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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/compiler.h"
6 
7 #include <algorithm>
8 
9 #include "src/ast/ast-numbering.h"
10 #include "src/ast/prettyprinter.h"
11 #include "src/ast/scopeinfo.h"
12 #include "src/ast/scopes.h"
13 #include "src/bootstrapper.h"
14 #include "src/codegen.h"
15 #include "src/compilation-cache.h"
16 #include "src/compiler/pipeline.h"
17 #include "src/crankshaft/hydrogen.h"
18 #include "src/debug/debug.h"
19 #include "src/debug/liveedit.h"
20 #include "src/deoptimizer.h"
21 #include "src/frames-inl.h"
22 #include "src/full-codegen/full-codegen.h"
23 #include "src/interpreter/interpreter.h"
24 #include "src/isolate-inl.h"
25 #include "src/log-inl.h"
26 #include "src/messages.h"
27 #include "src/parsing/parser.h"
28 #include "src/parsing/rewriter.h"
29 #include "src/parsing/scanner-character-streams.h"
30 #include "src/runtime-profiler.h"
31 #include "src/snapshot/code-serializer.h"
32 #include "src/typing-asm.h"
33 #include "src/vm-state-inl.h"
34 
35 namespace v8 {
36 namespace internal {
37 
38 
39 #define PARSE_INFO_GETTER(type, name)  \
40   type CompilationInfo::name() const { \
41     CHECK(parse_info());               \
42     return parse_info()->name();       \
43   }
44 
45 
46 #define PARSE_INFO_GETTER_WITH_DEFAULT(type, name, def) \
47   type CompilationInfo::name() const {                  \
48     return parse_info() ? parse_info()->name() : def;   \
49   }
50 
51 
52 PARSE_INFO_GETTER(Handle<Script>, script)
53 PARSE_INFO_GETTER(FunctionLiteral*, literal)
54 PARSE_INFO_GETTER_WITH_DEFAULT(Scope*, scope, nullptr)
55 PARSE_INFO_GETTER_WITH_DEFAULT(Handle<Context>, context,
56                                Handle<Context>::null())
57 PARSE_INFO_GETTER(Handle<SharedFunctionInfo>, shared_info)
58 
59 #undef PARSE_INFO_GETTER
60 #undef PARSE_INFO_GETTER_WITH_DEFAULT
61 
62 // A wrapper around a CompilationInfo that detaches the Handles from
63 // the underlying DeferredHandleScope and stores them in info_ on
64 // destruction.
65 class CompilationHandleScope BASE_EMBEDDED {
66  public:
CompilationHandleScope(CompilationInfo * info)67   explicit CompilationHandleScope(CompilationInfo* info)
68       : deferred_(info->isolate()), info_(info) {}
~CompilationHandleScope()69   ~CompilationHandleScope() { info_->set_deferred_handles(deferred_.Detach()); }
70 
71  private:
72   DeferredHandleScope deferred_;
73   CompilationInfo* info_;
74 };
75 
76 // Helper that times a scoped region and records the elapsed time.
77 struct ScopedTimer {
ScopedTimerv8::internal::ScopedTimer78   explicit ScopedTimer(base::TimeDelta* location) : location_(location) {
79     DCHECK(location_ != NULL);
80     timer_.Start();
81   }
82 
~ScopedTimerv8::internal::ScopedTimer83   ~ScopedTimer() { *location_ += timer_.Elapsed(); }
84 
85   base::ElapsedTimer timer_;
86   base::TimeDelta* location_;
87 };
88 
89 // ----------------------------------------------------------------------------
90 // Implementation of CompilationInfo
91 
has_shared_info() const92 bool CompilationInfo::has_shared_info() const {
93   return parse_info_ && !parse_info_->shared_info().is_null();
94 }
95 
CompilationInfo(ParseInfo * parse_info,Handle<JSFunction> closure)96 CompilationInfo::CompilationInfo(ParseInfo* parse_info,
97                                  Handle<JSFunction> closure)
98     : CompilationInfo(parse_info, {}, Code::ComputeFlags(Code::FUNCTION), BASE,
99                       parse_info->isolate(), parse_info->zone()) {
100   closure_ = closure;
101 
102   // Compiling for the snapshot typically results in different code than
103   // compiling later on. This means that code recompiled with deoptimization
104   // support won't be "equivalent" (as defined by SharedFunctionInfo::
105   // EnableDeoptimizationSupport), so it will replace the old code and all
106   // its type feedback. To avoid this, always compile functions in the snapshot
107   // with deoptimization support.
108   if (isolate_->serializer_enabled()) EnableDeoptimizationSupport();
109 
110   if (FLAG_function_context_specialization) MarkAsFunctionContextSpecializing();
111   if (FLAG_turbo_inlining) MarkAsInliningEnabled();
112   if (FLAG_turbo_source_positions) MarkAsSourcePositionsEnabled();
113   if (FLAG_turbo_splitting) MarkAsSplittingEnabled();
114 }
115 
CompilationInfo(Vector<const char> debug_name,Isolate * isolate,Zone * zone,Code::Flags code_flags)116 CompilationInfo::CompilationInfo(Vector<const char> debug_name,
117                                  Isolate* isolate, Zone* zone,
118                                  Code::Flags code_flags)
119     : CompilationInfo(nullptr, debug_name, code_flags, STUB, isolate, zone) {}
120 
CompilationInfo(ParseInfo * parse_info,Vector<const char> debug_name,Code::Flags code_flags,Mode mode,Isolate * isolate,Zone * zone)121 CompilationInfo::CompilationInfo(ParseInfo* parse_info,
122                                  Vector<const char> debug_name,
123                                  Code::Flags code_flags, Mode mode,
124                                  Isolate* isolate, Zone* zone)
125     : parse_info_(parse_info),
126       isolate_(isolate),
127       flags_(0),
128       code_flags_(code_flags),
129       mode_(mode),
130       osr_ast_id_(BailoutId::None()),
131       zone_(zone),
132       deferred_handles_(nullptr),
133       dependencies_(isolate, zone),
134       bailout_reason_(kNoReason),
135       prologue_offset_(Code::kPrologueOffsetNotSet),
136       track_positions_(FLAG_hydrogen_track_positions ||
137                        isolate->is_profiling()),
138       parameter_count_(0),
139       optimization_id_(-1),
140       osr_expr_stack_height_(0),
141       debug_name_(debug_name) {}
142 
~CompilationInfo()143 CompilationInfo::~CompilationInfo() {
144   DisableFutureOptimization();
145   dependencies()->Rollback();
146   delete deferred_handles_;
147 }
148 
149 
num_parameters() const150 int CompilationInfo::num_parameters() const {
151   return !IsStub() ? scope()->num_parameters() : parameter_count_;
152 }
153 
154 
num_parameters_including_this() const155 int CompilationInfo::num_parameters_including_this() const {
156   return num_parameters() + (is_this_defined() ? 1 : 0);
157 }
158 
159 
is_this_defined() const160 bool CompilationInfo::is_this_defined() const { return !IsStub(); }
161 
162 
163 // Primitive functions are unlikely to be picked up by the stack-walking
164 // profiler, so they trigger their own optimization when they're called
165 // for the SharedFunctionInfo::kCallsUntilPrimitiveOptimization-th time.
ShouldSelfOptimize()166 bool CompilationInfo::ShouldSelfOptimize() {
167   return FLAG_crankshaft &&
168          !(literal()->flags() & AstProperties::kDontSelfOptimize) &&
169          !literal()->dont_optimize() &&
170          literal()->scope()->AllowsLazyCompilation() &&
171          !shared_info()->optimization_disabled();
172 }
173 
174 
has_simple_parameters()175 bool CompilationInfo::has_simple_parameters() {
176   return scope()->has_simple_parameters();
177 }
178 
179 
GetDebugName() const180 base::SmartArrayPointer<char> CompilationInfo::GetDebugName() const {
181   if (parse_info() && parse_info()->literal()) {
182     AllowHandleDereference allow_deref;
183     return parse_info()->literal()->debug_name()->ToCString();
184   }
185   if (parse_info() && !parse_info()->shared_info().is_null()) {
186     return parse_info()->shared_info()->DebugName()->ToCString();
187   }
188   Vector<const char> name_vec = debug_name_;
189   if (name_vec.is_empty()) name_vec = ArrayVector("unknown");
190   base::SmartArrayPointer<char> name(new char[name_vec.length() + 1]);
191   memcpy(name.get(), name_vec.start(), name_vec.length());
192   name[name_vec.length()] = '\0';
193   return name;
194 }
195 
GetOutputStackFrameType() const196 StackFrame::Type CompilationInfo::GetOutputStackFrameType() const {
197   switch (output_code_kind()) {
198     case Code::STUB:
199     case Code::BYTECODE_HANDLER:
200     case Code::HANDLER:
201     case Code::BUILTIN:
202 #define CASE_KIND(kind) case Code::kind:
203       IC_KIND_LIST(CASE_KIND)
204 #undef CASE_KIND
205       return StackFrame::STUB;
206     case Code::WASM_FUNCTION:
207       return StackFrame::WASM;
208     case Code::JS_TO_WASM_FUNCTION:
209       return StackFrame::JS_TO_WASM;
210     case Code::WASM_TO_JS_FUNCTION:
211       return StackFrame::WASM_TO_JS;
212     default:
213       UNIMPLEMENTED();
214       return StackFrame::NONE;
215   }
216 }
217 
GetDeclareGlobalsFlags() const218 int CompilationInfo::GetDeclareGlobalsFlags() const {
219   DCHECK(DeclareGlobalsLanguageMode::is_valid(parse_info()->language_mode()));
220   return DeclareGlobalsEvalFlag::encode(parse_info()->is_eval()) |
221          DeclareGlobalsNativeFlag::encode(parse_info()->is_native()) |
222          DeclareGlobalsLanguageMode::encode(parse_info()->language_mode());
223 }
224 
ExpectsJSReceiverAsReceiver()225 bool CompilationInfo::ExpectsJSReceiverAsReceiver() {
226   return is_sloppy(parse_info()->language_mode()) && !parse_info()->is_native();
227 }
228 
229 #if DEBUG
PrintAstForTesting()230 void CompilationInfo::PrintAstForTesting() {
231   PrintF("--- Source from AST ---\n%s\n",
232          PrettyPrinter(isolate()).PrintProgram(literal()));
233 }
234 #endif
235 
236 // ----------------------------------------------------------------------------
237 // Implementation of CompilationJob
238 
CreateGraph()239 CompilationJob::Status CompilationJob::CreateGraph() {
240   DisallowJavascriptExecution no_js(isolate());
241   DCHECK(info()->IsOptimizing());
242 
243   if (FLAG_trace_opt) {
244     OFStream os(stdout);
245     os << "[compiling method " << Brief(*info()->closure()) << " using "
246        << compiler_name_;
247     if (info()->is_osr()) os << " OSR";
248     os << "]" << std::endl;
249   }
250 
251   // Delegate to the underlying implementation.
