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/compiler.h"
6
7#include <algorithm>
8#include <memory>
9
10#include "src/asmjs/asm-js.h"
11#include "src/asmjs/asm-typer.h"
12#include "src/ast/ast-numbering.h"
13#include "src/ast/prettyprinter.h"
14#include "src/ast/scopes.h"
15#include "src/bootstrapper.h"
16#include "src/codegen.h"
17#include "src/compilation-cache.h"
18#include "src/compiler-dispatcher/optimizing-compile-dispatcher.h"
19#include "src/compiler/pipeline.h"
20#include "src/crankshaft/hydrogen.h"
21#include "src/debug/debug.h"
22#include "src/debug/liveedit.h"
23#include "src/frames-inl.h"
24#include "src/full-codegen/full-codegen.h"
25#include "src/globals.h"
26#include "src/heap/heap.h"
27#include "src/interpreter/interpreter.h"
28#include "src/isolate-inl.h"
29#include "src/log-inl.h"
30#include "src/messages.h"
31#include "src/parsing/parser.h"
32#include "src/parsing/rewriter.h"
33#include "src/parsing/scanner-character-streams.h"
34#include "src/runtime-profiler.h"
35#include "src/snapshot/code-serializer.h"
36#include "src/vm-state-inl.h"
37
38namespace v8 {
39namespace internal {
40
41
42
43// A wrapper around a CompilationInfo that detaches the Handles from
44// the underlying DeferredHandleScope and stores them in info_ on
45// destruction.
46class CompilationHandleScope final {
47 public:
48  explicit CompilationHandleScope(CompilationInfo* info)
49      : deferred_(info->isolate()), info_(info) {}
50  ~CompilationHandleScope() { info_->set_deferred_handles(deferred_.Detach()); }
51
52 private:
53  DeferredHandleScope deferred_;
54  CompilationInfo* info_;
55};
56
57// Helper that times a scoped region and records the elapsed time.
58struct ScopedTimer {
59  explicit ScopedTimer(base::TimeDelta* location) : location_(location) {
60    DCHECK(location_ != NULL);
61    timer_.Start();
62  }
63
64  ~ScopedTimer() { *location_ += timer_.Elapsed(); }
65
66  base::ElapsedTimer timer_;
67  base::TimeDelta* location_;
68};
69
70// ----------------------------------------------------------------------------
71// Implementation of CompilationJob
72
73CompilationJob::Status CompilationJob::PrepareJob() {
74  DCHECK(ThreadId::Current().Equals(info()->isolate()->thread_id()));
75  DisallowJavascriptExecution no_js(isolate());
76
77  if (FLAG_trace_opt && info()->IsOptimizing()) {
78    OFStream os(stdout);
79    os << "[compiling method " << Brief(*info()->closure()) << " using "
80       << compiler_name_;
81    if (info()->is_osr()) os << " OSR";
82    os << "]" << std::endl;
83  }
84
85  // Delegate to the underlying implementation.
86  DCHECK(state() == State::kReadyToPrepare);
87  ScopedTimer t(&time_taken_to_prepare_);
88  return UpdateState(PrepareJobImpl(), State::kReadyToExecute);
89}
90
91CompilationJob::Status CompilationJob::ExecuteJob() {
92  std::unique_ptr<DisallowHeapAllocation> no_allocation;
93  std::unique_ptr<DisallowHandleAllocation> no_handles;
94  std::unique_ptr<DisallowHandleDereference> no_deref;
95  std::unique_ptr<DisallowCodeDependencyChange> no_dependency_change;
96  if (can_execute_on_background_thread()) {
97    no_allocation.reset(new DisallowHeapAllocation());
98    no_handles.reset(new DisallowHandleAllocation());
99    no_deref.reset(new DisallowHandleDereference());
100    no_dependency_change.reset(new DisallowCodeDependencyChange());
101  } else {
102    DCHECK(ThreadId::Current().Equals(info()->isolate()->thread_id()));
103  }
104
105  // Delegate to the underlying implementation.
106  DCHECK(state() == State::kReadyToExecute);
107  ScopedTimer t(&time_taken_to_execute_);
108  return UpdateState(ExecuteJobImpl(), State::kReadyToFinalize);
109}
110
111CompilationJob::Status CompilationJob::FinalizeJob() {
112  DCHECK(ThreadId::Current().Equals(info()->isolate()->thread_id()));
113  DisallowCodeDependencyChange no_dependency_change;
114  DisallowJavascriptExecution no_js(isolate());
115  DCHECK(!info()->dependencies()->HasAborted());
116
117  // Delegate to the underlying implementation.
118  DCHECK(state() == State::kReadyToFinalize);
119  ScopedTimer t(&time_taken_to_finalize_);
120  return UpdateState(FinalizeJobImpl(), State::kSucceeded);
121}
122
123CompilationJob::Status CompilationJob::RetryOptimization(BailoutReason reason) {
124  DCHECK(info_->IsOptimizing());
125  info_->RetryOptimization(reason);
126  state_ = State::kFailed;
127  return FAILED;
128}
129
130CompilationJob::Status CompilationJob::AbortOptimization(BailoutReason reason) {
131  DCHECK(info_->IsOptimizing());
132  info_->AbortOptimization(reason);
133  state_ = State::kFailed;
134  return FAILED;
135}
136
137void CompilationJob::RecordUnoptimizedCompilationStats() const {
138  int code_size;
139  if (info()->has_bytecode_array()) {
140    code_size = info()->bytecode_array()->SizeIncludingMetadata();
141  } else {
142    code_size = info()->code()->SizeIncludingMetadata();
143  }
144
145  Counters* counters = isolate()->counters();
146  // TODO(4280): Rename counters from "baseline" to "unoptimized" eventually.
147  counters->total_baseline_code_size()->Increment(code_size);
148  counters->total_baseline_compile_count()->Increment(1);
149
150  // TODO(5203): Add timers for each phase of compilation.
151}
152
153void CompilationJob::RecordOptimizedCompilationStats() const {
154  DCHECK(info()->IsOptimizing());
155  Handle<JSFunction> function = info()->closure();
156  if (!function->IsOptimized()) {
157    // Concurrent recompilation and OSR may race.  Increment only once.
158    int opt_count = function->shared()->opt_count();
159    function->shared()->set_opt_count(opt_count + 1);
160  }
161  double ms_creategraph = time_taken_to_prepare_.InMillisecondsF();
162  double ms_optimize = time_taken_to_execute_.InMillisecondsF();
163  double ms_codegen = time_taken_to_finalize_.InMillisecondsF();
164  if (FLAG_trace_opt) {
165    PrintF("[optimizing ");
166    function->ShortPrint();
167    PrintF(" - took %0.3f, %0.3f, %0.3f ms]\n", ms_creategraph, ms_optimize,
168           ms_codegen);
169  }
170  if (FLAG_trace_opt_stats) {
171    static double compilation_time = 0.0;
172    static int compiled_functions = 0;
173    static int code_size = 0;
174
175    compilation_time += (ms_creategraph + ms_optimize + ms_codegen);
176    compiled_functions++;
177    code_size += function->shared()->SourceSize();
178    PrintF("Compiled: %d functions with %d byte source size in %fms.\n",
179           compiled_functions, code_size, compilation_time);
180  }
181  if (FLAG_hydrogen_stats) {
182    isolate()->GetHStatistics()->IncrementSubtotals(time_taken_to_prepare_,
183                                                    time_taken_to_execute_,
184                                                    time_taken_to_finalize_);
185  }
186}
187
188Isolate* CompilationJob::isolate() const { return info()->isolate(); }
189
190namespace {
191
192void AddWeakObjectToCodeDependency(Isolate* isolate, Handle<HeapObject> object,
193                                   Handle<Code> code) {
194  Handle<WeakCell> cell = Code::WeakCellFor(code);
195  Heap* heap = isolate->heap();
196  if (heap->InNewSpace(*object)) {
197    heap->AddWeakNewSpaceObjectToCodeDependency(object, cell);
198  } else {
199    Handle<DependentCode> dep(heap->LookupWeakObjectToCodeDependency(object));
200    dep =
201        DependentCode::InsertWeakCode(dep, DependentCode::kWeakCodeGroup, cell);
202    heap->AddWeakObjectToCodeDependency(object, dep);
203  }
204}
205
206}  // namespace
207
208void CompilationJob::RegisterWeakObjectsInOptimizedCode(Handle<Code> code) {
209  // TODO(turbofan): Move this to pipeline.cc once Crankshaft dies.
