!function->is_compiled());
    815   if (function->shared()->is_compiled()) {
    816     return Handle<Code>(function->shared()->code());
    817   }
    818 
    819   CompilationInfoWithZone info(function);
    820   Handle<Code> result;
    821   ASSIGN_RETURN_ON_EXCEPTION(info.isolate(), result,
    822                              GetUnoptimizedCodeCommon(&info),
    823                              Code);
    824   return result;
    825 }
    826 
    827 
    828 MaybeHandle<Code> Compiler::GetLazyCode(Handle<JSFunction> function) {
    829   DCHECK(!function->GetIsolate()->has_pending_exception());
    830   DCHECK(!function->is_compiled());
    831 
    832   if (FLAG_turbo_asm && function->shared()->asm_function()) {
    833     CompilationInfoWithZone info(function);
    834 
    835     VMState<COMPILER> state(info.isolate());
    836     PostponeInterruptsScope postpone(info.isolate());
    837 
    838     info.SetOptimizing(BailoutId::None(),
    839                        Handle<Code>(function->shared()->code()));
    840 
    841     info.MarkAsContextSpecializing();
    842     info.MarkAsTypingEnabled();
    843     info.MarkAsInliningDisabled();
    844 
    845     if (GetOptimizedCodeNow(&info)) return info.code();
    846   }
    847 
    848   if (function->shared()->is_compiled()) {
    849     return Handle<Code>(function->shared()->code());
    850   }
    851 
    852   CompilationInfoWithZone info(function);
    853   Handle<Code> result;
    854   ASSIGN_RETURN_ON_EXCEPTION(info.isolate(), result,
    855                              GetUnoptimizedCodeCommon(&info), Code);
    856 
    857   if (FLAG_always_opt &&
    858       info.isolate()->use_crankshaft() &&
    859       !info.shared_info()->optimization_disabled() &&
    860       !info.isolate()->DebuggerHasBreakPoints()) {
    861     Handle<Code> opt_code;
    862     if (Compiler::GetOptimizedCode(
    863             function, result,
    864             Compiler::NOT_CONCURRENT).ToHandle(&opt_code)) {
    865       result = opt_code;
    866     }
    867   }
    868 
    869   return result;
    870 }
    871 
    872 
    873 MaybeHandle<Code> Compiler::GetUnoptimizedCode(
    874     Handle<SharedFunctionInfo> shared) {
    875   DCHECK(!shared->GetIsolate()->has_pending_exception());
    876   DCHECK(!shared->is_compiled());
    877 
    878   CompilationInfoWithZone info(shared);
    879   return GetUnoptimizedCodeCommon(&info);
    880 }
    881 
    882 
    883 bool Compiler::EnsureCompiled(Handle<JSFunction> function,
    884                               ClearExceptionFlag flag) {
    885   if (function->is_compiled()) return true;
    886   MaybeHandle<Code> maybe_code = Compiler::GetLazyCode(function);
    887   Handle<Code> code;
    888   if (!maybe_code.ToHandle(&code)) {
    889     if (flag == CLEAR_EXCEPTION) {
    890       function->GetIsolate()->clear_pending_exception();
    891     }
    892     return false;
    893   }
    894   function->ReplaceCode(*code);
    895   DCHECK(function->is_compiled());
    896   return true;
    897 }
    898 
    899 
    900 // TODO(turbofan): In the future, unoptimized code with deopt support could
    901 // be generated lazily once deopt is triggered.
    902 bool Compiler::EnsureDeoptimizationSupport(CompilationInfo* info) {
    903   if (!info->shared_info()->has_deoptimization_support()) {
    904     CompilationInfoWithZone unoptimized(info->shared_info());
    905     // Note that we use the same AST that we will use for generating the
    906     // optimized code.
    907     unoptimized.SetFunction(info->function());
    908     unoptimized.PrepareForCompilation(info->scope());
    909     unoptimized.SetContext(info->context());
    910     unoptimized.EnableDeoptimizationSupport();
    911     if (!FullCodeGenerator::MakeCode(&unoptimized)) return false;
    912 
    913     Handle<SharedFunctionInfo> shared = info->shared_info();
    914     shared->EnableDeoptimizationSupport(*unoptimized.code());
    915     shared->set_feedback_vector(*unoptimized.feedback_vector());
    916 
    917     // The scope info might not have been set if a lazily compiled
    918     // function is inlined before being called for the first time.