252   DCHECK_EQ(SUCCEEDED, last_status());
253   ScopedTimer t(&time_taken_to_create_graph_);
254   return SetLastStatus(CreateGraphImpl());
255 }
256 
OptimizeGraph()257 CompilationJob::Status CompilationJob::OptimizeGraph() {
258   DisallowHeapAllocation no_allocation;
259   DisallowHandleAllocation no_handles;
260   DisallowHandleDereference no_deref;
261   DisallowCodeDependencyChange no_dependency_change;
262 
263   // Delegate to the underlying implementation.
264   DCHECK_EQ(SUCCEEDED, last_status());
265   ScopedTimer t(&time_taken_to_optimize_);
266   return SetLastStatus(OptimizeGraphImpl());
267 }
268 
GenerateCode()269 CompilationJob::Status CompilationJob::GenerateCode() {
270   DisallowCodeDependencyChange no_dependency_change;
271   DisallowJavascriptExecution no_js(isolate());
272   DCHECK(!info()->dependencies()->HasAborted());
273 
274   // Delegate to the underlying implementation.
275   DCHECK_EQ(SUCCEEDED, last_status());
276   ScopedTimer t(&time_taken_to_codegen_);
277   return SetLastStatus(GenerateCodeImpl());
278 }
279 
280 
281 namespace {
282 
AddWeakObjectToCodeDependency(Isolate * isolate,Handle<HeapObject> object,Handle<Code> code)283 void AddWeakObjectToCodeDependency(Isolate* isolate, Handle<HeapObject> object,
284                                    Handle<Code> code) {
285   Handle<WeakCell> cell = Code::WeakCellFor(code);
286   Heap* heap = isolate->heap();
287   Handle<DependentCode> dep(heap->LookupWeakObjectToCodeDependency(object));
288   dep = DependentCode::InsertWeakCode(dep, DependentCode::kWeakCodeGroup, cell);
289   heap->AddWeakObjectToCodeDependency(object, dep);
290 }
291 
292 }  // namespace
293 
RegisterWeakObjectsInOptimizedCode(Handle<Code> code)294 void CompilationJob::RegisterWeakObjectsInOptimizedCode(Handle<Code> code) {
295   // TODO(turbofan): Move this to pipeline.cc once Crankshaft dies.
296   Isolate* const isolate = code->GetIsolate();
297   DCHECK(code->is_optimized_code());
298   std::vector<Handle<Map>> maps;
299   std::vector<Handle<HeapObject>> objects;
300   {
301     DisallowHeapAllocation no_gc;
302     int const mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
303                           RelocInfo::ModeMask(RelocInfo::CELL);
304     for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
305       RelocInfo::Mode mode = it.rinfo()->rmode();
306       if (mode == RelocInfo::CELL &&
307           code->IsWeakObjectInOptimizedCode(it.rinfo()->target_cell())) {
308         objects.push_back(handle(it.rinfo()->target_cell(), isolate));
309       } else if (mode == RelocInfo::EMBEDDED_OBJECT &&
310                  code->IsWeakObjectInOptimizedCode(
311                      it.rinfo()->target_object())) {
312         Handle<HeapObject> object(HeapObject::cast(it.rinfo()->target_object()),
313                                   isolate);
314         if (object->IsMap()) {
315           maps.push_back(Handle<Map>::cast(object));
316         } else {
317           objects.push_back(object);
318         }
319       }
320     }
321   }
322   for (Handle<Map> map : maps) {
323     if (map->dependent_code()->IsEmpty(DependentCode::kWeakCodeGroup)) {
324       isolate->heap()->AddRetainedMap(map);
325     }
326     Map::AddDependentCode(map, DependentCode::kWeakCodeGroup, code);
327   }
328   for (Handle<HeapObject> object : objects) {
329     AddWeakObjectToCodeDependency(isolate, object, code);
330   }
331   code->set_can_have_weak_objects(true);
332 }
333 
RecordOptimizationStats()334 void CompilationJob::RecordOptimizationStats() {
335   Handle<JSFunction> function = info()->closure();
336   if (!function->IsOptimized()) {
337     // Concurrent recompilation and OSR may race.  Increment only once.
338     int opt_count = function->shared()->opt_count();
339     function->shared()->set_opt_count(opt_count + 1);
340   }
341   double ms_creategraph = time_taken_to_create_graph_.InMillisecondsF();
342   double ms_optimize = time_taken_to_optimize_.InMillisecondsF();
343   double ms_codegen = time_taken_to_codegen_.InMillisecondsF();
344   if (FLAG_trace_opt) {
345     PrintF("[optimizing ");
346     function->ShortPrint();
347     PrintF(" - took %0.3f, %0.3f, %0.3f ms]\n", ms_creategraph, ms_optimize,
348            ms_codegen);
349   }
350   if (FLAG_trace_opt_stats) {
351     static double compilation_time = 0.0;
352     static int compiled_functions = 0;
353     static int code_size = 0;
354 
355     compilation_time += (ms_creategraph + ms_optimize + ms_codegen);
356     compiled_functions++;
357     code_size += function->shared()->SourceSize();
358     PrintF("Compiled: %d functions with %d byte source size in %fms.\n",
359            compiled_functions,
360            code_size,
361            compilation_time);
362   }
363   if (FLAG_hydrogen_stats) {
364     isolate()->GetHStatistics()->IncrementSubtotals(time_taken_to_create_graph_,
365                                                     time_taken_to_optimize_,
366                                                     time_taken_to_codegen_);
367   }
368 }
369 
370 // ----------------------------------------------------------------------------
371 // Local helper methods that make up the compilation pipeline.
372 
373 namespace {
374 
IsEvalToplevel(Handle<SharedFunctionInfo> shared)375 bool IsEvalToplevel(Handle<SharedFunctionInfo> shared) {
376   return shared->is_toplevel() && shared->script()->IsScript() &&
377          Script::cast(shared->script())->compilation_type() ==
378              Script::COMPILATION_TYPE_EVAL;
379 }
380 
RecordFunctionCompilation(CodeEventListener::LogEventsAndTags tag,CompilationInfo * info)381 void RecordFunctionCompilation(CodeEventListener::LogEventsAndTags tag,
382                                CompilationInfo* info) {
383   // Log the code generation. If source information is available include
384   // script name and line number. Check explicitly whether logging is
385   // enabled as finding the line number is not free.
386   if (info->isolate()->logger()->is_logging_code_events() ||
387       info->isolate()->is_profiling()) {
388     Handle<SharedFunctionInfo> shared = info->shared_info();
389     Handle<Script> script = info->parse_info()->script();
390     Handle<AbstractCode> abstract_code =
391         info->has_bytecode_array()
392             ? Handle<AbstractCode>::cast(info->bytecode_array())
393             : Handle<AbstractCode>::cast(info->code());
394     if (abstract_code.is_identical_to(
395             info->isolate()->builtins()->CompileLazy())) {
396       return;
397     }
398     int line_num = Script::GetLineNumber(script, shared->start_position()) + 1;
399     int column_num =
400         Script::GetColumnNumber(script, shared->start_position()) + 1;
401     String* script_name = script->name()->IsString()
402                               ? String::cast(script->name())
403                               : info->isolate()->heap()->empty_string();
404     CodeEventListener::LogEventsAndTags log_tag =
405         Logger::ToNativeByScript(tag, *script);
406     PROFILE(info->isolate(),
407             CodeCreateEvent(log_tag, *abstract_code, *shared, script_name,
408                             line_num, column_num));
409   }
410 }
411 
EnsureFeedbackMetadata(CompilationInfo * info)412 void EnsureFeedbackMetadata(CompilationInfo* info) {
413   DCHECK(info->has_shared_info());
414 
415   // If no type feedback metadata exists, we create it now. At this point the
416   // AstNumbering pass has already run. Note the snapshot can contain outdated
417   // vectors for a different configuration, hence we also recreate a new vector
418   // when the function is not compiled (i.e. no code was serialized).
419 
420   // TODO(mvstanton): reintroduce is_empty() predicate to feedback_metadata().
421   if (info->shared_info()->feedback_metadata()->length() == 0 ||
422       !info->shared_info()->is_compiled()) {
423     Handle<TypeFeedbackMetadata> feedback_metadata = TypeFeedbackMetadata::New(
424         info->isolate(), info->literal()->feedback_vector_spec());
425     info->shared_info()->set_feedback_metadata(*feedback_metadata);
426   }
427 
428   // It's very important that recompiles do not alter the structure of the type
429   // feedback vector. Verify that the structure fits the function literal.
430   CHECK(!info->shared_info()->feedback_metadata()->SpecDiffersFrom(
431       info->literal()->feedback_vector_spec()));
432 }
433 
UseIgnition(CompilationInfo * info)434 bool UseIgnition(CompilationInfo* info) {
435   DCHECK(info->has_shared_info());
436 
437   // When requesting debug code as a replacement for existing code, we provide
438   // the same kind as the existing code (to prevent implicit tier-change).
439   if (info->is_debug() && info->shared_info()->is_compiled()) {
440     return info->shared_info()->HasBytecodeArray();
441   }
442 
443   // For generator or async functions we might avoid Ignition wholesale.
444   if (info->shared_info()->is_resumable() && !FLAG_ignition_generators) {
445     return false;
446   }
447 
448   // Since we can't OSR from Ignition, skip Ignition for asm.js functions.
449   if (info->shared_info()->asm_function()) {
450     return false;
451   }
452 
453   // Checks whether top level functions should be passed by the filter.
454   if (info->shared_info()->is_toplevel()) {
455     Vector<const char> filter = CStrVector(FLAG_ignition_filter);
456     return (filter.length() == 0) || (filter.length() == 1 && filter[0] == '*');
457   }
458 
459   // Finally respect the filter.