210  Isolate* const isolate = code->GetIsolate();
211  DCHECK(code->is_optimized_code());
212  std::vector<Handle<Map>> maps;
213  std::vector<Handle<HeapObject>> objects;
214  {
215    DisallowHeapAllocation no_gc;
216    int const mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
217                          RelocInfo::ModeMask(RelocInfo::CELL);
218    for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
219      RelocInfo::Mode mode = it.rinfo()->rmode();
220      if (mode == RelocInfo::CELL &&
221          code->IsWeakObjectInOptimizedCode(it.rinfo()->target_cell())) {
222        objects.push_back(handle(it.rinfo()->target_cell(), isolate));
223      } else if (mode == RelocInfo::EMBEDDED_OBJECT &&
224                 code->IsWeakObjectInOptimizedCode(
225                     it.rinfo()->target_object())) {
226        Handle<HeapObject> object(HeapObject::cast(it.rinfo()->target_object()),
227                                  isolate);
228        if (object->IsMap()) {
229          maps.push_back(Handle<Map>::cast(object));
230        } else {
231          objects.push_back(object);
232        }
233      }
234    }
235  }
236  for (Handle<Map> map : maps) {
237    if (map->dependent_code()->IsEmpty(DependentCode::kWeakCodeGroup)) {
238      isolate->heap()->AddRetainedMap(map);
239    }
240    Map::AddDependentCode(map, DependentCode::kWeakCodeGroup, code);
241  }
242  for (Handle<HeapObject> object : objects) {
243    AddWeakObjectToCodeDependency(isolate, object, code);
244  }
245  code->set_can_have_weak_objects(true);
246}
247
248// ----------------------------------------------------------------------------
249// Local helper methods that make up the compilation pipeline.
250
251namespace {
252
253void RecordFunctionCompilation(CodeEventListener::LogEventsAndTags tag,
254                               CompilationInfo* info) {
255  // Log the code generation. If source information is available include
256  // script name and line number. Check explicitly whether logging is
257  // enabled as finding the line number is not free.
258  if (info->isolate()->logger()->is_logging_code_events() ||
259      info->isolate()->is_profiling()) {
260    Handle<SharedFunctionInfo> shared = info->shared_info();
261    Handle<Script> script = info->parse_info()->script();
262    Handle<AbstractCode> abstract_code =
263        info->has_bytecode_array()
264            ? Handle<AbstractCode>::cast(info->bytecode_array())
265            : Handle<AbstractCode>::cast(info->code());
266    if (abstract_code.is_identical_to(
267            info->isolate()->builtins()->CompileLazy())) {
268      return;
269    }
270    int line_num = Script::GetLineNumber(script, shared->start_position()) + 1;
271    int column_num =
272        Script::GetColumnNumber(script, shared->start_position()) + 1;
273    String* script_name = script->name()->IsString()
274                              ? String::cast(script->name())
275                              : info->isolate()->heap()->empty_string();
276    CodeEventListener::LogEventsAndTags log_tag =
277        Logger::ToNativeByScript(tag, *script);
278    PROFILE(info->isolate(),
279            CodeCreateEvent(log_tag, *abstract_code, *shared, script_name,
280                            line_num, column_num));
281  }
282}
283
284void EnsureFeedbackMetadata(CompilationInfo* info) {
285  DCHECK(info->has_shared_info());
286
287  // If no type feedback metadata exists, we create it now. At this point the
288  // AstNumbering pass has already run. Note the snapshot can contain outdated
289  // vectors for a different configuration, hence we also recreate a new vector
290  // when the function is not compiled (i.e. no code was serialized).
291
292  // TODO(mvstanton): reintroduce is_empty() predicate to feedback_metadata().
293  if (info->shared_info()->feedback_metadata()->length() == 0 ||
294      !info->shared_info()->is_compiled()) {
295    Handle<TypeFeedbackMetadata> feedback_metadata = TypeFeedbackMetadata::New(
296        info->isolate(), info->literal()->feedback_vector_spec());
297    info->shared_info()->set_feedback_metadata(*feedback_metadata);
298  }
299
300  // It's very important that recompiles do not alter the structure of the type
301  // feedback vector. Verify that the structure fits the function literal.
302  CHECK(!info->shared_info()->feedback_metadata()->SpecDiffersFrom(
303      info->literal()->feedback_vector_spec()));
304}
305
306bool UseTurboFan(Handle<SharedFunctionInfo> shared) {
307  bool optimization_disabled = shared->optimization_disabled();
308  bool dont_crankshaft = shared->dont_crankshaft();
309
310  // Check the enabling conditions for Turbofan.
311  // 1. "use asm" code.
312  bool is_turbofanable_asm =
313      FLAG_turbo_asm && shared->asm_function() && !optimization_disabled;
314
315  // 2. Fallback for features unsupported by Crankshaft.
316  bool is_unsupported_by_crankshaft_but_turbofanable =
317      dont_crankshaft && strcmp(FLAG_turbo_filter, "~~") == 0 &&
318      !optimization_disabled;
319
320  // 3. Explicitly enabled by the command-line filter.
321  bool passes_turbo_filter = shared->PassesFilter(FLAG_turbo_filter);
322
323  return is_turbofanable_asm || is_unsupported_by_crankshaft_but_turbofanable ||
324         passes_turbo_filter;
325}
326
327bool ShouldUseIgnition(CompilationInfo* info) {
328  DCHECK(info->has_shared_info());
329
330  // Skip Ignition for asm.js functions.
331  if (info->shared_info()->asm_function()) {
332    return false;
333  }
334
335  // When requesting debug code as a replacement for existing code, we provide
336  // the same kind as the existing code (to prevent implicit tier-change).
337  if (info->is_debug() && info->shared_info()->is_compiled()) {
338    return !info->shared_info()->HasBaselineCode();
339  }
340
341  // Code destined for TurboFan should be compiled with Ignition first.
342  if (UseTurboFan(info->shared_info())) return true;
343
344  // Only use Ignition for any other function if FLAG_ignition is true.
345  if (!FLAG_ignition) return false;
346
347  // Checks whether top level functions should be passed by the filter.
348  if (info->shared_info()->is_toplevel()) {
349    Vector<const char> filter = CStrVector(FLAG_ignition_filter);
350    return (filter.length() == 0) || (filter.length() == 1 && filter[0] == '*');
351  }
352
353  // Finally respect the filter.
354  return info->shared_info()->PassesFilter(FLAG_ignition_filter);
355}
356
357CompilationJob* GetUnoptimizedCompilationJob(CompilationInfo* info) {
358  // Function should have been parsed and analyzed before creating a compilation
359  // job.
360  DCHECK_NOT_NULL(info->literal());
361  DCHECK_NOT_NULL(info->scope());
362
363  EnsureFeedbackMetadata(info);
364  if (ShouldUseIgnition(info)) {
365    return interpreter::Interpreter::NewCompilationJob(info);
366  } else {
367    return FullCodeGenerator::NewCompilationJob(info);
368  }
369}
370
371void InstallSharedScopeInfo(CompilationInfo* info,
372                            Handle<SharedFunctionInfo> shared) {
373  Handle<ScopeInfo> scope_info = info->scope()->scope_info();
374  shared->set_scope_info(*scope_info);
375  Scope* outer_scope = info->scope()->GetOuterScopeWithContext();
376  if (outer_scope) {
377    shared->set_outer_scope_info(*outer_scope->scope_info());
378  }
379}
380
381void InstallSharedCompilationResult(CompilationInfo* info,
382                                    Handle<SharedFunctionInfo> shared) {
383  // TODO(mstarzinger): Compiling for debug code might be used to reveal inner
384  // functions via {FindSharedFunctionInfoInScript}, in which case we end up
385  // regenerating existing bytecode. Fix this!
386  if (info->is_debug() && info->has_bytecode_array()) {
387    shared->ClearBytecodeArray();
388  }
389  DCHECK(!info->code().is_null());
390  shared->ReplaceCode(*info->code());
391  if (info->has_bytecode_array()) {
392    DCHECK(!shared->HasBytecodeArray());  // Only compiled once.
393    shared->set_bytecode_array(*info->bytecode_array());
394  }
395}
396
397void InstallUnoptimizedCode(CompilationInfo* info) {
398  Handle<SharedFunctionInfo> shared = info->shared_info();
399
400  // Update the shared function info with the scope info.
401  InstallSharedScopeInfo(info, shared);
402
403  // Install compilation result on the shared function info
404  InstallSharedCompilationResult(info, shared);
405}
406
407CompilationJob::Status FinalizeUnoptimizedCompilationJob(CompilationJob* job) {
408  CompilationJob::Status status = job->FinalizeJob();
409  if (status == CompilationJob::SUCCEEDED) {
410    InstallUnoptimizedCode(job->info());
411    job->RecordUnoptimizedCompilationStats();
412  }
413  return status;
414}
415
416bool GenerateUnoptimizedCode(CompilationInfo* info) {
417  if (FLAG_validate_asm && info->scope()->asm_module() &&
418      !info->shared_info()->is_asm_wasm_broken() && !info->is_debug()) {
419    EnsureFeedbackMetadata(info);
420    MaybeHandle<FixedArray> wasm_data;
421    wasm_data = AsmJs::ConvertAsmToWasm(info->parse_info());
422    if (!wasm_data.is_null()) {
423      info->shared_info()->set_asm_wasm_data(*wasm_data.ToHandleChecked());
424      info->SetCode(info->isolate()->builtins()->InstantiateAsmJs());
425      InstallUnoptimizedCode(info);
426      return true;
427    }
428  }
429
430  std::unique_ptr<CompilationJob> job(GetUnoptimizedCompilationJob(info));
431  if (job->PrepareJob() != CompilationJob::SUCCEEDED) return false;
432  if (job->ExecuteJob() != CompilationJob::SUCCEEDED) return false;
433  if (FinalizeUnoptimizedCompilationJob(job.get()) !=
434      CompilationJob::SUCCEEDED) {
435    return false;
436  }
437  return true;
438}
439
440bool CompileUnoptimizedCode(CompilationInfo* info) {
441  DCHECK(AllowCompilation::IsAllowed(info->isolate()));
442  if (!Compiler::Analyze(info->parse_info()) ||
443      !GenerateUnoptimizedCode(info)) {
444    Isolate* isolate = info->isolate();
445    if (!isolate->has_pending_exception()) isolate->StackOverflow();
446    return false;
447  }
448  return true;
449}
450
451MUST_USE_RESULT MaybeHandle<Code> GetUnoptimizedCode(CompilationInfo* info) {
452  VMState<COMPILER> state(info->isolate());
453  PostponeInterruptsScope postpone(info->isolate());
454
455  // Parse and update CompilationInfo with the results.
