text: // Copyright 2011 the V8 project authors. All rights reserved.
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  //       notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  //       copyright notice, this list of conditions and the following
  //       disclaimer in the documentation and/or other materials provided
  //       with the distribution.
  //     * Neither the name of Google Inc. nor the names of its
  //       contributors may be used to endorse or promote products derived
  //       from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #include "v8.h"
  
  #include "compiler.h"
  
  #include "bootstrapper.h"
  #include "codegen.h"
  #include "compilation-cache.h"
  #include "debug.h"
  #include "full-codegen.h"
  #include "gdb-jit.h"
  #include "hydrogen.h"
  #include "isolate-inl.h"
  #include "lithium.h"
  #include "liveedit.h"
  #include "parser.h"
  #include "rewriter.h"
  #include "runtime-profiler.h"
  #include "scanner-character-streams.h"
  #include "scopeinfo.h"
  #include "scopes.h"
  #include "vm-state-inl.h"
  
  namespace v8 {
  namespace internal {
  
  
  CompilationInfo::CompilationInfo(Handle<Script> script)
      : isolate_(script->GetIsolate()),
        flags_(LanguageModeField::encode(CLASSIC_MODE)),
        function_(NULL),
        scope_(NULL),
        global_scope_(NULL),
        script_(script),
        extension_(NULL),
        pre_parse_data_(NULL),
        osr_ast_id_(AstNode::kNoNumber) {
    Initialize(NONOPT);
  }
  
  
  CompilationInfo::CompilationInfo(Handle<SharedFunctionInfo> shared_info)
      : isolate_(shared_info->GetIsolate()),
        flags_(LanguageModeField::encode(CLASSIC_MODE) |
               IsLazy::encode(true)),
        function_(NULL),
        scope_(NULL),
        global_scope_(NULL),
        shared_info_(shared_info),
        script_(Handle<Script>(Script::cast(shared_info->script()))),
        extension_(NULL),
        pre_parse_data_(NULL),
        osr_ast_id_(AstNode::kNoNumber) {
    Initialize(BASE);
  }
  
  
  CompilationInfo::CompilationInfo(Handle<JSFunction> closure)
      : isolate_(closure->GetIsolate()),
        flags_(LanguageModeField::encode(CLASSIC_MODE) |
               IsLazy::encode(true)),
        function_(NULL),
        scope_(NULL),
        global_scope_(NULL),
        closure_(closure),
        shared_info_(Handle<SharedFunctionInfo>(closure->shared())),
        script_(Handle<Script>(Script::cast(shared_info_->script()))),
        extension_(NULL),
        pre_parse_data_(NULL),
        osr_ast_id_(AstNode::kNoNumber) {
    Initialize(BASE);
  }
  
  
  // Disable optimization for the rest of the compilation pipeline.
  void CompilationInfo::DisableOptimization() {
    bool is_optimizable_closure =
      FLAG_optimize_closures &&
      closure_.is_null() &&
      !scope_->HasTrivialOuterContext() &&
      !scope_->outer_scope_calls_non_strict_eval() &&
      !scope_->inside_with();
    SetMode(is_optimizable_closure ? BASE : NONOPT);
  }
  
  
  void CompilationInfo::AbortOptimization() {
    Handle<Code> code(shared_info()->code());
    SetCode(code);
  }
  
  
  // Determine whether to use the full compiler for all code. If the flag
  // --always-full-compiler is specified this is the case. For the virtual frame
  // based compiler the full compiler is also used if a debugger is connected, as
  // the code from the full compiler supports mode precise break points. For the
  // crankshaft adaptive compiler debugging the optimized code is not possible at
  // all. However crankshaft support recompilation of functions, so in this case
  // the full compiler need not be be used if a debugger is attached, but only if
  // break points has actually been set.
  static bool is_debugging_active() {
  #ifdef ENABLE_DEBUGGER_SUPPORT
    Isolate* isolate = Isolate::Current();
    return V8::UseCrankshaft() ?
      isolate->debug()->has_break_points() :
      isolate->debugger()->IsDebuggerActive();
  #else
    return false;
  #endif
  }
  
  
  static bool AlwaysFullCompiler() {
    return FLAG_always_full_compiler || is_debugging_active();
  }
  
