The Tor Browser: js/src/jit/BaselineInspector.cpp@129ffea94266 (annotated)

js/src/jit/BaselineInspector.cpp@129ffea94266 (annotated)

js/src/jit/BaselineInspector.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: set ts=8 sts=4 et sw=4 tw=99:
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "jit/BaselineInspector.h"
 #include "mozilla/DebugOnly.h"
 #include "jit/BaselineIC.h"
 using namespace js;
 using namespace js::jit;
 using mozilla::DebugOnly;
 bool
 SetElemICInspector::sawOOBDenseWrite() const
 {
     if (!icEntry_)
         return false;
     // Check for a SetElem_DenseAdd stub.
     for (ICStub *stub = icEntry_->firstStub(); stub; stub = stub->next()) {
         if (stub->isSetElem_DenseAdd())
             return true;
     }
     // Check for a write hole bit on the SetElem_Fallback stub.
     ICStub *stub = icEntry_->fallbackStub();
     if (stub->isSetElem_Fallback())
         return stub->toSetElem_Fallback()->hasArrayWriteHole();
     return false;
 }
 bool
 SetElemICInspector::sawOOBTypedArrayWrite() const
 {
     if (!icEntry_)
         return false;
     // Check for SetElem_TypedArray stubs with expectOutOfBounds set.
     for (ICStub *stub = icEntry_->firstStub(); stub; stub = stub->next()) {
         if (!stub->isSetElem_TypedArray())
             continue;
         if (stub->toSetElem_TypedArray()->expectOutOfBounds())
             return true;
     }
     return false;
 }
 bool
 SetElemICInspector::sawDenseWrite() const
 {
     if (!icEntry_)
         return false;
     // Check for a SetElem_DenseAdd or SetElem_Dense stub.
     for (ICStub *stub = icEntry_->firstStub(); stub; stub = stub->next()) {
         if (stub->isSetElem_DenseAdd() || stub->isSetElem_Dense())
             return true;
     }
     return false;
 }
 bool
 SetElemICInspector::sawTypedArrayWrite() const
 {
     if (!icEntry_)
         return false;
     // Check for a SetElem_TypedArray stub.
     for (ICStub *stub = icEntry_->firstStub(); stub; stub = stub->next()) {
         if (stub->isSetElem_TypedArray())
             return true;
     }
     return false;
 }
 bool
 BaselineInspector::maybeShapesForPropertyOp(jsbytecode *pc, ShapeVector &shapes)
 {
     // Return a list of shapes seen by the baseline IC for the current op.
     // An empty list indicates no shapes are known, or there was an uncacheable
     // access.
     JS_ASSERT(shapes.empty());
     if (!hasBaselineScript())
         return true;
     JS_ASSERT(isValidPC(pc));
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.firstStub();
     while (stub->next()) {
         Shape *shape;
         if (stub->isGetProp_Native()) {
             shape = stub->toGetProp_Native()->shape();
         } else if (stub->isSetProp_Native()) {
             shape = stub->toSetProp_Native()->shape();
         } else {
             shapes.clear();
             return true;
         }
         // Don't add the same shape twice (this can happen if there are multiple
         // SetProp_Native stubs with different TypeObject's).
         bool found = false;
         for (size_t i = 0; i < shapes.length(); i++) {
             if (shapes[i] == shape) {
                 found = true;
                 break;
             }
         }
         if (!found && !shapes.append(shape))
             return false;
         stub = stub->next();
     }
     if (stub->isGetProp_Fallback()) {
         if (stub->toGetProp_Fallback()->hadUnoptimizableAccess())
             shapes.clear();
     } else {
         if (stub->toSetProp_Fallback()->hadUnoptimizableAccess())
             shapes.clear();
     }
     // Don't inline if there are more than 5 shapes.
     if (shapes.length() > 5)
         shapes.clear();
     return true;
 }
 ICStub *
 BaselineInspector::monomorphicStub(jsbytecode *pc)
 {
     if (!hasBaselineScript())
         return nullptr;
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.firstStub();
     ICStub *next = stub->next();
     if (!next || !next->isFallback())
         return nullptr;
     return stub;
 }
 bool
 BaselineInspector::dimorphicStub(jsbytecode *pc, ICStub **pfirst, ICStub **psecond)
 {
     if (!hasBaselineScript())
         return false;
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.firstStub();
     ICStub *next = stub->next();
     ICStub *after = next ? next->next() : nullptr;
     if (!after || !after->isFallback())
         return false;
     *pfirst = stub;
     *psecond = next;
     return true;
 }
 MIRType
 BaselineInspector::expectedResultType(jsbytecode *pc)
 {
     // Look at the IC entries for this op to guess what type it will produce,
     // returning MIRType_None otherwise.
     ICStub *stub = monomorphicStub(pc);
     if (!stub)
         return MIRType_None;
     switch (stub->kind()) {
