Tighten up checking.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52850 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2008-06-28 04:37:04 +00:00
parent 77455617fb
commit 3284d42c17

View File

@ -950,6 +950,8 @@ bool llvm::GetConstantStringInfo(Value *V, std::string &Str, uint64_t Offset) {
if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) {
GEP = GEPI;
} else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
if (CE->getOpcode() == Instruction::BitCast)
return GetConstantStringInfo(CE->getOperand(0), Str, Offset);
if (CE->getOpcode() != Instruction::GetElementPtr)
return false;
GEP = CE;
@ -960,12 +962,16 @@ bool llvm::GetConstantStringInfo(Value *V, std::string &Str, uint64_t Offset) {
if (GEP->getNumOperands() != 3)
return false;
// Make sure the index-ee is a pointer to array of i8.
const PointerType *PT = cast<PointerType>(GEP->getOperand(0)->getType());
const ArrayType *AT = dyn_cast<ArrayType>(PT->getElementType());
if (AT == 0 || AT->getElementType() != Type::Int8Ty)
return false;
// Check to make sure that the first operand of the GEP is an integer and
// has value 0 so that we are sure we're indexing into the initializer.
if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
if (!Idx->isZero())
return false;
} else
ConstantInt *FirstIdx = dyn_cast<ConstantInt>(GEP->getOperand(1));
if (FirstIdx == 0 || !FirstIdx->isZero())
return false;
// If the second index isn't a ConstantInt, then this is a variable index