    919     if (shared->scope_info() == ScopeInfo::Empty(info->isolate())) {
    920       Handle<ScopeInfo> target_scope_info =
    921           ScopeInfo::Create(info->scope(), info->zone());
    922       shared->set_scope_info(*target_scope_info);
    923     }
    924 
    925     // The existing unoptimized code was replaced with the new one.
    926     RecordFunctionCompilation(Logger::LAZY_COMPILE_TAG, &unoptimized, shared);
    927   }
    928   return true;
    929 }
    930 
    931 
    932 // Compile full code for debugging. This code will have debug break slots
    933 // and deoptimization information. Deoptimization information is required
    934 // in case that an optimized version of this function is still activated on
    935 // the stack. It will also make sure that the full code is compiled with
    936 // the same flags as the previous version, that is flags which can change
    937 // the code generated. The current method of mapping from already compiled
    938 // full code without debug break slots to full code with debug break slots
    939 // depends on the generated code is otherwise exactly the same.
    940 // If compilation fails, just keep the existing code.
    941 MaybeHandle<Code> Compiler::GetDebugCode(Handle<JSFunction> function) {
    942   CompilationInfoWithZone info(function);
    943   Isolate* isolate = info.isolate();
    944   VMState<COMPILER> state(isolate);
    945 
    946   info.MarkAsDebug();
    947 
    948   DCHECK(!isolate->has_pending_exception());
    949   Handle<Code> old_code(function->shared()->code());
    950   DCHECK(old_code->kind() == Code::FUNCTION);
    951   DCHECK(!old_code->has_debug_break_slots());
    952 
    953   info.MarkCompilingForDebugging();
    954   if (old_code->is_compiled_optimizable()) {
    955     info.EnableDeoptimizationSupport();
    956   } else {
    957     info.MarkNonOptimizable();
    958   }
    959   MaybeHandle<Code> maybe_new_code = GetUnoptimizedCodeCommon(&info);
    960   Handle<Code> new_code;
    961   if (!maybe_new_code.ToHandle(&new_code)) {
    962     isolate->clear_pending_exception();
    963   } else {
    964     DCHECK_EQ(old_code->is_compiled_optimizable(),
    965               new_code->is_compiled_optimizable());
    966   }
    967   return maybe_new_code;
    968 }
    969 
    970 
    971 void Compiler::CompileForLiveEdit(Handle<Script> script) {
    972   // TODO(635): support extensions.
    973   CompilationInfoWithZone info(script);
    974   PostponeInterruptsScope postpone(info.isolate());
    975   VMState<COMPILER> state(info.isolate());
    976 
    977   info.MarkAsGlobal();
    978   if (!Parser::Parse(&info)) return;
    979 
    980   LiveEditFunctionTracker tracker(info.isolate(), info.function());
    981   if (!CompileUnoptimizedCode(&info)) return;
    982   if (!info.shared_info().is_null()) {
    983     Handle<ScopeInfo> scope_info = ScopeInfo::Create(info.scope(),
    984                                                      info.zone());
    985     info.shared_info()->set_scope_info(*scope_info);
    986   }
    987   tracker.RecordRootFunctionInfo(info.code());
    988 }
    989 
    990 
    991 static Handle<SharedFunctionInfo> CompileToplevel(CompilationInfo* info) {
    992   Isolate* isolate = info->isolate();
    993   PostponeInterruptsScope postpone(isolate);
    994   DCHECK(!isolate->native_context().is_null());
    995   Handle<Script> script = info->script();
    996 
    997   // TODO(svenpanne) Obscure place for this, perhaps move to OnBeforeCompile?
    998   FixedArray* array = isolate->native_context()->embedder_data();
    999   script->set_context_data(array->get(0));
   1000 
   1001   isolate->debug()->OnBeforeCompile(script);
   1002 
   1003   DCHECK(info->is_eval() || info->is_global());
   1004 
   1005   Handle<SharedFunctionInfo> result;
   1006 
   1007   { VMState<COMPILER> state(info->isolate());
   1008     if (info->function() == NULL) {
   1009       // Parse the script if needed (if it's already parsed, function() is
   1010       // non-NULL).