456  if (!Parser::ParseStatic(info->parse_info())) return MaybeHandle<Code>();
457  DCHECK_EQ(info->shared_info()->language_mode(),
458            info->literal()->language_mode());
459
460  // Compile either unoptimized code or bytecode for the interpreter.
461  if (!CompileUnoptimizedCode(info)) return MaybeHandle<Code>();
462
463  // Record the function compilation event.
464  RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG, info);
465
466  return info->code();
467}
468
469MUST_USE_RESULT MaybeHandle<Code> GetCodeFromOptimizedCodeMap(
470    Handle<JSFunction> function, BailoutId osr_ast_id) {
471  Handle<SharedFunctionInfo> shared(function->shared());
472  DisallowHeapAllocation no_gc;
473  CodeAndLiterals cached = shared->SearchOptimizedCodeMap(
474      function->context()->native_context(), osr_ast_id);
475  if (cached.code != nullptr) {
476    // Caching of optimized code enabled and optimized code found.
477    if (cached.literals != nullptr) function->set_literals(cached.literals);
478    DCHECK(!cached.code->marked_for_deoptimization());
479    DCHECK(function->shared()->is_compiled());
480    return Handle<Code>(cached.code);
481  }
482  return MaybeHandle<Code>();
483}
484
485void InsertCodeIntoOptimizedCodeMap(CompilationInfo* info) {
486  Handle<Code> code = info->code();
487  if (code->kind() != Code::OPTIMIZED_FUNCTION) return;  // Nothing to do.
488
489  // Function context specialization folds-in the function context,
490  // so no sharing can occur.
491  if (info->is_function_context_specializing()) return;
492  // Frame specialization implies function context specialization.
493  DCHECK(!info->is_frame_specializing());
494
495  // TODO(4764): When compiling for OSR from bytecode, BailoutId might derive
496  // from bytecode offset and overlap with actual BailoutId. No caching!
497  if (info->is_osr() && info->is_optimizing_from_bytecode()) return;
498
499  // Cache optimized context-specific code.
500  Handle<JSFunction> function = info->closure();
501  Handle<SharedFunctionInfo> shared(function->shared());
502  Handle<LiteralsArray> literals(function->literals());
503  Handle<Context> native_context(function->context()->native_context());
504  SharedFunctionInfo::AddToOptimizedCodeMap(shared, native_context, code,
505                                            literals, info->osr_ast_id());
506}
507
508bool Renumber(ParseInfo* parse_info) {
509  if (!AstNumbering::Renumber(parse_info->isolate(), parse_info->zone(),
510                              parse_info->literal())) {
511    return false;
512  }
513  Handle<SharedFunctionInfo> shared_info = parse_info->shared_info();
514  if (!shared_info.is_null()) {
515    FunctionLiteral* lit = parse_info->literal();
516    shared_info->set_ast_node_count(lit->ast_node_count());
517    if (lit->dont_optimize_reason() != kNoReason) {
518      shared_info->DisableOptimization(lit->dont_optimize_reason());
519    }
520    if (lit->flags() & AstProperties::kDontCrankshaft) {
521      shared_info->set_dont_crankshaft(true);
522    }
523  }
524  return true;
525}
526
527bool GetOptimizedCodeNow(CompilationJob* job) {
528  CompilationInfo* info = job->info();
529  Isolate* isolate = info->isolate();
530
531  // Parsing is not required when optimizing from existing bytecode.
532  if (!info->is_optimizing_from_bytecode()) {
533    if (!Compiler::ParseAndAnalyze(info->parse_info())) return false;
534    EnsureFeedbackMetadata(info);
535  }
536
537  JSFunction::EnsureLiterals(info->closure());
538
539  TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
540  RuntimeCallTimerScope runtimeTimer(isolate,
541                                     &RuntimeCallStats::RecompileSynchronous);
542  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
543               "V8.RecompileSynchronous");
544
545  if (job->PrepareJob() != CompilationJob::SUCCEEDED ||
546      job->ExecuteJob() != CompilationJob::SUCCEEDED ||
547      job->FinalizeJob() != CompilationJob::SUCCEEDED) {
548    if (FLAG_trace_opt) {
549      PrintF("[aborted optimizing ");
550      info->closure()->ShortPrint();
551      PrintF(" because: %s]\n", GetBailoutReason(info->bailout_reason()));
552    }
553    return false;
554  }
555
556  // Success!
557  job->RecordOptimizedCompilationStats();
558  DCHECK(!isolate->has_pending_exception());
559  InsertCodeIntoOptimizedCodeMap(info);
560  RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG, info);
561  return true;
562}
563
564bool GetOptimizedCodeLater(CompilationJob* job) {
565  CompilationInfo* info = job->info();
566  Isolate* isolate = info->isolate();
567
568  if (!isolate->optimizing_compile_dispatcher()->IsQueueAvailable()) {
569    if (FLAG_trace_concurrent_recompilation) {
570      PrintF("  ** Compilation queue full, will retry optimizing ");
571      info->closure()->ShortPrint();
572      PrintF(" later.\n");
573    }
574    return false;
575  }
576
577  if (isolate->heap()->HighMemoryPressure()) {
578    if (FLAG_trace_concurrent_recompilation) {
579      PrintF("  ** High memory pressure, will retry optimizing ");
580      info->closure()->ShortPrint();
581      PrintF(" later.\n");
582    }
583    return false;
584  }
585
586  // Parsing is not required when optimizing from existing bytecode.
587  if (!info->is_optimizing_from_bytecode()) {
588    if (!Compiler::ParseAndAnalyze(info->parse_info())) return false;
589    EnsureFeedbackMetadata(info);
590  }
591
592  JSFunction::EnsureLiterals(info->closure());
593
594  TimerEventScope<TimerEventRecompileSynchronous> timer(info->isolate());
595  RuntimeCallTimerScope runtimeTimer(info->isolate(),
596                                     &RuntimeCallStats::RecompileSynchronous);
597  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
598               "V8.RecompileSynchronous");
599
600  if (job->PrepareJob() != CompilationJob::SUCCEEDED) return false;
601  isolate->optimizing_compile_dispatcher()->QueueForOptimization(job);
602
603  if (FLAG_trace_concurrent_recompilation) {
604    PrintF("  ** Queued ");
605    info->closure()->ShortPrint();
606    PrintF(" for concurrent optimization.\n");
607  }
608  return true;
609}
610
611MaybeHandle<Code> GetOptimizedCode(Handle<JSFunction> function,
612                                   Compiler::ConcurrencyMode mode,
613                                   BailoutId osr_ast_id = BailoutId::None(),
614                                   JavaScriptFrame* osr_frame = nullptr) {
615  Isolate* isolate = function->GetIsolate();
616  Handle<SharedFunctionInfo> shared(function->shared(), isolate);
617
618  bool ignition_osr = osr_frame && osr_frame->is_interpreted();
619  DCHECK_IMPLIES(ignition_osr, !osr_ast_id.IsNone());
620  DCHECK_IMPLIES(ignition_osr, FLAG_ignition_osr);
621
622  // Shared function no longer needs to be tiered up
623  shared->set_marked_for_tier_up(false);
624
625  Handle<Code> cached_code;
626  // TODO(4764): When compiling for OSR from bytecode, BailoutId might derive
627  // from bytecode offset and overlap with actual BailoutId. No lookup!
628  if (!ignition_osr &&
629      GetCodeFromOptimizedCodeMap(function, osr_ast_id)
630          .ToHandle(&cached_code)) {
631    if (FLAG_trace_opt) {
632      PrintF("[found optimized code for ");
633      function->ShortPrint();
634      if (!osr_ast_id.IsNone()) {
635        PrintF(" at OSR AST id %d", osr_ast_id.ToInt());
636      }
637      PrintF("]\n");
638    }
639    return cached_code;
640  }
641
642  // Reset profiler ticks, function is no longer considered hot.
643  if (shared->HasBaselineCode()) {
644    shared->code()->set_profiler_ticks(0);
645  } else if (shared->HasBytecodeArray()) {
646    shared->set_profiler_ticks(0);
647  }
648
649  VMState<COMPILER> state(isolate);
650  DCHECK(!isolate->has_pending_exception());
651  PostponeInterruptsScope postpone(isolate);
652  bool use_turbofan = UseTurboFan(shared) || ignition_osr;
653  std::unique_ptr<CompilationJob> job(
654      use_turbofan ? compiler::Pipeline::NewCompilationJob(function)
655                   : new HCompilationJob(function));
656  CompilationInfo* info = job->info();
657  ParseInfo* parse_info = info->parse_info();
658
659  info->SetOptimizingForOsr(osr_ast_id, osr_frame);
660
661  // Do not use Crankshaft/TurboFan if we need to be able to set break points.
