1// Copyright 2012 the V8 project authors. All rights reserved.
2// Redistribution and use in source and binary forms, with or without
3// modification, are permitted provided that the following conditions are
4// met:
5//
6//     * Redistributions of source code must retain the above copyright
7//       notice, this list of conditions and the following disclaimer.
8//     * Redistributions in binary form must reproduce the above
9//       copyright notice, this list of conditions and the following
10//       disclaimer in the documentation and/or other materials provided
11//       with the distribution.
12//     * Neither the name of Google Inc. nor the names of its
13//       contributors may be used to endorse or promote products derived
14//       from this software without specific prior written permission.
15//
16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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
50namespace v8 {
51namespace internal {
52
53
54CompilationInfo::CompilationInfo(Handle<Script> script)
55    : isolate_(script->GetIsolate()),
56      flags_(LanguageModeField::encode(CLASSIC_MODE)),
57      function_(NULL),
58      scope_(NULL),
59      global_scope_(NULL),
60      script_(script),
61      extension_(NULL),
62      pre_parse_data_(NULL),
63      osr_ast_id_(AstNode::kNoNumber) {
64  Initialize(BASE);
65}
66
67
68CompilationInfo::CompilationInfo(Handle<SharedFunctionInfo> shared_info)
69    : isolate_(shared_info->GetIsolate()),
70      flags_(LanguageModeField::encode(CLASSIC_MODE) |
71             IsLazy::encode(true)),
72      function_(NULL),
73      scope_(NULL),
74      global_scope_(NULL),
75      shared_info_(shared_info),
76      script_(Handle<Script>(Script::cast(shared_info->script()))),
77      extension_(NULL),
78      pre_parse_data_(NULL),
79      osr_ast_id_(AstNode::kNoNumber) {
80  Initialize(BASE);
81}
82
83
84CompilationInfo::CompilationInfo(Handle<JSFunction> closure)
85    : isolate_(closure->GetIsolate()),
86      flags_(LanguageModeField::encode(CLASSIC_MODE) |
87             IsLazy::encode(true)),
88      function_(NULL),
89      scope_(NULL),
90      global_scope_(NULL),
91      closure_(closure),
92      shared_info_(Handle<SharedFunctionInfo>(closure->shared())),
93      script_(Handle<Script>(Script::cast(shared_info_->script()))),
94      extension_(NULL),
95      pre_parse_data_(NULL),
96      osr_ast_id_(AstNode::kNoNumber) {
97  Initialize(BASE);
98}
99
100
101// Disable optimization for the rest of the compilation pipeline.
102void CompilationInfo::DisableOptimization() {
103  bool is_optimizable_closure =
104    FLAG_optimize_closures &&
105    closure_.is_null() &&
106    !scope_->HasTrivialOuterContext() &&
107    !scope_->outer_scope_calls_non_strict_eval() &&
108    !scope_->inside_with();
109  SetMode(is_optimizable_closure ? BASE : NONOPT);
110}
111
112
113// Primitive functions are unlikely to be picked up by the stack-walking
114// profiler, so they trigger their own optimization when they're called
115// for the SharedFunctionInfo::kCallsUntilPrimitiveOptimization-th time.
116bool CompilationInfo::ShouldSelfOptimize() {
117  return FLAG_self_optimization &&
118      FLAG_crankshaft &&
119      !function()->flags()->Contains(kDontSelfOptimize) &&
120      !function()->flags()->Contains(kDontOptimize) &&
121      function()->scope()->AllowsLazyRecompilation() &&
122      (shared_info().is_null() || !shared_info()->optimization_disabled());
123}
124
125
126void CompilationInfo::AbortOptimization() {
127  Handle<Code> code(shared_info()->code());
128  SetCode(code);
129}
130
131
132// Determine whether to use the full compiler for all code. If the flag
133// --always-full-compiler is specified this is the case. For the virtual frame
134// based compiler the full compiler is also used if a debugger is connected, as
135// the code from the full compiler supports mode precise break points. For the
136// crankshaft adaptive compiler debugging the optimized code is not possible at
137// all. However crankshaft support recompilation of functions, so in this case
138// the full compiler need not be be used if a debugger is attached, but only if
139// break points has actually been set.