  
  static void FinishOptimization(Handle<JSFunction> function, int64_t start) {
    int opt_count = function->shared()->opt_count();
    function->shared()->set_opt_count(opt_count + 1);
    double ms = static_cast<double>(OS::Ticks() - start) / 1000;
    if (FLAG_trace_opt) {
      PrintF("[optimizing: ");
      function->PrintName();
      PrintF(" / %" V8PRIxPTR, reinterpret_cast<intptr_t>(*function));
      PrintF(" - took %0.3f ms]\n", ms);
    }
    if (FLAG_trace_opt_stats) {
      static double compilation_time = 0.0;
      static int compiled_functions = 0;
      static int code_size = 0;
  
      compilation_time += ms;
      compiled_functions++;
      code_size += function->shared()->SourceSize();
      PrintF("Compiled: %d functions with %d byte source size in %fms.\n",
             compiled_functions,
             code_size,
             compilation_time);
    }
  }
  
  
  static bool MakeCrankshaftCode(CompilationInfo* info) {
    // Test if we can optimize this function when asked to. We can only
    // do this after the scopes are computed.
    if (!info->AllowOptimize()) {
      info->DisableOptimization();
    } else if (info->IsOptimizable()) {
      info->EnableDeoptimizationSupport();
    }
  
    // In case we are not optimizing simply return the code from
    // the full code generator.
    if (!info->IsOptimizing()) {
      return FullCodeGenerator::MakeCode(info);
    }
  
    // We should never arrive here if there is not code object on the
    // shared function object.
    Handle<Code> code(info->shared_info()->code());
    ASSERT(code->kind() == Code::FUNCTION);
  
    // We should never arrive here if optimization has been disabled on the
    // shared function info.
    ASSERT(!info->shared_info()->optimization_disabled());
  
    // Fall back to using the full code generator if it's not possible
    // to use the Hydrogen-based optimizing compiler. We already have
    // generated code for this from the shared function object.
    if (AlwaysFullCompiler() || !FLAG_use_hydrogen) {
      info->SetCode(code);
      return true;
    }
  
    // Limit the number of times we re-compile a functions with
    // the optimizing compiler.
    const int kMaxOptCount =
        FLAG_deopt_every_n_times == 0 ? Compiler::kDefaultMaxOptCount : 1000;
    if (info->shared_info()->opt_count() > kMaxOptCount) {
      info->AbortOptimization();
      Handle<JSFunction> closure = info->closure();
      info->shared_info()->DisableOptimization(*closure);
      // True indicates the compilation pipeline is still going, not
      // necessarily that we optimized the code.
      return true;
    }
  
    // Due to an encoding limit on LUnallocated operands in the Lithium
    // language, we cannot optimize functions with too many formal parameters
    // or perform on-stack replacement for function with too many
    // stack-allocated local variables.
    //
    // The encoding is as a signed value, with parameters and receiver using
    // the negative indices and locals the non-negative ones.
    const int parameter_limit = -LUnallocated::kMinFixedIndex;
    const int locals_limit = LUnallocated::kMaxFixedIndex;
    Scope* scope = info->scope();
    if ((scope->num_parameters() + 1) > parameter_limit ||
        (info->osr_ast_id() != AstNode::kNoNumber &&
         scope->num_parameters() + 1 + scope->num_stack_slots() > locals_limit)) {
      info->AbortOptimization();
      Handle<JSFunction> closure = info->closure();
      info->shared_info()->DisableOptimization(*closure);
      // True indicates the compilation pipeline is still going, not
      // necessarily that we optimized the code.
      return true;
    }
  
    // Take --hydrogen-filter into account.
    Vector<const char> filter = CStrVector(FLAG_hydrogen_filter);
    Handle<String> name = info->function()->debug_name();
    bool match = filter.is_empty() || name->IsEqualTo(filter);
    if (!match) {
      info->SetCode(code);
      return true;
    }
  