662  if (info->shared_info()->HasDebugInfo()) {
663    info->AbortOptimization(kFunctionBeingDebugged);
664    return MaybeHandle<Code>();
665  }
666
667  // Limit the number of times we try to optimize functions.
668  const int kMaxOptCount =
669      FLAG_deopt_every_n_times == 0 ? FLAG_max_opt_count : 1000;
670  if (info->shared_info()->opt_count() > kMaxOptCount) {
671    info->AbortOptimization(kOptimizedTooManyTimes);
672    return MaybeHandle<Code>();
673  }
674
675  TimerEventScope<TimerEventOptimizeCode> optimize_code_timer(isolate);
676  RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::OptimizeCode);
677  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.OptimizeCode");
678
679  // TurboFan can optimize directly from existing bytecode.
680  if (use_turbofan && ShouldUseIgnition(info)) {
681    if (info->is_osr() && !ignition_osr) return MaybeHandle<Code>();
682    if (!Compiler::EnsureBytecode(info)) {
683      if (isolate->has_pending_exception()) isolate->clear_pending_exception();
684      return MaybeHandle<Code>();
685    }
686    info->MarkAsOptimizeFromBytecode();
687  }
688
689  // Verify that OSR compilations are delegated to the correct graph builder.
690  // Depending on the underlying frame the semantics of the {BailoutId} differ
691  // and the various graph builders hard-code a certain semantic:
692  //  - Interpreter : The BailoutId represents a bytecode offset.
693  //  - FullCodegen : The BailoutId represents the id of an AST node.
694  DCHECK_IMPLIES(info->is_osr() && ignition_osr,
695                 info->is_optimizing_from_bytecode());
696  DCHECK_IMPLIES(info->is_osr() && !ignition_osr,
697                 !info->is_optimizing_from_bytecode());
698
699  // In case of concurrent recompilation, all handles below this point will be
700  // allocated in a deferred handle scope that is detached and handed off to
701  // the background thread when we return.
702  std::unique_ptr<CompilationHandleScope> compilation;
703  if (mode == Compiler::CONCURRENT) {
704    compilation.reset(new CompilationHandleScope(info));
705  }
706
707  // In case of TurboFan, all handles below will be canonicalized.
708  std::unique_ptr<CanonicalHandleScope> canonical;
709  if (use_turbofan) canonical.reset(new CanonicalHandleScope(info->isolate()));
710
711  // Reopen handles in the new CompilationHandleScope.
712  info->ReopenHandlesInNewHandleScope();
713  parse_info->ReopenHandlesInNewHandleScope();
714
715  if (mode == Compiler::CONCURRENT) {
716    if (GetOptimizedCodeLater(job.get())) {
717      job.release();  // The background recompile job owns this now.
718      return isolate->builtins()->InOptimizationQueue();
719    }
720  } else {
721    if (GetOptimizedCodeNow(job.get())) return info->code();
722  }
723
724  if (isolate->has_pending_exception()) isolate->clear_pending_exception();
725  return MaybeHandle<Code>();
726}
727
728CompilationJob::Status FinalizeOptimizedCompilationJob(CompilationJob* job) {
729  CompilationInfo* info = job->info();
730  Isolate* isolate = info->isolate();
731
732  TimerEventScope<TimerEventRecompileSynchronous> timer(info->isolate());
733  RuntimeCallTimerScope runtimeTimer(isolate,
734                                     &RuntimeCallStats::RecompileSynchronous);
735  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
736               "V8.RecompileSynchronous");
737
738  Handle<SharedFunctionInfo> shared = info->shared_info();
739
740  // Reset profiler ticks, function is no longer considered hot.
741  if (shared->HasBaselineCode()) {
742    shared->code()->set_profiler_ticks(0);
743  } else if (shared->HasBytecodeArray()) {
744    shared->set_profiler_ticks(0);
745  }
746
747  DCHECK(!shared->HasDebugInfo());
748
749  // 1) Optimization on the concurrent thread may have failed.
750  // 2) The function may have already been optimized by OSR.  Simply continue.
751  //    Except when OSR already disabled optimization for some reason.
752  // 3) The code may have already been invalidated due to dependency change.
753  // 4) Code generation may have failed.
754  if (job->state() == CompilationJob::State::kReadyToFinalize) {
755    if (shared->optimization_disabled()) {
756      job->RetryOptimization(kOptimizationDisabled);
757    } else if (info->dependencies()->HasAborted()) {
758      job->RetryOptimization(kBailedOutDueToDependencyChange);
759    } else if (job->FinalizeJob() == CompilationJob::SUCCEEDED) {
760      job->RecordOptimizedCompilationStats();
761      RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG, info);
762      if (shared
763              ->SearchOptimizedCodeMap(info->context()->native_context(),
764                                       info->osr_ast_id())
765              .code == nullptr) {
766        InsertCodeIntoOptimizedCodeMap(info);
767      }
768      if (FLAG_trace_opt) {
769        PrintF("[completed optimizing ");
770        info->closure()->ShortPrint();
771        PrintF("]\n");
772      }
773      info->closure()->ReplaceCode(*info->code());
774      return CompilationJob::SUCCEEDED;
775    }
776  }
777
778  DCHECK(job->state() == CompilationJob::State::kFailed);
779  if (FLAG_trace_opt) {
780    PrintF("[aborted optimizing ");
781    info->closure()->ShortPrint();
782    PrintF(" because: %s]\n", GetBailoutReason(info->bailout_reason()));
783  }
784  info->closure()->ReplaceCode(shared->code());
785  return CompilationJob::FAILED;
786}
787
788MaybeHandle<Code> GetBaselineCode(Handle<JSFunction> function) {
789  Isolate* isolate = function->GetIsolate();
790  VMState<COMPILER> state(isolate);
791  PostponeInterruptsScope postpone(isolate);
792  Zone zone(isolate->allocator(), ZONE_NAME);
793  ParseInfo parse_info(&zone, handle(function->shared()));
794  CompilationInfo info(&parse_info, function);
795
796  // Function no longer needs to be tiered up
797  function->shared()->set_marked_for_tier_up(false);
798
799  // Reset profiler ticks, function is no longer considered hot.
800  if (function->shared()->HasBytecodeArray()) {
801    function->shared()->set_profiler_ticks(0);
802  }
803
804  // Nothing left to do if the function already has baseline code.
805  if (function->shared()->code()->kind() == Code::FUNCTION) {
806    return Handle<Code>(function->shared()->code());
807  }
808
809  // We do not switch to baseline code when the debugger might have created a
810  // copy of the bytecode with break slots to be able to set break points.
811  if (function->shared()->HasDebugInfo()) {
812    return MaybeHandle<Code>();
813  }
814
815  // TODO(4280): For now we do not switch generators or async functions to
816  // baseline code because there might be suspended activations stored in
817  // generator objects on the heap. We could eventually go directly to
818  // TurboFan in this case.
819  if (IsResumableFunction(function->shared()->kind())) {
820    return MaybeHandle<Code>();
821  }
822
823  if (FLAG_trace_opt) {
824    OFStream os(stdout);
825    os << "[switching method " << Brief(*function) << " to baseline code]"
826       << std::endl;
827  }
828
829  // Parse and update CompilationInfo with the results.
830  if (!Parser::ParseStatic(info.parse_info())) return MaybeHandle<Code>();
831  Handle<SharedFunctionInfo> shared = info.shared_info();
832  DCHECK_EQ(shared->language_mode(), info.literal()->language_mode());
833
834  // Compile baseline code using the full code generator.
835  if (!Compiler::Analyze(info.parse_info()) ||
836      !FullCodeGenerator::MakeCode(&info)) {
837    if (!isolate->has_pending_exception()) isolate->StackOverflow();
838    return MaybeHandle<Code>();
839  }
840
841  // Update the shared function info with the scope info.
842  InstallSharedScopeInfo(&info, shared);
843
844  // Install compilation result on the shared function info
845  InstallSharedCompilationResult(&info, shared);
846
847  // Record the function compilation event.