       case ICStub::BinaryArith_Int32:
         if (stub->toBinaryArith_Int32()->allowDouble())
             return MIRType_Double;
         return MIRType_Int32;
       case ICStub::BinaryArith_BooleanWithInt32:
       case ICStub::UnaryArith_Int32:
       case ICStub::BinaryArith_DoubleWithInt32:
         return MIRType_Int32;
       case ICStub::BinaryArith_Double:
       case ICStub::UnaryArith_Double:
         return MIRType_Double;
       case ICStub::BinaryArith_StringConcat:
       case ICStub::BinaryArith_StringObjectConcat:
         return MIRType_String;
       default:
         return MIRType_None;
     }
 }
 // Whether a baseline stub kind is suitable for a double comparison that
 // converts its operands to doubles.
 static bool
 CanUseDoubleCompare(ICStub::Kind kind)
 {
     return kind == ICStub::Compare_Double || kind == ICStub::Compare_NumberWithUndefined;
 }
 // Whether a baseline stub kind is suitable for an int32 comparison that
 // converts its operands to int32.
 static bool
 CanUseInt32Compare(ICStub::Kind kind)
 {
     return kind == ICStub::Compare_Int32 || kind == ICStub::Compare_Int32WithBoolean;
 }
 MCompare::CompareType
 BaselineInspector::expectedCompareType(jsbytecode *pc)
 {
     ICStub *first = monomorphicStub(pc), *second = nullptr;
     if (!first && !dimorphicStub(pc, &first, &second))
         return MCompare::Compare_Unknown;
     if (CanUseInt32Compare(first->kind()) && (!second || CanUseInt32Compare(second->kind()))) {
         ICCompare_Int32WithBoolean *coerce =
             first->isCompare_Int32WithBoolean()
             ? first->toCompare_Int32WithBoolean()
             : ((second && second->isCompare_Int32WithBoolean())
                ? second->toCompare_Int32WithBoolean()
                : nullptr);
         if (coerce) {
             return coerce->lhsIsInt32()
                    ? MCompare::Compare_Int32MaybeCoerceRHS
                    : MCompare::Compare_Int32MaybeCoerceLHS;
         }
         return MCompare::Compare_Int32;
     }
     if (CanUseDoubleCompare(first->kind()) && (!second || CanUseDoubleCompare(second->kind()))) {
         ICCompare_NumberWithUndefined *coerce =
             first->isCompare_NumberWithUndefined()
             ? first->toCompare_NumberWithUndefined()
             : (second && second->isCompare_NumberWithUndefined())
               ? second->toCompare_NumberWithUndefined()
               : nullptr;
         if (coerce) {
             return coerce->lhsIsUndefined()
                    ? MCompare::Compare_DoubleMaybeCoerceLHS
                    : MCompare::Compare_DoubleMaybeCoerceRHS;
         }
         return MCompare::Compare_Double;
     }
     return MCompare::Compare_Unknown;
 }
 static bool
 TryToSpecializeBinaryArithOp(ICStub **stubs,
                              uint32_t nstubs,
                              MIRType *result)
 {
     DebugOnly<bool> sawInt32 = false;
     bool sawDouble = false;
     bool sawOther = false;
     for (uint32_t i = 0; i < nstubs; i++) {
         switch (stubs[i]->kind()) {
           case ICStub::BinaryArith_Int32:
             sawInt32 = true;
             break;
           case ICStub::BinaryArith_BooleanWithInt32:
             sawInt32 = true;
             break;
           case ICStub::BinaryArith_Double:
             sawDouble = true;
             break;
           case ICStub::BinaryArith_DoubleWithInt32:
             sawDouble = true;
             break;
           default:
             sawOther = true;
             break;
         }
     }
     if (sawOther)
         return false;
     if (sawDouble) {
         *result = MIRType_Double;
         return true;
     }
     JS_ASSERT(sawInt32);
     *result = MIRType_Int32;
     return true;
 }
 MIRType
 BaselineInspector::expectedBinaryArithSpecialization(jsbytecode *pc)
 {
     if (!hasBaselineScript())
         return MIRType_None;
     MIRType result;
     ICStub *stubs[2];
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.fallbackStub();
     if (stub->isBinaryArith_Fallback() &&
         stub->toBinaryArith_Fallback()->hadUnoptimizableOperands())
     {
         return MIRType_None;
     }
     stubs[0] = monomorphicStub(pc);
     if (stubs[0]) {
         if (TryToSpecializeBinaryArithOp(stubs, 1, &result))
             return result;
     }
     if (dimorphicStub(pc, &stubs[0], &stubs[1])) {
         if (TryToSpecializeBinaryArithOp(stubs, 2, &result))
             return result;
     }
     return MIRType_None;
 }
 bool
 BaselineInspector::hasSeenNonNativeGetElement(jsbytecode *pc)
 {
     if (!hasBaselineScript())
         return false;
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.fallbackStub();
     if (stub->isGetElem_Fallback())
         return stub->toGetElem_Fallback()->hasNonNativeAccess();