140static bool is_debugging_active() {
141#ifdef ENABLE_DEBUGGER_SUPPORT
142  Isolate* isolate = Isolate::Current();
143  return V8::UseCrankshaft() ?
144    isolate->debug()->has_break_points() :
145    isolate->debugger()->IsDebuggerActive();
146#else
147  return false;
148#endif
149}
150
151
152static bool AlwaysFullCompiler() {
153  return FLAG_always_full_compiler || is_debugging_active();
154}
155
156
157static void FinishOptimization(Handle<JSFunction> function, int64_t start) {
158  int opt_count = function->shared()->opt_count();
159  function->shared()->set_opt_count(opt_count + 1);
160  double ms = static_cast<double>(OS::Ticks() - start) / 1000;
161  if (FLAG_trace_opt) {
162    PrintF("[optimizing: ");
163    function->PrintName();
164    PrintF(" / %" V8PRIxPTR, reinterpret_cast<intptr_t>(*function));
165    PrintF(" - took %0.3f ms]\n", ms);
166  }
167  if (FLAG_trace_opt_stats) {
168    static double compilation_time = 0.0;
169    static int compiled_functions = 0;
170    static int code_size = 0;
171
172    compilation_time += ms;
173    compiled_functions++;
174    code_size += function->shared()->SourceSize();
175    PrintF("Compiled: %d functions with %d byte source size in %fms.\n",
176           compiled_functions,
177           code_size,
178           compilation_time);
179  }
180}
181
182
183static bool MakeCrankshaftCode(CompilationInfo* info) {
184  // Test if we can optimize this function when asked to. We can only
185  // do this after the scopes are computed.
186  if (!V8::UseCrankshaft()) {
187    info->DisableOptimization();
188  }
189
190  // In case we are not optimizing simply return the code from
191  // the full code generator.
192  if (!info->IsOptimizing()) {
193    return FullCodeGenerator::MakeCode(info);
194  }
195
196  // We should never arrive here if there is not code object on the
197  // shared function object.
198  Handle<Code> code(info->shared_info()->code());
199  ASSERT(code->kind() == Code::FUNCTION);
200
201  // We should never arrive here if optimization has been disabled on the
202  // shared function info.
203  ASSERT(!info->shared_info()->optimization_disabled());
204
205  // Fall back to using the full code generator if it's not possible
206  // to use the Hydrogen-based optimizing compiler. We already have
207  // generated code for this from the shared function object.
208  if (AlwaysFullCompiler()) {
209    info->SetCode(code);
210    return true;
211  }
212
213  // Limit the number of times we re-compile a functions with
214  // the optimizing compiler.
215  const int kMaxOptCount =
216      FLAG_deopt_every_n_times == 0 ? Compiler::kDefaultMaxOptCount : 1000;
217  if (info->shared_info()->opt_count() > kMaxOptCount) {
218    info->AbortOptimization();
219    info->shared_info()->DisableOptimization();
220    // True indicates the compilation pipeline is still going, not
221    // necessarily that we optimized the code.
222    return true;
223  }
224
225  // Due to an encoding limit on LUnallocated operands in the Lithium
226  // language, we cannot optimize functions with too many formal parameters
227  // or perform on-stack replacement for function with too many
228  // stack-allocated local variables.
229  //
230  // The encoding is as a signed value, with parameters and receiver using
231  // the negative indices and locals the non-negative ones.
232  const int parameter_limit = -LUnallocated::kMinFixedIndex;
233  const int locals_limit = LUnallocated::kMaxFixedIndex;
234  Scope* scope = info->scope();
235  if ((scope->num_parameters() + 1) > parameter_limit ||
236      (info->osr_ast_id() != AstNode::kNoNumber &&
237       scope->num_parameters() + 1 + scope->num_stack_slots() > locals_limit)) {
238    info->AbortOptimization();
239    info->shared_info()->DisableOptimization();
240    // True indicates the compilation pipeline is still going, not
241    // necessarily that we optimized the code.