460   return info->shared_info()->PassesFilter(FLAG_ignition_filter);
461 }
462 
CodeAndMetadataSize(CompilationInfo * info)463 int CodeAndMetadataSize(CompilationInfo* info) {
464   if (info->has_bytecode_array()) {
465     return info->bytecode_array()->SizeIncludingMetadata();
466   }
467   return info->code()->SizeIncludingMetadata();
468 }
469 
GenerateUnoptimizedCode(CompilationInfo * info)470 bool GenerateUnoptimizedCode(CompilationInfo* info) {
471   bool success;
472   EnsureFeedbackMetadata(info);
473   if (FLAG_validate_asm && info->scope()->asm_module()) {
474     AsmTyper typer(info->isolate(), info->zone(), *(info->script()),
475                    info->literal());
476     if (FLAG_enable_simd_asmjs) {
477       typer.set_allow_simd(true);
478     }
479     if (!typer.Validate()) {
480       DCHECK(!info->isolate()->has_pending_exception());
481       PrintF("Validation of asm.js module failed: %s", typer.error_message());
482     }
483   }
484   if (FLAG_ignition && UseIgnition(info)) {
485     success = interpreter::Interpreter::MakeBytecode(info);
486   } else {
487     success = FullCodeGenerator::MakeCode(info);
488   }
489   if (success) {
490     Isolate* isolate = info->isolate();
491     Counters* counters = isolate->counters();
492     // TODO(4280): Rename counters from "baseline" to "unoptimized" eventually.
493     counters->total_baseline_code_size()->Increment(CodeAndMetadataSize(info));
494     counters->total_baseline_compile_count()->Increment(1);
495   }
496   return success;
497 }
498 
CompileUnoptimizedCode(CompilationInfo * info)499 bool CompileUnoptimizedCode(CompilationInfo* info) {
500   DCHECK(AllowCompilation::IsAllowed(info->isolate()));
501   if (!Compiler::Analyze(info->parse_info()) ||
502       !GenerateUnoptimizedCode(info)) {
503     Isolate* isolate = info->isolate();
504     if (!isolate->has_pending_exception()) isolate->StackOverflow();
505     return false;
506   }
507   return true;
508 }
509 
InstallSharedScopeInfo(CompilationInfo * info,Handle<SharedFunctionInfo> shared)510 void InstallSharedScopeInfo(CompilationInfo* info,
511                             Handle<SharedFunctionInfo> shared) {
512   Handle<ScopeInfo> scope_info =
513       ScopeInfo::Create(info->isolate(), info->zone(), info->scope());
514   shared->set_scope_info(*scope_info);
515 }
516 
InstallSharedCompilationResult(CompilationInfo * info,Handle<SharedFunctionInfo> shared)517 void InstallSharedCompilationResult(CompilationInfo* info,
518                                     Handle<SharedFunctionInfo> shared) {
519   // TODO(mstarzinger): Compiling for debug code might be used to reveal inner
520   // functions via {FindSharedFunctionInfoInScript}, in which case we end up
521   // regenerating existing bytecode. Fix this!
522   if (info->is_debug() && info->has_bytecode_array()) {
523     shared->ClearBytecodeArray();
524   }
525   // Assert that we are not overwriting (possibly patched) debug code.
526   DCHECK(!shared->HasDebugInfo());
527   DCHECK(!info->code().is_null());
528   shared->ReplaceCode(*info->code());
529   if (info->has_bytecode_array()) {
530     DCHECK(!shared->HasBytecodeArray());  // Only compiled once.
531     shared->set_bytecode_array(*info->bytecode_array());
532   }
533 }
534 
GetUnoptimizedCode(CompilationInfo * info)535 MUST_USE_RESULT MaybeHandle<Code> GetUnoptimizedCode(CompilationInfo* info) {
536   VMState<COMPILER> state(info->isolate());
537   PostponeInterruptsScope postpone(info->isolate());
538 
539   // Parse and update CompilationInfo with the results.
540   if (!Parser::ParseStatic(info->parse_info())) return MaybeHandle<Code>();
541   Handle<SharedFunctionInfo> shared = info->shared_info();
542   DCHECK_EQ(shared->language_mode(), info->literal()->language_mode());
543 
544   // Compile either unoptimized code or bytecode for the interpreter.
545   if (!CompileUnoptimizedCode(info)) return MaybeHandle<Code>();
546 
547   // Update the shared function info with the scope info.
548   InstallSharedScopeInfo(info, shared);
549 
550   // Install compilation result on the shared function info
551   InstallSharedCompilationResult(info, shared);
552 
553   // Record the function compilation event.
554   RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG, info);
555 
556   return info->code();
557 }
558 
GetCodeFromOptimizedCodeMap(Handle<JSFunction> function,BailoutId osr_ast_id)559 MUST_USE_RESULT MaybeHandle<Code> GetCodeFromOptimizedCodeMap(
560     Handle<JSFunction> function, BailoutId osr_ast_id) {
561   Handle<SharedFunctionInfo> shared(function->shared());
562   DisallowHeapAllocation no_gc;
563   CodeAndLiterals cached = shared->SearchOptimizedCodeMap(
564       function->context()->native_context(), osr_ast_id);
565   if (cached.code != nullptr) {
566     // Caching of optimized code enabled and optimized code found.
567     if (cached.literals != nullptr) function->set_literals(cached.literals);
568     DCHECK(!cached.code->marked_for_deoptimization());
569     DCHECK(function->shared()->is_compiled());
570     return Handle<Code>(cached.code);
571   }
572   return MaybeHandle<Code>();
573 }
574 
InsertCodeIntoOptimizedCodeMap(CompilationInfo * info)575 void InsertCodeIntoOptimizedCodeMap(CompilationInfo* info) {
576   Handle<Code> code = info->code();
577   if (code->kind() != Code::OPTIMIZED_FUNCTION) return;  // Nothing to do.
578 
579   // Function context specialization folds-in the function context,
580   // so no sharing can occur.
581   if (info->is_function_context_specializing()) return;
582   // Frame specialization implies function context specialization.
583   DCHECK(!info->is_frame_specializing());
584 
585   // Cache optimized context-specific code.
586   Handle<JSFunction> function = info->closure();
587   Handle<SharedFunctionInfo> shared(function->shared());
588   Handle<LiteralsArray> literals(function->literals());
589   Handle<Context> native_context(function->context()->native_context());
590   SharedFunctionInfo::AddToOptimizedCodeMap(shared, native_context, code,
591                                             literals, info->osr_ast_id());
592 
593   // Do not cache (native) context-independent code compiled for OSR.
594   if (code->is_turbofanned() && info->is_osr()) return;
595 
596   // Cache optimized (native) context-independent code.
597   if (FLAG_turbo_cache_shared_code && code->is_turbofanned() &&
598       !info->is_native_context_specializing()) {
599     DCHECK(!info->is_function_context_specializing());
600     DCHECK(info->osr_ast_id().IsNone());
601     Handle<SharedFunctionInfo> shared(function->shared());
602     SharedFunctionInfo::AddSharedCodeToOptimizedCodeMap(shared, code);
603   }
604 }
605 
Renumber(ParseInfo * parse_info)606 bool Renumber(ParseInfo* parse_info) {
607   if (!AstNumbering::Renumber(parse_info->isolate(), parse_info->zone(),
608                               parse_info->literal())) {
609     return false;
610   }
611   Handle<SharedFunctionInfo> shared_info = parse_info->shared_info();
612   if (!shared_info.is_null()) {
613     FunctionLiteral* lit = parse_info->literal();
614     shared_info->set_ast_node_count(lit->ast_node_count());
615     if (lit->dont_optimize_reason() != kNoReason) {
616       shared_info->DisableOptimization(lit->dont_optimize_reason());
617     }
618     shared_info->set_dont_crankshaft(
619         shared_info->dont_crankshaft() ||
620         (lit->flags() & AstProperties::kDontCrankshaft));
621   }
622   return true;
623 }
624 
UseTurboFan(Handle<SharedFunctionInfo> shared)625 bool UseTurboFan(Handle<SharedFunctionInfo> shared) {
626   bool optimization_disabled = shared->optimization_disabled();
627   bool dont_crankshaft = shared->dont_crankshaft();
628 
629   // Check the enabling conditions for Turbofan.
630   // 1. "use asm" code.
631   bool is_turbofanable_asm =
632       FLAG_turbo_asm && shared->asm_function() && !optimization_disabled;
633 
634   // 2. Fallback for features unsupported by Crankshaft.
635   bool is_unsupported_by_crankshaft_but_turbofanable =
636       dont_crankshaft && strcmp(FLAG_turbo_filter, "~~") == 0 &&
637       !optimization_disabled;
638 
639   // 3. Explicitly enabled by the command-line filter.
640   bool passes_turbo_filter = shared->PassesFilter(FLAG_turbo_filter);
641 
642   return is_turbofanable_asm || is_unsupported_by_crankshaft_but_turbofanable ||
643          passes_turbo_filter;
644 }
645 
GetOptimizedCodeNow(CompilationJob * job)646 bool GetOptimizedCodeNow(CompilationJob* job) {
647   CompilationInfo* info = job->info();
648   Isolate* isolate = info->isolate();
649 
650   // Parsing is not required when optimizing from existing bytecode.
651   if (!info->is_optimizing_from_bytecode()) {
652     if (!Compiler::ParseAndAnalyze(info->parse_info())) return false;
653     EnsureFeedbackMetadata(info);
654   }
655 
656   JSFunction::EnsureLiterals(info->closure());
657 
658   TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
659   RuntimeCallTimerScope runtimeTimer(isolate,
660                                      &RuntimeCallStats::RecompileSynchronous);
661   TRACE_EVENT0("v8", "V8.RecompileSynchronous");
662 
663   if (job->CreateGraph() != CompilationJob::SUCCEEDED ||
664       job->OptimizeGraph() != CompilationJob::SUCCEEDED ||
665       job->GenerateCode() != CompilationJob::SUCCEEDED) {
666     if (FLAG_trace_opt) {
667       PrintF("[aborted optimizing ");
668       info->closure()->ShortPrint();
669       PrintF(" because: %s]\n", GetBailoutReason(info->bailout_reason()));
670     }
671     return false;
672   }
673 
674   // Success!
675   job->RecordOptimizationStats();
676   DCHECK(!isolate->has_pending_exception());
677   InsertCodeIntoOptimizedCodeMap(info);
678   RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG, info);
679   return true;
680 }
681 
GetOptimizedCodeLater(CompilationJob * job)682 bool GetOptimizedCodeLater(CompilationJob* job) {
683   CompilationInfo* info = job->info();
684   Isolate* isolate = info->isolate();
685 
686   if (!isolate->optimizing_compile_dispatcher()->IsQueueAvailable()) {
687     if (FLAG_trace_concurrent_recompilation) {
688       PrintF("  ** Compilation queue full, will retry optimizing ");
689       info->closure()->ShortPrint();
690       PrintF(" later.\n");
691     }
692     return false;
693   }
694 
695   // All handles below this point will be allocated in a deferred handle scope
696   // that is detached and handed off to the background thread when we return.