   1011       bool parse_allow_lazy =
   1012           (info->compile_options() == ScriptCompiler::kConsumeParserCache ||
   1013            String::cast(script->source())->length() >
   1014                FLAG_min_preparse_length) &&
   1015           !Compiler::DebuggerWantsEagerCompilation(info);
   1016 
   1017       if (!parse_allow_lazy &&
   1018           (info->compile_options() == ScriptCompiler::kProduceParserCache ||
   1019            info->compile_options() == ScriptCompiler::kConsumeParserCache)) {
   1020         // We are going to parse eagerly, but we either 1) have cached data
   1021         // produced by lazy parsing or 2) are asked to generate cached data.
   1022         // Eager parsing cannot benefit from cached data, and producing cached
   1023         // data while parsing eagerly is not implemented.
   1024         info->SetCachedData(NULL, ScriptCompiler::kNoCompileOptions);
   1025       }
   1026       if (!Parser::Parse(info, parse_allow_lazy)) {
   1027         return Handle<SharedFunctionInfo>::null();
   1028       }
   1029     }
   1030 
   1031     FunctionLiteral* lit = info->function();
   1032     LiveEditFunctionTracker live_edit_tracker(isolate, lit);
   1033 
   1034     // Measure how long it takes to do the compilation; only take the
   1035     // rest of the function into account to avoid overlap with the
   1036     // parsing statistics.
   1037     HistogramTimer* rate = info->is_eval()
   1038           ? info->isolate()->counters()->compile_eval()
   1039           : info->isolate()->counters()->compile();
   1040     HistogramTimerScope timer(rate);
   1041 
   1042     // Compile the code.
   1043     if (!CompileUnoptimizedCode(info)) {
   1044       return Handle<SharedFunctionInfo>::null();
   1045     }
   1046 
   1047     // Allocate function.
   1048     DCHECK(!info->code().is_null());
   1049     result = isolate->factory()->NewSharedFunctionInfo(
   1050         lit->name(), lit->materialized_literal_count(), lit->kind(),
   1051         info->code(), ScopeInfo::Create(info->scope(), info->zone()),
   1052         info->feedback_vector());
   1053 
   1054     DCHECK_EQ(RelocInfo::kNoPosition, lit->function_token_position());
   1055     SetFunctionInfo(result, lit, true, script);
   1056 
   1057     Handle<String> script_name = script->name()->IsString()
   1058         ? Handle<String>(String::cast(script->name()))
   1059         : isolate->factory()->empty_string();
   1060     Logger::LogEventsAndTags log_tag = info->is_eval()
   1061         ? Logger::EVAL_TAG
   1062         : Logger::ToNativeByScript(Logger::SCRIPT_TAG, *script);
   1063 
   1064     PROFILE(isolate, CodeCreateEvent(
   1065                 log_tag, *info->code(), *result, info, *script_name));
   1066     GDBJIT(AddCode(script_name, script, info->code(), info));
   1067 
   1068     // Hint to the runtime system used when allocating space for initial
   1069     // property space by setting the expected number of properties for
   1070     // the instances of the function.
   1071     SetExpectedNofPropertiesFromEstimate(result,
   1072                                          lit->expected_property_count());
   1073 
   1074     if (!script.is_null())
   1075       script->set_compilation_state(Script::COMPILATION_STATE_COMPILED);
   1076 
   1077     live_edit_tracker.RecordFunctionInfo(result, lit, info->zone());
   1078   }
   1079 
   1080   isolate->debug()->OnAfterCompile(script);
   1081 
   1082   return result;
   1083 }
   1084 
   1085 
   1086 MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
   1087     Handle<String> source, Handle<SharedFunctionInfo> outer_info,
   1088     Handle<Context> context, StrictMode strict_mode,
   1089     ParseRestriction restriction, int scope_position) {
   1090   Isolate* isolate = source->GetIsolate();
   1091   int source_length = source->length();
   1092   isolate->counters()->total_eval_size()->Increment(source_length);
   1093   isolate->counters()->total_compile_size()->Increment(source_length);
   1094 
   1095   CompilationCache* compilation_cache = isolate->compilation_cache();
   1096   MaybeHandle<SharedFunctionInfo> maybe_shared_info =
   1097       compilation_cache->LookupEval(source, outer_info, context, strict_mode,
   1098                                     scope_position);
   1099   Handle<SharedFunctionInfo> shared_info;
   1100 
   1101   if (!maybe_shared_info.ToHandle(&shared_info)) {
   1102     Handle<Script> script = isolate->factory()->NewScript(source);
   1103     CompilationInfoWithZone info(script);
   1104     info.MarkAsEval();
   1105     if (context->IsNativeContext()) info.MarkAsGlobal();
   1106     info.SetStrictMode(strict_mode);
   1107     info.SetParseRestriction(restriction);
   1108     info.SetContext(context);
   1109 
   1110     Debug::RecordEvalCaller(script);
   1111 
   1112     shared_info = CompileToplevel(&info);
   1113 
   1114     if (shared_info.is_null()) {
   1115       return MaybeHandle<JSFunction>();
   1116     } else {
   1117       // Explicitly disable optimization for eval code. We're not yet prepared
   1118       // to handle eval-code in the optimizing compiler.
