- if (TD) {
- if (Align == 0 && Ty && Ty->isSized())
- Align = TD->getABITypeAlignment(Ty);
-
- if (Align != 0) {
- int64_t Offset = 0;
- if (Value *Base = GetPointerBaseWithConstantOffset(Ptr, Offset, *TD)) {
- unsigned BaseAlign = 0;
- if (AllocaInst *AI = dyn_cast<AllocaInst>(Base)) {
- BaseAlign = AI->getAlignment();
- if (BaseAlign == 0 && AI->getAllocatedType()->isSized())
- BaseAlign = TD->getABITypeAlignment(AI->getAllocatedType());
- } else if (GlobalValue *GV = dyn_cast<GlobalVariable>(Base)) {
- BaseAlign = GV->getAlignment();
- if (BaseAlign == 0 && GV->getType()->getElementType()->isSized())
- BaseAlign = TD->getABITypeAlignment(GV->getType()->getElementType());
- }
- Assert1((!BaseAlign || Align <= MinAlign(BaseAlign, Offset)),
- "Undefined behavior: Memory reference address is misaligned",
- &I);
+ // Check for buffer overflows and misalignment.
+ // Only handles memory references that read/write something simple like an
+ // alloca instruction or a global variable.
+ int64_t Offset = 0;
+ if (Value *Base = GetPointerBaseWithConstantOffset(Ptr, Offset, *DL)) {
+ // OK, so the access is to a constant offset from Ptr. Check that Ptr is
+ // something we can handle and if so extract the size of this base object
+ // along with its alignment.
+ uint64_t BaseSize = MemoryLocation::UnknownSize;
+ unsigned BaseAlign = 0;
+
+ if (AllocaInst *AI = dyn_cast<AllocaInst>(Base)) {
+ Type *ATy = AI->getAllocatedType();
+ if (!AI->isArrayAllocation() && ATy->isSized())
+ BaseSize = DL->getTypeAllocSize(ATy);
+ BaseAlign = AI->getAlignment();
+ if (BaseAlign == 0 && ATy->isSized())
+ BaseAlign = DL->getABITypeAlignment(ATy);
+ } else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Base)) {
+ // If the global may be defined differently in another compilation unit
+ // then don't warn about funky memory accesses.
+ if (GV->hasDefinitiveInitializer()) {
+ Type *GTy = GV->getType()->getElementType();
+ if (GTy->isSized())
+ BaseSize = DL->getTypeAllocSize(GTy);
+ BaseAlign = GV->getAlignment();
+ if (BaseAlign == 0 && GTy->isSized())
+ BaseAlign = DL->getABITypeAlignment(GTy);