242    return true;
243  }
244
245  // Take --hydrogen-filter into account.
246  Handle<String> name = info->function()->debug_name();
247  if (*FLAG_hydrogen_filter != '\0') {
248    Vector<const char> filter = CStrVector(FLAG_hydrogen_filter);
249    if ((filter[0] == '-'
250         && name->IsEqualTo(filter.SubVector(1, filter.length())))
251        || (filter[0] != '-' && !name->IsEqualTo(filter))) {
252      info->SetCode(code);
253      return true;
254    }
255  }
256
257  // Recompile the unoptimized version of the code if the current version
258  // doesn't have deoptimization support. Alternatively, we may decide to
259  // run the full code generator to get a baseline for the compile-time
260  // performance of the hydrogen-based compiler.
261  int64_t start = OS::Ticks();
262  bool should_recompile = !info->shared_info()->has_deoptimization_support();
263  if (should_recompile || FLAG_hydrogen_stats) {
264    HPhase phase(HPhase::kFullCodeGen);
265    CompilationInfo unoptimized(info->shared_info());
266    // Note that we use the same AST that we will use for generating the
267    // optimized code.
268    unoptimized.SetFunction(info->function());
269    unoptimized.SetScope(info->scope());
270    if (should_recompile) unoptimized.EnableDeoptimizationSupport();
271    bool succeeded = FullCodeGenerator::MakeCode(&unoptimized);
272    if (should_recompile) {
273      if (!succeeded) return false;
274      Handle<SharedFunctionInfo> shared = info->shared_info();
275      shared->EnableDeoptimizationSupport(*unoptimized.code());
276      // The existing unoptimized code was replaced with the new one.
277      Compiler::RecordFunctionCompilation(
278          Logger::LAZY_COMPILE_TAG, &unoptimized, shared);
279    }
280  }
281
282  // Check that the unoptimized, shared code is ready for
283  // optimizations.  When using the always_opt flag we disregard the
284  // optimizable marker in the code object and optimize anyway. This
285  // is safe as long as the unoptimized code has deoptimization
286  // support.
287  ASSERT(FLAG_always_opt || code->optimizable());
288  ASSERT(info->shared_info()->has_deoptimization_support());
289
290  if (FLAG_trace_hydrogen) {
291    PrintF("-----------------------------------------------------------\n");
292    PrintF("Compiling method %s using hydrogen\n", *name->ToCString());
293    HTracer::Instance()->TraceCompilation(info->function());
294  }
295
296  Handle<Context> global_context(info->closure()->context()->global_context());
297  TypeFeedbackOracle oracle(code, global_context, info->isolate());
298  HGraphBuilder builder(info, &oracle);
299  HPhase phase(HPhase::kTotal);
300  HGraph* graph = builder.CreateGraph();
301  if (info->isolate()->has_pending_exception()) {
302    info->SetCode(Handle<Code>::null());
303    return false;
304  }
305
306  if (graph != NULL) {
307    Handle<Code> optimized_code = graph->Compile(info);
308    if (!optimized_code.is_null()) {
309      info->SetCode(optimized_code);
310      FinishOptimization(info->closure(), start);
311      return true;
312    }
313  }
314
315  // Keep using the shared code.
316  info->AbortOptimization();
317  if (!builder.inline_bailout()) {
318    // Mark the shared code as unoptimizable unless it was an inlined
319    // function that bailed out.
320    info->shared_info()->DisableOptimization();
321  }
322  // True indicates the compilation pipeline is still going, not necessarily
323  // that we optimized the code.
324  return true;
325}
326
327
328static bool GenerateCode(CompilationInfo* info) {
329  return info->IsCompilingForDebugging() || !V8::UseCrankshaft() ?
330      FullCodeGenerator::MakeCode(info) :
331      MakeCrankshaftCode(info);
332}
333
334
335static bool MakeCode(CompilationInfo* info) {
336  // Precondition: code has been parsed.  Postcondition: the code field in
337  // the compilation info is set if compilation succeeded.