697   CompilationHandleScope handle_scope(info);
698 
699   // Parsing is not required when optimizing from existing bytecode.
700   if (!info->is_optimizing_from_bytecode()) {
701     if (!Compiler::ParseAndAnalyze(info->parse_info())) return false;
702     EnsureFeedbackMetadata(info);
703   }
704 
705   JSFunction::EnsureLiterals(info->closure());
706 
707   // Reopen handles in the new CompilationHandleScope.
708   info->ReopenHandlesInNewHandleScope();
709   info->parse_info()->ReopenHandlesInNewHandleScope();
710 
711   TimerEventScope<TimerEventRecompileSynchronous> timer(info->isolate());
712   RuntimeCallTimerScope runtimeTimer(info->isolate(),
713                                      &RuntimeCallStats::RecompileSynchronous);
714   TRACE_EVENT0("v8", "V8.RecompileSynchronous");
715 
716   if (job->CreateGraph() != CompilationJob::SUCCEEDED) return false;
717   isolate->optimizing_compile_dispatcher()->QueueForOptimization(job);
718 
719   if (FLAG_trace_concurrent_recompilation) {
720     PrintF("  ** Queued ");
721     info->closure()->ShortPrint();
722     PrintF(" for concurrent optimization.\n");
723   }
724   return true;
725 }
726 
GetOptimizedCode(Handle<JSFunction> function,Compiler::ConcurrencyMode mode,BailoutId osr_ast_id=BailoutId::None (),JavaScriptFrame * osr_frame=nullptr)727 MaybeHandle<Code> GetOptimizedCode(Handle<JSFunction> function,
728                                    Compiler::ConcurrencyMode mode,
729                                    BailoutId osr_ast_id = BailoutId::None(),
730                                    JavaScriptFrame* osr_frame = nullptr) {
731   Isolate* isolate = function->GetIsolate();
732   Handle<SharedFunctionInfo> shared(function->shared(), isolate);
733 
734   Handle<Code> cached_code;
735   if (GetCodeFromOptimizedCodeMap(function, osr_ast_id)
736           .ToHandle(&cached_code)) {
737     if (FLAG_trace_opt) {
738       PrintF("[found optimized code for ");
739       function->ShortPrint();
740       if (!osr_ast_id.IsNone()) {
741         PrintF(" at OSR AST id %d", osr_ast_id.ToInt());
742       }
743       PrintF("]\n");
744     }
745     return cached_code;
746   }
747 
748   // Reset profiler ticks, function is no longer considered hot.
749   if (shared->is_compiled()) {
750     shared->code()->set_profiler_ticks(0);
751   }
752 
753   VMState<COMPILER> state(isolate);
754   DCHECK(!isolate->has_pending_exception());
755   PostponeInterruptsScope postpone(isolate);
756   bool use_turbofan = UseTurboFan(shared);
757   base::SmartPointer<CompilationJob> job(
758       use_turbofan ? compiler::Pipeline::NewCompilationJob(function)
759                    : new HCompilationJob(function));
760   CompilationInfo* info = job->info();
761   ParseInfo* parse_info = info->parse_info();
762 
763   info->SetOptimizingForOsr(osr_ast_id, osr_frame);
764 
765   // Do not use Crankshaft/TurboFan if we need to be able to set break points.
766   if (info->shared_info()->HasDebugInfo()) {
767     info->AbortOptimization(kFunctionBeingDebugged);
768     return MaybeHandle<Code>();
769   }
770 
771   // Limit the number of times we try to optimize functions.
772   const int kMaxOptCount =
773       FLAG_deopt_every_n_times == 0 ? FLAG_max_opt_count : 1000;
774   if (info->shared_info()->opt_count() > kMaxOptCount) {
775     info->AbortOptimization(kOptimizedTooManyTimes);
776     return MaybeHandle<Code>();
777   }
778 
779   CanonicalHandleScope canonical(isolate);
780   TimerEventScope<TimerEventOptimizeCode> optimize_code_timer(isolate);
781   RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::OptimizeCode);
782   TRACE_EVENT0("v8", "V8.OptimizeCode");
783 
784   // TurboFan can optimize directly from existing bytecode.
785   if (FLAG_turbo_from_bytecode && use_turbofan &&
786       info->shared_info()->HasBytecodeArray()) {
787     info->MarkAsOptimizeFromBytecode();
788   }
789 
790   if (IsEvalToplevel(shared)) {
791     parse_info->set_eval();
792     if (function->context()->IsNativeContext()) parse_info->set_global();
793     parse_info->set_toplevel();
794     parse_info->set_allow_lazy_parsing(false);
795     parse_info->set_lazy(false);
796   }
797 
798   if (mode == Compiler::CONCURRENT) {
799     if (GetOptimizedCodeLater(job.get())) {
800       job.Detach();   // The background recompile job owns this now.
801       return isolate->builtins()->InOptimizationQueue();
802     }
803   } else {
804     if (GetOptimizedCodeNow(job.get())) return info->code();
805   }
806 
807   if (isolate->has_pending_exception()) isolate->clear_pending_exception();
808   return MaybeHandle<Code>();
809 }
810 
811 class InterpreterActivationsFinder : public ThreadVisitor,
812                                      public OptimizedFunctionVisitor {
813  public:
InterpreterActivationsFinder(SharedFunctionInfo * shared)814   explicit InterpreterActivationsFinder(SharedFunctionInfo* shared)
815       : shared_(shared), has_activations_(false) {}
816 
VisitThread(Isolate * isolate,ThreadLocalTop * top)817   void VisitThread(Isolate* isolate, ThreadLocalTop* top) {
818     Address* activation_pc_address = nullptr;
819     JavaScriptFrameIterator it(isolate, top);
820     for (; !it.done(); it.Advance()) {
821       JavaScriptFrame* frame = it.frame();
822       if (!frame->is_interpreted()) continue;
823       if (frame->function()->shared() == shared_) {
824         has_activations_ = true;
825         activation_pc_address = frame->pc_address();
826       }
827     }
828 
829     if (activation_pc_address) {
830       activation_pc_addresses_.push_back(activation_pc_address);
831     }
832   }
833 
VisitFunction(JSFunction * function)834   void VisitFunction(JSFunction* function) {
835     if (function->Inlines(shared_)) has_activations_ = true;
836   }
837 
EnterContext(Context * context)838   void EnterContext(Context* context) {}
LeaveContext(Context * context)839   void LeaveContext(Context* context) {}
840 
MarkActivationsForBaselineOnReturn(Isolate * isolate)841   bool MarkActivationsForBaselineOnReturn(Isolate* isolate) {
842     if (activation_pc_addresses_.empty()) return false;
843 
844     for (Address* activation_pc_address : activation_pc_addresses_) {
845       DCHECK(isolate->inner_pointer_to_code_cache()
846                  ->GetCacheEntry(*activation_pc_address)
847                  ->code->is_interpreter_trampoline_builtin());
848       *activation_pc_address =
849           isolate->builtins()->InterpreterMarkBaselineOnReturn()->entry();
850     }
851     return true;
852   }
853 
has_activations()854   bool has_activations() { return has_activations_; }
855 
856  private:
857   SharedFunctionInfo* shared_;
858   bool has_activations_;
859   std::vector<Address*> activation_pc_addresses_;
860 };
861 
HasInterpreterActivations(Isolate * isolate,InterpreterActivationsFinder * activations_finder)862 bool HasInterpreterActivations(
863     Isolate* isolate, InterpreterActivationsFinder* activations_finder) {
864   activations_finder->VisitThread(isolate, isolate->thread_local_top());
865   isolate->thread_manager()->IterateArchivedThreads(activations_finder);
866   if (FLAG_turbo_from_bytecode) {
867     // If we are able to optimize functions directly from bytecode, then there
868     // might be optimized functions that rely on bytecode being around. We need
869     // to prevent switching the given function to baseline code in those cases.
870     Deoptimizer::VisitAllOptimizedFunctions(isolate, activations_finder);
871   }
872   return activations_finder->has_activations();
873 }
874 
GetBaselineCode(Handle<JSFunction> function)875 MaybeHandle<Code> GetBaselineCode(Handle<JSFunction> function) {
876   Isolate* isolate = function->GetIsolate();
877   VMState<COMPILER> state(isolate);
878   PostponeInterruptsScope postpone(isolate);
879   Zone zone(isolate->allocator());
880   ParseInfo parse_info(&zone, function);
881   CompilationInfo info(&parse_info, function);
882 
883   // Reset profiler ticks, function is no longer considered hot.
884   if (function->shared()->HasBytecodeArray()) {
885     function->shared()->set_profiler_ticks(0);
886   }
887 
888   // Nothing left to do if the function already has baseline code.
889   if (function->shared()->code()->kind() == Code::FUNCTION) {
890     return Handle<Code>(function->shared()->code());
891   }
892 
893   // We do not switch to baseline code when the debugger might have created a
894   // copy of the bytecode with break slots to be able to set break points.
895   if (function->shared()->HasDebugInfo()) {
896     return MaybeHandle<Code>();
897   }
898 
899   // TODO(4280): For now we do not switch generators or async functions to
900   // baseline code because there might be suspended activations stored in
901   // generator objects on the heap. We could eventually go directly to
902   // TurboFan in this case.
903   if (function->shared()->is_resumable()) {
904     return MaybeHandle<Code>();
905   }
906 
907   // TODO(4280): For now we disable switching to baseline code in the presence
908   // of interpreter activations of the given function. The reasons are:
909   //  1) The debugger assumes each function is either full-code or bytecode.
910   //  2) The underlying bytecode is cleared below, breaking stack unwinding.
911   InterpreterActivationsFinder activations_finder(function->shared());
912   if (HasInterpreterActivations(isolate, &activations_finder)) {
913     if (FLAG_trace_opt) {
914       OFStream os(stdout);
915       os << "[unable to switch " << Brief(*function) << " due to activations]"
916          << std::endl;
917     }
918 
919     if (activations_finder.MarkActivationsForBaselineOnReturn(isolate)) {
920       if (FLAG_trace_opt) {
921         OFStream os(stdout);
922         os << "[marking " << Brief(function->shared())
923            << " for baseline recompilation on return]" << std::endl;
924       }
925     }
926 
927     return MaybeHandle<Code>();
928   }
929 
930   if (FLAG_trace_opt) {
931     OFStream os(stdout);
932     os << "[switching method " << Brief(*function) << " to baseline code]"
933        << std::endl;
934   }
935 
936   // Parse and update CompilationInfo with the results.
