src/3rdparty/v8/src/compiler.cc

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  27
  28 #include "v8.h"
  29
  30 #include "compiler.h"
  31
  32 #include "bootstrapper.h"
  33 #include "codegen.h"
  34 #include "compilation-cache.h"
  35 #include "debug.h"
  36 #include "full-codegen.h"
  37 #include "gdb-jit.h"
  38 #include "hydrogen.h"
  39 #include "isolate-inl.h"
  40 #include "lithium.h"
  41 #include "liveedit.h"
  42 #include "parser.h"
  43 #include "rewriter.h"
  44 #include "runtime-profiler.h"
  45 #include "scanner-character-streams.h"
  46 #include "scopeinfo.h"
  47 #include "scopes.h"
  48 #include "vm-state-inl.h"
  49
  50 namespace v8 {
  51 namespace internal {
  52
  53
  54 CompilationInfo::CompilationInfo(Handle<Script> script)
  55     : isolate_(script->GetIsolate()),
  56       flags_(0),
  57       function_(NULL),
  58       scope_(NULL),
  59       script_(script),
  60       extension_(NULL),
  61       pre_parse_data_(NULL),
  62       osr_ast_id_(AstNode::kNoNumber) {
  63   Initialize(NONOPT);
  64 }
  65
  66
  67 CompilationInfo::CompilationInfo(Handle<SharedFunctionInfo> shared_info)
  68     : isolate_(shared_info->GetIsolate()),
  69       flags_(IsLazy::encode(true)),
  70       function_(NULL),
  71       scope_(NULL),
  72       shared_info_(shared_info),
  73       script_(Handle<Script>(Script::cast(shared_info->script()))),
  74       extension_(NULL),
  75       pre_parse_data_(NULL),
  76       osr_ast_id_(AstNode::kNoNumber) {
  77   Initialize(BASE);
  78 }
  79
  80
  81 CompilationInfo::CompilationInfo(Handle<JSFunction> closure)
  82     : isolate_(closure->GetIsolate()),
  83       flags_(IsLazy::encode(true)),
  84       function_(NULL),
  85       scope_(NULL),
  86       closure_(closure),
  87       shared_info_(Handle<SharedFunctionInfo>(closure->shared())),
  88       script_(Handle<Script>(Script::cast(shared_info_->script()))),
  89       extension_(NULL),
  90       pre_parse_data_(NULL),
  91       osr_ast_id_(AstNode::kNoNumber) {
  92   Initialize(BASE);
  93 }
  94
  95
  96 // Disable optimization for the rest of the compilation pipeline.
  97 void CompilationInfo::DisableOptimization() {
  98   bool is_optimizable_closure =
  99     FLAG_optimize_closures &&
 100     closure_.is_null() &&
 101     !scope_->HasTrivialOuterContext() &&
 102     !scope_->outer_scope_calls_non_strict_eval() &&
 103     !scope_->inside_with();
 104   SetMode(is_optimizable_closure ? BASE : NONOPT);
 105 }
 106
 107
 108 void CompilationInfo::AbortOptimization() {
 109   Handle<Code> code(shared_info()->code());
 110   SetCode(code);
 111 }
 112
 113
 114 // Determine whether to use the full compiler for all code. If the flag
 115 // --always-full-compiler is specified this is the case. For the virtual frame
 116 // based compiler the full compiler is also used if a debugger is connected, as
 117 // the code from the full compiler supports mode precise break points. For the
 118 // crankshaft adaptive compiler debugging the optimized code is not possible at
 119 // all. However crankshaft support recompilation of functions, so in this case
 120 // the full compiler need not be be used if a debugger is attached, but only if
 121 // break points has actually been set.
 122 static bool is_debugging_active() {
 123 #ifdef ENABLE_DEBUGGER_SUPPORT
 124   Isolate* isolate = Isolate::Current();
 125   return V8::UseCrankshaft() ?