   1119       shared_info->DisableOptimization(kEval);
   1120 
   1121       // If caller is strict mode, the result must be in strict mode as well.
   1122       DCHECK(strict_mode == SLOPPY || shared_info->strict_mode() == STRICT);
   1123       if (!shared_info->dont_cache()) {
   1124         compilation_cache->PutEval(source, outer_info, context, shared_info,
   1125                                    scope_position);
   1126       }
   1127     }
   1128   } else if (shared_info->ic_age() != isolate->heap()->global_ic_age()) {
   1129     shared_info->ResetForNewContext(isolate->heap()->global_ic_age());
   1130   }
   1131 
   1132   return isolate->factory()->NewFunctionFromSharedFunctionInfo(
   1133       shared_info, context, NOT_TENURED);
   1134 }
   1135 
   1136 
   1137 Handle<SharedFunctionInfo> Compiler::CompileScript(
   1138     Handle<String> source, Handle<Object> script_name, int line_offset,
   1139     int column_offset, bool is_shared_cross_origin, Handle<Context> context,
   1140     v8::Extension* extension, ScriptData** cached_data,
   1141     ScriptCompiler::CompileOptions compile_options, NativesFlag natives) {
   1142   if (compile_options == ScriptCompiler::kNoCompileOptions) {
   1143     cached_data = NULL;
   1144   } else if (compile_options == ScriptCompiler::kProduceParserCache ||
   1145              compile_options == ScriptCompiler::kProduceCodeCache) {
   1146     DCHECK(cached_data && !*cached_data);
   1147     DCHECK(extension == NULL);
   1148   } else {
   1149     DCHECK(compile_options == ScriptCompiler::kConsumeParserCache ||
   1150            compile_options == ScriptCompiler::kConsumeCodeCache);
   1151     DCHECK(cached_data && *cached_data);
   1152     DCHECK(extension == NULL);
   1153   }
   1154   Isolate* isolate = source->GetIsolate();
   1155   int source_length = source->length();
   1156   isolate->counters()->total_load_size()->Increment(source_length);
   1157   isolate->counters()->total_compile_size()->Increment(source_length);
   1158 
   1159   CompilationCache* compilation_cache = isolate->compilation_cache();
   1160 
   1161   // Do a lookup in the compilation cache but not for extensions.
   1162   MaybeHandle<SharedFunctionInfo> maybe_result;
   1163   Handle<SharedFunctionInfo> result;
   1164   if (extension == NULL) {
   1165     if (FLAG_serialize_toplevel &&
   1166         compile_options == ScriptCompiler::kConsumeCodeCache &&
   1167         !isolate->debug()->is_loaded()) {
   1168       HistogramTimerScope timer(isolate->counters()->compile_deserialize());
   1169       return CodeSerializer::Deserialize(isolate, *cached_data, source);
   1170     } else {
   1171       maybe_result = compilation_cache->LookupScript(
   1172           source, script_name, line_offset, column_offset,
   1173           is_shared_cross_origin, context);
   1174     }
   1175   }
   1176 
   1177   base::ElapsedTimer timer;
   1178   if (FLAG_profile_deserialization && FLAG_serialize_toplevel &&
   1179       compile_options == ScriptCompiler::kProduceCodeCache) {
   1180     timer.Start();
   1181   }
   1182 
   1183   if (!maybe_result.ToHandle(&result)) {
   1184     // No cache entry found. Compile the script.
   1185 
   1186     // Create a script object describing the script to be compiled.
