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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 = pc() - Assembler::kCallTargetAddressOffset;
     44 
     45 #ifdef ENABLE_DEBUGGER_SUPPORT
     46   Debug* debug = Isolate::Current()->debug();
     47   // First check if any break points are active if not just return the address
     48   // of the call.
     49   if (!debug->has_break_points()) return result;
     50 
     51   // At least one break point is active perform additional test to ensure that
     52   // break point locations are updated correctly.
     53   if (debug->IsDebugBreak(Assembler::target_address_at(result))) {
     54     // If the call site is a call to debug break then return the address in
     55     // the original code instead of the address in the running code. This will
     56     // cause the original code to be updated and keeps the breakpoint active in
     57     // the running code.
     58     return OriginalCodeAddress();
     59   } else {
     60     // No break point here just return the address of the call.
     61     return result;
     62   }
     63 #else
     64   return result;
     65 #endif
     66 }
     67 
     68 
     69 Code* IC::GetTargetAtAddress(Address address) {
     70   // Get the target address of the IC.
     71   Address target = Assembler::target_address_at(address);
     72   // Convert target address to the code object. Code::GetCodeFromTargetAddress
     73   // is safe for use during GC where the map might be marked.
     74   Code* result = Code::GetCodeFromTargetAddress(target);
     75   ASSERT(result->is_inline_cache_stub());
     76   return result;
     77 }
     78 
     79 
     80 void IC::SetTargetAtAddress(Address address, Code* target) {
     81   ASSERT(target->is_inline_cache_stub() || target->is_compare_ic_stub());
     82   Code* old_target = GetTargetAtAddress(address);
     83 #ifdef DEBUG
     84   // STORE_IC and KEYED_STORE_IC use Code::extra_ic_state() to mark
     85   // ICs as strict mode. The strict-ness of the IC must be preserved.
     86   if (old_target->kind() == Code::STORE_IC ||
     87       old_target->kind() == Code::KEYED_STORE_IC) {
     88     ASSERT(Code::GetStrictMode(old_target->extra_ic_state()) ==
     89            Code::GetStrictMode(target->extra_ic_state()));
     90   }
     91 #endif
     92   Assembler::set_target_address_at(address, target->instruction_start());
     93   target->GetHeap()->incremental_marking()->RecordCodeTargetPatch(address,
     94                                                                   target);
     95   PostPatching(address, target, old_target);
     96 }
     97 
     98 
     99 InlineCacheHolderFlag IC::GetCodeCacheForObject(Object* object,
    100                                                 JSObject* holder) {
    101   if (object->IsJSObject()) {
    102     return GetCodeCacheForObject(JSObject::cast(object), holder);
    103   }
    104   // If the object is a value, we use the prototype map for the cache.
    105   ASSERT(object->IsString() || object->IsNumber() || object->IsBoolean());
    106   return PROTOTYPE_MAP;
    107 }
    108 
    109 
    110 InlineCacheHolderFlag IC::GetCodeCacheForObject(JSObject* object,
    111                                                 JSObject* holder) {
    112   // Fast-properties and global objects store stubs in their own maps.
    113   // Slow properties objects use prototype's map (unless the property is its own
    114   // when holder == object). It works because slow properties objects having
    115   // the same prototype (or a prototype with the same map) and not having
    116   // the property are interchangeable for such a stub.
    117   if (holder != object &&
    118       !object->HasFastProperties() &&
    119       !object->IsJSGlobalProxy() &&
    120       !object->IsJSGlobalObject()) {
    121     return PROTOTYPE_MAP;
    122   }
    123   return OWN_MAP;
    124 }
    125 
    126 
    127 JSObject* IC::GetCodeCacheHolder(Object* object, InlineCacheHolderFlag holder) {
    128   Object* map_owner = (holder == OWN_MAP ? object : object->GetPrototype());
    129   ASSERT(map_owner->IsJSObject());
    130   return JSObject::cast(map_owner);
    131 }
    132 
    133 
    134 } }  // namespace v8::internal
    135 
    136 #endif  // V8_IC_INL_H_
    137