    // Recompile the unoptimized version of the code if the current version
    // doesn't have deoptimization support. Alternatively, we may decide to
    // run the full code generator to get a baseline for the compile-time
    // performance of the hydrogen-based compiler.
    int64_t start = OS::Ticks();
    bool should_recompile = !info->shared_info()->has_deoptimization_support();
    if (should_recompile || FLAG_hydrogen_stats) {
      HPhase phase(HPhase::kFullCodeGen);
      CompilationInfo unoptimized(info->shared_info());
      // Note that we use the same AST that we will use for generating the
      // optimized code.
      unoptimized.SetFunction(info->function());
      unoptimized.SetScope(info->scope());
      if (should_recompile) unoptimized.EnableDeoptimizationSupport();
      bool succeeded = FullCodeGenerator::MakeCode(&unoptimized);
      if (should_recompile) {
        if (!succeeded) return false;
        Handle<SharedFunctionInfo> shared = info->shared_info();
        shared->EnableDeoptimizationSupport(*unoptimized.code());
        // The existing unoptimized code was replaced with the new one.
        Compiler::RecordFunctionCompilation(
            Logger::LAZY_COMPILE_TAG, &unoptimized, shared);
      }
    }
  
    // Check that the unoptimized, shared code is ready for
    // optimizations.  When using the always_opt flag we disregard the
    // optimizable marker in the code object and optimize anyway. This
    // is safe as long as the unoptimized code has deoptimization
    // support.
    ASSERT(FLAG_always_opt || code->optimizable());
    ASSERT(info->shared_info()->has_deoptimization_support());
  
    if (FLAG_trace_hydrogen) {
      PrintF("-----------------------------------------------------------\n");
      PrintF("Compiling method %s using hydrogen\n", *name->ToCString());
      HTracer::Instance()->TraceCompilation(info->function());
    }
  
    Handle<Context> global_context(info->closure()->context()->global_context());
    TypeFeedbackOracle oracle(code, global_context, info->isolate());
    HGraphBuilder builder(info, &oracle);
    HPhase phase(HPhase::kTotal);
    HGraph* graph = builder.CreateGraph();
    if (info->isolate()->has_pending_exception()) {
      info->SetCode(Handle<Code>::null());
      return false;
    }
  
    if (graph != NULL && FLAG_build_lithium) {
      Handle<Code> optimized_code = graph->Compile(info);
      if (!optimized_code.is_null()) {
        info->SetCode(optimized_code);
        FinishOptimization(info->closure(), start);
        return true;
      }
    }
  
    // Keep using the shared code.
    info->AbortOptimization();
    if (!builder.inline_bailout()) {
      // Mark the shared code as unoptimizable unless it was an inlined
      // function that bailed out.
      Handle<JSFunction> closure = info->closure();
      info->shared_info()->DisableOptimization(*closure);
    }
    // True indicates the compilation pipeline is still going, not necessarily
    // that we optimized the code.
    return true;
  }
  
  
  static bool GenerateCode(CompilationInfo* info) {
    return info->IsCompilingForDebugging() || !V8::UseCrankshaft() ?
        FullCodeGenerator::MakeCode(info) :
        MakeCrankshaftCode(info);
  }
  
  
  static bool MakeCode(CompilationInfo* info) {
    // Precondition: code has been parsed.  Postcondition: the code field in
    // the compilation info is set if compilation succeeded.
    ASSERT(info->function() != NULL);
    return Rewriter::Rewrite(info) && Scope::Analyze(info) && GenerateCode(info);
  }
  
  
  #ifdef ENABLE_DEBUGGER_SUPPORT
  bool Compiler::MakeCodeForLiveEdit(CompilationInfo* info) {
    // Precondition: code has been parsed.  Postcondition: the code field in
    // the compilation info is set if compilation succeeded.
    bool succeeded = MakeCode(info);
    if (!info->shared_info().is_null()) {
      Handle<ScopeInfo> scope_info = ScopeInfo::Create(info->scope());
      info->shared_info()->set_scope_info(*scope_info);
    }
    return succeeded;
  }
  #endif
  
  
  static Handle<SharedFunctionInfo> MakeFunctionInfo(CompilationInfo* info) {
    Isolate* isolate = info->isolate();
    ZoneScope zone_scope(isolate, DELETE_ON_EXIT);
    PostponeInterruptsScope postpone(isolate);
  
    ASSERT(!isolate->global_context().is_null());
    Handle<Script> script = info->script();
    script->set_context_data((*isolate->global_context())->data());
  