 126     isolate->debug()->has_break_points() :
 127     isolate->debugger()->IsDebuggerActive();
 128 #else
 129   return false;
 130 #endif
 131 }
 132
 133
 134 static bool AlwaysFullCompiler() {
 135   return FLAG_always_full_compiler || is_debugging_active();
 136 }
 137
 138
 139 static void FinishOptimization(Handle<JSFunction> function, int64_t start) {
 140   int opt_count = function->shared()->opt_count();
 141   function->shared()->set_opt_count(opt_count + 1);
 142   double ms = static_cast<double>(OS::Ticks() - start) / 1000;
 143   if (FLAG_trace_opt) {
 144     PrintF("[optimizing: ");
 145     function->PrintName();
 146     PrintF(" / %" V8PRIxPTR, reinterpret_cast<intptr_t>(*function));
 147     PrintF(" - took %0.3f ms]\n", ms);
 148   }
 149   if (FLAG_trace_opt_stats) {
 150     static double compilation_time = 0.0;
 151     static int compiled_functions = 0;
 152     static int code_size = 0;
 153
 154     compilation_time += ms;
 155     compiled_functions++;
 156     code_size += function->shared()->SourceSize();
 157     PrintF("Compiled: %d functions with %d byte source size in %fms.\n",
 158            compiled_functions,
 159            code_size,
 160            compilation_time);
 161   }
 162 }
 163
 164
 165 static bool MakeCrankshaftCode(CompilationInfo* info) {
 166   // Test if we can optimize this function when asked to. We can only
 167   // do this after the scopes are computed.
 168   if (!info->AllowOptimize()) info->DisableOptimization();
 169
 170   // In case we are not optimizing simply return the code from
 171   // the full code generator.
 172   if (!info->IsOptimizing()) {
 173     return FullCodeGenerator::MakeCode(info);
 174   }
 175
 176   // We should never arrive here if there is not code object on the
 177   // shared function object.
 178   Handle<Code> code(info->shared_info()->code());
 179   ASSERT(code->kind() == Code::FUNCTION);
 180
 181   // We should never arrive here if optimization has been disabled on the
 182   // shared function info.
 183   ASSERT(!info->shared_info()->optimization_disabled());
 184
 185   // Fall back to using the full code generator if it's not possible
 186   // to use the Hydrogen-based optimizing compiler. We already have
 187   // generated code for this from the shared function object.
 188   if (AlwaysFullCompiler() || !FLAG_use_hydrogen) {
 189     info->SetCode(code);
 190     return true;
 191   }
 192
 193   // Limit the number of times we re-compile a functions with
 194   // the optimizing compiler.
 195   const int kMaxOptCount =
 196       FLAG_deopt_every_n_times == 0 ? Compiler::kDefaultMaxOptCount : 1000;
 197   if (info->shared_info()->opt_count() > kMaxOptCount) {
 198     info->AbortOptimization();
 199     Handle<JSFunction> closure = info->closure();
 200     info->shared_info()->DisableOptimization(*closure);
 201     // True indicates the compilation pipeline is still going, not
 202     // necessarily that we optimized the code.
 203     return true;
 204   }
 205
 206   // Due to an encoding limit on LUnallocated operands in the Lithium
 207   // language, we cannot optimize functions with too many formal parameters
 208   // or perform on-stack replacement for function with too many
 209   // stack-allocated local variables.
 210   //
 211   // The encoding is as a signed value, with parameters and receiver using
 212   // the negative indices and locals the non-negative ones.
 213   const int parameter_limit = -LUnallocated::kMinFixedIndex;
 214   const int locals_limit = LUnallocated::kMaxFixedIndex;
 215   Scope* scope = info->scope();
 216   if ((scope->num_parameters() + 1) > parameter_limit ||
 217       (info->osr_ast_id() != AstNode::kNoNumber &&
 218        scope->num_parameters() + 1 + scope->num_stack_slots() > locals_limit)) {
 219     info->AbortOptimization();
 220     Handle<JSFunction> closure = info->closure();
 221     info->shared_info()->DisableOptimization(*closure);
 222     // True indicates the compilation pipeline is still going, not
 223     // necessarily that we optimized the code.
 224     return true;
 225   }
 226
 227   // Take --hydrogen-filter into account.
 228   Vector<const char> filter = CStrVector(FLAG_hydrogen_filter);
 229   Handle<String> name = info->function()->debug_name();
 230   bool match = filter.is_empty() || name->IsEqualTo(filter);
 231   if (!match) {
 232     info->SetCode(code);
 233     return true;
 234   }
 235
 236   // Recompile the unoptimized version of the code if the current version
 237   // doesn't have deoptimization support. Alternatively, we may decide to
 238   // run the full code generator to get a baseline for the compile-time
 239   // performance of the hydrogen-based compiler.