338  ASSERT(info->function() != NULL);
339  return Rewriter::Rewrite(info) && Scope::Analyze(info) && GenerateCode(info);
340}
341
342
343#ifdef ENABLE_DEBUGGER_SUPPORT
344bool Compiler::MakeCodeForLiveEdit(CompilationInfo* info) {
345  // Precondition: code has been parsed.  Postcondition: the code field in
346  // the compilation info is set if compilation succeeded.
347  bool succeeded = MakeCode(info);
348  if (!info->shared_info().is_null()) {
349    Handle<ScopeInfo> scope_info = ScopeInfo::Create(info->scope());
350    info->shared_info()->set_scope_info(*scope_info);
351  }
352  return succeeded;
353}
354#endif
355
356
357static Handle<SharedFunctionInfo> MakeFunctionInfo(CompilationInfo* info) {
358  Isolate* isolate = info->isolate();
359  ZoneScope zone_scope(isolate, DELETE_ON_EXIT);
360  PostponeInterruptsScope postpone(isolate);
361
362  ASSERT(!isolate->global_context().is_null());
363  Handle<Script> script = info->script();
364  script->set_context_data((*isolate->global_context())->data());
365
366#ifdef ENABLE_DEBUGGER_SUPPORT
367  if (info->is_eval()) {
368    Script::CompilationType compilation_type = Script::COMPILATION_TYPE_EVAL;
369    script->set_compilation_type(Smi::FromInt(compilation_type));
370    // For eval scripts add information on the function from which eval was
371    // called.
372    if (info->is_eval()) {
373      StackTraceFrameIterator it(isolate);
374      if (!it.done()) {
375        script->set_eval_from_shared(
376            JSFunction::cast(it.frame()->function())->shared());
377        Code* code = it.frame()->LookupCode();
378        int offset = static_cast<int>(
379            it.frame()->pc() - code->instruction_start());
380        script->set_eval_from_instructions_offset(Smi::FromInt(offset));
381      }
382    }
383  }
384
385  // Notify debugger
386  isolate->debugger()->OnBeforeCompile(script);
387#endif
388
389  // Only allow non-global compiles for eval.
390  ASSERT(info->is_eval() || info->is_global());
391  ParsingFlags flags = kNoParsingFlags;
392  if (info->pre_parse_data() != NULL ||
393      String::cast(script->source())->length() > FLAG_min_preparse_length) {
394    flags = kAllowLazy;
395  }
396  if (!ParserApi::Parse(info, flags)) {
397    return Handle<SharedFunctionInfo>::null();
398  }
399
400  // Measure how long it takes to do the compilation; only take the
401  // rest of the function into account to avoid overlap with the
402  // parsing statistics.
403  HistogramTimer* rate = info->is_eval()
404      ? info->isolate()->counters()->compile_eval()
405      : info->isolate()->counters()->compile();
406  HistogramTimerScope timer(rate);
407
408  // Compile the code.
409  FunctionLiteral* lit = info->function();
410  LiveEditFunctionTracker live_edit_tracker(isolate, lit);
411  if (!MakeCode(info)) {
412    if (!isolate->has_pending_exception()) isolate->StackOverflow();
413    return Handle<SharedFunctionInfo>::null();
414  }
415
416  // Allocate function.