  #ifdef ENABLE_DEBUGGER_SUPPORT
    if (info->is_eval()) {
      Script::CompilationType compilation_type = Script::COMPILATION_TYPE_EVAL;
      script->set_compilation_type(Smi::FromInt(compilation_type));
      // For eval scripts add information on the function from which eval was
      // called.
      if (info->is_eval()) {
        StackTraceFrameIterator it(isolate);
        if (!it.done()) {
          script->set_eval_from_shared(
              JSFunction::cast(it.frame()->function())->shared());
          Code* code = it.frame()->LookupCode();
          int offset = static_cast<int>(
              it.frame()->pc() - code->instruction_start());
          script->set_eval_from_instructions_offset(Smi::FromInt(offset));
        }
      }
    }
  
    // Notify debugger
    isolate->debugger()->OnBeforeCompile(script);
  #endif
  
    // Only allow non-global compiles for eval.
    ASSERT(info->is_eval() || info->is_global());
    ParsingFlags flags = kNoParsingFlags;
    if (info->pre_parse_data() != NULL ||
        String::cast(script->source())->length() > FLAG_min_preparse_length) {
      flags = kAllowLazy;
    }
    if (!ParserApi::Parse(info, flags)) {
      return Handle<SharedFunctionInfo>::null();
    }
  
    // Measure how long it takes to do the compilation; only take the
    // rest of the function into account to avoid overlap with the
    // parsing statistics.
    HistogramTimer* rate = info->is_eval()
        ? info->isolate()->counters()->compile_eval()
        : info->isolate()->counters()->compile();
    HistogramTimerScope timer(rate);
  
    // Compile the code.
    FunctionLiteral* lit = info->function();
    LiveEditFunctionTracker live_edit_tracker(isolate, lit);
    if (!MakeCode(info)) {
      if (!isolate->has_pending_exception()) isolate->StackOverflow();
      return Handle<SharedFunctionInfo>::null();
    }
  
    // Allocate function.
    ASSERT(!info->code().is_null());
    Handle<SharedFunctionInfo> result =
        isolate->factory()->NewSharedFunctionInfo(
            lit->name(),
            lit->materialized_literal_count(),
            info->code(),
            ScopeInfo::Create(info->scope()));
  
    ASSERT_EQ(RelocInfo::kNoPosition, lit->function_token_position());
    Compiler::SetFunctionInfo(result, lit, true, script);
  
    if (script->name()->IsString()) {
      PROFILE(isolate, CodeCreateEvent(
          info->is_eval()
              ? Logger::EVAL_TAG
              : Logger::ToNativeByScript(Logger::SCRIPT_TAG, *script),
          *info->code(),
          *result,
          String::cast(script->name())));
      GDBJIT(AddCode(Handle<String>(String::cast(script->name())),
                     script,
                     info->code(),
                     info));
    } else {
      PROFILE(isolate, CodeCreateEvent(
          info->is_eval()
              ? Logger::EVAL_TAG
              : Logger::ToNativeByScript(Logger::SCRIPT_TAG, *script),
          *info->code(),
          *result,
          isolate->heap()->empty_string()));
      GDBJIT(AddCode(Handle<String>(), script, info->code(), info));
    }
  
    // Hint to the runtime system used when allocating space for initial
    // property space by setting the expected number of properties for
    // the instances of the function.
    SetExpectedNofPropertiesFromEstimate(result, lit->expected_property_count());
  
  #ifdef ENABLE_DEBUGGER_SUPPORT
    // Notify debugger
    isolate->debugger()->OnAfterCompile(
        script, Debugger::NO_AFTER_COMPILE_FLAGS);
  #endif
  
    live_edit_tracker.RecordFunctionInfo(result, lit);
  
    return result;
  }
  
  
  Handle<SharedFunctionInfo> Compiler::Compile(Handle<String> source,
                                               Handle<Object> script_name,
                                               int line_offset,
                                               int column_offset,
                                               v8::Extension* extension,
                                               ScriptDataImpl* pre_data,
                                               Handle<Object> script_data,
                                               NativesFlag natives) {
    Isolate* isolate = source->GetIsolate();
    int source_length = source->length();
    isolate->counters()->total_load_size()->Increment(source_length);
    isolate->counters()->total_compile_size()->Increment(source_length);
  