937   if (!Parser::ParseStatic(info.parse_info())) return MaybeHandle<Code>();
938   Handle<SharedFunctionInfo> shared = info.shared_info();
939   DCHECK_EQ(shared->language_mode(), info.literal()->language_mode());
940 
941   // Compile baseline code using the full code generator.
942   if (!Compiler::Analyze(info.parse_info()) ||
943       !FullCodeGenerator::MakeCode(&info)) {
944     if (!isolate->has_pending_exception()) isolate->StackOverflow();
945     return MaybeHandle<Code>();
946   }
947 
948   // TODO(4280): For now we play it safe and remove the bytecode array when we
949   // switch to baseline code. We might consider keeping around the bytecode so
950   // that it can be used as the "source of truth" eventually.
951   shared->ClearBytecodeArray();
952 
953   // Update the shared function info with the scope info.
954   InstallSharedScopeInfo(&info, shared);
955 
956   // Install compilation result on the shared function info
957   InstallSharedCompilationResult(&info, shared);
958 
959   // Record the function compilation event.
960   RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG, &info);
961 
962   return info.code();
963 }
964 
GetLazyCode(Handle<JSFunction> function)965 MaybeHandle<Code> GetLazyCode(Handle<JSFunction> function) {
966   Isolate* isolate = function->GetIsolate();
967   DCHECK(!isolate->has_pending_exception());
968   DCHECK(!function->is_compiled());
969   TimerEventScope<TimerEventCompileCode> compile_timer(isolate);
970   RuntimeCallTimerScope runtimeTimer(isolate,
971                                      &RuntimeCallStats::CompileCodeLazy);
972   TRACE_EVENT0("v8", "V8.CompileCode");
973   AggregatedHistogramTimerScope timer(isolate->counters()->compile_lazy());
974 
975   if (FLAG_turbo_cache_shared_code) {
976     Handle<Code> cached_code;
977     if (GetCodeFromOptimizedCodeMap(function, BailoutId::None())
978             .ToHandle(&cached_code)) {
979       if (FLAG_trace_opt) {
980         PrintF("[found optimized code for ");
981         function->ShortPrint();
982         PrintF(" during unoptimized compile]\n");
983       }
984       DCHECK(function->shared()->is_compiled());
985       return cached_code;
986     }
987   }
988 
989   if (function->shared()->is_compiled()) {
990     return Handle<Code>(function->shared()->code());
991   }
992 
993   Zone zone(isolate->allocator());
994   ParseInfo parse_info(&zone, function);
995   CompilationInfo info(&parse_info, function);
996   Handle<Code> result;
997   ASSIGN_RETURN_ON_EXCEPTION(isolate, result, GetUnoptimizedCode(&info), Code);
998 
999   if (FLAG_always_opt) {
1000     Handle<Code> opt_code;
1001     if (GetOptimizedCode(function, Compiler::NOT_CONCURRENT)
1002             .ToHandle(&opt_code)) {
1003       result = opt_code;
1004     }
1005   }
1006 
1007   return result;
1008 }
1009 
1010 
NewSharedFunctionInfoForLiteral(Isolate * isolate,FunctionLiteral * literal,Handle<Script> script)1011 Handle<SharedFunctionInfo> NewSharedFunctionInfoForLiteral(
1012     Isolate* isolate, FunctionLiteral* literal, Handle<Script> script) {
1013   Handle<Code> code = isolate->builtins()->CompileLazy();
1014   Handle<ScopeInfo> scope_info = handle(ScopeInfo::Empty(isolate));
1015   Handle<SharedFunctionInfo> result = isolate->factory()->NewSharedFunctionInfo(
1016       literal->name(), literal->materialized_literal_count(), literal->kind(),
1017       code, scope_info);
1018   SharedFunctionInfo::InitFromFunctionLiteral(result, literal);
1019   SharedFunctionInfo::SetScript(result, script);
1020   return result;
1021 }
1022 
CompileToplevel(CompilationInfo * info)1023 Handle<SharedFunctionInfo> CompileToplevel(CompilationInfo* info) {
1024   Isolate* isolate = info->isolate();
1025   TimerEventScope<TimerEventCompileCode> timer(isolate);
1026   RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::CompileCode);
1027   TRACE_EVENT0("v8", "V8.CompileCode");
1028   PostponeInterruptsScope postpone(isolate);
1029   DCHECK(!isolate->native_context().is_null());
1030   ParseInfo* parse_info = info->parse_info();
1031   Handle<Script> script = parse_info->script();
1032 
1033   // TODO(svenpanne) Obscure place for this, perhaps move to OnBeforeCompile?
1034   FixedArray* array = isolate->native_context()->embedder_data();
1035   script->set_context_data(array->get(v8::Context::kDebugIdIndex));
1036 
1037   isolate->debug()->OnBeforeCompile(script);
1038 
1039   DCHECK(parse_info->is_eval() || parse_info->is_global() ||
1040          parse_info->is_module());
1041 
1042   parse_info->set_toplevel();
1043 
1044   Handle<SharedFunctionInfo> result;
1045 
1046   { VMState<COMPILER> state(info->isolate());
1047     if (parse_info->literal() == NULL) {
1048       // Parse the script if needed (if it's already parsed, literal() is
1049       // non-NULL). If compiling for debugging, we may eagerly compile inner
1050       // functions, so do not parse lazily in that case.
1051       ScriptCompiler::CompileOptions options = parse_info->compile_options();
1052       bool parse_allow_lazy = (options == ScriptCompiler::kConsumeParserCache ||
1053                                String::cast(script->source())->length() >
1054                                    FLAG_min_preparse_length) &&
1055                               !info->is_debug();
1056 
1057       // Consider parsing eagerly when targeting the code cache.
1058       parse_allow_lazy &= !(FLAG_serialize_eager && info->will_serialize());
1059 
1060       // Consider parsing eagerly when targeting Ignition.
1061       parse_allow_lazy &= !(FLAG_ignition && FLAG_ignition_eager &&
1062                             !isolate->serializer_enabled());
1063 
1064       parse_info->set_allow_lazy_parsing(parse_allow_lazy);
1065       if (!parse_allow_lazy &&
1066           (options == ScriptCompiler::kProduceParserCache ||
1067            options == ScriptCompiler::kConsumeParserCache)) {
1068         // We are going to parse eagerly, but we either 1) have cached data
1069         // produced by lazy parsing or 2) are asked to generate cached data.
1070         // Eager parsing cannot benefit from cached data, and producing cached
1071         // data while parsing eagerly is not implemented.
1072         parse_info->set_cached_data(nullptr);
1073         parse_info->set_compile_options(ScriptCompiler::kNoCompileOptions);
1074       }
1075       if (!Parser::ParseStatic(parse_info)) {
1076         return Handle<SharedFunctionInfo>::null();
1077       }
1078     }
1079 
1080     DCHECK(!info->is_debug() || !parse_info->allow_lazy_parsing());
1081 
1082     FunctionLiteral* lit = parse_info->literal();
1083 
1084     // Measure how long it takes to do the compilation; only take the
1085     // rest of the function into account to avoid overlap with the
1086     // parsing statistics.
1087     RuntimeCallTimerScope runtimeTimer(
1088         isolate, parse_info->is_eval() ? &RuntimeCallStats::CompileEval
1089                                        : &RuntimeCallStats::Compile);
1090     HistogramTimer* rate = parse_info->is_eval()
1091                                ? info->isolate()->counters()->compile_eval()
1092                                : info->isolate()->counters()->compile();
1093     HistogramTimerScope timer(rate);
1094     TRACE_EVENT0("v8", parse_info->is_eval() ? "V8.CompileEval" : "V8.Compile");
1095 
1096     // Allocate a shared function info object.
1097     DCHECK_EQ(RelocInfo::kNoPosition, lit->function_token_position());
1098     result = NewSharedFunctionInfoForLiteral(isolate, lit, script);
1099     result->set_is_toplevel(true);
1100     if (parse_info->is_eval()) {
1101       // Eval scripts cannot be (re-)compiled without context.
1102       result->set_allows_lazy_compilation_without_context(false);
1103     }
1104     parse_info->set_shared_info(result);
1105 
1106     // Compile the code.
1107     if (!CompileUnoptimizedCode(info)) {
1108       return Handle<SharedFunctionInfo>::null();
1109     }
1110 
1111     // Update the shared function info with the scope info.
1112     InstallSharedScopeInfo(info, result);
1113 
1114     // Install compilation result on the shared function info
1115     InstallSharedCompilationResult(info, result);
1116 
1117     Handle<String> script_name =
1118         script->name()->IsString()
1119             ? Handle<String>(String::cast(script->name()))
1120             : isolate->factory()->empty_string();
1121     CodeEventListener::LogEventsAndTags log_tag =
1122         parse_info->is_eval()
1123             ? CodeEventListener::EVAL_TAG
1124             : Logger::ToNativeByScript(CodeEventListener::SCRIPT_TAG, *script);
1125 
1126     PROFILE(isolate, CodeCreateEvent(log_tag, result->abstract_code(), *result,
1127                                      *script_name));
1128 
1129     if (!script.is_null())
1130       script->set_compilation_state(Script::COMPILATION_STATE_COMPILED);
1131   }
1132 
1133   return result;
1134 }
1135 
1136 }  // namespace
1137 
1138 // ----------------------------------------------------------------------------
1139 // Implementation of Compiler
1140 
Analyze(ParseInfo * info)1141 bool Compiler::Analyze(ParseInfo* info) {
1142   DCHECK_NOT_NULL(info->literal());
1143   if (!Rewriter::Rewrite(info)) return false;
1144   if (!Scope::Analyze(info)) return false;
1145   if (!Renumber(info)) return false;
1146   DCHECK_NOT_NULL(info->scope());
1147   return true;
1148 }
1149 
ParseAndAnalyze(ParseInfo * info)1150 bool Compiler::ParseAndAnalyze(ParseInfo* info) {
1151   if (!Parser::ParseStatic(info)) return false;
1152   if (!Compiler::Analyze(info)) return false;
1153   DCHECK_NOT_NULL(info->literal());
1154   DCHECK_NOT_NULL(info->scope());
1155   return true;
1156 }
1157 
Compile(Handle<JSFunction> function,ClearExceptionFlag flag)1158 bool Compiler::Compile(Handle<JSFunction> function, ClearExceptionFlag flag) {
1159   if (function->is_compiled()) return true;
1160   Isolate* isolate = function->GetIsolate();
1161   DCHECK(AllowCompilation::IsAllowed(isolate));
1162 
1163   // Start a compilation.
