Port jump and call instruction decoding and patching for x64.

runtime/vm/instructions_x64.h

+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// Classes that describe assembly patterns as used by inline caches.
+
+#ifndef VM_INSTRUCTIONS_X64_H_
+#define VM_INSTRUCTIONS_X64_H_
+
+#ifndef VM_INSTRUCTIONS_H_
+#error Do not include instructions_ia32.h directly; use instructions.h instead.
+#endif
+

[srdjan, 2011/12/09 22:39:07]

Does this header file differ from instructions_ia32.h? If not (or only
slightly), we should merge the two header files into one.

[regis, 2011/12/09 22:46:31]

They are different, because of the constant defining the length of jump/call
sequence in bytes.
I suggest we wait to see how the arm version will look like before trying to
factorize this header.

[srdjan, 2011/12/21 22:30:31]

Agreed.

+#include "vm/allocation.h"
+
+namespace dart {
+
+// Forward declarations.
+class RawClass;
+class Immediate;
+class RawObject;
+
+// Abstract class for all instruction pattern classes.
+class Instruction : public ValueObject {
+ public:
+  explicit Instruction(uword pc) : start_(pc) {
+    ASSERT(pc != 0);
+  }
+  virtual ~Instruction() {}
+
+  // Call to check if the instruction pattern at 'pc' match the instruction.
+  virtual bool IsValid() const {
+    return TestBytesWith(pattern(), pattern_length_in_bytes());
+  }
+
+  // 'pattern' returns the expected byte pattern in form of an integer array
+  // with length of 'pattern_length_in_bytes'. A '-1' element means 'any byte'.
+  virtual const int* pattern() const = 0;
+  virtual int pattern_length_in_bytes() const = 0;
+
+ protected:
+  uword start() const { return start_; }
+
+ private:
+  // Returns true if the 'num_bytes' bytes at 'start_' correspond to
+  // array of integers 'data'. 'data' elements are either a byte or -1, which
+  // represents any byte.
+  bool TestBytesWith(const int* data, int num_bytes) const;
+
+  const uword start_;
+
+  DISALLOW_COPY_AND_ASSIGN(Instruction);
+};
+
+
+class CallOrJump : public Instruction {
+ public:
+  virtual int pattern_length_in_bytes() const {
+    return kLengthInBytes;
+  }
+  uword TargetAddress() const;
+  void SetTargetAddress(uword new_target) const;
+
+ protected:
+  explicit CallOrJump(uword pc) : Instruction(pc) {}
+  static const int kLengthInBytes = 13;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallOrJump);
+};
+
+
+class Call : public CallOrJump {
+ public:
+  explicit Call(uword pc) : CallOrJump(pc) {}
+  static int InstructionLength() {
+    return kLengthInBytes;
+  }
+
+ private:
+  virtual const int* pattern() const;
+
+  DISALLOW_COPY_AND_ASSIGN(Call);
+};
+
+
+class Jump : public CallOrJump {
+ public:
+  explicit Jump(uword pc) : CallOrJump(pc) {}
+
+ private:
+  virtual const int* pattern() const;
+
+  DISALLOW_COPY_AND_ASSIGN(Jump);
+};
+
+
+}  // namespace dart
+
+#endif  // VM_INSTRUCTIONS_X64_H_