   1187     Handle<Script> script = isolate->factory()->NewScript(source);
   1188     if (natives == NATIVES_CODE) {
   1189       script->set_type(Smi::FromInt(Script::TYPE_NATIVE));
   1190     }
   1191     if (!script_name.is_null()) {
   1192       script->set_name(*script_name);
   1193       script->set_line_offset(Smi::FromInt(line_offset));
   1194       script->set_column_offset(Smi::FromInt(column_offset));
   1195     }
   1196     script->set_is_shared_cross_origin(is_shared_cross_origin);
   1197 
   1198     // Compile the function and add it to the cache.
   1199     CompilationInfoWithZone info(script);
   1200     info.MarkAsGlobal();
   1201     info.SetCachedData(cached_data, compile_options);
   1202     info.SetExtension(extension);
   1203     info.SetContext(context);
   1204     if (FLAG_serialize_toplevel &&
   1205         compile_options == ScriptCompiler::kProduceCodeCache) {
   1206       info.PrepareForSerializing();
   1207     }
   1208     if (FLAG_use_strict) info.SetStrictMode(STRICT);
   1209 
   1210     result = CompileToplevel(&info);
   1211     if (extension == NULL && !result.is_null() && !result->dont_cache()) {
   1212       compilation_cache->PutScript(source, context, result);
   1213       if (FLAG_serialize_toplevel &&
   1214           compile_options == ScriptCompiler::kProduceCodeCache) {
   1215         HistogramTimerScope histogram_timer(
   1216             isolate->counters()->compile_serialize());
   1217         *cached_data = CodeSerializer::Serialize(isolate, result, source);
   1218         if (FLAG_profile_deserialization) {
   1219           PrintF("[Compiling and serializing %d bytes took %0.3f ms]\n",
   1220                  (*cached_data)->length(), timer.Elapsed().InMillisecondsF());
   1221         }
   1222       }
   1223     }
   1224 
   1225     if (result.is_null()) isolate->ReportPendingMessages();
   1226   } else if (result->ic_age() != isolate->heap()->global_ic_age()) {
   1227     result->ResetForNewContext(isolate->heap()->global_ic_age());
   1228   }
   1229   return result;
   1230 }
   1231 
   1232 
   1233 Handle<SharedFunctionInfo> Compiler::CompileStreamedScript(
   1234     CompilationInfo* info, int source_length) {
   1235   Isolate* isolate = info->isolate();
   1236   isolate->counters()->total_load_size()->Increment(source_length);
   1237   isolate->counters()->total_compile_size()->Increment(source_length);
   1238 
   1239   if (FLAG_use_strict) info->SetStrictMode(STRICT);
   1240   // TODO(marja): FLAG_serialize_toplevel is not honoured and won't be; when the
   1241   // real code caching lands, streaming needs to be adapted to use it.
   1242   return CompileToplevel(info);
   1243 }
   1244 
   1245 
   1246 Handle<SharedFunctionInfo> Compiler::BuildFunctionInfo(
   1247     FunctionLiteral* literal, Handle<Script> script,
   1248     CompilationInfo* outer_info) {
   1249   // Precondition: code has been parsed and scopes have been analyzed.
   1250   CompilationInfoWithZone info(script);
   1251   info.SetFunction(literal);
   1252   info.PrepareForCompilation(literal->scope());
   1253   info.SetStrictMode(literal->scope()->strict_mode());
   1254   if (outer_info->will_serialize()) info.PrepareForSerializing();
   1255 
   1256   Isolate* isolate = info.isolate();
   1257   Factory* factory = isolate->factory();
   1258   LiveEditFunctionTracker live_edit_tracker(isolate, literal);
   1259   // Determine if the function can be lazily compiled. This is necessary to
   1260   // allow some of our builtin JS files to be lazily compiled. These
   1261   // builtins cannot be handled lazily by the parser, since we have to know
   1262   // if a function uses the special natives syntax, which is something the
   1263   // parser records.
   1264   // If the debugger requests compilation for break points, we cannot be
   1265   // aggressive about lazy compilation, because it might trigger compilation
   1266   // of functions without an outer context when setting a breakpoint through
   1267   // Debug::FindSharedFunctionInfoInScript.
