ic-inl.h

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// Copyright 2012 the V8 project authors. All rights reserved.
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// modification, are permitted provided that the following conditions are
// met:
//
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#ifndef V8_IC_INL_H_
#define V8_IC_INL_H_

#include "ic.h"

#include "compiler.h"
#include "debug.h"
#include "macro-assembler.h"

namespace v8 {
namespace internal {


Address IC::address() const {
  // Get the address of the call.
  Address result = Assembler::target_address_from_return_address(pc());

#ifdef ENABLE_DEBUGGER_SUPPORT
  Debug* debug = Isolate::Current()->debug();
  // First check if any break points are active if not just return the address
  // of the call.
  if (!debug->has_break_points()) return result;

  // At least one break point is active perform additional test to ensure that
  // break point locations are updated correctly.
  if (debug->IsDebugBreak(Assembler::target_address_at(result))) {
    // If the call site is a call to debug break then return the address in
    // the original code instead of the address in the running code. This will
    // cause the original code to be updated and keeps the breakpoint active in
    // the running code.
    return OriginalCodeAddress();
  } else {
    // No break point here just return the address of the call.
    return result;
  }
#else
  return result;
#endif
}


Code* IC::GetTargetAtAddress(Address address) {
  // Get the target address of the IC.
  Address target = Assembler::target_address_at(address);
  // Convert target address to the code object. Code::GetCodeFromTargetAddress
  // is safe for use during GC where the map might be marked.
  Code* result = Code::GetCodeFromTargetAddress(target);
  ASSERT(result->is_inline_cache_stub());
  return result;
}


void IC::SetTargetAtAddress(Address address, Code* target) {
  ASSERT(target->is_inline_cache_stub() || target->is_compare_ic_stub());
  Heap* heap = target->GetHeap();
  Code* old_target = GetTargetAtAddress(address);
#ifdef DEBUG
  // STORE_IC and KEYED_STORE_IC use Code::extra_ic_state() to mark
  // ICs as strict mode. The strict-ness of the IC must be preserved.
  if (old_target->kind() == Code::STORE_IC ||
      old_target->kind() == Code::KEYED_STORE_IC) {
    ASSERT(Code::GetStrictMode(old_target->extra_ic_state()) ==
           Code::GetStrictMode(target->extra_ic_state()));
  }
#endif
  Assembler::set_target_address_at(address, target->instruction_start());
  if (heap->gc_state() == Heap::MARK_COMPACT) {
    heap->mark_compact_collector()->RecordCodeTargetPatch(address, target);
  } else {
    heap->incremental_marking()->RecordCodeTargetPatch(address, target);
  }
  PostPatching(address, target, old_target);
}


InlineCacheHolderFlag IC::GetCodeCacheForObject(Object* object,
                                                JSObject* holder) {
  if (object->IsJSObject()) {
    return GetCodeCacheForObject(JSObject::cast(object), holder);
  }
  // If the object is a value, we use the prototype map for the cache.
  ASSERT(object->IsString() || object->IsNumber() || object->IsBoolean());
  return PROTOTYPE_MAP;
}


InlineCacheHolderFlag IC::GetCodeCacheForObject(JSObject* object,
                                                JSObject* holder) {
  // Fast-properties and global objects store stubs in their own maps.
  // Slow properties objects use prototype's map (unless the property is its own
  // when holder == object). It works because slow properties objects having
  // the same prototype (or a prototype with the same map) and not having
  // the property are interchangeable for such a stub.
  if (holder != object &&
      !object->HasFastProperties() &&
      !object->IsJSGlobalProxy() &&
      !object->IsJSGlobalObject()) {
    return PROTOTYPE_MAP;
  }
  return OWN_MAP;
}


JSObject* IC::GetCodeCacheHolder(Object* object, InlineCacheHolderFlag holder) {
  Object* map_owner = (holder == OWN_MAP ? object : object->GetPrototype());
  ASSERT(map_owner->IsJSObject());
  return JSObject::cast(map_owner);
}


} }  // namespace v8::internal

#endif  // V8_IC_INL_H_