417  ASSERT(!info->code().is_null());
418  Handle<SharedFunctionInfo> result =
419      isolate->factory()->NewSharedFunctionInfo(
420          lit->name(),
421          lit->materialized_literal_count(),
422          info->code(),
423          ScopeInfo::Create(info->scope()));
424
425  ASSERT_EQ(RelocInfo::kNoPosition, lit->function_token_position());
426  Compiler::SetFunctionInfo(result, lit, true, script);
427
428  if (script->name()->IsString()) {
429    PROFILE(isolate, CodeCreateEvent(
430        info->is_eval()
431            ? Logger::EVAL_TAG
432            : Logger::ToNativeByScript(Logger::SCRIPT_TAG, *script),
433        *info->code(),
434        *result,
435        String::cast(script->name())));
436    GDBJIT(AddCode(Handle<String>(String::cast(script->name())),
437                   script,
438                   info->code(),
439                   info));
440  } else {
441    PROFILE(isolate, CodeCreateEvent(
442        info->is_eval()
443            ? Logger::EVAL_TAG
444            : Logger::ToNativeByScript(Logger::SCRIPT_TAG, *script),
445        *info->code(),
446        *result,
447        isolate->heap()->empty_string()));
448    GDBJIT(AddCode(Handle<String>(), script, info->code(), info));
449  }
450
451  // Hint to the runtime system used when allocating space for initial
452  // property space by setting the expected number of properties for
453  // the instances of the function.
454  SetExpectedNofPropertiesFromEstimate(result, lit->expected_property_count());
455
456  script->set_compilation_state(
457      Smi::FromInt(Script::COMPILATION_STATE_COMPILED));
458
459#ifdef ENABLE_DEBUGGER_SUPPORT
460  // Notify debugger
461  isolate->debugger()->OnAfterCompile(
462      script, Debugger::NO_AFTER_COMPILE_FLAGS);
463#endif
464
465  live_edit_tracker.RecordFunctionInfo(result, lit);
466
467  return result;
468}
469
470
471Handle<SharedFunctionInfo> Compiler::Compile(Handle<String> source,
472                                             Handle<Object> script_name,
473                                             int line_offset,
474                                             int column_offset,
475                                             v8::Extension* extension,
476                                             ScriptDataImpl* pre_data,
477                                             Handle<Object> script_data,
478                                             NativesFlag natives) {
479  Isolate* isolate = source->GetIsolate();
480  int source_length = source->length();
481  isolate->counters()->total_load_size()->Increment(source_length);
482  isolate->counters()->total_compile_size()->Increment(source_length);
483
484  // The VM is in the COMPILER state until exiting this function.
485  VMState state(isolate, COMPILER);
486
487  CompilationCache* compilation_cache = isolate->compilation_cache();
488
489  // Do a lookup in the compilation cache but not for extensions.
490  Handle<SharedFunctionInfo> result;
491  if (extension == NULL) {
492    result = compilation_cache->LookupScript(source,
493                                             script_name,
494                                             line_offset,
495                                             column_offset);
496  }
497
498  if (result.is_null()) {
499    // No cache entry found. Do pre-parsing, if it makes sense, and compile
500    // the script.
501    // Building preparse data that is only used immediately after is only a
502    // saving if we might skip building the AST for lazily compiled functions.
503    // I.e., preparse data isn't relevant when the lazy flag is off, and
504    // for small sources, odds are that there aren't many functions
505    // that would be compiled lazily anyway, so we skip the preparse step
506    // in that case too.
507
508    // Create a script object describing the script to be compiled.
509    Handle<Script> script = FACTORY->NewScript(source);
510    if (natives == NATIVES_CODE) {
511      script->set_type(Smi::FromInt(Script::TYPE_NATIVE));
512    }
513    if (!script_name.is_null()) {
514      script->set_name(*script_name);
515      script->set_line_offset(Smi::FromInt(line_offset));
516      script->set_column_offset(Smi::FromInt(column_offset));
517    }
518
519    script->set_data(script_data.is_null() ? HEAP->undefined_value()
520                                           : *script_data);
521
522    // Compile the function and add it to the cache.