   1268   bool allow_lazy_without_ctx = literal->AllowsLazyCompilationWithoutContext();
   1269   bool allow_lazy = literal->AllowsLazyCompilation() &&
   1270       !DebuggerWantsEagerCompilation(&info, allow_lazy_without_ctx);
   1271 
   1272   // Generate code
   1273   Handle<ScopeInfo> scope_info;
   1274   if (FLAG_lazy && allow_lazy && !literal->is_parenthesized()) {
   1275     Handle<Code> code = isolate->builtins()->CompileLazy();
   1276     info.SetCode(code);
   1277     scope_info = Handle<ScopeInfo>(ScopeInfo::Empty(isolate));
   1278   } else if (FullCodeGenerator::MakeCode(&info)) {
   1279     DCHECK(!info.code().is_null());
   1280     scope_info = ScopeInfo::Create(info.scope(), info.zone());
   1281   } else {
   1282     return Handle<SharedFunctionInfo>::null();
   1283   }
   1284 
   1285   // Create a shared function info object.
   1286   Handle<SharedFunctionInfo> result = factory->NewSharedFunctionInfo(
   1287       literal->name(), literal->materialized_literal_count(), literal->kind(),
   1288       info.code(), scope_info, info.feedback_vector());
   1289   SetFunctionInfo(result, literal, false, script);
   1290   RecordFunctionCompilation(Logger::FUNCTION_TAG, &info, result);
   1291   result->set_allows_lazy_compilation(allow_lazy);
   1292   result->set_allows_lazy_compilation_without_context(allow_lazy_without_ctx);
   1293 
   1294   // Set the expected number of properties for instances and return
   1295   // the resulting function.
   1296   SetExpectedNofPropertiesFromEstimate(result,
   1297                                        literal->expected_property_count());
   1298   live_edit_tracker.RecordFunctionInfo(result, literal, info.zone());
   1299   return result;
   1300 }
   1301 
   1302 
   1303 MaybeHandle<Code> Compiler::GetOptimizedCode(Handle<JSFunction> function,
   1304                                              Handle<Code> current_code,
   1305                                              ConcurrencyMode mode,
   1306                                              BailoutId osr_ast_id) {
   1307   Handle<Code> cached_code;
   1308   if (GetCodeFromOptimizedCodeMap(
   1309           function, osr_ast_id).ToHandle(&cached_code)) {
   1310     return cached_code;
   1311   }
   1312 
   1313   SmartPointer<CompilationInfo> info(new CompilationInfoWithZone(function));
   1314   Isolate* isolate = info->isolate();
   1315   DCHECK(AllowCompilation::IsAllowed(isolate));
   1316   VMState<COMPILER> state(isolate);
   1317   DCHECK(!isolate->has_pending_exception());
   1318   PostponeInterruptsScope postpone(isolate);
   1319 
   1320   Handle<SharedFunctionInfo> shared = info->shared_info();
   1321   if (shared->code()->kind() != Code::FUNCTION ||
   1322       ScopeInfo::Empty(isolate) == shared->scope_info()) {
   1323     // The function was never compiled. Compile it unoptimized first.
   1324     // TODO(titzer): reuse the AST and scope info from this compile.
   1325     CompilationInfoWithZone nested(function);
   1326     nested.EnableDeoptimizationSupport();
   1327     if (!GetUnoptimizedCodeCommon(&nested).ToHandle(&current_code)) {
   1328       return MaybeHandle<Code>();
   1329     }
   1330     shared->ReplaceCode(*current_code);
   1331   }
   1332   current_code->set_profiler_ticks(0);
   1333 
   1334   info->SetOptimizing(osr_ast_id, current_code);
   1335 
   1336   if (mode == CONCURRENT) {
   1337     if (GetOptimizedCodeLater(info.get())) {
   1338       info.Detach();  // The background recompile job owns this now.
   1339       return isolate->builtins()->InOptimizationQueue();
   1340     }
   1341   } else {
   1342     if (GetOptimizedCodeNow(info.get())) return info->code();
   1343   }
   1344 
   1345   if (isolate->has_pending_exception()) isolate->clear_pending_exception();
   1346   return MaybeHandle<Code>();
   1347 }
   1348 
   1349 
   1350 Handle<Code> Compiler::GetConcurrentlyOptimizedCode(OptimizedCompileJob* job) {
   1351   // Take ownership of compilation info.  Deleting compilation info
   1352   // also tears down the zone and the recompile job.