 240   int64_t start = OS::Ticks();
 241   bool should_recompile = !info->shared_info()->has_deoptimization_support();
 242   if (should_recompile || FLAG_hydrogen_stats) {
 243     HPhase phase(HPhase::kFullCodeGen);
 244     CompilationInfo unoptimized(info->shared_info());
 245     // Note that we use the same AST that we will use for generating the
 246     // optimized code.
 247     unoptimized.SetFunction(info->function());
 248     unoptimized.SetScope(info->scope());
 249     if (should_recompile) unoptimized.EnableDeoptimizationSupport();
 250     bool succeeded = FullCodeGenerator::MakeCode(&unoptimized);
 251     if (should_recompile) {
 252       if (!succeeded) return false;
 253       Handle<SharedFunctionInfo> shared = info->shared_info();
 254       shared->EnableDeoptimizationSupport(*unoptimized.code());
 255       // The existing unoptimized code was replaced with the new one.
 256       Compiler::RecordFunctionCompilation(
 257           Logger::LAZY_COMPILE_TAG, &unoptimized, shared);
 258     }
 259   }
 260
 261   // Check that the unoptimized, shared code is ready for
 262   // optimizations.  When using the always_opt flag we disregard the
 263   // optimizable marker in the code object and optimize anyway. This
 264   // is safe as long as the unoptimized code has deoptimization
 265   // support.
 266   ASSERT(FLAG_always_opt || code->optimizable());
 267   ASSERT(info->shared_info()->has_deoptimization_support());
 268
 269   if (FLAG_trace_hydrogen) {
 270     PrintF("-----------------------------------------------------------\n");
 271     PrintF("Compiling method %s using hydrogen\n", *name->ToCString());
 272     HTracer::Instance()->TraceCompilation(info->function());
 273   }
 274
 275   Handle<Context> global_context(info->closure()->context()->global_context());
 276   TypeFeedbackOracle oracle(code, global_context, info->isolate());
 277   HGraphBuilder builder(info, &oracle);
 278   HPhase phase(HPhase::kTotal);
 279   HGraph* graph = builder.CreateGraph();
 280   if (info->isolate()->has_pending_exception()) {
 281     info->SetCode(Handle<Code>::null());
 282     return false;
 283   }
 284
 285   if (graph != NULL && FLAG_build_lithium) {
 286     Handle<Code> optimized_code = graph->Compile(info);
 287     if (!optimized_code.is_null()) {
 288       info->SetCode(optimized_code);
 289       FinishOptimization(info->closure(), start);
 290       return true;
 291     }
 292   }
 293
 294   // Keep using the shared code.
 295   info->AbortOptimization();
 296   if (!builder.inline_bailout()) {
 297     // Mark the shared code as unoptimizable unless it was an inlined
 298     // function that bailed out.
 299     Handle<JSFunction> closure = info->closure();
 300     info->shared_info()->DisableOptimization(*closure);
 301   }
 302   // True indicates the compilation pipeline is still going, not necessarily
 303   // that we optimized the code.
 304   return true;
 305 }
 306
 307
 308 static bool GenerateCode(CompilationInfo* info) {
 309   return info->IsCompilingForDebugging() || !V8::UseCrankshaft() ?
 310       FullCodeGenerator::MakeCode(info) :
 311       MakeCrankshaftCode(info);
 312 }
 313
 314
 315 static bool MakeCode(CompilationInfo* info) {
 316   // Precondition: code has been parsed.  Postcondition: the code field in
 317   // the compilation info is set if compilation succeeded.
 318   ASSERT(info->function() != NULL);
 319   return Rewriter::Rewrite(info) && Scope::Analyze(info) && GenerateCode(info);
 320 }
 321
 322
 323 #ifdef ENABLE_DEBUGGER_SUPPORT
 324 bool Compiler::MakeCodeForLiveEdit(CompilationInfo* info) {
 325   // Precondition: code has been parsed.  Postcondition: the code field in
 326   // the compilation info is set if compilation succeeded.