    // The VM is in the COMPILER state until exiting this function.
    VMState state(isolate, COMPILER);
  
    CompilationCache* compilation_cache = isolate->compilation_cache();
  
    // Do a lookup in the compilation cache but not for extensions.
    Handle<SharedFunctionInfo> result;
    if (extension == NULL) {
      result = compilation_cache->LookupScript(source,
                                               script_name,
                                               line_offset,
                                               column_offset);
    }
  
    if (result.is_null()) {
      // No cache entry found. Do pre-parsing, if it makes sense, and compile
      // the script.
      // Building preparse data that is only used immediately after is only a
      // saving if we might skip building the AST for lazily compiled functions.
      // I.e., preparse data isn't relevant when the lazy flag is off, and
      // for small sources, odds are that there aren't many functions
      // that would be compiled lazily anyway, so we skip the preparse step
      // in that case too.
      int flags = kNoParsingFlags;
      if ((natives == NATIVES_CODE) || FLAG_allow_natives_syntax) {
        flags |= kAllowNativesSyntax;
      }
      if (natives != NATIVES_CODE && FLAG_harmony_scoping) {
        flags |= EXTENDED_MODE;
      }
  
      // Create a script object describing the script to be compiled.
      Handle<Script> script = FACTORY->NewScript(source);
      if (natives == NATIVES_CODE) {
        script->set_type(Smi::FromInt(Script::TYPE_NATIVE));
      }
      if (!script_name.is_null()) {
        script->set_name(*script_name);
        script->set_line_offset(Smi::FromInt(line_offset));
        script->set_column_offset(Smi::FromInt(column_offset));
      }
  
      script->set_data(script_data.is_null() ? HEAP->undefined_value()
                                             : *script_data);
  
      // Compile the function and add it to the cache.
      CompilationInfo info(script);
      info.MarkAsGlobal();
      info.SetExtension(extension);
      info.SetPreParseData(pre_data);
      result = MakeFunctionInfo(&info);
      if (extension == NULL && !result.is_null()) {
        compilation_cache->PutScript(source, result);
      }
    }
  
    if (result.is_null()) isolate->ReportPendingMessages();
    return result;
  }
  
  
  Handle<SharedFunctionInfo> Compiler::CompileEval(Handle<String> source,
                                                   Handle<Context> context,
                                                   bool is_global,
                                                   LanguageMode language_mode,
                                                   int scope_position) {
    Isolate* isolate = source->GetIsolate();
    int source_length = source->length();
    isolate->counters()->total_eval_size()->Increment(source_length);
    isolate->counters()->total_compile_size()->Increment(source_length);
  
    // The VM is in the COMPILER state until exiting this function.
    VMState state(isolate, COMPILER);
  
    // Do a lookup in the compilation cache; if the entry is not there, invoke
    // the compiler and add the result to the cache.
    Handle<SharedFunctionInfo> result;
    CompilationCache* compilation_cache = isolate->compilation_cache();
    result = compilation_cache->LookupEval(source,
                                           context,
                                           is_global,
                                           language_mode,
                                           scope_position);
  
    if (result.is_null()) {
      // Create a script object describing the script to be compiled.
      Handle<Script> script = isolate->factory()->NewScript(source);
      CompilationInfo info(script);
      info.MarkAsEval();
      if (is_global) info.MarkAsGlobal();
      info.SetLanguageMode(language_mode);
      info.SetCallingContext(context);
      result = MakeFunctionInfo(&info);
      if (!result.is_null()) {
        // If caller is strict mode, the result must be in strict mode or
        // extended mode as well, but not the other way around. Consider:
        // eval("'use strict'; ...");
        ASSERT(language_mode != STRICT_MODE || !result->is_classic_mode());
        // If caller is in extended mode, the result must also be in
        // extended mode.
        ASSERT(language_mode != EXTENDED_MODE ||
               result->is_extended_mode());
        compilation_cache->PutEval(
            source, context, is_global, result, scope_position);
      }
    }
  
    return result;
  }
  
  
  bool Compiler::CompileLazy(CompilationInfo* info) {
    Isolate* isolate = info->isolate();
  
    ZoneScope zone_scope(isolate, DELETE_ON_EXIT);
  