   1353   SmartPointer<CompilationInfo> info(job->info());
   1354   Isolate* isolate = info->isolate();
   1355 
   1356   VMState<COMPILER> state(isolate);
   1357   TimerEventScope<TimerEventRecompileSynchronous> timer(info->isolate());
   1358 
   1359   Handle<SharedFunctionInfo> shared = info->shared_info();
   1360   shared->code()->set_profiler_ticks(0);
   1361 
   1362   // 1) Optimization on the concurrent thread may have failed.
   1363   // 2) The function may have already been optimized by OSR.  Simply continue.
   1364   //    Except when OSR already disabled optimization for some reason.
   1365   // 3) The code may have already been invalidated due to dependency change.
   1366   // 4) Debugger may have been activated.
   1367   // 5) Code generation may have failed.
   1368   if (job->last_status() == OptimizedCompileJob::SUCCEEDED) {
   1369     if (shared->optimization_disabled()) {
   1370       job->RetryOptimization(kOptimizationDisabled);
   1371     } else if (info->HasAbortedDueToDependencyChange()) {
   1372       job->RetryOptimization(kBailedOutDueToDependencyChange);
   1373     } else if (isolate->DebuggerHasBreakPoints()) {
   1374       job->RetryOptimization(kDebuggerHasBreakPoints);
   1375     } else if (job->GenerateCode() == OptimizedCompileJob::SUCCEEDED) {
   1376       RecordFunctionCompilation(Logger::LAZY_COMPILE_TAG, info.get(), shared);
   1377       if (info->shared_info()->SearchOptimizedCodeMap(
   1378               info->context()->native_context(), info->osr_ast_id()) == -1) {
   1379         InsertCodeIntoOptimizedCodeMap(info.get());
   1380       }
   1381       if (FLAG_trace_opt) {
   1382         PrintF("[completed optimizing ");
   1383         info->closure()->ShortPrint();
   1384         PrintF("]\n");
   1385       }
   1386       return Handle<Code>(*info->code());
   1387     }
   1388   }
   1389 
   1390   DCHECK(job->last_status() != OptimizedCompileJob::SUCCEEDED);
   1391   if (FLAG_trace_opt) {
   1392     PrintF("[aborted optimizing ");
   1393     info->closure()->ShortPrint();
   1394     PrintF(" because: %s]\n", GetBailoutReason(info->bailout_reason()));
   1395   }
   1396   return Handle<Code>::null();
   1397 }
   1398 
   1399 
   1400 bool Compiler::DebuggerWantsEagerCompilation(CompilationInfo* info,
   1401                                              bool allow_lazy_without_ctx) {
   1402   return LiveEditFunctionTracker::IsActive(info->isolate()) ||
   1403          (info->isolate()->DebuggerHasBreakPoints() && !allow_lazy_without_ctx);
   1404 }
   1405 
   1406 
   1407 CompilationPhase::CompilationPhase(const char* name, CompilationInfo* info)
   1408     : name_(name), info_(info), zone_(info->isolate()) {
   1409   if (FLAG_hydrogen_stats) {
   1410     info_zone_start_allocation_size_ = info->zone()->allocation_size();
   1411     timer_.Start();
   1412   }
   1413 }
   1414 
   1415 
   1416 CompilationPhase::~CompilationPhase() {
   1417   if (FLAG_hydrogen_stats) {
   1418     unsigned size = zone()->allocation_size();
   1419     size += info_->zone()->allocation_size() - info_zone_start_allocation_size_;
   1420     isolate()->GetHStatistics()->SaveTiming(name_, timer_.Elapsed(), size);
   1421   }
   1422 }
   1423 
   1424 
   1425 bool CompilationPhase::ShouldProduceTraceOutput() const {
   1426   // Trace if the appropriate trace flag is set and the phase name's first
   1427   // character is in the FLAG_trace_phase command line parameter.
   1428   AllowHandleDereference allow_deref;
   1429   bool tracing_on = info()->IsStub()
   1430       ? FLAG_trace_hydrogen_stubs
   1431       : (FLAG_trace_hydrogen &&
   1432          info()->closure()->PassesFilter(FLAG_trace_hydrogen_filter));
   1433   return (tracing_on &&
   1434       base::OS::StrChr(const_cast<char*>(FLAG_trace_phase), name_[0]) != NULL);
   1435 }
   1436 
   1437 } }  // namespace v8::internal
   1438