[cfe-commits] r73946 - in /cfe/trunk: include/clang/Analysis/PathSensitive/ValueManager.h lib/Analysis/RegionStore.cpp lib/Analysis/SVals.cpp

[Zhongxing Xu]

2009/6/24 Ted Kremenek <kremenek at apple.com>:
> Hi Zhongxing,
>
> Is this approach going to scale?  For even moderate sized arrays this seems
> like it is going to result in a bunch of excess storage.  For large arrays
> this might not scale at all.  Was there some particular motivation behind
> this change?

I was to make the array case consistent with the struct case. But now
I realized that for the array case we can use the uniform default
value safely. I'll revert to that approach.

>
> Ted
>
> On Jun 22, 2009, at 10:23 PM, Zhongxing Xu wrote:
>
>> Author: zhongxingxu
>> Date: Tue Jun 23 00:23:38 2009
>> New Revision: 73946
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=73946&view=rev
>> Log:
>> Instead of setting the default value of the array region, bind the rest of
>> the
>> array elements to 0 explicitly. Create 0 values with the element type.
>>
>> Modified:
>>   cfe/trunk/include/clang/Analysis/PathSensitive/ValueManager.h
>>   cfe/trunk/lib/Analysis/RegionStore.cpp
>>   cfe/trunk/lib/Analysis/SVals.cpp
>>
>> Modified: cfe/trunk/include/clang/Analysis/PathSensitive/ValueManager.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/PathSensitive/ValueManager.h?rev=73946&r1=73945&r2=73946&view=diff
>>
>>
>> ==============================================================================
>> --- cfe/trunk/include/clang/Analysis/PathSensitive/ValueManager.h
>> (original)
>> +++ cfe/trunk/include/clang/Analysis/PathSensitive/ValueManager.h Tue Jun
>> 23 00:23:38 2009
>> @@ -89,6 +89,8 @@
>>  SVal getFunctionPointer(const FunctionDecl* FD);
>>
>>  NonLoc makeNonLoc(SymbolRef sym);
>> +
>> +  NonLoc makeNonLoc(const llvm::APSInt& V);
>>
>>  NonLoc makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode op,
>>                    const llvm::APSInt& rhs, QualType T);
>>
>> Modified: cfe/trunk/lib/Analysis/RegionStore.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/RegionStore.cpp?rev=73946&r1=73945&r2=73946&view=diff
>>
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Analysis/RegionStore.cpp (original)
>> +++ cfe/trunk/lib/Analysis/RegionStore.cpp Tue Jun 23 00:23:38 2009
>> @@ -1079,17 +1079,11 @@
>>                                             SVal Init) {
>>
>>  QualType T = R->getValueType(getContext());
>> -  assert(T->isArrayType());
>> -
>> -  // When we are binding the whole array, it always has default value 0.
>> -  state = state->set<RegionDefaultValue>(R,
>> NonLoc::MakeIntVal(getBasicVals(),
>> -                                                               0,
>> false));
>> -
>>  ConstantArrayType* CAT = cast<ConstantArrayType>(T.getTypePtr());
>> +  QualType ElementTy = CAT->getElementType();
>>
>>  llvm::APSInt Size(CAT->getSize(), false);
>> -  llvm::APSInt i = getBasicVals().getValue(0, Size.getBitWidth(),
>> -                                           Size.isUnsigned());
>> +  llvm::APSInt i(llvm::APInt::getNullValue(Size.getBitWidth()), false);
>>
>>  // Check if the init expr is a StringLiteral.
>>  if (isa<loc::MemRegionVal>(Init)) {
>> @@ -1106,10 +1100,8 @@
>>      if (j >= len)
>>        break;
>>
>> -      SVal Idx = NonLoc::MakeVal(getBasicVals(), i);
>> -      ElementRegion* ER =
>> -        MRMgr.getElementRegion(cast<ArrayType>(T)->getElementType(),
>> -                               Idx, R, getContext());
>> +      SVal Idx = ValMgr.makeNonLoc(i);
>> +      ElementRegion* ER = MRMgr.getElementRegion(ElementTy,
>> Idx,R,getContext());
>>
>>      SVal V = NonLoc::MakeVal(getBasicVals(), str[j], sizeof(char)*8,
>> true);
>>      state = Bind(state, loc::MemRegionVal(ER), V);
>> @@ -1122,14 +1114,12 @@
>>  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
>>
>>  for (; i < Size; ++i, ++VI) {
>> -    // The init list might be shorter than the array decl.
>> +    // The init list might be shorter than the array length.
>>    if (VI == VE)
>>      break;
>>
>> -    SVal Idx = NonLoc::MakeVal(getBasicVals(), i);
>> -    ElementRegion* ER =
>> -      MRMgr.getElementRegion(cast<ArrayType>(T)->getElementType(),
>> -                             Idx, R, getContext());
>> +    SVal Idx = ValMgr.makeNonLoc(i);
>> +    ElementRegion* ER = MRMgr.getElementRegion(ElementTy, Idx, R,
>> getContext());
>>
>>    if (CAT->getElementType()->isStructureType())
>>      state = BindStruct(state, ER, *VI);
>> @@ -1137,6 +1127,18 @@
>>      state = Bind(state, Loc::MakeVal(ER), *VI);
>>  }
>>
>> +  // If the init list is shorter than the array length, bind the rest
>> elements
>> +  // to 0.
>> +  if (ElementTy->isIntegerType()) {
>> +    while (i < Size) {
>> +      SVal Idx = ValMgr.makeNonLoc(i);
>> +      ElementRegion* ER = MRMgr.getElementRegion(ElementTy,
>> Idx,R,getContext());
>> +      SVal V = ValMgr.makeZeroVal(ElementTy);
>> +      state = Bind(state, Loc::MakeVal(ER), V);
>> +      ++i;
>> +    }
>> +  }
>> +
>>  return state;
>> }
>>
>>
>> Modified: cfe/trunk/lib/Analysis/SVals.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/SVals.cpp?rev=73946&r1=73945&r2=73946&view=diff
>>
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Analysis/SVals.cpp (original)
>> +++ cfe/trunk/lib/Analysis/SVals.cpp Tue Jun 23 00:23:38 2009
>> @@ -264,6 +264,10 @@
>>  return nonloc::SymbolVal(sym);
>> }
>>
>> +NonLoc ValueManager::makeNonLoc(const APSInt& V) {
>> +  return nonloc::ConcreteInt(BasicVals.getValue(V));
>> +}
>> +
>> NonLoc ValueManager::makeNonLoc(const SymExpr *lhs, BinaryOperator::Opcode
>> op,
>>                                const APSInt& v, QualType T) {
>>  // The Environment ensures we always get a persistent APSInt in
>>
>>
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>
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