523    CompilationInfo info(script);
524    info.MarkAsGlobal();
525    info.SetExtension(extension);
526    info.SetPreParseData(pre_data);
527    if (FLAG_use_strict) {
528      info.SetLanguageMode(FLAG_harmony_scoping ? EXTENDED_MODE : STRICT_MODE);
529    }
530    result = MakeFunctionInfo(&info);
531    if (extension == NULL && !result.is_null()) {
532      compilation_cache->PutScript(source, result);
533    }
534  } else {
535    if (result->ic_age() != HEAP->global_ic_age()) {
536      result->ResetForNewContext(HEAP->global_ic_age());
537    }
538  }
539
540  if (result.is_null()) isolate->ReportPendingMessages();
541  return result;
542}
543
544
545Handle<SharedFunctionInfo> Compiler::CompileEval(Handle<String> source,
546                                                 Handle<Context> context,
547                                                 bool is_global,
548                                                 LanguageMode language_mode,
549                                                 int scope_position) {
550  Isolate* isolate = source->GetIsolate();
551  int source_length = source->length();
552  isolate->counters()->total_eval_size()->Increment(source_length);
553  isolate->counters()->total_compile_size()->Increment(source_length);
554
555  // The VM is in the COMPILER state until exiting this function.
556  VMState state(isolate, COMPILER);
557
558  // Do a lookup in the compilation cache; if the entry is not there, invoke
559  // the compiler and add the result to the cache.
560  Handle<SharedFunctionInfo> result;
561  CompilationCache* compilation_cache = isolate->compilation_cache();
562  result = compilation_cache->LookupEval(source,
563                                         context,
564                                         is_global,
565                                         language_mode,
566                                         scope_position);
567
568  if (result.is_null()) {
569    // Create a script object describing the script to be compiled.
570    Handle<Script> script = isolate->factory()->NewScript(source);
571    CompilationInfo info(script);
572    info.MarkAsEval();
573    if (is_global) info.MarkAsGlobal();
574    info.SetLanguageMode(language_mode);
575    info.SetCallingContext(context);
576    result = MakeFunctionInfo(&info);
577    if (!result.is_null()) {
578      // Explicitly disable optimization for eval code. We're not yet prepared
579      // to handle eval-code in the optimizing compiler.
580      result->DisableOptimization();
581
582      // If caller is strict mode, the result must be in strict mode or
583      // extended mode as well, but not the other way around. Consider:
584      // eval("'use strict'; ...");
585      ASSERT(language_mode != STRICT_MODE || !result->is_classic_mode());
586      // If caller is in extended mode, the result must also be in
587      // extended mode.
588      ASSERT(language_mode != EXTENDED_MODE ||
589             result->is_extended_mode());
590      compilation_cache->PutEval(
591          source, context, is_global, result, scope_position);
592    }
593  } else {
594    if (result->ic_age() != HEAP->global_ic_age()) {
595      result->ResetForNewContext(HEAP->global_ic_age());
596    }
597  }
598
599  return result;
600}
601
602
603bool Compiler::CompileLazy(CompilationInfo* info) {
604  Isolate* isolate = info->isolate();
605
606  ZoneScope zone_scope(isolate, DELETE_ON_EXIT);
607
608  // The VM is in the COMPILER state until exiting this function.
609  VMState state(isolate, COMPILER);
610
611  PostponeInterruptsScope postpone(isolate);
612
613  Handle<SharedFunctionInfo> shared = info->shared_info();
614  int compiled_size = shared->end_position() - shared->start_position();
615  isolate->counters()->total_compile_size()->Increment(compiled_size);
616
617  // Generate the AST for the lazily compiled function.
618  if (ParserApi::Parse(info, kNoParsingFlags)) {
619    // Measure how long it takes to do the lazy compilation; only take the
620    // rest of the function into account to avoid overlap with the lazy
621    // parsing statistics.
622    HistogramTimerScope timer(isolate->counters()->compile_lazy());
623
624    // After parsing we know the function's language mode. Remember it.
625    LanguageMode language_mode = info->function()->language_mode();
626    info->SetLanguageMode(language_mode);
627    shared->set_language_mode(language_mode);
628
629    // Compile the code.
630    if (!MakeCode(info)) {
631      if (!isolate->has_pending_exception()) {
632        isolate->StackOverflow();
633      }
634    } else {
635      ASSERT(!info->code().is_null());
636      Handle<Code> code = info->code();
637      // Set optimizable to false if this is disallowed by the shared
638      // function info, e.g., we might have flushed the code and must
639      // reset this bit when lazy compiling the code again.
