Named lookups on HTML documents produce inconsistent results in JavaScriptCore bindings

https://bugs.webkit.org/show_bug.cgi?id=104623

Reviewed by Geoffrey Garen.

Source/JavaScriptCore:

Add the notion of objects that HasImpureGetOwnPropertySlot, and use that to inhibit prototype chain caching
in some cases. This appears to be perf-neutral on benchmarks that we track.

* dfg/DFGRepatch.cpp:
(JSC::DFG::tryCacheGetByID):
(JSC::DFG::tryBuildGetByIDProtoList):
* jit/JITStubs.cpp:
(JSC::JITThunks::tryCacheGetByID):
(JSC::DEFINE_STUB_FUNCTION):
* runtime/JSTypeInfo.h:
(JSC):
(JSC::TypeInfo::hasImpureGetOwnPropertySlot):
* runtime/Operations.h:
(JSC::normalizePrototypeChainForChainAccess):

Source/WebCore:

All DOM objects that have named getters or directly override getOwnPropertySlot are now marked as
HasImpureGetOwnPropertySlot.

Tests: fast/js/prototype-chain-caching-with-impure-get-own-property-slot-traps
        fast/js/dfg-prototype-chain-caching-with-impure-get-own-property-slot-traps

* bindings/scripts/CodeGeneratorJS.pm:
(GenerateHeader):

LayoutTests:

* fast/js/dfg-prototype-chain-caching-with-impure-get-own-property-slot-traps-expected.txt: Added.
* fast/js/dfg-prototype-chain-caching-with-impure-get-own-property-slot-traps.html: Added.
* fast/js/prototype-chain-caching-with-impure-get-own-property-slot-traps-expected.txt: Added.
* fast/js/prototype-chain-caching-with-impure-get-own-property-slot-traps.html: Added.
* fast/js/script-tests/dfg-prototype-chain-caching-with-impure-get-own-property-slot-traps.js: Added.
(f):
* fast/js/script-tests/prototype-chain-caching-with-impure-get-own-property-slot-traps.js: Added.
(f):

Change-Id: Ie17e39f2b8139778455e28aca9428698f4dd362f
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@137700 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/Source/JavaScriptCore/runtime/JSTypeInfo.h b/Source/JavaScriptCore/runtime/JSTypeInfo.h
index 6f63260fe..07dd0c9d4 100644
--- a/Source/JavaScriptCore/runtime/JSTypeInfo.h
+++ b/Source/JavaScriptCore/runtime/JSTypeInfo.h
@@ -46,6 +46,7 @@ namespace JSC {
     static const unsigned OverridesVisitChildren = 1 << 7;
     static const unsigned OverridesGetPropertyNames = 1 << 8;
     static const unsigned ProhibitsPropertyCaching = 1 << 9;
+    static const unsigned HasImpureGetOwnPropertySlot = 1 << 10;
 
     class TypeInfo {
     public:
@@ -80,6 +81,7 @@ namespace JSC {
         bool overridesVisitChildren() const { return isSetOnFlags1(OverridesVisitChildren); }
         bool overridesGetPropertyNames() const { return isSetOnFlags2(OverridesGetPropertyNames); }
         bool prohibitsPropertyCaching() const { return isSetOnFlags2(ProhibitsPropertyCaching); }
+        bool hasImpureGetOwnPropertySlot() const { return isSetOnFlags2(HasImpureGetOwnPropertySlot); }
 
         static ptrdiff_t flagsOffset()
         {
diff --git a/Source/JavaScriptCore/runtime/Operations.h b/Source/JavaScriptCore/runtime/Operations.h
index 7301bf6ec..8e0a0a393 100644
--- a/Source/JavaScriptCore/runtime/Operations.h
+++ b/Source/JavaScriptCore/runtime/Operations.h
@@ -302,15 +302,18 @@ namespace JSC {
 
 #define InvalidPrototypeChain (std::numeric_limits<size_t>::max())
 
-    inline size_t normalizePrototypeChain(CallFrame* callFrame, JSValue base, JSValue slotBase, const Identifier& propertyName, PropertyOffset& slotOffset)
+    inline size_t normalizePrototypeChainForChainAccess(CallFrame* callFrame, JSValue base, JSValue slotBase, const Identifier& propertyName, PropertyOffset& slotOffset)
     {
         JSCell* cell = base.asCell();
         size_t count = 0;
-
+        
         while (slotBase != cell) {
             if (cell->isProxy())
                 return InvalidPrototypeChain;
             
+            if (cell->structure()->typeInfo().hasImpureGetOwnPropertySlot())
+                return InvalidPrototypeChain;
+            
             JSValue v = cell->structure()->prototypeForLookup(callFrame);
 
             // If we didn't find slotBase in base's prototype chain, then base
@@ -328,7 +331,7 @@ namespace JSC {
                 if (slotBase == cell)
                     slotOffset = cell->structure()->get(callFrame->globalData(), propertyName); 
             }
-
+            
             ++count;
         }