848  RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG, &info);
849
850  return info.code();
851}
852
853MaybeHandle<Code> GetLazyCode(Handle<JSFunction> function) {
854  Isolate* isolate = function->GetIsolate();
855  DCHECK(!isolate->has_pending_exception());
856  DCHECK(!function->is_compiled());
857  TimerEventScope<TimerEventCompileCode> compile_timer(isolate);
858  RuntimeCallTimerScope runtimeTimer(isolate,
859                                     &RuntimeCallStats::CompileCodeLazy);
860  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileCode");
861  AggregatedHistogramTimerScope timer(isolate->counters()->compile_lazy());
862
863  Handle<Code> cached_code;
864  if (GetCodeFromOptimizedCodeMap(function, BailoutId::None())
865          .ToHandle(&cached_code)) {
866    if (FLAG_trace_opt) {
867      PrintF("[found optimized code for ");
868      function->ShortPrint();
869      PrintF(" during unoptimized compile]\n");
870    }
871    DCHECK(function->shared()->is_compiled());
872    return cached_code;
873  }
874
875  if (function->shared()->marked_for_tier_up()) {
876    DCHECK(FLAG_mark_shared_functions_for_tier_up);
877
878    function->shared()->set_marked_for_tier_up(false);
879
880    switch (Compiler::NextCompilationTier(*function)) {
881      case Compiler::BASELINE: {
882        if (FLAG_trace_opt) {
883          PrintF("[recompiling function ");
884          function->ShortPrint();
885          PrintF(
886              " to baseline eagerly (shared function marked for tier up)]\n");
887        }
888
889        Handle<Code> code;
890        if (GetBaselineCode(function).ToHandle(&code)) {
891          return code;
892        }
893        break;
894      }
895      case Compiler::OPTIMIZED: {
896        if (FLAG_trace_opt) {
897          PrintF("[optimizing method ");
898          function->ShortPrint();
899          PrintF(" eagerly (shared function marked for tier up)]\n");
900        }
901
902        Handle<Code> code;
903        // TODO(leszeks): Look into performing this compilation concurrently.
904        if (GetOptimizedCode(function, Compiler::NOT_CONCURRENT)
905                .ToHandle(&code)) {
906          return code;
907        }
908        break;
909      }
910      default:
911        UNREACHABLE();
912    }
913  }
914
915  if (function->shared()->is_compiled()) {
916    return Handle<Code>(function->shared()->code());
917  }
918
919  if (function->shared()->HasBytecodeArray()) {
920    Handle<Code> entry = isolate->builtins()->InterpreterEntryTrampoline();
921    function->shared()->ReplaceCode(*entry);
922    return entry;
923  }
924
925  Zone zone(isolate->allocator(), ZONE_NAME);
926  ParseInfo parse_info(&zone, handle(function->shared()));
927  CompilationInfo info(&parse_info, function);
928  Handle<Code> result;
929  ASSIGN_RETURN_ON_EXCEPTION(isolate, result, GetUnoptimizedCode(&info), Code);
930
931  if (FLAG_always_opt) {
932    Handle<Code> opt_code;
933    if (GetOptimizedCode(function, Compiler::NOT_CONCURRENT)
934            .ToHandle(&opt_code)) {
935      result = opt_code;
936    }
937  }
938
939  return result;
940}
941
942
943Handle<SharedFunctionInfo> NewSharedFunctionInfoForLiteral(
944    Isolate* isolate, FunctionLiteral* literal, Handle<Script> script) {
945  Handle<Code> code = isolate->builtins()->CompileLazy();
946  Handle<ScopeInfo> scope_info = handle(ScopeInfo::Empty(isolate));
947  Handle<SharedFunctionInfo> result = isolate->factory()->NewSharedFunctionInfo(
948      literal->name(), literal->materialized_literal_count(), literal->kind(),
949      code, scope_info);
950  SharedFunctionInfo::InitFromFunctionLiteral(result, literal);
951  SharedFunctionInfo::SetScript(result, script);
952  return result;
953}
954
955Handle<SharedFunctionInfo> CompileToplevel(CompilationInfo* info) {
956  Isolate* isolate = info->isolate();
957  TimerEventScope<TimerEventCompileCode> timer(isolate);
958  RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::CompileCode);
959  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileCode");
960  PostponeInterruptsScope postpone(isolate);
961  DCHECK(!isolate->native_context().is_null());
962  ParseInfo* parse_info = info->parse_info();
963  Handle<Script> script = parse_info->script();
964
965  // TODO(svenpanne) Obscure place for this, perhaps move to OnBeforeCompile?
966  FixedArray* array = isolate->native_context()->embedder_data();
967  script->set_context_data(array->get(v8::Context::kDebugIdIndex));
968
969  isolate->debug()->OnBeforeCompile(script);
970
971  Handle<SharedFunctionInfo> result;
972
973  { VMState<COMPILER> state(info->isolate());
974    if (parse_info->literal() == nullptr && !Parser::ParseStatic(parse_info)) {
975      return Handle<SharedFunctionInfo>::null();
976    }
977
978    FunctionLiteral* lit = parse_info->literal();
979
980    // Measure how long it takes to do the compilation; only take the
981    // rest of the function into account to avoid overlap with the
982    // parsing statistics.
983    RuntimeCallTimerScope runtimeTimer(
984        isolate, parse_info->is_eval() ? &RuntimeCallStats::CompileEval
985                                       : &RuntimeCallStats::Compile);
986    HistogramTimer* rate = parse_info->is_eval()
987                               ? info->isolate()->counters()->compile_eval()
988                               : info->isolate()->counters()->compile();
989    HistogramTimerScope timer(rate);
990    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
991                 parse_info->is_eval() ? "V8.CompileEval" : "V8.Compile");
992
993    // Allocate a shared function info object.
994    DCHECK_EQ(kNoSourcePosition, lit->function_token_position());
995    result = NewSharedFunctionInfoForLiteral(isolate, lit, script);
996    result->set_is_toplevel(true);
997    parse_info->set_shared_info(result);
998
999    // Compile the code.
1000    if (!CompileUnoptimizedCode(info)) {
1001      return Handle<SharedFunctionInfo>::null();
1002    }
1003
1004    Handle<String> script_name =
1005        script->name()->IsString()
1006            ? Handle<String>(String::cast(script->name()))
1007            : isolate->factory()->empty_string();
1008    CodeEventListener::LogEventsAndTags log_tag =
1009        parse_info->is_eval()
1010            ? CodeEventListener::EVAL_TAG
1011            : Logger::ToNativeByScript(CodeEventListener::SCRIPT_TAG, *script);
1012
1013    PROFILE(isolate, CodeCreateEvent(log_tag, result->abstract_code(), *result,
1014                                     *script_name));
1015
1016    if (!script.is_null())
1017      script->set_compilation_state(Script::COMPILATION_STATE_COMPILED);
1018  }
1019
1020  return result;
1021}
1022
1023}  // namespace
1024
1025// ----------------------------------------------------------------------------
1026// Implementation of Compiler
1027
1028bool Compiler::Analyze(ParseInfo* info) {
1029  DCHECK_NOT_NULL(info->literal());
1030  if (!Rewriter::Rewrite(info)) return false;
1031  DeclarationScope::Analyze(info, AnalyzeMode::kRegular);
1032  if (!Renumber(info)) return false;
1033  DCHECK_NOT_NULL(info->scope());
1034  return true;
1035}
1036
1037bool Compiler::ParseAndAnalyze(ParseInfo* info) {
1038  if (!Parser::ParseStatic(info)) return false;
1039  if (!Compiler::Analyze(info)) return false;
1040  DCHECK_NOT_NULL(info->literal());
1041  DCHECK_NOT_NULL(info->scope());
1042  return true;
1043}
1044
1045bool Compiler::Compile(Handle<JSFunction> function, ClearExceptionFlag flag) {
1046  if (function->is_compiled()) return true;
1047  Isolate* isolate = function->GetIsolate();
1048  DCHECK(AllowCompilation::IsAllowed(isolate));
1049
1050  // Start a compilation.
1051  Handle<Code> code;
1052  if (!GetLazyCode(function).ToHandle(&code)) {
1053    if (flag == CLEAR_EXCEPTION) {
1054      isolate->clear_pending_exception();
1055    }
1056    return false;
1057  }
1058
1059  // Install code on closure.
1060  function->ReplaceCode(*code);
1061  JSFunction::EnsureLiterals(function);
1062
1063  // Check postconditions on success.
1064  DCHECK(!isolate->has_pending_exception());
1065  DCHECK(function->shared()->is_compiled());
1066  DCHECK(function->is_compiled());
1067  return true;
1068}
1069
1070bool Compiler::CompileBaseline(Handle<JSFunction> function) {
1071  Isolate* isolate = function->GetIsolate();
1072  DCHECK(AllowCompilation::IsAllowed(isolate));
1073
1074  // Start a compilation.
1075  Handle<Code> code;
1076  if (!GetBaselineCode(function).ToHandle(&code)) {
1077    // Baseline generation failed, get unoptimized code.
1078    DCHECK(function->shared()->is_compiled());
1079    code = handle(function->shared()->code());
1080    isolate->clear_pending_exception();
1081  }
1082
1083  // Install code on closure.
1084  function->ReplaceCode(*code);
1085  JSFunction::EnsureLiterals(function);
1086
1087  // Check postconditions on success.
1088  DCHECK(!isolate->has_pending_exception());
1089  DCHECK(function->shared()->is_compiled());
1090  DCHECK(function->is_compiled());
1091  return true;
1092}
1093
1094bool Compiler::CompileOptimized(Handle<JSFunction> function,
1095                                ConcurrencyMode mode) {
1096  if (function->IsOptimized()) return true;
1097  Isolate* isolate = function->GetIsolate();
1098  DCHECK(AllowCompilation::IsAllowed(isolate));
1099
1100  // Start a compilation.
1101  Handle<Code> code;
1102  if (!GetOptimizedCode(function, mode).ToHandle(&code)) {
1103    // Optimization failed, get unoptimized code.