 327   bool succeeded = MakeCode(info);
 328   if (!info->shared_info().is_null()) {
 329     Handle<SerializedScopeInfo> scope_info =
 330         SerializedScopeInfo::Create(info->scope());
 331     info->shared_info()->set_scope_info(*scope_info);
 332   }
 333   return succeeded;
 334 }
 335 #endif
 336
 337
 338 static Handle<SharedFunctionInfo> MakeFunctionInfo(CompilationInfo* info) {
 339   Isolate* isolate = info->isolate();
 340   ZoneScope zone_scope(isolate, DELETE_ON_EXIT);
 341   PostponeInterruptsScope postpone(isolate);
 342
 343   ASSERT(!isolate->global_context().is_null());
 344   Handle<Script> script = info->script();
 345   script->set_context_data((*isolate->global_context())->data());
 346
 347 #ifdef ENABLE_DEBUGGER_SUPPORT
 348   if (info->is_eval()) {
 349     Script::CompilationType compilation_type = Script::COMPILATION_TYPE_EVAL;
 350     script->set_compilation_type(Smi::FromInt(compilation_type));
 351     // For eval scripts add information on the function from which eval was
 352     // called.
 353     if (info->is_eval()) {
 354       StackTraceFrameIterator it(isolate);
 355       if (!it.done()) {
 356         script->set_eval_from_shared(
 357             JSFunction::cast(it.frame()->function())->shared());
 358         Code* code = it.frame()->LookupCode();
 359         int offset = static_cast<int>(
 360             it.frame()->pc() - code->instruction_start());
 361         script->set_eval_from_instructions_offset(Smi::FromInt(offset));
 362       }
 363     }
 364   }
 365
 366   // Notify debugger
 367   isolate->debugger()->OnBeforeCompile(script);
 368 #endif
 369
 370   // Only allow non-global compiles for eval.
 371   ASSERT(info->is_eval() || info->is_global());
 372
 373   if (!ParserApi::Parse(info)) return Handle<SharedFunctionInfo>::null();
 374
 375   // Measure how long it takes to do the compilation; only take the
 376   // rest of the function into account to avoid overlap with the
 377   // parsing statistics.
 378   HistogramTimer* rate = info->is_eval()
 379       ? info->isolate()->counters()->compile_eval()
 380       : info->isolate()->counters()->compile();
 381   HistogramTimerScope timer(rate);
 382
 383   // Compile the code.
 384   FunctionLiteral* lit = info->function();
 385   LiveEditFunctionTracker live_edit_tracker(isolate, lit);
 386   if (!MakeCode(info)) {
 387     isolate->StackOverflow();
 388     return Handle<SharedFunctionInfo>::null();
 389   }
 390
 391   // Allocate function.
 392   ASSERT(!info->code().is_null());
 393   Handle<SharedFunctionInfo> result =
 394       isolate->factory()->NewSharedFunctionInfo(
 395           lit->name(),
 396           lit->materialized_literal_count(),
 397           info->code(),
 398           SerializedScopeInfo::Create(info->scope()));
 399
 400   ASSERT_EQ(RelocInfo::kNoPosition, lit->function_token_position());
 401   Compiler::SetFunctionInfo(result, lit, true, script);
 402
 403   if (script->name()->IsString()) {
 404     PROFILE(isolate, CodeCreateEvent(
 405         info->is_eval()
 406             ? Logger::EVAL_TAG
 407             : Logger::ToNativeByScript(Logger::SCRIPT_TAG, *script),
 408         *info->code(),
 409         *result,
 410         String::cast(script->name())));
 411     GDBJIT(AddCode(Handle<String>(String::cast(script->name())),
 412                    script,
 413                    info->code(),
 414                    info));
 415   } else {
 416     PROFILE(isolate, CodeCreateEvent(
 417         info->is_eval()
 418             ? Logger::EVAL_TAG
 419             : Logger::ToNativeByScript(Logger::SCRIPT_TAG, *script),
 420         *info->code(),
 421         *result,
 422         isolate->heap()->empty_string()));
 423     GDBJIT(AddCode(Handle<String>(), script, info->code(), info));
 424   }
 425
 426   // Hint to the runtime system used when allocating space for initial
 427   // property space by setting the expected number of properties for
 428   // the instances of the function.
