// Copyright 2010 the V8 project authors. All rights reserved.
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// modification, are permitted provided that the following conditions are
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//
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#ifndef V8_MIPS_CODEGEN_MIPS_H_
#define V8_MIPS_CODEGEN_MIPS_H_

namespace v8 {
namespace internal {

// Forward declarations
class CompilationInfo;
class DeferredCode;
class RegisterAllocator;
class RegisterFile;

enum InitState { CONST_INIT, NOT_CONST_INIT };
enum TypeofState { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };


// -------------------------------------------------------------------------
// Code generation state

// The state is passed down the AST by the code generator (and back up, in
// the form of the state of the label pair).  It is threaded through the
// call stack.  Constructing a state implicitly pushes it on the owning code
// generator's stack of states, and destroying one implicitly pops it.

class CodeGenState BASE_EMBEDDED {
 public:
  // Create an initial code generator state.  Destroying the initial state
  // leaves the code generator with a NULL state.
  explicit CodeGenState(CodeGenerator* owner);

  // Create a code generator state based on a code generator's current
  // state.  The new state has its own typeof state and pair of branch
  // labels.
  CodeGenState(CodeGenerator* owner,
               JumpTarget* true_target,
               JumpTarget* false_target);

  // Destroy a code generator state and restore the owning code generator's
  // previous state.
  ~CodeGenState();

  TypeofState typeof_state() const { return typeof_state_; }
  JumpTarget* true_target() const { return true_target_; }
  JumpTarget* false_target() const { return false_target_; }

 private:
  // The owning code generator.
  CodeGenerator* owner_;

  // A flag indicating whether we are compiling the immediate subexpression
  // of a typeof expression.
  TypeofState typeof_state_;

  JumpTarget* true_target_;
  JumpTarget* false_target_;

  // The previous state of the owning code generator, restored when
  // this state is destroyed.
  CodeGenState* previous_;
};


// -------------------------------------------------------------------------
// CodeGenerator

class CodeGenerator: public AstVisitor {
 public:
  // Compilation mode.  Either the compiler is used as the primary
  // compiler and needs to setup everything or the compiler is used as
  // the secondary compiler for split compilation and has to handle
  // bailouts.
  enum Mode {
    PRIMARY,
    SECONDARY
  };

  // Takes a function literal, generates code for it. This function should only
  // be called by compiler.cc.
  static Handle<Code> MakeCode(CompilationInfo* info);

  // Printing of AST, etc. as requested by flags.
  static void MakeCodePrologue(CompilationInfo* info);

  // Allocate and install the code.
  static Handle<Code> MakeCodeEpilogue(MacroAssembler* masm,
                                       Code::Flags flags,
                                       CompilationInfo* info);

#ifdef ENABLE_LOGGING_AND_PROFILING
  static bool ShouldGenerateLog(Expression* type);
#endif

  static void SetFunctionInfo(Handle<JSFunction> fun,
                              FunctionLiteral* lit,
                              bool is_toplevel,
                              Handle<Script> script);

  static void RecordPositions(MacroAssembler* masm, int pos);

  // Accessors
  MacroAssembler* masm() { return masm_; }
  VirtualFrame* frame() const { return frame_; }
  inline Handle<Script> script();

  bool has_valid_frame() const { return frame_ != NULL; }

  // Set the virtual frame to be new_frame, with non-frame register
  // reference counts given by non_frame_registers.  The non-frame
  // register reference counts of the old frame are returned in
  // non_frame_registers.
  void SetFrame(VirtualFrame* new_frame, RegisterFile* non_frame_registers);

  void DeleteFrame();

  RegisterAllocator* allocator() const { return allocator_; }

  CodeGenState* state() { return state_; }
  void set_state(CodeGenState* state) { state_ = state; }

  void AddDeferred(DeferredCode* code) { deferred_.Add(code); }

  static const int kUnknownIntValue = -1;

  // Number of instructions used for the JS return sequence. The constant is
  // used by the debugger to patch the JS return sequence.
  static const int kJSReturnSequenceLength = 6;

 private:
  // Construction/Destruction.
  explicit CodeGenerator(MacroAssembler* masm);
  virtual ~CodeGenerator() { delete masm_; }

  // Accessors.
  inline bool is_eval();
  Scope* scope() const { return scope_; }

  // Generating deferred code.
  void ProcessDeferred();

  // State
  bool has_cc() const  { return cc_reg_ != cc_always; }
  TypeofState typeof_state() const { return state_->typeof_state(); }
  JumpTarget* true_target() const  { return state_->true_target(); }
  JumpTarget* false_target() const  { return state_->false_target(); }

  // We don't track loop nesting level on mips yet.
  int loop_nesting() const { return 0; }

  // Node visitors.
  void VisitStatements(ZoneList<Statement*>* statements);