1104    DCHECK(!isolate->has_pending_exception());
1105    if (function->shared()->is_compiled()) {
1106      code = handle(function->shared()->code(), isolate);
1107    } else if (function->shared()->HasBytecodeArray()) {
1108      code = isolate->builtins()->InterpreterEntryTrampoline();
1109      function->shared()->ReplaceCode(*code);
1110    } else {
1111      Zone zone(isolate->allocator(), ZONE_NAME);
1112      ParseInfo parse_info(&zone, handle(function->shared()));
1113      CompilationInfo info(&parse_info, function);
1114      if (!GetUnoptimizedCode(&info).ToHandle(&code)) {
1115        return false;
1116      }
1117    }
1118  }
1119
1120  // Install code on closure.
1121  function->ReplaceCode(*code);
1122  JSFunction::EnsureLiterals(function);
1123
1124  // Check postconditions on success.
1125  DCHECK(!isolate->has_pending_exception());
1126  DCHECK(function->shared()->is_compiled());
1127  DCHECK(function->is_compiled());
1128  return true;
1129}
1130
1131bool Compiler::CompileDebugCode(Handle<SharedFunctionInfo> shared) {
1132  Isolate* isolate = shared->GetIsolate();
1133  DCHECK(AllowCompilation::IsAllowed(isolate));
1134
1135  // Start a compilation.
1136  Zone zone(isolate->allocator(), ZONE_NAME);
1137  ParseInfo parse_info(&zone, shared);
1138  CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1139  info.MarkAsDebug();
1140  if (GetUnoptimizedCode(&info).is_null()) {
1141    isolate->clear_pending_exception();
1142    return false;
1143  }
1144
1145  // Check postconditions on success.
1146  DCHECK(!isolate->has_pending_exception());
1147  DCHECK(shared->is_compiled());
1148  DCHECK(shared->HasDebugCode());
1149  return true;
1150}
1151
1152MaybeHandle<JSArray> Compiler::CompileForLiveEdit(Handle<Script> script) {
1153  Isolate* isolate = script->GetIsolate();
1154  DCHECK(AllowCompilation::IsAllowed(isolate));
1155
1156  // In order to ensure that live edit function info collection finds the newly
1157  // generated shared function infos, clear the script's list temporarily
1158  // and restore it at the end of this method.
1159  Handle<Object> old_function_infos(script->shared_function_infos(), isolate);
1160  script->set_shared_function_infos(Smi::kZero);
1161
1162  // Start a compilation.
1163  Zone zone(isolate->allocator(), ZONE_NAME);
1164  ParseInfo parse_info(&zone, script);
1165  CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1166  info.MarkAsDebug();
1167
1168  // TODO(635): support extensions.
1169  const bool compilation_succeeded = !CompileToplevel(&info).is_null();
1170  Handle<JSArray> infos;
1171  if (compilation_succeeded) {
1172    // Check postconditions on success.
1173    DCHECK(!isolate->has_pending_exception());
1174    infos = LiveEditFunctionTracker::Collect(parse_info.literal(), script,
1175                                             &zone, isolate);
1176  }
1177
1178  // Restore the original function info list in order to remain side-effect
1179  // free as much as possible, since some code expects the old shared function
1180  // infos to stick around.
1181  script->set_shared_function_infos(*old_function_infos);
1182
1183  return infos;
1184}
1185
1186bool Compiler::EnsureBytecode(CompilationInfo* info) {
1187  if (!ShouldUseIgnition(info)) return false;
1188  if (!info->shared_info()->HasBytecodeArray()) {
1189    Handle<Code> original_code(info->shared_info()->code());
1190    if (GetUnoptimizedCode(info).is_null()) return false;
1191    if (info->shared_info()->HasAsmWasmData()) return false;
1192    DCHECK(info->shared_info()->is_compiled());
1193    if (original_code->kind() == Code::FUNCTION) {
1194      // Generating bytecode will install the {InterpreterEntryTrampoline} as
1195      // shared code on the function. To avoid an implicit tier down we restore
1196      // original baseline code in case it existed beforehand.
1197      info->shared_info()->ReplaceCode(*original_code);
1198    }
1199  }
1200  DCHECK(info->shared_info()->HasBytecodeArray());
1201  return true;
1202}
1203
1204// TODO(turbofan): In the future, unoptimized code with deopt support could
1205// be generated lazily once deopt is triggered.
1206bool Compiler::EnsureDeoptimizationSupport(CompilationInfo* info) {
1207  DCHECK_NOT_NULL(info->literal());
1208  DCHECK_NOT_NULL(info->scope());
1209  Handle<SharedFunctionInfo> shared = info->shared_info();
1210  if (!shared->has_deoptimization_support()) {
1211    Zone zone(info->isolate()->allocator(), ZONE_NAME);
1212    CompilationInfo unoptimized(info->parse_info(), info->closure());
1213    unoptimized.EnableDeoptimizationSupport();
1214
1215    // TODO(4280): For now we do not switch generators or async functions to
1216    // baseline code because there might be suspended activations stored in
1217    // generator objects on the heap. We could eventually go directly to
1218    // TurboFan in this case.
1219    if (IsResumableFunction(shared->kind())) return false;
1220
1221    // When we call PrepareForSerializing below, we will change the shared
1222    // ParseInfo. Make sure to reset it.
1223    bool old_will_serialize_value = info->parse_info()->will_serialize();
1224
1225    // If the current code has reloc info for serialization, also include
1226    // reloc info for serialization for the new code, so that deopt support
1227    // can be added without losing IC state.
1228    if (shared->code()->kind() == Code::FUNCTION &&
1229        shared->code()->has_reloc_info_for_serialization()) {
1230      unoptimized.PrepareForSerializing();
1231    }
1232    EnsureFeedbackMetadata(&unoptimized);
1233    if (!FullCodeGenerator::MakeCode(&unoptimized)) return false;
1234
1235    info->parse_info()->set_will_serialize(old_will_serialize_value);
1236
1237    // The scope info might not have been set if a lazily compiled
1238    // function is inlined before being called for the first time.
1239    if (shared->scope_info() == ScopeInfo::Empty(info->isolate())) {
1240      InstallSharedScopeInfo(info, shared);
1241    }
1242
1243    // Install compilation result on the shared function info
1244    shared->EnableDeoptimizationSupport(*unoptimized.code());
1245
1246    // The existing unoptimized code was replaced with the new one.
1247    RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG,
1248                              &unoptimized);
1249  }
1250  return true;
1251}
1252
1253// static
1254Compiler::CompilationTier Compiler::NextCompilationTier(JSFunction* function) {
1255  Handle<SharedFunctionInfo> shared(function->shared(), function->GetIsolate());
1256  if (shared->IsInterpreted()) {
1257    if (UseTurboFan(shared)) {
1258      return OPTIMIZED;
1259    } else {
1260      return BASELINE;
1261    }
1262  } else {
1263    return OPTIMIZED;
1264  }
1265}
1266
1267MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
1268    Handle<String> source, Handle<SharedFunctionInfo> outer_info,
1269    Handle<Context> context, LanguageMode language_mode,
1270    ParseRestriction restriction, int eval_scope_position, int eval_position,
1271    int line_offset, int column_offset, Handle<Object> script_name,
1272    ScriptOriginOptions options) {
1273  Isolate* isolate = source->GetIsolate();
1274  int source_length = source->length();
1275  isolate->counters()->total_eval_size()->Increment(source_length);
1276  isolate->counters()->total_compile_size()->Increment(source_length);
1277
1278  CompilationCache* compilation_cache = isolate->compilation_cache();
1279  MaybeHandle<SharedFunctionInfo> maybe_shared_info =
1280      compilation_cache->LookupEval(source, outer_info, context, language_mode,
1281                                    eval_scope_position);
1282  Handle<SharedFunctionInfo> shared_info;
1283
1284  Handle<Script> script;
1285  if (!maybe_shared_info.ToHandle(&shared_info)) {
1286    script = isolate->factory()->NewScript(source);
1287    if (FLAG_trace_deopt) Script::InitLineEnds(script);
1288    if (!script_name.is_null()) {
1289      script->set_name(*script_name);
1290      script->set_line_offset(line_offset);
1291      script->set_column_offset(column_offset);
1292    }
1293    script->set_origin_options(options);
1294    script->set_compilation_type(Script::COMPILATION_TYPE_EVAL);
1295    Script::SetEvalOrigin(script, outer_info, eval_position);
1296
1297    Zone zone(isolate->allocator(), ZONE_NAME);
1298    ParseInfo parse_info(&zone, script);
1299    CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1300    parse_info.set_eval();
1301    parse_info.set_language_mode(language_mode);
1302    parse_info.set_parse_restriction(restriction);
1303    if (!context->IsNativeContext()) {
1304      parse_info.set_outer_scope_info(handle(context->scope_info()));
1305    }
1306
1307    shared_info = CompileToplevel(&info);
1308
1309    if (shared_info.is_null()) {
1310      return MaybeHandle<JSFunction>();
1311    } else {
1312      // If caller is strict mode, the result must be in strict mode as well.