 429   SetExpectedNofPropertiesFromEstimate(result, lit->expected_property_count());
 430
 431 #ifdef ENABLE_DEBUGGER_SUPPORT
 432   // Notify debugger
 433   isolate->debugger()->OnAfterCompile(
 434       script, Debugger::NO_AFTER_COMPILE_FLAGS);
 435 #endif
 436
 437   live_edit_tracker.RecordFunctionInfo(result, lit);
 438
 439   return result;
 440 }
 441
 442
 443 Handle<SharedFunctionInfo> Compiler::Compile(Handle<String> source,
 444                                              Handle<Object> script_name,
 445                                              int line_offset,
 446                                              int column_offset,
 447                                              v8::Extension* extension,
 448                                              ScriptDataImpl* input_pre_data,
 449                                              Handle<Object> script_data,
 450                                              NativesFlag natives,
 451                                              v8::Script::CompileFlags compile_flags) {
 452   Isolate* isolate = source->GetIsolate();
 453   int source_length = source->length();
 454   isolate->counters()->total_load_size()->Increment(source_length);
 455   isolate->counters()->total_compile_size()->Increment(source_length);
 456
 457   // The VM is in the COMPILER state until exiting this function.
 458   VMState state(isolate, COMPILER);
 459
 460   CompilationCache* compilation_cache = isolate->compilation_cache();
 461
 462   // Do a lookup in the compilation cache but not for extensions.
 463   Handle<SharedFunctionInfo> result;
 464   if (extension == NULL) {
 465     result = compilation_cache->LookupScript(source,
 466                                              script_name,
 467                                              line_offset,
 468                                              column_offset);
 469   }
 470
 471   if (result.is_null()) {
 472     // No cache entry found. Do pre-parsing, if it makes sense, and compile
 473     // the script.
 474     // Building preparse data that is only used immediately after is only a
 475     // saving if we might skip building the AST for lazily compiled functions.
 476     // I.e., preparse data isn't relevant when the lazy flag is off, and
 477     // for small sources, odds are that there aren't many functions
 478     // that would be compiled lazily anyway, so we skip the preparse step
 479     // in that case too.
 480     ScriptDataImpl* pre_data = input_pre_data;
 481     int flags = kNoParsingFlags;
 482     if ((natives == NATIVES_CODE) || FLAG_allow_natives_syntax) {
 483       flags |= kAllowNativesSyntax;
 484     }
 485     if (natives != NATIVES_CODE && FLAG_harmony_scoping) {
 486       flags |= kHarmonyScoping;
 487     }
 488     if (pre_data == NULL
 489         && source_length >= FLAG_min_preparse_length) {
 490       if (source->IsExternalTwoByteString()) {
 491         ExternalTwoByteStringUC16CharacterStream stream(
 492             Handle<ExternalTwoByteString>::cast(source), 0, source->length());
 493         pre_data = ParserApi::PartialPreParse(&stream, extension, flags);
 494       } else {
 495         GenericStringUC16CharacterStream stream(source, 0, source->length());
 496         pre_data = ParserApi::PartialPreParse(&stream, extension, flags);
 497       }
 498     }
 499
 500     // Create a script object describing the script to be compiled.
 501     Handle<Script> script = FACTORY->NewScript(source);
 502     if (natives == NATIVES_CODE || compile_flags & v8::Script::NativeMode) {
 503       script->set_type(Smi::FromInt(Script::TYPE_NATIVE));
 504     }
 505     if (!script_name.is_null()) {
 506       script->set_name(*script_name);
 507       script->set_line_offset(Smi::FromInt(line_offset));
 508       script->set_column_offset(Smi::FromInt(column_offset));
 509     }
 510
 511     script->set_data(script_data.is_null() ? HEAP->undefined_value()
 512                                            : *script_data);
 513
 514     // Compile the function and add it to the cache.
 515     CompilationInfo info(script);
 516     info.MarkAsGlobal();
 517     info.SetExtension(extension);
 518     info.SetPreParseData(pre_data);
 519     if (compile_flags & v8::Script::QmlMode) info.MarkAsQmlMode();
 520     result = MakeFunctionInfo(&info);
 521     if (extension == NULL && !result.is_null()) {
 522       compilation_cache->PutScript(source, result);
 523     }
 524
 525     // Get rid of the pre-parsing data (if necessary).