#define DEF_VISIT(type) \
  void Visit##type(type* node);
  AST_NODE_LIST(DEF_VISIT)
#undef DEF_VISIT

  // Main code generation function
  void Generate(CompilationInfo* info, Mode mode);

  struct InlineRuntimeLUT {
    void (CodeGenerator::*method)(ZoneList<Expression*>*);
    const char* name;
  };

  static InlineRuntimeLUT* FindInlineRuntimeLUT(Handle<String> name);
  bool CheckForInlineRuntimeCall(CallRuntime* node);
  static bool PatchInlineRuntimeEntry(Handle<String> name,
                                      const InlineRuntimeLUT& new_entry,
                                      InlineRuntimeLUT* old_entry);

  static Handle<Code> ComputeLazyCompile(int argc);
  void ProcessDeclarations(ZoneList<Declaration*>* declarations);

  Handle<Code> ComputeCallInitialize(int argc, InLoopFlag in_loop);

  // Declare global variables and functions in the given array of
  // name/value pairs.
  void DeclareGlobals(Handle<FixedArray> pairs);

  // Support for type checks.
  void GenerateIsSmi(ZoneList<Expression*>* args);
  void GenerateIsNonNegativeSmi(ZoneList<Expression*>* args);
  void GenerateIsArray(ZoneList<Expression*>* args);
  void GenerateIsRegExp(ZoneList<Expression*>* args);

  // Support for construct call checks.
  void GenerateIsConstructCall(ZoneList<Expression*>* args);

  // Support for arguments.length and arguments[?].
  void GenerateArgumentsLength(ZoneList<Expression*>* args);
  void GenerateArgumentsAccess(ZoneList<Expression*>* args);

  // Support for accessing the class and value fields of an object.
  void GenerateClassOf(ZoneList<Expression*>* args);
  void GenerateValueOf(ZoneList<Expression*>* args);
  void GenerateSetValueOf(ZoneList<Expression*>* args);

  // Fast support for charCodeAt(n).
  void GenerateFastCharCodeAt(ZoneList<Expression*>* args);

  // Fast support for object equality testing.
  void GenerateObjectEquals(ZoneList<Expression*>* args);

  void GenerateLog(ZoneList<Expression*>* args);

  // Fast support for Math.random().
  void GenerateRandomPositiveSmi(ZoneList<Expression*>* args);

  void GenerateIsObject(ZoneList<Expression*>* args);
  void GenerateIsFunction(ZoneList<Expression*>* args);
  void GenerateIsUndetectableObject(ZoneList<Expression*>* args);
  void GenerateStringAdd(ZoneList<Expression*>* args);
  void GenerateSubString(ZoneList<Expression*>* args);
  void GenerateStringCompare(ZoneList<Expression*>* args);
  void GenerateRegExpExec(ZoneList<Expression*>* args);
  void GenerateNumberToString(ZoneList<Expression*>* args);


  // Fast support for Math.sin and Math.cos.
  inline void GenerateMathSin(ZoneList<Expression*>* args);
  inline void GenerateMathCos(ZoneList<Expression*>* args);

  // Simple condition analysis.
  enum ConditionAnalysis {
    ALWAYS_TRUE,
    ALWAYS_FALSE,
    DONT_KNOW
  };
  ConditionAnalysis AnalyzeCondition(Expression* cond);

  // Methods used to indicate which source code is generated for. Source
  // positions are collected by the assembler and emitted with the relocation
  // information.
  void CodeForFunctionPosition(FunctionLiteral* fun);
  void CodeForReturnPosition(FunctionLiteral* fun);
  void CodeForStatementPosition(Statement* node);
  void CodeForDoWhileConditionPosition(DoWhileStatement* stmt);
  void CodeForSourcePosition(int pos);

#ifdef DEBUG
  // True if the registers are valid for entry to a block.
  bool HasValidEntryRegisters();
#endif

  bool is_eval_;  // Tells whether code is generated for eval.

  Handle<Script> script_;
  List<DeferredCode*> deferred_;

  // Assembler
  MacroAssembler* masm_;  // to generate code

  CompilationInfo* info_;

  // Code generation state
  Scope* scope_;
  VirtualFrame* frame_;
  RegisterAllocator* allocator_;
  Condition cc_reg_;
  CodeGenState* state_;

  // Jump targets
  BreakTarget function_return_;

  // True if the function return is shadowed (ie, jumping to the target
  // function_return_ does not jump to the true function return, but rather
  // to some unlinking code).
  bool function_return_is_shadowed_;

  static InlineRuntimeLUT kInlineRuntimeLUT[];

  friend class VirtualFrame;
  friend class JumpTarget;
  friend class Reference;
  friend class FastCodeGenerator;
  friend class FullCodeGenSyntaxChecker;

  DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
};


} }  // namespace v8::internal

#endif  // V8_MIPS_CODEGEN_MIPS_H_