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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 #ifndef V8_IC_INL_H_
     29 #define V8_IC_INL_H_
     30 
     31 #include "ic.h"
     32 
     33 #include "compiler.h"
     34 #include "debug.h"
     35 #include "macro-assembler.h"
     36 
     37 namespace v8 {
     38 namespace internal {
     39 
     40 
     41 Address IC::address() const {
     42   // Get the address of the call.
     43   Address result = Assembler::target_address_from_return_address(pc());
     44 
     45 #ifdef ENABLE_DEBUGGER_SUPPORT
     46   ASSERT(Isolate::Current() == isolate());
     47   Debug* debug = isolate()->debug();
     48   // First check if any break points are active if not just return the address
     49   // of the call.
     50   if (!debug->has_break_points()) return result;
     51 
     52   // At least one break point is active perform additional test to ensure that
     53   // break point locations are updated correctly.
     54   if (debug->IsDebugBreak(Assembler::target_address_at(result))) {
     55     // If the call site is a call to debug break then return the address in
     56     // the original code instead of the address in the running code. This will
     57     // cause the original code to be updated and keeps the breakpoint active in
     58     // the running code.
     59     return OriginalCodeAddress();
     60   } else {
     61     // No break point here just return the address of the call.
     62     return result;
     63   }
     64 #else
     65   return result;
     66 #endif
     67 }
     68 
     69 
     70 Code* IC::GetTargetAtAddress(Address address) {
     71   // Get the target address of the IC.
     72   Address target = Assembler::target_address_at(address);
     73   // Convert target address to the code object. Code::GetCodeFromTargetAddress
     74   // is safe for use during GC where the map might be marked.
     75   Code* result = Code::GetCodeFromTargetAddress(target);
     76   ASSERT(result->is_inline_cache_stub());
     77   return result;
     78 }
     79 
     80 
     81 void IC::SetTargetAtAddress(Address address, Code* target) {
     82   ASSERT(target->is_inline_cache_stub() || target->is_compare_ic_stub());
     83   Heap* heap = target->GetHeap();
     84   Code* old_target = GetTargetAtAddress(address);
     85 #ifdef DEBUG
     86   // STORE_IC and KEYED_STORE_IC use Code::extra_ic_state() to mark
     87   // ICs as strict mode. The strict-ness of the IC must be preserved.
     88   if (old_target->kind() == Code::STORE_IC ||
     89       old_target->kind() == Code::KEYED_STORE_IC) {
     90     ASSERT(Code::GetStrictMode(old_target->extra_ic_state()) ==
     91            Code::GetStrictMode(target->extra_ic_state()));
     92   }
     93 #endif
     94   Assembler::set_target_address_at(address, target->instruction_start());
     95   if (heap->gc_state() == Heap::MARK_COMPACT) {
     96     heap->mark_compact_collector()->RecordCodeTargetPatch(address, target);
     97   } else {
     98     heap->incremental_marking()->RecordCodeTargetPatch(address, target);
     99   }
    100   PostPatching(address, target, old_target);
    101 }
    102 
    103 
    104 InlineCacheHolderFlag IC::GetCodeCacheForObject(Object* object,
    105                                                 JSObject* holder) {
    106   if (object->IsJSObject()) {
    107     return GetCodeCacheForObject(JSObject::cast(object), holder);
    108   }
    109   // If the object is a value, we use the prototype map for the cache.
    110   ASSERT(object->IsString() || object->IsSymbol() ||
    111          object->IsNumber() || object->IsBoolean());
    112   return PROTOTYPE_MAP;
    113 }
    114 
    115 
    116 InlineCacheHolderFlag IC::GetCodeCacheForObject(JSObject* object,
    117                                                 JSObject* holder) {
    118   // Fast-properties and global objects store stubs in their own maps.
    119   // Slow properties objects use prototype's map (unless the property is its own
    120   // when holder == object). It works because slow properties objects having
    121   // the same prototype (or a prototype with the same map) and not having
    122   // the property are interchangeable for such a stub.
    123   if (holder != object &&
    124       !object->HasFastProperties() &&
    125       !object->IsJSGlobalProxy() &&
    126       !object->IsJSGlobalObject()) {
    127     return PROTOTYPE_MAP;
    128   }
    129   return OWN_MAP;
    130 }
    131 
    132 
    133 JSObject* IC::GetCodeCacheHolder(Isolate* isolate,
    134                                  Object* object,
    135                                  InlineCacheHolderFlag holder) {
    136   Object* map_owner =
    137       holder == OWN_MAP ? object : object->GetPrototype(isolate);
    138   ASSERT(map_owner->IsJSObject());
    139   return JSObject::cast(map_owner);
    140 }
    141 
    142 
    143 } }  // namespace v8::internal
    144 
    145 #endif  // V8_IC_INL_H_
    146