1313      DCHECK(is_sloppy(language_mode) ||
1314             is_strict(shared_info->language_mode()));
1315      compilation_cache->PutEval(source, outer_info, context, shared_info,
1316                                 eval_scope_position);
1317    }
1318  }
1319
1320  Handle<JSFunction> result =
1321      isolate->factory()->NewFunctionFromSharedFunctionInfo(
1322          shared_info, context, NOT_TENURED);
1323
1324  // OnAfterCompile has to be called after we create the JSFunction, which we
1325  // may require to recompile the eval for debugging, if we find a function
1326  // that contains break points in the eval script.
1327  isolate->debug()->OnAfterCompile(script);
1328
1329  return result;
1330}
1331
1332namespace {
1333
1334bool CodeGenerationFromStringsAllowed(Isolate* isolate,
1335                                      Handle<Context> context) {
1336  DCHECK(context->allow_code_gen_from_strings()->IsFalse(isolate));
1337  // Check with callback if set.
1338  AllowCodeGenerationFromStringsCallback callback =
1339      isolate->allow_code_gen_callback();
1340  if (callback == NULL) {
1341    // No callback set and code generation disallowed.
1342    return false;
1343  } else {
1344    // Callback set. Let it decide if code generation is allowed.
1345    VMState<EXTERNAL> state(isolate);
1346    return callback(v8::Utils::ToLocal(context));
1347  }
1348}
1349
1350}  // namespace
1351
1352MaybeHandle<JSFunction> Compiler::GetFunctionFromString(
1353    Handle<Context> context, Handle<String> source,
1354    ParseRestriction restriction) {
1355  Isolate* const isolate = context->GetIsolate();
1356  Handle<Context> native_context(context->native_context(), isolate);
1357
1358  // Check if native context allows code generation from
1359  // strings. Throw an exception if it doesn't.
1360  if (native_context->allow_code_gen_from_strings()->IsFalse(isolate) &&
1361      !CodeGenerationFromStringsAllowed(isolate, native_context)) {
1362    Handle<Object> error_message =
1363        native_context->ErrorMessageForCodeGenerationFromStrings();
1364    THROW_NEW_ERROR(isolate, NewEvalError(MessageTemplate::kCodeGenFromStrings,
1365                                          error_message),
1366                    JSFunction);
1367  }
1368
1369  // Compile source string in the native context.
1370  int eval_scope_position = 0;
1371  int eval_position = kNoSourcePosition;
1372  Handle<SharedFunctionInfo> outer_info(native_context->closure()->shared());
1373  return Compiler::GetFunctionFromEval(source, outer_info, native_context,
1374                                       SLOPPY, restriction, eval_scope_position,
1375                                       eval_position);
1376}
1377
1378Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForScript(
1379    Handle<String> source, Handle<Object> script_name, int line_offset,
1380    int column_offset, ScriptOriginOptions resource_options,
1381    Handle<Object> source_map_url, Handle<Context> context,
1382    v8::Extension* extension, ScriptData** cached_data,
1383    ScriptCompiler::CompileOptions compile_options, NativesFlag natives,
1384    bool is_module) {
1385  Isolate* isolate = source->GetIsolate();
1386  if (compile_options == ScriptCompiler::kNoCompileOptions) {
1387    cached_data = NULL;
1388  } else if (compile_options == ScriptCompiler::kProduceParserCache ||
1389             compile_options == ScriptCompiler::kProduceCodeCache) {
1390    DCHECK(cached_data && !*cached_data);
1391    DCHECK(extension == NULL);
1392    DCHECK(!isolate->debug()->is_loaded());
1393  } else {
1394    DCHECK(compile_options == ScriptCompiler::kConsumeParserCache ||
1395           compile_options == ScriptCompiler::kConsumeCodeCache);
1396    DCHECK(cached_data && *cached_data);
1397    DCHECK(extension == NULL);
1398  }
1399  int source_length = source->length();
1400  isolate->counters()->total_load_size()->Increment(source_length);
1401  isolate->counters()->total_compile_size()->Increment(source_length);
1402
1403  LanguageMode language_mode = construct_language_mode(FLAG_use_strict);
1404  CompilationCache* compilation_cache = isolate->compilation_cache();
1405
1406  // Do a lookup in the compilation cache but not for extensions.
1407  MaybeHandle<SharedFunctionInfo> maybe_result;
1408  Handle<SharedFunctionInfo> result;
1409  if (extension == NULL) {
1410    // First check per-isolate compilation cache.
1411    maybe_result = compilation_cache->LookupScript(
1412        source, script_name, line_offset, column_offset, resource_options,
1413        context, language_mode);
1414    if (maybe_result.is_null() && FLAG_serialize_toplevel &&
1415        compile_options == ScriptCompiler::kConsumeCodeCache &&
1416        !isolate->debug()->is_loaded()) {
1417      // Then check cached code provided by embedder.
1418      HistogramTimerScope timer(isolate->counters()->compile_deserialize());
1419      RuntimeCallTimerScope runtimeTimer(isolate,
1420                                         &RuntimeCallStats::CompileDeserialize);
1421      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
1422                   "V8.CompileDeserialize");
1423      Handle<SharedFunctionInfo> result;
1424      if (CodeSerializer::Deserialize(isolate, *cached_data, source)
1425              .ToHandle(&result)) {
1426        // Promote to per-isolate compilation cache.
1427        compilation_cache->PutScript(source, context, language_mode, result);
1428        return result;
1429      }
1430      // Deserializer failed. Fall through to compile.
1431    }
1432  }
1433
1434  base::ElapsedTimer timer;
1435  if (FLAG_profile_deserialization && FLAG_serialize_toplevel &&
1436      compile_options == ScriptCompiler::kProduceCodeCache) {
1437    timer.Start();
1438  }
1439
1440  if (!maybe_result.ToHandle(&result) ||
1441      (FLAG_serialize_toplevel &&
1442       compile_options == ScriptCompiler::kProduceCodeCache)) {
1443    // No cache entry found, or embedder wants a code cache. Compile the script.
1444
1445    // Create a script object describing the script to be compiled.
1446    Handle<Script> script = isolate->factory()->NewScript(source);
1447    if (FLAG_trace_deopt) Script::InitLineEnds(script);
1448    if (natives == NATIVES_CODE) {
1449      script->set_type(Script::TYPE_NATIVE);
1450      script->set_hide_source(true);
1451    } else if (natives == EXTENSION_CODE) {
1452      script->set_type(Script::TYPE_EXTENSION);
1453      script->set_hide_source(true);
1454    }
1455    if (!script_name.is_null()) {
1456      script->set_name(*script_name);
1457      script->set_line_offset(line_offset);
1458      script->set_column_offset(column_offset);
1459    }
1460    script->set_origin_options(resource_options);
1461    if (!source_map_url.is_null()) {
1462      script->set_source_mapping_url(*source_map_url);
1463    }
1464
1465    // Compile the function and add it to the cache.
1466    Zone zone(isolate->allocator(), ZONE_NAME);
1467    ParseInfo parse_info(&zone, script);
1468    CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1469    if (is_module) parse_info.set_module();
1470    if (compile_options != ScriptCompiler::kNoCompileOptions) {
1471      parse_info.set_cached_data(cached_data);
1472    }
1473    parse_info.set_compile_options(compile_options);
1474    parse_info.set_extension(extension);
1475    if (!context->IsNativeContext()) {
1476      parse_info.set_outer_scope_info(handle(context->scope_info()));
1477    }
1478    if (FLAG_serialize_toplevel &&
1479        compile_options == ScriptCompiler::kProduceCodeCache) {
1480      info.PrepareForSerializing();
1481    }
1482
1483    parse_info.set_language_mode(
1484        static_cast<LanguageMode>(parse_info.language_mode() | language_mode));
1485    result = CompileToplevel(&info);
1486    if (extension == NULL && !result.is_null()) {
1487      compilation_cache->PutScript(source, context, language_mode, result);
1488      if (FLAG_serialize_toplevel &&
1489          compile_options == ScriptCompiler::kProduceCodeCache) {
1490        HistogramTimerScope histogram_timer(
1491            isolate->counters()->compile_serialize());
1492        RuntimeCallTimerScope runtimeTimer(isolate,
1493                                           &RuntimeCallStats::CompileSerialize);
1494        TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
1495                     "V8.CompileSerialize");
1496        *cached_data = CodeSerializer::Serialize(isolate, result, source);
1497        if (FLAG_profile_deserialization) {
1498          PrintF("[Compiling and serializing took %0.3f ms]\n",
1499                 timer.Elapsed().InMillisecondsF());
1500        }
1501      }
1502    }
1503
1504    if (result.is_null()) {
1505      isolate->ReportPendingMessages();
1506    } else {
1507      isolate->debug()->OnAfterCompile(script);
1508    }
1509  } else if (result->ic_age() != isolate->heap()->global_ic_age()) {
1510    result->ResetForNewContext(isolate->heap()->global_ic_age());
1511  }
1512  return result;
1513}
1514
1515Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForStreamedScript(
1516    Handle<Script> script, ParseInfo* parse_info, int source_length) {
1517  Isolate* isolate = script->GetIsolate();
1518  // TODO(titzer): increment the counters in caller.