 526     if (input_pre_data == NULL && pre_data != NULL) {
 527       delete pre_data;
 528     }
 529   }
 530
 531   if (result.is_null()) isolate->ReportPendingMessages();
 532   return result;
 533 }
 534
 535
 536 Handle<SharedFunctionInfo> Compiler::CompileEval(Handle<String> source,
 537                                                  Handle<Context> context,
 538                                                  bool is_global,
 539                                                  StrictModeFlag strict_mode,
 540                                                  bool qml_mode) {
 541   Isolate* isolate = source->GetIsolate();
 542   int source_length = source->length();
 543   isolate->counters()->total_eval_size()->Increment(source_length);
 544   isolate->counters()->total_compile_size()->Increment(source_length);
 545
 546   // The VM is in the COMPILER state until exiting this function.
 547   VMState state(isolate, COMPILER);
 548
 549   // Do a lookup in the compilation cache; if the entry is not there, invoke
 550   // the compiler and add the result to the cache.
 551   Handle<SharedFunctionInfo> result;
 552   CompilationCache* compilation_cache = isolate->compilation_cache();
 553   result = compilation_cache->LookupEval(source,
 554                                          context,
 555                                          is_global,
 556                                          strict_mode);
 557
 558   if (result.is_null()) {
 559     // Create a script object describing the script to be compiled.
 560     Handle<Script> script = isolate->factory()->NewScript(source);
 561     CompilationInfo info(script);
 562     info.MarkAsEval();
 563     if (is_global) info.MarkAsGlobal();
 564     info.SetStrictModeFlag(strict_mode);
 565     if (qml_mode) info.MarkAsQmlMode();
 566     info.SetCallingContext(context);
 567     result = MakeFunctionInfo(&info);
 568     if (!result.is_null()) {
 569       CompilationCache* compilation_cache = isolate->compilation_cache();
 570       // If caller is strict mode, the result must be strict as well,
 571       // but not the other way around. Consider:
 572       // eval("'use strict'; ...");
 573       // TODO(keuchel): adapt this for extended mode.
 574       ASSERT(strict_mode == kNonStrictMode || result->strict_mode());
 575       compilation_cache->PutEval(source, context, is_global, result);
 576     }
 577   }
 578
 579   return result;
 580 }
 581
 582
 583 bool Compiler::CompileLazy(CompilationInfo* info) {
 584   Isolate* isolate = info->isolate();
 585
 586   ZoneScope zone_scope(isolate, DELETE_ON_EXIT);
 587
 588   // The VM is in the COMPILER state until exiting this function.
 589   VMState state(isolate, COMPILER);
 590
 591   PostponeInterruptsScope postpone(isolate);
 592
 593   Handle<SharedFunctionInfo> shared = info->shared_info();
 594   int compiled_size = shared->end_position() - shared->start_position();
 595   isolate->counters()->total_compile_size()->Increment(compiled_size);
 596
 597   // Generate the AST for the lazily compiled function.
 598   if (ParserApi::Parse(info)) {
 599     // Measure how long it takes to do the lazy compilation; only take the
 600     // rest of the function into account to avoid overlap with the lazy
 601     // parsing statistics.
 602     HistogramTimerScope timer(isolate->counters()->compile_lazy());
 603
 604     // After parsing we know function's strict mode. Remember it.
 605     StrictModeFlag strict_mode = info->function()->strict_mode_flag();
 606     ASSERT(info->strict_mode_flag() == kNonStrictMode ||
 607            info->strict_mode_flag() == strict_mode);
 608     ASSERT(shared->strict_mode_flag() == kNonStrictMode ||
 609            shared->strict_mode_flag() == strict_mode);
 610     info->SetStrictModeFlag(strict_mode);
 611     shared->set_strict_mode_flag(strict_mode);
 612
 613     // After parsing we know function's qml mode. Remember it.
 614     if (info->function()->qml_mode()) {
 615       shared->set_qml_mode(true);
 616       info->MarkAsQmlMode();
 617     }
 618
 619     // Compile the code.