640      if (shared->optimization_disabled()) code->set_optimizable(false);
641
642      Handle<JSFunction> function = info->closure();
643      RecordFunctionCompilation(Logger::LAZY_COMPILE_TAG, info, shared);
644
645      if (info->IsOptimizing()) {
646        ASSERT(shared->scope_info() != ScopeInfo::Empty());
647        function->ReplaceCode(*code);
648      } else {
649        // Update the shared function info with the compiled code and the
650        // scope info.  Please note, that the order of the shared function
651        // info initialization is important since set_scope_info might
652        // trigger a GC, causing the ASSERT below to be invalid if the code
653        // was flushed. By setting the code object last we avoid this.
654        Handle<ScopeInfo> scope_info = ScopeInfo::Create(info->scope());
655        shared->set_scope_info(*scope_info);
656        shared->set_code(*code);
657        if (!function.is_null()) {
658          function->ReplaceCode(*code);
659          ASSERT(!function->IsOptimized());
660        }
661
662        // Set the expected number of properties for instances.
663        FunctionLiteral* lit = info->function();
664        int expected = lit->expected_property_count();
665        SetExpectedNofPropertiesFromEstimate(shared, expected);
666
667        // Set the optimization hints after performing lazy compilation, as
668        // these are not set when the function is set up as a lazily
669        // compiled function.
670        shared->SetThisPropertyAssignmentsInfo(
671            lit->has_only_simple_this_property_assignments(),
672            *lit->this_property_assignments());
673
674        // Check the function has compiled code.
675        ASSERT(shared->is_compiled());
676        shared->set_code_age(0);
677        shared->set_dont_optimize(lit->flags()->Contains(kDontOptimize));
678        shared->set_dont_inline(lit->flags()->Contains(kDontInline));
679        shared->set_ast_node_count(lit->ast_node_count());
680
681        if (V8::UseCrankshaft()&&
682            !function.is_null() &&
683            !shared->optimization_disabled()) {
684          // If we're asked to always optimize, we compile the optimized
685          // version of the function right away - unless the debugger is
686          // active as it makes no sense to compile optimized code then.
687          if (FLAG_always_opt &&
688              !Isolate::Current()->DebuggerHasBreakPoints()) {
689            CompilationInfo optimized(function);
690            optimized.SetOptimizing(AstNode::kNoNumber);
691            return CompileLazy(&optimized);
692          }
693        }
694      }
695
696      return true;
697    }
698  }
699
700  ASSERT(info->code().is_null());
701  return false;
702}
703
704
705Handle<SharedFunctionInfo> Compiler::BuildFunctionInfo(FunctionLiteral* literal,
706                                                       Handle<Script> script) {
707  // Precondition: code has been parsed and scopes have been analyzed.
708  CompilationInfo info(script);
709  info.SetFunction(literal);
710  info.SetScope(literal->scope());
711  info.SetLanguageMode(literal->scope()->language_mode());
712
713  LiveEditFunctionTracker live_edit_tracker(info.isolate(), literal);
714  // Determine if the function can be lazily compiled. This is necessary to
715  // allow some of our builtin JS files to be lazily compiled. These
716  // builtins cannot be handled lazily by the parser, since we have to know
717  // if a function uses the special natives syntax, which is something the
718  // parser records.
719  bool allow_lazy = literal->AllowsLazyCompilation() &&
720      !LiveEditFunctionTracker::IsActive(info.isolate());
721
722  Handle<ScopeInfo> scope_info(ScopeInfo::Empty());
723
724  // Generate code
725  if (FLAG_lazy && allow_lazy) {
726    Handle<Code> code = info.isolate()->builtins()->LazyCompile();
727    info.SetCode(code);
728  } else if ((V8::UseCrankshaft() && MakeCrankshaftCode(&info)) ||
729             (!V8::UseCrankshaft() && FullCodeGenerator::MakeCode(&info))) {
730    ASSERT(!info.code().is_null());
731    scope_info = ScopeInfo::Create(info.scope());
732  } else {
733    return Handle<SharedFunctionInfo>::null();
734  }
735
736  // Create a shared function info object.
