[turbofan] Split CodeGenerator::GenerateCode into AssembleCode and FinishCodeObject.

src/compiler/code-generator.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_CODE_GENERATOR_H_
 #define V8_COMPILER_CODE_GENERATOR_H_
 
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/unwinding-info-writer.h"
@@ skipping 30 matching lines @@
 
  private:
   Instruction* instr_;
   size_t pos_;
 };
 
 
 // Generates native code for a sequence of instructions.
 class CodeGenerator final : public GapResolver::Assembler {
  public:
-  explicit CodeGenerator(Frame* frame, Linkage* linkage,
-                         InstructionSequence* code, CompilationInfo* info);
+  CodeGenerator(Zone* zone, CompilationInfo* info);
 
-  // Generate native code.
-  Handle<Code> GenerateCode();
+  // Initialize before calling AssembleCode or FinishCodeObject.
+  void Initialize(Frame* frame, Linkage* linkage, InstructionSequence* code);
+
+  // Generate native code. This function can be run off the main thread.
+  bool AssembleCode();
+
+  // Finishes the code object generated in AssembleCode. This function returns
+  // an empty handle if AssembleCode() fails or has not been called.
+  Handle<Code> FinishCodeObject();
 
   InstructionSequence* code() const { return code_; }
   FrameAccessState* frame_access_state() const { return frame_access_state_; }
   const Frame* frame() const { return frame_access_state_->frame(); }
   Isolate* isolate() const { return info_->isolate(); }
   Linkage* linkage() const { return linkage_; }
+  bool assemble_code_successful() { return assemble_code_successful_; }
 
   Label* GetLabel(RpoNumber rpo) { return &labels_[rpo.ToSize()]; }
 
  private:
   MacroAssembler* masm() { return &masm_; }
   GapResolver* resolver() { return &resolver_; }
   SafepointTableBuilder* safepoints() { return &safepoints_; }
   Zone* zone() const { return code()->zone(); }
   CompilationInfo* info() const { return info_; }
 
-  // Create the FrameAccessState object. The Frame is immutable from here on.
-  void CreateFrameAccessState(Frame* frame);
-
   // Architecture - specific frame finalization.
   void FinishFrame(Frame* frame);
 
   // Checks if {block} will appear directly after {current_block_} when
   // assembling code, in which case, a fall-through can be used.
   bool IsNextInAssemblyOrder(RpoNumber block) const;
 
   // Record a safepoint with the given pointer map.
   void RecordSafepoint(ReferenceMap* references, Safepoint::Kind kind,
                        int arguments, Safepoint::DeoptMode deopt_mode);
@@ skipping 165 matching lines @@
   };
 
   struct HandlerInfo {
     Label* handler;
     int pc_offset;
   };
 
   friend class OutOfLineCode;
 
   FrameAccessState* frame_access_state_;
-  Linkage* const linkage_;
-  InstructionSequence* const code_;
+  Linkage* linkage_;
+  InstructionSequence* code_;
   UnwindingInfoWriter unwinding_info_writer_;
   CompilationInfo* const info_;
-  Label* const labels_;
+  Label* labels_;
   Label return_label_;
   RpoNumber current_block_;
   SourcePosition current_source_position_;
   MacroAssembler masm_;
   GapResolver resolver_;
   SafepointTableBuilder safepoints_;
   ZoneVector<HandlerInfo> handlers_;
   ZoneDeque<DeoptimizationExit*> deoptimization_exits_;
   ZoneDeque<DeoptimizationState*> deoptimization_states_;
   ZoneDeque<Handle<Object>> deoptimization_literals_;
   size_t inlined_function_count_;
   TranslationBuffer translations_;
   int last_lazy_deopt_pc_;
   JumpTable* jump_tables_;
   OutOfLineCode* ools_;
   int osr_pc_offset_;
   SourcePositionTableBuilder source_position_table_builder_;
+  bool assemble_code_successful_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_CODE_GENERATOR_H