Track prologue offset of Code and use for more precise return addresses

runtime/vm/instructions_ia32.h

 // Copyright (c) 2012, 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_IA32_H_
 #define VM_INSTRUCTIONS_IA32_H_
 
 #ifndef VM_INSTRUCTIONS_H_
 #error Do not include instructions_ia32.h directly; use instructions.h instead.
@@ skipping 88 matching lines @@
  public:
   explicit ReturnPattern(uword pc) : InstructionPattern(pc) {}
 
   virtual const int* pattern() const;
   virtual int pattern_length_in_bytes() const { return kLengthInBytes; }
 
  private:
   static const int kLengthInBytes = 1;
 };
 
+

[srdjan, 2015/05/21 16:06:33]

Please add tests for these two new patterns, best use Assembler::EnterFrame
since the pattern is tied to this. Also for X64. 

Maybe instead of tests add an assert in EnterFrame, that the pattern matches
what EnterFrame is emitting.

[Cutch, 2015/05/22 01:11:14]

Done.

+class ProloguePattern : public InstructionPattern {
+ public:
+  explicit ProloguePattern(uword pc) : InstructionPattern(pc) {}
+
+  virtual const int* pattern() const;

[srdjan, 2015/05/21 16:06:33]

I wonder why we are using int instead of intptr_t here. It is not the objective
of this CL to do that cleanup.

[Cutch, 2015/05/22 01:11:14]

Acknowledged.

+  virtual int pattern_length_in_bytes() const { return kLengthInBytes; }
+
+ private:
+  static const int kLengthInBytes = 3;
+};
+
+
+class SetFramePointerPattern : public InstructionPattern {
+ public:
+  explicit SetFramePointerPattern(uword pc) : InstructionPattern(pc) {}
+
+  virtual const int* pattern() const;
+  virtual int pattern_length_in_bytes() const { return kLengthInBytes; }
+
+ private:
+  static const int kLengthInBytes = 2;
+};
+
 }  // namespace dart
 
 #endif  // VM_INSTRUCTIONS_IA32_H_