1164   Handle<Code> code;
1165   if (!GetLazyCode(function).ToHandle(&code)) {
1166     if (flag == CLEAR_EXCEPTION) {
1167       isolate->clear_pending_exception();
1168     }
1169     return false;
1170   }
1171 
1172   // Install code on closure.
1173   function->ReplaceCode(*code);
1174   JSFunction::EnsureLiterals(function);
1175 
1176   // Check postconditions on success.
1177   DCHECK(!isolate->has_pending_exception());
1178   DCHECK(function->shared()->is_compiled());
1179   DCHECK(function->is_compiled());
1180   return true;
1181 }
1182 
CompileBaseline(Handle<JSFunction> function)1183 bool Compiler::CompileBaseline(Handle<JSFunction> function) {
1184   Isolate* isolate = function->GetIsolate();
1185   DCHECK(AllowCompilation::IsAllowed(isolate));
1186 
1187   // Start a compilation.
1188   Handle<Code> code;
1189   if (!GetBaselineCode(function).ToHandle(&code)) {
1190     // Baseline generation failed, get unoptimized code.
1191     DCHECK(function->shared()->is_compiled());
1192     code = handle(function->shared()->code());
1193     isolate->clear_pending_exception();
1194   }
1195 
1196   // Install code on closure.
1197   function->ReplaceCode(*code);
1198   JSFunction::EnsureLiterals(function);
1199 
1200   // Check postconditions on success.
1201   DCHECK(!isolate->has_pending_exception());
1202   DCHECK(function->shared()->is_compiled());
1203   DCHECK(function->is_compiled());
1204   return true;
1205 }
1206 
CompileOptimized(Handle<JSFunction> function,ConcurrencyMode mode)1207 bool Compiler::CompileOptimized(Handle<JSFunction> function,
1208                                 ConcurrencyMode mode) {
1209   if (function->IsOptimized()) return true;
1210   Isolate* isolate = function->GetIsolate();
1211   DCHECK(AllowCompilation::IsAllowed(isolate));
1212 
1213   // Start a compilation.
1214   Handle<Code> code;
1215   if (!GetOptimizedCode(function, mode).ToHandle(&code)) {
1216     // Optimization failed, get unoptimized code.
1217     DCHECK(!isolate->has_pending_exception());
1218     if (function->shared()->is_compiled()) {
1219       code = handle(function->shared()->code(), isolate);
1220     } else {
1221       Zone zone(isolate->allocator());
1222       ParseInfo parse_info(&zone, function);
1223       CompilationInfo info(&parse_info, function);
1224       if (!GetUnoptimizedCode(&info).ToHandle(&code)) {
1225         return false;
1226       }
1227     }
1228   }
1229 
1230   // Install code on closure.
1231   function->ReplaceCode(*code);
1232   JSFunction::EnsureLiterals(function);
1233 
1234   // Check postconditions on success.
1235   DCHECK(!isolate->has_pending_exception());
1236   DCHECK(function->shared()->is_compiled());
1237   DCHECK(function->is_compiled());
1238   return true;
1239 }
1240 
CompileDebugCode(Handle<JSFunction> function)1241 bool Compiler::CompileDebugCode(Handle<JSFunction> function) {
1242   Isolate* isolate = function->GetIsolate();
1243   DCHECK(AllowCompilation::IsAllowed(isolate));
1244 
1245   // Start a compilation.
1246   Zone zone(isolate->allocator());
1247   ParseInfo parse_info(&zone, function);
1248   CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1249   if (IsEvalToplevel(handle(function->shared()))) {
1250     parse_info.set_eval();
1251     if (function->context()->IsNativeContext()) parse_info.set_global();
1252     parse_info.set_toplevel();
1253     parse_info.set_allow_lazy_parsing(false);
1254     parse_info.set_lazy(false);
1255   }
1256   info.MarkAsDebug();
1257   if (GetUnoptimizedCode(&info).is_null()) {
1258     isolate->clear_pending_exception();
1259     return false;
1260   }
1261 
1262   // Check postconditions on success.
1263   DCHECK(!isolate->has_pending_exception());
1264   DCHECK(function->shared()->is_compiled());
1265   DCHECK(function->shared()->HasDebugCode());
1266   return true;
1267 }
1268 
CompileDebugCode(Handle<SharedFunctionInfo> shared)1269 bool Compiler::CompileDebugCode(Handle<SharedFunctionInfo> shared) {
1270   Isolate* isolate = shared->GetIsolate();
1271   DCHECK(AllowCompilation::IsAllowed(isolate));
1272 
1273   // Start a compilation.
1274   Zone zone(isolate->allocator());
1275   ParseInfo parse_info(&zone, shared);
1276   CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1277   DCHECK(shared->allows_lazy_compilation_without_context());
1278   DCHECK(!IsEvalToplevel(shared));
1279   info.MarkAsDebug();
1280   if (GetUnoptimizedCode(&info).is_null()) {
1281     isolate->clear_pending_exception();
1282     return false;
1283   }
1284 
1285   // Check postconditions on success.
1286   DCHECK(!isolate->has_pending_exception());
1287   DCHECK(shared->is_compiled());
1288   DCHECK(shared->HasDebugCode());
1289   return true;
1290 }
1291 
CompileForLiveEdit(Handle<Script> script)1292 MaybeHandle<JSArray> Compiler::CompileForLiveEdit(Handle<Script> script) {
1293   Isolate* isolate = script->GetIsolate();
1294   DCHECK(AllowCompilation::IsAllowed(isolate));
1295 
1296   // In order to ensure that live edit function info collection finds the newly
1297   // generated shared function infos, clear the script's list temporarily
1298   // and restore it at the end of this method.
1299   Handle<Object> old_function_infos(script->shared_function_infos(), isolate);
1300   script->set_shared_function_infos(Smi::FromInt(0));
1301 
1302   // Start a compilation.
1303   Zone zone(isolate->allocator());
1304   ParseInfo parse_info(&zone, script);
1305   CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1306   parse_info.set_global();
1307   info.MarkAsDebug();
1308 
1309   // TODO(635): support extensions.
1310   const bool compilation_succeeded = !CompileToplevel(&info).is_null();
1311   Handle<JSArray> infos;
1312   if (compilation_succeeded) {
1313     // Check postconditions on success.
1314     DCHECK(!isolate->has_pending_exception());
1315     infos = LiveEditFunctionTracker::Collect(parse_info.literal(), script,
1316                                              &zone, isolate);
1317   }
1318 
1319   // Restore the original function info list in order to remain side-effect
1320   // free as much as possible, since some code expects the old shared function
1321   // infos to stick around.
1322   script->set_shared_function_infos(*old_function_infos);
1323 
1324   return infos;
1325 }
1326 
1327 // TODO(turbofan): In the future, unoptimized code with deopt support could
1328 // be generated lazily once deopt is triggered.
EnsureDeoptimizationSupport(CompilationInfo * info)1329 bool Compiler::EnsureDeoptimizationSupport(CompilationInfo* info) {
1330   DCHECK_NOT_NULL(info->literal());
1331   DCHECK_NOT_NULL(info->scope());
1332   Handle<SharedFunctionInfo> shared = info->shared_info();
1333   if (!shared->has_deoptimization_support()) {
1334     Zone zone(info->isolate()->allocator());
1335     CompilationInfo unoptimized(info->parse_info(), info->closure());
1336     unoptimized.EnableDeoptimizationSupport();
1337 
1338     // TODO(4280): For now we do not switch generators or async functions to
1339     // baseline code because there might be suspended activations stored in
1340     // generator objects on the heap. We could eventually go directly to
1341     // TurboFan in this case.
1342     if (shared->is_resumable()) return false;
1343 
1344     // TODO(4280): For now we disable switching to baseline code in the presence
1345     // of interpreter activations of the given function. The reasons are:
1346     //  1) The debugger assumes each function is either full-code or bytecode.
1347     //  2) The underlying bytecode is cleared below, breaking stack unwinding.
1348     // The expensive check for activations only needs to be done when the given
1349     // function has bytecode, otherwise we can be sure there are no activations.
1350     if (shared->HasBytecodeArray()) {
1351       InterpreterActivationsFinder activations_finder(*shared);
1352       if (HasInterpreterActivations(info->isolate(), &activations_finder)) {
1353         return false;
1354       }
1355     }
1356 
1357     // If the current code has reloc info for serialization, also include
1358     // reloc info for serialization for the new code, so that deopt support
1359     // can be added without losing IC state.
1360     if (shared->code()->kind() == Code::FUNCTION &&
1361         shared->code()->has_reloc_info_for_serialization()) {
1362       unoptimized.PrepareForSerializing();
1363     }
1364     EnsureFeedbackMetadata(&unoptimized);
1365     if (!FullCodeGenerator::MakeCode(&unoptimized)) return false;
1366 
1367     // TODO(4280): For now we play it safe and remove the bytecode array when we
1368     // switch to baseline code. We might consider keeping around the bytecode so
1369     // that it can be used as the "source of truth" eventually.
1370     shared->ClearBytecodeArray();
1371 
1372     // The scope info might not have been set if a lazily compiled
1373     // function is inlined before being called for the first time.
1374     if (shared->scope_info() == ScopeInfo::Empty(info->isolate())) {
1375       InstallSharedScopeInfo(info, shared);
1376     }
1377 
1378     // Install compilation result on the shared function info
1379     shared->EnableDeoptimizationSupport(*unoptimized.code());
1380 
1381     // The existing unoptimized code was replaced with the new one.