 620     if (!MakeCode(info)) {
 621       if (!isolate->has_pending_exception()) {
 622         isolate->StackOverflow();
 623       }
 624     } else {
 625       ASSERT(!info->code().is_null());
 626       Handle<Code> code = info->code();
 627       // Set optimizable to false if this is disallowed by the shared
 628       // function info, e.g., we might have flushed the code and must
 629       // reset this bit when lazy compiling the code again.
 630       if (shared->optimization_disabled()) code->set_optimizable(false);
 631
 632       Handle<JSFunction> function = info->closure();
 633       RecordFunctionCompilation(Logger::LAZY_COMPILE_TAG, info, shared);
 634
 635       if (info->IsOptimizing()) {
 636         ASSERT(shared->scope_info() != SerializedScopeInfo::Empty());
 637         function->ReplaceCode(*code);
 638       } else {
 639         // Update the shared function info with the compiled code and the
 640         // scope info.  Please note, that the order of the shared function
 641         // info initialization is important since set_scope_info might
 642         // trigger a GC, causing the ASSERT below to be invalid if the code
 643         // was flushed. By settting the code object last we avoid this.
 644         Handle<SerializedScopeInfo> scope_info =
 645             SerializedScopeInfo::Create(info->scope());
 646         shared->set_scope_info(*scope_info);
 647         shared->set_code(*code);
 648         if (!function.is_null()) {
 649           function->ReplaceCode(*code);
 650           ASSERT(!function->IsOptimized());
 651         }
 652
 653         // Set the expected number of properties for instances.
 654         FunctionLiteral* lit = info->function();
 655         int expected = lit->expected_property_count();
 656         SetExpectedNofPropertiesFromEstimate(shared, expected);
 657
 658         // Set the optimization hints after performing lazy compilation, as
 659         // these are not set when the function is set up as a lazily
 660         // compiled function.
 661         shared->SetThisPropertyAssignmentsInfo(
 662             lit->has_only_simple_this_property_assignments(),
 663             *lit->this_property_assignments());
 664
 665         // Check the function has compiled code.
 666         ASSERT(shared->is_compiled());
 667         shared->set_code_age(0);
 668
 669         if (info->AllowOptimize() && !shared->optimization_disabled()) {
 670           // If we're asked to always optimize, we compile the optimized
 671           // version of the function right away - unless the debugger is
 672           // active as it makes no sense to compile optimized code then.
 673           if (FLAG_always_opt &&
 674               !Isolate::Current()->DebuggerHasBreakPoints()) {
 675             CompilationInfo optimized(function);
 676             optimized.SetOptimizing(AstNode::kNoNumber);
 677             return CompileLazy(&optimized);
 678           }
 679         }
 680       }
 681
 682       return true;
 683     }
 684   }
 685
 686   ASSERT(info->code().is_null());
 687   return false;
 688 }
 689
 690
 691 Handle<SharedFunctionInfo> Compiler::BuildFunctionInfo(FunctionLiteral* literal,
 692                                                        Handle<Script> script) {
 693   // Precondition: code has been parsed and scopes have been analyzed.
 694   CompilationInfo info(script);
 695   info.SetFunction(literal);
 696   info.SetScope(literal->scope());
 697   info.SetStrictModeFlag(literal->scope()->strict_mode_flag());
 698
 699   LiveEditFunctionTracker live_edit_tracker(info.isolate(), literal);
 700   // Determine if the function can be lazily compiled. This is necessary to
 701   // allow some of our builtin JS files to be lazily compiled. These
 702   // builtins cannot be handled lazily by the parser, since we have to know
 703   // if a function uses the special natives syntax, which is something the
 704   // parser records.
 705   bool allow_lazy = literal->AllowsLazyCompilation() &&
 706       !LiveEditFunctionTracker::IsActive(info.isolate());
 707
 708   Handle<SerializedScopeInfo> scope_info(SerializedScopeInfo::Empty());
 709
 710   // Generate code
 711   if (FLAG_lazy && allow_lazy) {
 712     Handle<Code> code = info.isolate()->builtins()->LazyCompile();
 713     info.SetCode(code);
 714   } else if ((V8::UseCrankshaft() && MakeCrankshaftCode(&info)) ||
 715              (!V8::UseCrankshaft() && FullCodeGenerator::MakeCode(&info))) {
 716     ASSERT(!info.code().is_null());
 717     scope_info = SerializedScopeInfo::Create(info.scope());
 718   } else {
 719     return Handle<SharedFunctionInfo>::null();
 720   }
 721
 722   // Create a shared function info object.
