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      1 // Copyright 2006-2008 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 #include "debug.h"
     33 #include "macro-assembler.h"
     34 
     35 namespace v8 {
     36 namespace internal {
     37 
     38 
     39 Address IC::address() {
     40   // Get the address of the call.
     41   Address result = pc() - Assembler::kCallTargetAddressOffset;
     42 
     43 #ifdef ENABLE_DEBUGGER_SUPPORT
     44   Debug* debug = Isolate::Current()->debug();
     45   // First check if any break points are active if not just return the address
     46   // of the call.
     47   if (!debug->has_break_points()) return result;
     48 
     49   // At least one break point is active perform additional test to ensure that
     50   // break point locations are updated correctly.
     51   if (debug->IsDebugBreak(Assembler::target_address_at(result))) {
     52     // If the call site is a call to debug break then return the address in
     53     // the original code instead of the address in the running code. This will
     54     // cause the original code to be updated and keeps the breakpoint active in
     55     // the running code.
     56     return OriginalCodeAddress();
     57   } else {
     58     // No break point here just return the address of the call.
     59     return result;
     60   }
     61 #else
     62   return result;
     63 #endif
     64 }
     65 
     66 
     67 Code* IC::GetTargetAtAddress(Address address) {
     68   // Get the target address of the IC.
     69   Address target = Assembler::target_address_at(address);
     70   // Convert target address to the code object. Code::GetCodeFromTargetAddress
     71   // is safe for use during GC where the map might be marked.
     72   Code* result = Code::GetCodeFromTargetAddress(target);
     73   ASSERT(result->is_inline_cache_stub());
     74   return result;
     75 }
     76 
     77 
     78 void IC::SetTargetAtAddress(Address address, Code* target) {
     79   ASSERT(target->is_inline_cache_stub() || target->is_compare_ic_stub());
     80 #ifdef DEBUG
     81   // STORE_IC and KEYED_STORE_IC use Code::extra_ic_state() to mark
     82   // ICs as strict mode. The strict-ness of the IC must be preserved.
     83   Code* old_target = GetTargetAtAddress(address);
     84   if (old_target->kind() == Code::STORE_IC ||
     85       old_target->kind() == Code::KEYED_STORE_IC) {
     86     ASSERT(old_target->extra_ic_state() == target->extra_ic_state());
     87   }
     88 #endif
     89   Assembler::set_target_address_at(address, target->instruction_start());
     90 }
     91 
     92 
     93 InlineCacheHolderFlag IC::GetCodeCacheForObject(Object* object,
     94                                                 JSObject* holder) {
     95   if (object->IsJSObject()) {
     96     return GetCodeCacheForObject(JSObject::cast(object), holder);
     97   }
     98   // If the object is a value, we use the prototype map for the cache.
     99   ASSERT(object->IsString() || object->IsNumber() || object->IsBoolean());
    100   return PROTOTYPE_MAP;
    101 }
    102 
    103 
    104 InlineCacheHolderFlag IC::GetCodeCacheForObject(JSObject* object,
    105                                                 JSObject* holder) {
    106   // Fast-properties and global objects store stubs in their own maps.
    107   // Slow properties objects use prototype's map (unless the property is its own
    108   // when holder == object). It works because slow properties objects having
    109   // the same prototype (or a prototype with the same map) and not having
    110   // the property are interchangeable for such a stub.
    111   if (holder != object &&
    112       !object->HasFastProperties() &&
    113       !object->IsJSGlobalProxy() &&
    114       !object->IsJSGlobalObject()) {
    115     return PROTOTYPE_MAP;
    116   }
    117   return OWN_MAP;
    118 }
    119 
    120 
    121 JSObject* IC::GetCodeCacheHolder(Object* object, InlineCacheHolderFlag holder) {
    122   Object* map_owner = (holder == OWN_MAP ? object : object->GetPrototype());
    123   ASSERT(map_owner->IsJSObject());
    124   return JSObject::cast(map_owner);
    125 }
    126 
    127 
    128 } }  // namespace v8::internal
    129 
    130 #endif  // V8_IC_INL_H_
    131