    // The VM is in the COMPILER state until exiting this function.
    VMState state(isolate, COMPILER);
  
    PostponeInterruptsScope postpone(isolate);
  
    Handle<SharedFunctionInfo> shared = info->shared_info();
    int compiled_size = shared->end_position() - shared->start_position();
    isolate->counters()->total_compile_size()->Increment(compiled_size);
  
    // Generate the AST for the lazily compiled function.
    if (ParserApi::Parse(info, kNoParsingFlags)) {
      // Measure how long it takes to do the lazy compilation; only take the
      // rest of the function into account to avoid overlap with the lazy
      // parsing statistics.
      HistogramTimerScope timer(isolate->counters()->compile_lazy());
  
      // After parsing we know the function's language mode. Remember it.
      LanguageMode language_mode = info->function()->language_mode();
      info->SetLanguageMode(language_mode);
      shared->set_language_mode(language_mode);
  
      // Compile the code.
      if (!MakeCode(info)) {
        if (!isolate->has_pending_exception()) {
          isolate->StackOverflow();
        }
      } else {
        ASSERT(!info->code().is_null());
        Handle<Code> code = info->code();
        // Set optimizable to false if this is disallowed by the shared
        // function info, e.g., we might have flushed the code and must
        // reset this bit when lazy compiling the code again.
        if (shared->optimization_disabled()) code->set_optimizable(false);
  
        Handle<JSFunction> function = info->closure();
        RecordFunctionCompilation(Logger::LAZY_COMPILE_TAG, info, shared);
  
        if (info->IsOptimizing()) {
          ASSERT(shared->scope_info() != ScopeInfo::Empty());
          function->ReplaceCode(*code);
        } else {
          // Update the shared function info with the compiled code and the
          // scope info.  Please note, that the order of the shared function
          // info initialization is important since set_scope_info might
          // trigger a GC, causing the ASSERT below to be invalid if the code
          // was flushed. By settting the code object last we avoid this.
          Handle<ScopeInfo> scope_info = ScopeInfo::Create(info->scope());
          shared->set_scope_info(*scope_info);
          shared->set_code(*code);
          if (!function.is_null()) {
            function->ReplaceCode(*code);
            ASSERT(!function->IsOptimized());
          }
  
          // Set the expected number of properties for instances.
          FunctionLiteral* lit = info->function();
          int expected = lit->expected_property_count();
          SetExpectedNofPropertiesFromEstimate(shared, expected);
  
          // Set the optimization hints after performing lazy compilation, as
          // these are not set when the function is set up as a lazily
          // compiled function.
          shared->SetThisPropertyAssignmentsInfo(
              lit->has_only_simple_this_property_assignments(),
              *lit->this_property_assignments());
  
          // Check the function has compiled code.
          ASSERT(shared->is_compiled());
          shared->set_code_age(0);
  
          if (info->AllowOptimize() && !shared->optimization_disabled()) {
            // If we're asked to always optimize, we compile the optimized
            // version of the function right away - unless the debugger is
            // active as it makes no sense to compile optimized code then.
            if (FLAG_always_opt &&
                !Isolate::Current()->DebuggerHasBreakPoints()) {
              CompilationInfo optimized(function);
              optimized.SetOptimizing(AstNode::kNoNumber);
              return CompileLazy(&optimized);
            }
          }
        }
  
        return true;
      }
    }
  
    ASSERT(info->code().is_null());
    return false;
  }
  
  
  Handle<SharedFunctionInfo> Compiler::BuildFunctionInfo(FunctionLiteral* literal,
                                                         Handle<Script> script) {
    // Precondition: code has been parsed and scopes have been analyzed.
    CompilationInfo info(script);
    info.SetFunction(literal);
    info.SetScope(literal->scope());
    info.SetLanguageMode(literal->scope()->language_mode());
  
    LiveEditFunctionTracker live_edit_tracker(info.isolate(), literal);
    // Determine if the function can be lazily compiled. This is necessary to
    // allow some of our builtin JS files to be lazily compiled. These
    // builtins cannot be handled lazily by the parser, since we have to know
    // if a function uses the special natives syntax, which is something the
    // parser records.
    bool allow_lazy = literal->AllowsLazyCompilation() &&
        !LiveEditFunctionTracker::IsActive(info.isolate());
  