1382     RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG,
1383                               &unoptimized);
1384   }
1385   return true;
1386 }
1387 
GetFunctionFromEval(Handle<String> source,Handle<SharedFunctionInfo> outer_info,Handle<Context> context,LanguageMode language_mode,ParseRestriction restriction,int eval_scope_position,int eval_position,int line_offset,int column_offset,Handle<Object> script_name,ScriptOriginOptions options)1388 MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
1389     Handle<String> source, Handle<SharedFunctionInfo> outer_info,
1390     Handle<Context> context, LanguageMode language_mode,
1391     ParseRestriction restriction, int eval_scope_position, int eval_position,
1392     int line_offset, int column_offset, Handle<Object> script_name,
1393     ScriptOriginOptions options) {
1394   Isolate* isolate = source->GetIsolate();
1395   int source_length = source->length();
1396   isolate->counters()->total_eval_size()->Increment(source_length);
1397   isolate->counters()->total_compile_size()->Increment(source_length);
1398 
1399   CompilationCache* compilation_cache = isolate->compilation_cache();
1400   MaybeHandle<SharedFunctionInfo> maybe_shared_info =
1401       compilation_cache->LookupEval(source, outer_info, context, language_mode,
1402                                     eval_scope_position);
1403   Handle<SharedFunctionInfo> shared_info;
1404 
1405   Handle<Script> script;
1406   if (!maybe_shared_info.ToHandle(&shared_info)) {
1407     script = isolate->factory()->NewScript(source);
1408     if (!script_name.is_null()) {
1409       script->set_name(*script_name);
1410       script->set_line_offset(line_offset);
1411       script->set_column_offset(column_offset);
1412     }
1413     script->set_origin_options(options);
1414     script->set_compilation_type(Script::COMPILATION_TYPE_EVAL);
1415     Script::SetEvalOrigin(script, outer_info, eval_position);
1416 
1417     Zone zone(isolate->allocator());
1418     ParseInfo parse_info(&zone, script);
1419     CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1420     parse_info.set_eval();
1421     if (context->IsNativeContext()) parse_info.set_global();
1422     parse_info.set_language_mode(language_mode);
1423     parse_info.set_parse_restriction(restriction);
1424     parse_info.set_context(context);
1425 
1426     shared_info = CompileToplevel(&info);
1427 
1428     if (shared_info.is_null()) {
1429       return MaybeHandle<JSFunction>();
1430     } else {
1431       // If caller is strict mode, the result must be in strict mode as well.
1432       DCHECK(is_sloppy(language_mode) ||
1433              is_strict(shared_info->language_mode()));
1434       compilation_cache->PutEval(source, outer_info, context, shared_info,
1435                                  eval_scope_position);
1436     }
1437   }
1438 
1439   Handle<JSFunction> result =
1440       isolate->factory()->NewFunctionFromSharedFunctionInfo(
1441           shared_info, context, NOT_TENURED);
1442 
1443   // OnAfterCompile has to be called after we create the JSFunction, which we
1444   // may require to recompile the eval for debugging, if we find a function
1445   // that contains break points in the eval script.
1446   isolate->debug()->OnAfterCompile(script);
1447 
1448   return result;
1449 }
1450 
GetSharedFunctionInfoForScript(Handle<String> source,Handle<Object> script_name,int line_offset,int column_offset,ScriptOriginOptions resource_options,Handle<Object> source_map_url,Handle<Context> context,v8::Extension * extension,ScriptData ** cached_data,ScriptCompiler::CompileOptions compile_options,NativesFlag natives,bool is_module)1451 Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForScript(
1452     Handle<String> source, Handle<Object> script_name, int line_offset,
1453     int column_offset, ScriptOriginOptions resource_options,
1454     Handle<Object> source_map_url, Handle<Context> context,
1455     v8::Extension* extension, ScriptData** cached_data,
1456     ScriptCompiler::CompileOptions compile_options, NativesFlag natives,
1457     bool is_module) {
1458   Isolate* isolate = source->GetIsolate();
1459   if (compile_options == ScriptCompiler::kNoCompileOptions) {
1460     cached_data = NULL;
1461   } else if (compile_options == ScriptCompiler::kProduceParserCache ||
1462              compile_options == ScriptCompiler::kProduceCodeCache) {
1463     DCHECK(cached_data && !*cached_data);
1464     DCHECK(extension == NULL);
1465     DCHECK(!isolate->debug()->is_loaded());
1466   } else {
1467     DCHECK(compile_options == ScriptCompiler::kConsumeParserCache ||
1468            compile_options == ScriptCompiler::kConsumeCodeCache);
1469     DCHECK(cached_data && *cached_data);
1470     DCHECK(extension == NULL);
1471   }
1472   int source_length = source->length();
1473   isolate->counters()->total_load_size()->Increment(source_length);
1474   isolate->counters()->total_compile_size()->Increment(source_length);
1475 
1476   LanguageMode language_mode = construct_language_mode(FLAG_use_strict);
1477   CompilationCache* compilation_cache = isolate->compilation_cache();
1478 
1479   // Do a lookup in the compilation cache but not for extensions.
1480   MaybeHandle<SharedFunctionInfo> maybe_result;
1481   Handle<SharedFunctionInfo> result;
1482   if (extension == NULL) {
1483     // First check per-isolate compilation cache.
1484     maybe_result = compilation_cache->LookupScript(
1485         source, script_name, line_offset, column_offset, resource_options,
1486         context, language_mode);
1487     if (maybe_result.is_null() && FLAG_serialize_toplevel &&
1488         compile_options == ScriptCompiler::kConsumeCodeCache &&
1489         !isolate->debug()->is_loaded()) {
1490       // Then check cached code provided by embedder.
1491       HistogramTimerScope timer(isolate->counters()->compile_deserialize());
1492       RuntimeCallTimerScope runtimeTimer(isolate,
1493                                          &RuntimeCallStats::CompileDeserialize);
1494       TRACE_EVENT0("v8", "V8.CompileDeserialize");
1495       Handle<SharedFunctionInfo> result;
1496       if (CodeSerializer::Deserialize(isolate, *cached_data, source)
1497               .ToHandle(&result)) {
1498         // Promote to per-isolate compilation cache.
1499         compilation_cache->PutScript(source, context, language_mode, result);
1500         return result;
1501       }
1502       // Deserializer failed. Fall through to compile.
1503     }
1504   }
1505 
1506   base::ElapsedTimer timer;
1507   if (FLAG_profile_deserialization && FLAG_serialize_toplevel &&
1508       compile_options == ScriptCompiler::kProduceCodeCache) {
1509     timer.Start();
1510   }
1511 
1512   if (!maybe_result.ToHandle(&result) ||
1513       (FLAG_serialize_toplevel &&
1514        compile_options == ScriptCompiler::kProduceCodeCache)) {
1515     // No cache entry found, or embedder wants a code cache. Compile the script.
1516 
1517     // Create a script object describing the script to be compiled.
1518     Handle<Script> script = isolate->factory()->NewScript(source);
1519     if (natives == NATIVES_CODE) {
1520       script->set_type(Script::TYPE_NATIVE);
1521       script->set_hide_source(true);
1522     } else if (natives == EXTENSION_CODE) {
1523       script->set_type(Script::TYPE_EXTENSION);
1524       script->set_hide_source(true);
1525     }
1526     if (!script_name.is_null()) {
1527       script->set_name(*script_name);
1528       script->set_line_offset(line_offset);
1529       script->set_column_offset(column_offset);
1530     }
1531     script->set_origin_options(resource_options);
1532     if (!source_map_url.is_null()) {
1533       script->set_source_mapping_url(*source_map_url);
1534     }
1535 
1536     // Compile the function and add it to the cache.
1537     Zone zone(isolate->allocator());
1538     ParseInfo parse_info(&zone, script);
1539     CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1540     if (is_module) {
1541       parse_info.set_module();
1542     } else {
1543       parse_info.set_global();
1544     }
1545     if (compile_options != ScriptCompiler::kNoCompileOptions) {
1546       parse_info.set_cached_data(cached_data);
1547     }
1548     parse_info.set_compile_options(compile_options);
1549     parse_info.set_extension(extension);
1550     parse_info.set_context(context);
1551     if (FLAG_serialize_toplevel &&
1552         compile_options == ScriptCompiler::kProduceCodeCache) {
1553       info.PrepareForSerializing();
1554     }
1555 
1556     parse_info.set_language_mode(
1557         static_cast<LanguageMode>(parse_info.language_mode() | language_mode));
1558     result = CompileToplevel(&info);
1559     if (extension == NULL && !result.is_null()) {
1560       compilation_cache->PutScript(source, context, language_mode, result);
1561       if (FLAG_serialize_toplevel &&
1562           compile_options == ScriptCompiler::kProduceCodeCache) {
1563         HistogramTimerScope histogram_timer(
1564             isolate->counters()->compile_serialize());
1565         RuntimeCallTimerScope runtimeTimer(isolate,
1566                                            &RuntimeCallStats::CompileSerialize);
1567         TRACE_EVENT0("v8", "V8.CompileSerialize");
1568         *cached_data = CodeSerializer::Serialize(isolate, result, source);
1569         if (FLAG_profile_deserialization) {
1570           PrintF("[Compiling and serializing took %0.3f ms]\n",
1571                  timer.Elapsed().InMillisecondsF());
1572         }
1573       }
1574     }
1575 
1576     if (result.is_null()) {
1577       isolate->ReportPendingMessages();
1578     } else {
1579       isolate->debug()->OnAfterCompile(script);
1580     }
1581   } else if (result->ic_age() != isolate->heap()->global_ic_age()) {
1582     result->ResetForNewContext(isolate->heap()->global_ic_age());
1583   }
1584   return result;
1585 }
1586 
GetSharedFunctionInfoForStreamedScript(Handle<Script> script,ParseInfo * parse_info,int source_length)1587 Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForStreamedScript(
1588     Handle<Script> script, ParseInfo* parse_info, int source_length) {
1589   Isolate* isolate = script->GetIsolate();
1590   // TODO(titzer): increment the counters in caller.
1591   isolate->counters()->total_load_size()->Increment(source_length);
1592   isolate->counters()->total_compile_size()->Increment(source_length);
1593 
1594   LanguageMode language_mode = construct_language_mode(FLAG_use_strict);
1595   parse_info->set_language_mode(
1596       static_cast<LanguageMode>(parse_info->language_mode() | language_mode));
1597 
1598   CompilationInfo compile_info(parse_info, Handle<JSFunction>::null());
1599 
1600   // The source was parsed lazily, so compiling for debugging is not possible.
1601   DCHECK(!compile_info.is_debug());
1602 
1603   Handle<SharedFunctionInfo> result = CompileToplevel(&compile_info);
1604   if (!result.is_null()) isolate->debug()->OnAfterCompile(script);
1605   return result;
1606 }
1607 
1608 
GetSharedFunctionInfo(FunctionLiteral * literal,Handle<Script> script,CompilationInfo * outer_info)1609 Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
1610     FunctionLiteral* literal, Handle<Script> script,
1611     CompilationInfo* outer_info) {
1612   // Precondition: code has been parsed and scopes have been analyzed.
1613   Isolate* isolate = outer_info->isolate();
1614   MaybeHandle<SharedFunctionInfo> maybe_existing;
1615 
1616   // Find any previously allocated shared function info for the given literal.