1519  isolate->counters()->total_load_size()->Increment(source_length);
1520  isolate->counters()->total_compile_size()->Increment(source_length);
1521
1522  LanguageMode language_mode = construct_language_mode(FLAG_use_strict);
1523  parse_info->set_language_mode(
1524      static_cast<LanguageMode>(parse_info->language_mode() | language_mode));
1525
1526  CompilationInfo compile_info(parse_info, Handle<JSFunction>::null());
1527
1528  // The source was parsed lazily, so compiling for debugging is not possible.
1529  DCHECK(!compile_info.is_debug());
1530
1531  Handle<SharedFunctionInfo> result = CompileToplevel(&compile_info);
1532  if (!result.is_null()) isolate->debug()->OnAfterCompile(script);
1533  return result;
1534}
1535
1536
1537Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
1538    FunctionLiteral* literal, Handle<Script> script,
1539    CompilationInfo* outer_info) {
1540  // Precondition: code has been parsed and scopes have been analyzed.
1541  Isolate* isolate = outer_info->isolate();
1542  MaybeHandle<SharedFunctionInfo> maybe_existing;
1543
1544  // Find any previously allocated shared function info for the given literal.
1545  if (outer_info->shared_info()->never_compiled()) {
1546    // On the first compile, there are no existing shared function info for
1547    // inner functions yet, so do not try to find them. All bets are off for
1548    // live edit though.
1549    SLOW_DCHECK(script->FindSharedFunctionInfo(literal).is_null() ||
1550                isolate->debug()->live_edit_enabled());
1551  } else {
1552    maybe_existing = script->FindSharedFunctionInfo(literal);
1553  }
1554
1555  // We found an existing shared function info. If it has any sort of code
1556  // attached, don't worry about compiling and simply return it. Otherwise,
1557  // continue to decide whether to eagerly compile.
1558  // Note that we also carry on if we are compiling eager to obtain code for
1559  // debugging, unless we already have code with debug break slots.
1560  Handle<SharedFunctionInfo> existing;
1561  if (maybe_existing.ToHandle(&existing)) {
1562    DCHECK(!existing->is_toplevel());
1563    if (existing->HasBaselineCode() || existing->HasBytecodeArray()) {
1564      if (!outer_info->is_debug() || existing->HasDebugCode()) {
1565        return existing;
1566      }
1567    }
1568  }
1569
1570  // Allocate a shared function info object.
1571  Handle<SharedFunctionInfo> result;
1572  if (!maybe_existing.ToHandle(&result)) {
1573    result = NewSharedFunctionInfoForLiteral(isolate, literal, script);
1574    result->set_is_toplevel(false);
1575
1576    // If the outer function has been compiled before, we cannot be sure that
1577    // shared function info for this function literal has been created for the
1578    // first time. It may have already been compiled previously.
1579    result->set_never_compiled(outer_info->shared_info()->never_compiled());
1580  }
1581
1582  Zone zone(isolate->allocator(), ZONE_NAME);
1583  ParseInfo parse_info(&zone, script);
1584  CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1585  parse_info.set_literal(literal);
1586  parse_info.set_shared_info(result);
1587  parse_info.set_language_mode(literal->scope()->language_mode());
1588  parse_info.set_ast_value_factory(
1589      outer_info->parse_info()->ast_value_factory());
1590  parse_info.set_ast_value_factory_owned(false);
1591
1592  if (outer_info->will_serialize()) info.PrepareForSerializing();
1593  if (outer_info->is_debug()) info.MarkAsDebug();
1594
1595  // If this inner function is already compiled, we don't need to compile
1596  // again. When compiling for debug, we are not interested in having debug
1597  // break slots in inner functions, neither for setting break points nor
1598  // for revealing inner functions.
1599  // This is especially important for generators. We must not replace the
1600  // code for generators, as there may be suspended generator objects.
1601  if (!result->is_compiled()) {
1602    if (!literal->ShouldEagerCompile()) {
1603      info.SetCode(isolate->builtins()->CompileLazy());
1604      Scope* outer_scope = literal->scope()->GetOuterScopeWithContext();
1605      if (outer_scope) {
1606        result->set_outer_scope_info(*outer_scope->scope_info());
1607      }
1608    } else {
1609      // Generate code
1610      TimerEventScope<TimerEventCompileCode> timer(isolate);
1611      RuntimeCallTimerScope runtimeTimer(isolate,
1612                                         &RuntimeCallStats::CompileCode);
1613      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileCode");
1614      if (Renumber(info.parse_info()) && GenerateUnoptimizedCode(&info)) {
1615        // Code generation will ensure that the feedback vector is present and
1616        // appropriately sized.
1617        DCHECK(!info.code().is_null());
1618        if (literal->should_be_used_once_hint()) {
1619          info.code()->MarkToBeExecutedOnce(isolate);
1620        }
1621      } else {
1622        return Handle<SharedFunctionInfo>::null();
1623      }
1624    }
1625  }
1626
1627  if (maybe_existing.is_null()) {
1628    RecordFunctionCompilation(CodeEventListener::FUNCTION_TAG, &info);
1629  }
1630
1631  return result;
1632}
1633
1634Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForNative(
1635    v8::Extension* extension, Handle<String> name) {
1636  Isolate* isolate = name->GetIsolate();
1637  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
1638
1639  // Compute the function template for the native function.
1640  v8::Local<v8::FunctionTemplate> fun_template =
1641      extension->GetNativeFunctionTemplate(v8_isolate,
1642                                           v8::Utils::ToLocal(name));
1643  DCHECK(!fun_template.IsEmpty());
1644
1645  // Instantiate the function and create a shared function info from it.
1646  Handle<JSFunction> fun = Handle<JSFunction>::cast(Utils::OpenHandle(
1647      *fun_template->GetFunction(v8_isolate->GetCurrentContext())
1648           .ToLocalChecked()));
1649  Handle<Code> code = Handle<Code>(fun->shared()->code());
1650  Handle<Code> construct_stub = Handle<Code>(fun->shared()->construct_stub());
1651  Handle<SharedFunctionInfo> shared = isolate->factory()->NewSharedFunctionInfo(
1652      name, fun->shared()->num_literals(), FunctionKind::kNormalFunction, code,
1653      Handle<ScopeInfo>(fun->shared()->scope_info()));
1654  shared->set_outer_scope_info(fun->shared()->outer_scope_info());
1655  shared->SetConstructStub(*construct_stub);
1656  shared->set_feedback_metadata(fun->shared()->feedback_metadata());
1657
1658  // Copy the function data to the shared function info.
1659  shared->set_function_data(fun->shared()->function_data());
1660  int parameters = fun->shared()->internal_formal_parameter_count();
1661  shared->set_internal_formal_parameter_count(parameters);
1662
1663  return shared;
1664}
1665
1666MaybeHandle<Code> Compiler::GetOptimizedCodeForOSR(Handle<JSFunction> function,
1667                                                   BailoutId osr_ast_id,
1668                                                   JavaScriptFrame* osr_frame) {
1669  DCHECK(!osr_ast_id.IsNone());
1670  DCHECK_NOT_NULL(osr_frame);
1671  return GetOptimizedCode(function, NOT_CONCURRENT, osr_ast_id, osr_frame);
1672}
1673
1674CompilationJob* Compiler::PrepareUnoptimizedCompilationJob(
1675    CompilationInfo* info) {
1676  VMState<COMPILER> state(info->isolate());
1677  std::unique_ptr<CompilationJob> job(GetUnoptimizedCompilationJob(info));
1678  if (job->PrepareJob() != CompilationJob::SUCCEEDED) {
1679    return nullptr;
1680  }
1681  return job.release();
1682}
1683
1684bool Compiler::FinalizeCompilationJob(CompilationJob* raw_job) {
1685  // Take ownership of compilation job.  Deleting job also tears down the zone.
1686  std::unique_ptr<CompilationJob> job(raw_job);
1687
1688  VMState<COMPILER> state(job->info()->isolate());
1689  if (job->info()->IsOptimizing()) {
1690    return FinalizeOptimizedCompilationJob(job.get()) ==
1691           CompilationJob::SUCCEEDED;
1692  } else {
1693    if (FinalizeUnoptimizedCompilationJob(job.get()) ==
1694        CompilationJob::SUCCEEDED) {
1695      RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG,
1696                                job->info());
1697      return true;
1698    }
1699    return false;
1700  }
1701}
1702
1703void Compiler::PostInstantiation(Handle<JSFunction> function,
1704                                 PretenureFlag pretenure) {
1705  Handle<SharedFunctionInfo> shared(function->shared());
1706
1707  if (FLAG_always_opt && shared->allows_lazy_compilation()) {
1708    function->MarkForOptimization();
1709  }
1710
1711  CodeAndLiterals cached = shared->SearchOptimizedCodeMap(
1712      function->context()->native_context(), BailoutId::None());
1713  if (cached.code != nullptr) {
1714    // Caching of optimized code enabled and optimized code found.
1715    DCHECK(!cached.code->marked_for_deoptimization());
1716    DCHECK(function->shared()->is_compiled());
1717    function->ReplaceCode(cached.code);
1718  }
1719
1720  if (cached.literals != nullptr) {
1721    DCHECK(shared->is_compiled());
1722    function->set_literals(cached.literals);
1723  } else if (shared->is_compiled()) {
1724    // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
1725    JSFunction::EnsureLiterals(function);
1726  }
1727}
1728
1729}  // namespace internal
1730}  // namespace v8
1731