src/code-stubs.h

// Copyright 2006-2008 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
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//       with the distribution.
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//
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#ifndef V8_CODE_STUBS_H_
#define V8_CODE_STUBS_H_

namespace v8 {
namespace internal {


// Stub is base classes of all stubs.
class CodeStub BASE_EMBEDDED {
 public:
  enum Major {
    CallFunction,
    GenericBinaryOp,
    SmiOp,
    Compare,
    RecordWrite,  // Last stub that allows stub calls inside.
    ConvertToDouble,
    WriteInt32ToHeapNumber,
    StackCheck,
    UnarySub,
    RevertToNumber,
    ToBoolean,
    Instanceof,
    CounterOp,
    ArgumentsAccess,
    Runtime,
    CEntry,
    JSEntry,
    GetProperty,   // ARM only
    SetProperty,   // ARM only
    InvokeBuiltin,  // ARM only
    JSExit,        // ARM only
    RegExpCEntry,  // ARM only
    NUMBER_OF_IDS
  };

  // Retrieve the code for the stub. Generate the code if needed.
  Handle<Code> GetCode();

  static Major MajorKeyFromKey(uint32_t key) {
    return static_cast<Major>(MajorKeyBits::decode(key));
  };
  static int MinorKeyFromKey(uint32_t key) {
    return MinorKeyBits::decode(key);
  };
  static const char* MajorName(Major major_key);

  virtual ~CodeStub() {}

 protected:
  static const int kMajorBits = 5;
  static const int kMinorBits = kBitsPerInt - kSmiTagSize - kMajorBits;

 private:
  // Generates the assembler code for the stub.
  virtual void Generate(MacroAssembler* masm) = 0;

  // Returns information for computing the number key.
  virtual Major MajorKey() = 0;
  virtual int MinorKey() = 0;

  // The CallFunctionStub needs to override this so it can encode whether a
  // lazily generated function should be fully optimized or not.
  virtual InLoopFlag InLoop() { return NOT_IN_LOOP; }

  // Returns a name for logging/debugging purposes.
  virtual const char* GetName() { return MajorName(MajorKey()); }

#ifdef DEBUG
  virtual void Print() { PrintF("%s\n", GetName()); }
#endif

  // Computes the key based on major and minor.
  uint32_t GetKey() {
    ASSERT(static_cast<int>(MajorKey()) < NUMBER_OF_IDS);
    return MinorKeyBits::encode(MinorKey()) |
           MajorKeyBits::encode(MajorKey());
  }

  bool AllowsStubCalls() { return MajorKey() <= RecordWrite; }

  class MajorKeyBits: public BitField<uint32_t, 0, kMajorBits> {};
  class MinorKeyBits: public BitField<uint32_t, kMajorBits, kMinorBits> {};

  friend class BreakPointIterator;
};

} }  // namespace v8::internal

#endif  // V8_CODE_STUBS_H_