1617   if (outer_info->shared_info()->never_compiled()) {
1618     // On the first compile, there are no existing shared function info for
1619     // inner functions yet, so do not try to find them. All bets are off for
1620     // live edit though.
1621     SLOW_DCHECK(script->FindSharedFunctionInfo(literal).is_null() ||
1622                 isolate->debug()->live_edit_enabled());
1623   } else {
1624     maybe_existing = script->FindSharedFunctionInfo(literal);
1625   }
1626 
1627   // We found an existing shared function info. If it's already compiled,
1628   // don't worry about compiling it, and simply return it. If it's not yet
1629   // compiled, continue to decide whether to eagerly compile.
1630   // Carry on if we are compiling eager to obtain code for debugging,
1631   // unless we already have code with debut break slots.
1632   Handle<SharedFunctionInfo> existing;
1633   if (maybe_existing.ToHandle(&existing) && existing->is_compiled()) {
1634     DCHECK(!existing->is_toplevel());
1635     if (!outer_info->is_debug() || existing->HasDebugCode()) {
1636       return existing;
1637     }
1638   }
1639 
1640   // Allocate a shared function info object.
1641   Handle<SharedFunctionInfo> result;
1642   if (!maybe_existing.ToHandle(&result)) {
1643     result = NewSharedFunctionInfoForLiteral(isolate, literal, script);
1644     result->set_is_toplevel(false);
1645 
1646     // If the outer function has been compiled before, we cannot be sure that
1647     // shared function info for this function literal has been created for the
1648     // first time. It may have already been compiled previously.
1649     result->set_never_compiled(outer_info->shared_info()->never_compiled());
1650   }
1651 
1652   Zone zone(isolate->allocator());
1653   ParseInfo parse_info(&zone, script);
1654   CompilationInfo info(&parse_info, Handle<JSFunction>::null());
1655   parse_info.set_literal(literal);
1656   parse_info.set_shared_info(result);
1657   parse_info.set_scope(literal->scope());
1658   parse_info.set_language_mode(literal->scope()->language_mode());
1659   if (outer_info->will_serialize()) info.PrepareForSerializing();
1660   if (outer_info->is_debug()) info.MarkAsDebug();
1661 
1662   // Determine if the function can be lazily compiled. This is necessary to
1663   // allow some of our builtin JS files to be lazily compiled. These
1664   // builtins cannot be handled lazily by the parser, since we have to know
1665   // if a function uses the special natives syntax, which is something the
1666   // parser records.
1667   // If the debugger requests compilation for break points, we cannot be
1668   // aggressive about lazy compilation, because it might trigger compilation
1669   // of functions without an outer context when setting a breakpoint through
1670   // Debug::FindSharedFunctionInfoInScript.
1671   bool allow_lazy = literal->AllowsLazyCompilation() && !info.is_debug();
1672   bool lazy = FLAG_lazy && allow_lazy && !literal->should_eager_compile();
1673 
1674   // Consider compiling eagerly when targeting the code cache.
1675   lazy &= !(FLAG_serialize_eager && info.will_serialize());
1676 
1677   // Consider compiling eagerly when compiling bytecode for Ignition.
1678   lazy &=
1679       !(FLAG_ignition && FLAG_ignition_eager && !isolate->serializer_enabled());
1680 
1681   // Generate code
1682   TimerEventScope<TimerEventCompileCode> timer(isolate);
1683   RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::CompileCode);
1684   TRACE_EVENT0("v8", "V8.CompileCode");
1685   if (lazy) {
1686     info.SetCode(isolate->builtins()->CompileLazy());
1687   } else if (Renumber(info.parse_info()) && GenerateUnoptimizedCode(&info)) {
1688     // Code generation will ensure that the feedback vector is present and
1689     // appropriately sized.
1690     DCHECK(!info.code().is_null());
1691     if (literal->should_eager_compile() &&
1692         literal->should_be_used_once_hint()) {
1693       info.code()->MarkToBeExecutedOnce(isolate);
1694     }
1695     // Update the shared function info with the scope info.
1696     InstallSharedScopeInfo(&info, result);
1697     // Install compilation result on the shared function info.
1698     InstallSharedCompilationResult(&info, result);
1699   } else {
1700     return Handle<SharedFunctionInfo>::null();
1701   }
1702 
1703   if (maybe_existing.is_null()) {
1704     RecordFunctionCompilation(CodeEventListener::FUNCTION_TAG, &info);
1705   }
1706 
1707   return result;
1708 }
1709 
GetSharedFunctionInfoForNative(v8::Extension * extension,Handle<String> name)1710 Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForNative(
1711     v8::Extension* extension, Handle<String> name) {
1712   Isolate* isolate = name->GetIsolate();
1713   v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
1714 
1715   // Compute the function template for the native function.
1716   v8::Local<v8::FunctionTemplate> fun_template =
1717       extension->GetNativeFunctionTemplate(v8_isolate,
1718                                            v8::Utils::ToLocal(name));
1719   DCHECK(!fun_template.IsEmpty());
1720 
1721   // Instantiate the function and create a shared function info from it.
1722   Handle<JSFunction> fun = Handle<JSFunction>::cast(Utils::OpenHandle(
1723       *fun_template->GetFunction(v8_isolate->GetCurrentContext())
1724            .ToLocalChecked()));
1725   Handle<Code> code = Handle<Code>(fun->shared()->code());
1726   Handle<Code> construct_stub = Handle<Code>(fun->shared()->construct_stub());
1727   Handle<SharedFunctionInfo> shared = isolate->factory()->NewSharedFunctionInfo(
1728       name, fun->shared()->num_literals(), FunctionKind::kNormalFunction, code,
1729       Handle<ScopeInfo>(fun->shared()->scope_info()));
1730   shared->set_construct_stub(*construct_stub);
1731   shared->set_feedback_metadata(fun->shared()->feedback_metadata());
1732 
1733   // Copy the function data to the shared function info.
1734   shared->set_function_data(fun->shared()->function_data());
1735   int parameters = fun->shared()->internal_formal_parameter_count();
1736   shared->set_internal_formal_parameter_count(parameters);
1737 
1738   return shared;
1739 }
1740 
GetOptimizedCodeForOSR(Handle<JSFunction> function,BailoutId osr_ast_id,JavaScriptFrame * osr_frame)1741 MaybeHandle<Code> Compiler::GetOptimizedCodeForOSR(Handle<JSFunction> function,
1742                                                    BailoutId osr_ast_id,
1743                                                    JavaScriptFrame* osr_frame) {
1744   DCHECK(!osr_ast_id.IsNone());
1745   DCHECK_NOT_NULL(osr_frame);
1746   return GetOptimizedCode(function, NOT_CONCURRENT, osr_ast_id, osr_frame);
1747 }
1748 
FinalizeCompilationJob(CompilationJob * raw_job)1749 void Compiler::FinalizeCompilationJob(CompilationJob* raw_job) {
1750   // Take ownership of compilation job.  Deleting job also tears down the zone.
1751   base::SmartPointer<CompilationJob> job(raw_job);
1752   CompilationInfo* info = job->info();
1753   Isolate* isolate = info->isolate();
1754 
1755   VMState<COMPILER> state(isolate);
1756   TimerEventScope<TimerEventRecompileSynchronous> timer(info->isolate());
1757   RuntimeCallTimerScope runtimeTimer(isolate,
1758                                      &RuntimeCallStats::RecompileSynchronous);
1759   TRACE_EVENT0("v8", "V8.RecompileSynchronous");
1760 
1761   Handle<SharedFunctionInfo> shared = info->shared_info();
1762   shared->code()->set_profiler_ticks(0);
1763 
1764   DCHECK(!shared->HasDebugInfo());
1765 
1766   // 1) Optimization on the concurrent thread may have failed.
1767   // 2) The function may have already been optimized by OSR.  Simply continue.
1768   //    Except when OSR already disabled optimization for some reason.
1769   // 3) The code may have already been invalidated due to dependency change.
1770   // 4) Code generation may have failed.
1771   if (job->last_status() == CompilationJob::SUCCEEDED) {
1772     if (shared->optimization_disabled()) {
1773       job->RetryOptimization(kOptimizationDisabled);
1774     } else if (info->dependencies()->HasAborted()) {
1775       job->RetryOptimization(kBailedOutDueToDependencyChange);
1776     } else if (job->GenerateCode() == CompilationJob::SUCCEEDED) {
1777       job->RecordOptimizationStats();
1778       RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG, info);
1779       if (shared->SearchOptimizedCodeMap(info->context()->native_context(),
1780                                          info->osr_ast_id()).code == nullptr) {
1781         InsertCodeIntoOptimizedCodeMap(info);
1782       }
1783       if (FLAG_trace_opt) {
1784         PrintF("[completed optimizing ");
1785         info->closure()->ShortPrint();
1786         PrintF("]\n");
1787       }
1788       info->closure()->ReplaceCode(*info->code());
1789       return;
1790     }
1791   }
1792 
1793   DCHECK(job->last_status() != CompilationJob::SUCCEEDED);
1794   if (FLAG_trace_opt) {
1795     PrintF("[aborted optimizing ");
1796     info->closure()->ShortPrint();
1797     PrintF(" because: %s]\n", GetBailoutReason(info->bailout_reason()));
1798   }
1799   info->closure()->ReplaceCode(shared->code());
1800 }
1801 
PostInstantiation(Handle<JSFunction> function,PretenureFlag pretenure)1802 void Compiler::PostInstantiation(Handle<JSFunction> function,
1803                                  PretenureFlag pretenure) {
1804   Handle<SharedFunctionInfo> shared(function->shared());
1805 
1806   if (FLAG_always_opt && shared->allows_lazy_compilation()) {
1807     function->MarkForOptimization();
1808   }
1809 
1810   CodeAndLiterals cached = shared->SearchOptimizedCodeMap(
1811       function->context()->native_context(), BailoutId::None());
1812   if (cached.code != nullptr) {
1813     // Caching of optimized code enabled and optimized code found.
1814     DCHECK(!cached.code->marked_for_deoptimization());
1815     DCHECK(function->shared()->is_compiled());
1816     function->ReplaceCode(cached.code);
1817   }
1818 
1819   if (cached.literals != nullptr) {
1820     DCHECK(shared->is_compiled());
1821     function->set_literals(cached.literals);
1822   } else if (shared->is_compiled()) {
1823     // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
1824     JSFunction::EnsureLiterals(function);
1825   }
1826 }
1827 
1828 }  // namespace internal
1829 }  // namespace v8
1830