diff options
Diffstat (limited to 'lib/Analysis/TypeMetadataUtils.cpp')
-rw-r--r-- | lib/Analysis/TypeMetadataUtils.cpp | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/lib/Analysis/TypeMetadataUtils.cpp b/lib/Analysis/TypeMetadataUtils.cpp index 9311dfbc6eba..072d291f3f93 100644 --- a/lib/Analysis/TypeMetadataUtils.cpp +++ b/lib/Analysis/TypeMetadataUtils.cpp @@ -127,3 +127,35 @@ void llvm::findDevirtualizableCallsForTypeCheckedLoad( findCallsAtConstantOffset(DevirtCalls, &HasNonCallUses, LoadedPtr, Offset->getZExtValue(), CI, DT); } + +Constant *llvm::getPointerAtOffset(Constant *I, uint64_t Offset, Module &M) { + if (I->getType()->isPointerTy()) { + if (Offset == 0) + return I; + return nullptr; + } + + const DataLayout &DL = M.getDataLayout(); + + if (auto *C = dyn_cast<ConstantStruct>(I)) { + const StructLayout *SL = DL.getStructLayout(C->getType()); + if (Offset >= SL->getSizeInBytes()) + return nullptr; + + unsigned Op = SL->getElementContainingOffset(Offset); + return getPointerAtOffset(cast<Constant>(I->getOperand(Op)), + Offset - SL->getElementOffset(Op), M); + } + if (auto *C = dyn_cast<ConstantArray>(I)) { + ArrayType *VTableTy = C->getType(); + uint64_t ElemSize = DL.getTypeAllocSize(VTableTy->getElementType()); + + unsigned Op = Offset / ElemSize; + if (Op >= C->getNumOperands()) + return nullptr; + + return getPointerAtOffset(cast<Constant>(I->getOperand(Op)), + Offset % ElemSize, M); + } + return nullptr; +} |