     return false;
 }
 bool
 BaselineInspector::hasSeenNegativeIndexGetElement(jsbytecode *pc)
 {
     if (!hasBaselineScript())
         return false;
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.fallbackStub();
     if (stub->isGetElem_Fallback())
         return stub->toGetElem_Fallback()->hasNegativeIndex();
     return false;
 }
 bool
 BaselineInspector::hasSeenAccessedGetter(jsbytecode *pc)
 {
     if (!hasBaselineScript())
         return false;
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.fallbackStub();
     if (stub->isGetProp_Fallback())
         return stub->toGetProp_Fallback()->hasAccessedGetter();
     return false;
 }
 bool
 BaselineInspector::hasSeenNonStringIterNext(jsbytecode *pc)
 {
     JS_ASSERT(JSOp(*pc) == JSOP_ITERNEXT);
     if (!hasBaselineScript())
         return false;
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.fallbackStub();
     return stub->toIteratorNext_Fallback()->hasNonStringResult();
 }
 bool
 BaselineInspector::hasSeenDoubleResult(jsbytecode *pc)
 {
     if (!hasBaselineScript())
         return false;
     const ICEntry &entry = icEntryFromPC(pc);
     ICStub *stub = entry.fallbackStub();
     JS_ASSERT(stub->isUnaryArith_Fallback() || stub->isBinaryArith_Fallback());
     if (stub->isUnaryArith_Fallback())
         return stub->toUnaryArith_Fallback()->sawDoubleResult();
     else
         return stub->toBinaryArith_Fallback()->sawDoubleResult();
     return false;
 }
 JSObject *
 BaselineInspector::getTemplateObject(jsbytecode *pc)
 {
     if (!hasBaselineScript())
         return nullptr;
     const ICEntry &entry = icEntryFromPC(pc);
     for (ICStub *stub = entry.firstStub(); stub; stub = stub->next()) {
         switch (stub->kind()) {
           case ICStub::NewArray_Fallback:
             return stub->toNewArray_Fallback()->templateObject();
           case ICStub::NewObject_Fallback:
             return stub->toNewObject_Fallback()->templateObject();
           case ICStub::Rest_Fallback:
             return stub->toRest_Fallback()->templateObject();
           case ICStub::Call_Scripted:
             if (JSObject *obj = stub->toCall_Scripted()->templateObject())
                 return obj;
             break;
           default:
             break;
         }
     }
     return nullptr;
 }
 JSObject *
 BaselineInspector::getTemplateObjectForNative(jsbytecode *pc, Native native)
 {
     if (!hasBaselineScript())
         return nullptr;
     const ICEntry &entry = icEntryFromPC(pc);
     for (ICStub *stub = entry.firstStub(); stub; stub = stub->next()) {
         if (stub->isCall_Native() && stub->toCall_Native()->callee()->native() == native)
             return stub->toCall_Native()->templateObject();
     }
     return nullptr;
 }
 DeclEnvObject *
 BaselineInspector::templateDeclEnvObject()
 {
     if (!hasBaselineScript())
         return nullptr;
     JSObject *res = &templateCallObject()->as<ScopeObject>().enclosingScope();
     JS_ASSERT(res);
     return &res->as<DeclEnvObject>();
 }
 CallObject *
 BaselineInspector::templateCallObject()
 {
     if (!hasBaselineScript())
         return nullptr;
     JSObject *res = baselineScript()->templateScope();
     JS_ASSERT(res);
     return &res->as<CallObject>();
 }
 JSObject *
 BaselineInspector::commonGetPropFunction(jsbytecode *pc, Shape **lastProperty, JSFunction **commonGetter)
 {
     if (!hasBaselineScript())
         return nullptr;
     const ICEntry &entry = icEntryFromPC(pc);
     for (ICStub *stub = entry.firstStub(); stub; stub = stub->next()) {
         if (stub->isGetProp_CallScripted()  ||
             stub->isGetProp_CallNative()    ||
             stub->isGetProp_CallNativePrototype())
         {
             ICGetPropCallGetter *nstub = static_cast<ICGetPropCallGetter *>(stub);
             *lastProperty = nstub->holderShape();
             *commonGetter = nstub->getter();
             return nstub->holder();
         }
     }
     return nullptr;
 }
 JSObject *
 BaselineInspector::commonSetPropFunction(jsbytecode *pc, Shape **lastProperty, JSFunction **commonSetter)
 {
     if (!hasBaselineScript())
         return nullptr;
     const ICEntry &entry = icEntryFromPC(pc);
     for (ICStub *stub = entry.firstStub(); stub; stub = stub->next()) {
         if (stub->isSetProp_CallScripted() || stub->isSetProp_CallNative()) {
             ICSetPropCallSetter *nstub = static_cast<ICSetPropCallSetter *>(stub);
             *lastProperty = nstub->holderShape();
             *commonSetter = nstub->setter();
             return nstub->holder();
         }
     }
     return nullptr;
 }

The Tor Browser / annotate

js/src/jit/BaselineInspector.cpp@129ffea94266 (annotated)

js/src/jit/BaselineInspector.cpp