 723   Handle<SharedFunctionInfo> result =
 724       FACTORY->NewSharedFunctionInfo(literal->name(),
 725                                      literal->materialized_literal_count(),
 726                                      info.code(),
 727                                      scope_info);
 728   SetFunctionInfo(result, literal, false, script);
 729   RecordFunctionCompilation(Logger::FUNCTION_TAG, &info, result);
 730   result->set_allows_lazy_compilation(allow_lazy);
 731
 732   // Set the expected number of properties for instances and return
 733   // the resulting function.
 734   SetExpectedNofPropertiesFromEstimate(result,
 735                                        literal->expected_property_count());
 736   live_edit_tracker.RecordFunctionInfo(result, literal);
 737   return result;
 738 }
 739
 740
 741 // Sets the function info on a function.
 742 // The start_position points to the first '(' character after the function name
 743 // in the full script source. When counting characters in the script source the
 744 // the first character is number 0 (not 1).
 745 void Compiler::SetFunctionInfo(Handle<SharedFunctionInfo> function_info,
 746                                FunctionLiteral* lit,
 747                                bool is_toplevel,
 748                                Handle<Script> script) {
 749   function_info->set_length(lit->num_parameters());
 750   function_info->set_formal_parameter_count(lit->num_parameters());
 751   function_info->set_script(*script);
 752   function_info->set_function_token_position(lit->function_token_position());
 753   function_info->set_start_position(lit->start_position());
 754   function_info->set_end_position(lit->end_position());
 755   function_info->set_is_expression(lit->is_expression());
 756   function_info->set_is_anonymous(lit->is_anonymous());
 757   function_info->set_is_toplevel(is_toplevel);
 758   function_info->set_inferred_name(*lit->inferred_name());
 759   function_info->SetThisPropertyAssignmentsInfo(
 760       lit->has_only_simple_this_property_assignments(),
 761       *lit->this_property_assignments());
 762   function_info->set_allows_lazy_compilation(lit->AllowsLazyCompilation());
 763   function_info->set_strict_mode_flag(lit->strict_mode_flag());
 764   function_info->set_qml_mode(lit->qml_mode());
 765   function_info->set_uses_arguments(lit->scope()->arguments() != NULL);
 766   function_info->set_has_duplicate_parameters(lit->has_duplicate_parameters());
 767 }
 768
 769
 770 void Compiler::RecordFunctionCompilation(Logger::LogEventsAndTags tag,
 771                                          CompilationInfo* info,
 772                                          Handle<SharedFunctionInfo> shared) {
 773   // SharedFunctionInfo is passed separately, because if CompilationInfo
 774   // was created using Script object, it will not have it.
 775
 776   // Log the code generation. If source information is available include
 777   // script name and line number. Check explicitly whether logging is
 778   // enabled as finding the line number is not free.
 779   if (info->isolate()->logger()->is_logging() ||
 780       CpuProfiler::is_profiling(info->isolate())) {
 781     Handle<Script> script = info->script();
 782     Handle<Code> code = info->code();
 783     if (*code == info->isolate()->builtins()->builtin(Builtins::kLazyCompile))
 784       return;
 785     if (script->name()->IsString()) {
 786       int line_num = GetScriptLineNumber(script, shared->start_position()) + 1;
 787       USE(line_num);
 788       PROFILE(info->isolate(),
 789               CodeCreateEvent(Logger::ToNativeByScript(tag, *script),
 790                               *code,
 791                               *shared,
 792                               String::cast(script->name()),
 793                               line_num));
 794     } else {
 795       PROFILE(info->isolate(),
 796               CodeCreateEvent(Logger::ToNativeByScript(tag, *script),
 797                               *code,
 798                               *shared,
 799                               shared->DebugName()));
 800     }
 801   }
 802
 803   GDBJIT(AddCode(Handle<String>(shared->DebugName()),
 804                  Handle<Script>(info->script()),
 805                  Handle<Code>(info->code()),
 806                  info));
 807 }
 808
 809 } }  // namespace v8::internal