    Handle<ScopeInfo> scope_info(ScopeInfo::Empty());
  
    // Generate code
    if (FLAG_lazy && allow_lazy) {
      Handle<Code> code = info.isolate()->builtins()->LazyCompile();
      info.SetCode(code);
    } else if ((V8::UseCrankshaft() && MakeCrankshaftCode(&info)) ||
               (!V8::UseCrankshaft() && FullCodeGenerator::MakeCode(&info))) {
      ASSERT(!info.code().is_null());
      scope_info = ScopeInfo::Create(info.scope());
    } else {
      return Handle<SharedFunctionInfo>::null();
    }
  
    // Create a shared function info object.
    Handle<SharedFunctionInfo> result =
        FACTORY->NewSharedFunctionInfo(literal->name(),
                                       literal->materialized_literal_count(),
                                       info.code(),
                                       scope_info);
    SetFunctionInfo(result, literal, false, script);
    RecordFunctionCompilation(Logger::FUNCTION_TAG, &info, result);
    result->set_allows_lazy_compilation(allow_lazy);
  
    // Set the expected number of properties for instances and return
    // the resulting function.
    SetExpectedNofPropertiesFromEstimate(result,
                                         literal->expected_property_count());
    live_edit_tracker.RecordFunctionInfo(result, literal);
    return result;
  }
  
  
  // Sets the function info on a function.
  // The start_position points to the first '(' character after the function name
  // in the full script source. When counting characters in the script source the
  // the first character is number 0 (not 1).
  void Compiler::SetFunctionInfo(Handle<SharedFunctionInfo> function_info,
                                 FunctionLiteral* lit,
                                 bool is_toplevel,
                                 Handle<Script> script) {
    function_info->set_length(lit->parameter_count());
    function_info->set_formal_parameter_count(lit->parameter_count());
    function_info->set_script(*script);
    function_info->set_function_token_position(lit->function_token_position());
    function_info->set_start_position(lit->start_position());
    function_info->set_end_position(lit->end_position());
    function_info->set_is_expression(lit->is_expression());
    function_info->set_is_anonymous(lit->is_anonymous());
    function_info->set_is_toplevel(is_toplevel);
    function_info->set_inferred_name(*lit->inferred_name());
    function_info->SetThisPropertyAssignmentsInfo(
        lit->has_only_simple_this_property_assignments(),
        *lit->this_property_assignments());
    function_info->set_allows_lazy_compilation(lit->AllowsLazyCompilation());
    function_info->set_language_mode(lit->language_mode());
    function_info->set_uses_arguments(lit->scope()->arguments() != NULL);
    function_info->set_has_duplicate_parameters(lit->has_duplicate_parameters());
  }
  
  
  void Compiler::RecordFunctionCompilation(Logger::LogEventsAndTags tag,
                                           CompilationInfo* info,
                                           Handle<SharedFunctionInfo> shared) {
    // SharedFunctionInfo is passed separately, because if CompilationInfo
    // was created using Script object, it will not have it.
  
    // Log the code generation. If source information is available include
    // script name and line number. Check explicitly whether logging is
    // enabled as finding the line number is not free.
    if (info->isolate()->logger()->is_logging() ||
        CpuProfiler::is_profiling(info->isolate())) {
      Handle<Script> script = info->script();
      Handle<Code> code = info->code();
      if (*code == info->isolate()->builtins()->builtin(Builtins::kLazyCompile))
        return;
      if (script->name()->IsString()) {
        int line_num = GetScriptLineNumber(script, shared->start_position()) + 1;
        USE(line_num);
        PROFILE(info->isolate(),
                CodeCreateEvent(Logger::ToNativeByScript(tag, *script),
                                *code,
                                *shared,
                                String::cast(script->name()),
                                line_num));
      } else {
        PROFILE(info->isolate(),
                CodeCreateEvent(Logger::ToNativeByScript(tag, *script),
                                *code,
                                *shared,
                                shared->DebugName()));
      }
    }
  
    GDBJIT(AddCode(Handle<String>(shared->DebugName()),
                   Handle<Script>(info->script()),
                   Handle<Code>(info->code()),
                   info));
  }
  
  } }  // namespace v8::internal
  