Support compaction for code space pages.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 202 matching lines @@
     NONE,  // never recorded
     LAST_CODE_ENUM = DEBUG_BREAK,
     LAST_GCED_ENUM = GLOBAL_PROPERTY_CELL,
     // Modes <= LAST_COMPACT_ENUM are guaranteed to have compact encoding.
     LAST_COMPACT_ENUM = CODE_TARGET_WITH_ID
   };
 
 
   RelocInfo() {}
   RelocInfo(byte* pc, Mode rmode, intptr_t data)
-      : pc_(pc), rmode_(rmode), data_(data) {
+      : pc_(pc), rmode_(rmode), data_(data), host_(NULL) {

[Erik Corry, 2011/09/06 14:10:31]

If you omit this function the compiler will help you find the places it was
called so you can verify that it is correct to pass NULL at this point.

[Vyacheslav Egorov (Chromium), 2011/09/06 15:01:42]

Done.

+  }
+
+  RelocInfo(byte* pc, Mode rmode, intptr_t data, Code* host)
+      : pc_(pc), rmode_(rmode), data_(data), host_(host) {
   }
 
   static inline bool IsConstructCall(Mode mode) {
     return mode == CONSTRUCT_CALL;
   }
   static inline bool IsCodeTarget(Mode mode) {
     return mode <= LAST_CODE_ENUM;
   }
   // Is the relocation mode affected by GC?
   static inline bool IsGCRelocMode(Mode mode) {
@@ skipping 20 matching lines @@
   static inline bool IsDebugBreakSlot(Mode mode) {
     return mode == DEBUG_BREAK_SLOT;
   }
   static inline int ModeMask(Mode mode) { return 1 << mode; }
 
   // Accessors
   byte* pc() const { return pc_; }
   void set_pc(byte* pc) { pc_ = pc; }
   Mode rmode() const {  return rmode_; }
   intptr_t data() const { return data_; }
+  Code* host() const { return host_; }
 
   // Apply a relocation by delta bytes
   INLINE(void apply(intptr_t delta));
 
   // Is the pointer this relocation info refers to coded like a plain pointer
   // or is it strange in some way (eg relative or patched into a series of
   // instructions).
   bool IsCodedSpecially();
 
   // Read/modify the code target in the branch/call instruction
   // this relocation applies to;
   // can only be called if IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY
   INLINE(Address target_address());
-  INLINE(void set_target_address(Address target, Code* host));
+  INLINE(void set_target_address(Address target));
   INLINE(Object* target_object());
   INLINE(Handle<Object> target_object_handle(Assembler* origin));
   INLINE(Object** target_object_address());
-  INLINE(void set_target_object(Object* target, Code* code));
+  INLINE(void set_target_object(Object* target));
   INLINE(JSGlobalPropertyCell* target_cell());
   INLINE(Handle<JSGlobalPropertyCell> target_cell_handle());
-  INLINE(void set_target_cell(JSGlobalPropertyCell* cell, Code* code));
+  INLINE(void set_target_cell(JSGlobalPropertyCell* cell));
 
 
   // Read the address of the word containing the target_address in an
   // instruction stream.  What this means exactly is architecture-independent.
   // The only architecture-independent user of this function is the serializer.
   // The serializer uses it to find out how many raw bytes of instruction to
   // output before the next target.  Architecture-independent code shouldn't
   // dereference the pointer it gets back from this.
   INLINE(Address target_address_address());
   // This indicates how much space a target takes up when deserializing a code
@@ skipping 54 matching lines @@
   static const int kApplyMask;  // Modes affected by apply. Depends on arch.
 
  private:
   // On ARM, note that pc_ is the address of the constant pool entry
   // to be relocated and not the address of the instruction
   // referencing the constant pool entry (except when rmode_ ==
   // comment).
   byte* pc_;
   Mode rmode_;
   intptr_t data_;
+  Code* host_;
 #ifdef V8_TARGET_ARCH_MIPS
   // Code and Embedded Object pointers in mips are stored split
   // across two consecutive 32-bit instructions. Heap management
   // routines expect to access these pointers indirectly. The following
   // location provides a place for these pointers to exist natually
   // when accessed via the Iterator.
   Object *reconstructed_obj_ptr_;
   // External-reference pointers are also split across instruction-pairs
   // in mips, but are accessed via indirect pointers. This location
   // provides a place for that pointer to exist naturally. Its address
@@ skipping 499 matching lines @@
  public:
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_