737  Handle<SharedFunctionInfo> result =
738      FACTORY->NewSharedFunctionInfo(literal->name(),
739                                     literal->materialized_literal_count(),
740                                     info.code(),
741                                     scope_info);
742  SetFunctionInfo(result, literal, false, script);
743  RecordFunctionCompilation(Logger::FUNCTION_TAG, &info, result);
744  result->set_allows_lazy_compilation(allow_lazy);
745
746  // Set the expected number of properties for instances and return
747  // the resulting function.
748  SetExpectedNofPropertiesFromEstimate(result,
749                                       literal->expected_property_count());
750  live_edit_tracker.RecordFunctionInfo(result, literal);
751  return result;
752}
753
754
755// Sets the function info on a function.
756// The start_position points to the first '(' character after the function name
757// in the full script source. When counting characters in the script source the
758// the first character is number 0 (not 1).
759void Compiler::SetFunctionInfo(Handle<SharedFunctionInfo> function_info,
760                               FunctionLiteral* lit,
761                               bool is_toplevel,
762                               Handle<Script> script) {
763  function_info->set_length(lit->parameter_count());
764  function_info->set_formal_parameter_count(lit->parameter_count());
765  function_info->set_script(*script);
766  function_info->set_function_token_position(lit->function_token_position());
767  function_info->set_start_position(lit->start_position());
768  function_info->set_end_position(lit->end_position());
769  function_info->set_is_expression(lit->is_expression());
770  function_info->set_is_anonymous(lit->is_anonymous());
771  function_info->set_is_toplevel(is_toplevel);
772  function_info->set_inferred_name(*lit->inferred_name());
773  function_info->SetThisPropertyAssignmentsInfo(
774      lit->has_only_simple_this_property_assignments(),
775      *lit->this_property_assignments());
776  function_info->set_allows_lazy_compilation(lit->AllowsLazyCompilation());
777  function_info->set_language_mode(lit->language_mode());
778  function_info->set_uses_arguments(lit->scope()->arguments() != NULL);
779  function_info->set_has_duplicate_parameters(lit->has_duplicate_parameters());
780  function_info->set_ast_node_count(lit->ast_node_count());
781  function_info->set_is_function(lit->is_function());
782  function_info->set_dont_optimize(lit->flags()->Contains(kDontOptimize));
783  function_info->set_dont_inline(lit->flags()->Contains(kDontInline));
784}
785
786
787void Compiler::RecordFunctionCompilation(Logger::LogEventsAndTags tag,
788                                         CompilationInfo* info,
789                                         Handle<SharedFunctionInfo> shared) {
790  // SharedFunctionInfo is passed separately, because if CompilationInfo
791  // was created using Script object, it will not have it.
792
793  // Log the code generation. If source information is available include
794  // script name and line number. Check explicitly whether logging is
795  // enabled as finding the line number is not free.
796  if (info->isolate()->logger()->is_logging() ||
797      CpuProfiler::is_profiling(info->isolate())) {
798    Handle<Script> script = info->script();
799    Handle<Code> code = info->code();
800    if (*code == info->isolate()->builtins()->builtin(Builtins::kLazyCompile))
801      return;
802    if (script->name()->IsString()) {
803      int line_num = GetScriptLineNumber(script, shared->start_position()) + 1;
804      USE(line_num);
805      PROFILE(info->isolate(),
806              CodeCreateEvent(Logger::ToNativeByScript(tag, *script),
807                              *code,
808                              *shared,
809                              String::cast(script->name()),
810                              line_num));
811    } else {
812      PROFILE(info->isolate(),
813              CodeCreateEvent(Logger::ToNativeByScript(tag, *script),
814                              *code,
815                              *shared,
816                              shared->DebugName()));
817    }
818  }
819
820  GDBJIT(AddCode(Handle<String>(shared->DebugName()),
821                 Handle<Script>(info->script()),
822                 Handle<Code>(info->code()),
823                 info));
824}
825
826} }  // namespace v8::internal
827