[esan|cfrag] Handle complex GEP instr in the cfrag tool
Summary:
Iterates all (except the first and the last) operands within each GEP
instruction for instrumentation.
Adds test struct_field_gep.ll.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, bruening, llvm-commits
Differential Revision: http://reviews.llvm.org/D21242
llvm-svn: 272442
diff --git a/llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp
index 83ae3d5..40a9fce 100644
--- a/llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp
@@ -656,45 +656,52 @@
bool EfficiencySanitizer::instrumentGetElementPtr(Instruction *I, Module &M) {
GetElementPtrInst *GepInst = dyn_cast<GetElementPtrInst>(I);
- if (GepInst == nullptr || !isa<StructType>(GepInst->getSourceElementType()) ||
- StructTyMap.count(GepInst->getSourceElementType()) == 0 ||
- !GepInst->hasAllConstantIndices() ||
- // Only handle simple struct field GEP.
- GepInst->getNumIndices() != 2) {
+ bool Res = false;
+ if (GepInst == nullptr || GepInst->getNumIndices() == 1) {
++NumIgnoredGEPs;
return false;
}
- StructType *StructTy = dyn_cast<StructType>(GepInst->getSourceElementType());
- if (shouldIgnoreStructType(StructTy)) {
- ++NumIgnoredGEPs;
- return false;
+ Type *SourceTy = GepInst->getSourceElementType();
+ // Iterate all (except the first and the last) idx within each GEP instruction
+ // for possible nested struct field address calculation.
+ for (unsigned i = 1; i < GepInst->getNumIndices(); ++i) {
+ SmallVector<Value *, 8> IdxVec(GepInst->idx_begin(),
+ GepInst->idx_begin() + i);
+ StructType *StructTy = dyn_cast<StructType>(
+ GetElementPtrInst::getIndexedType(SourceTy, IdxVec));
+ if (StructTy == nullptr || shouldIgnoreStructType(StructTy) ||
+ StructTyMap.count(StructTy) == 0)
+ continue;
+ // Get the StructTy's subfield index.
+ ConstantInt *Idx = dyn_cast<ConstantInt>(GepInst->getOperand(i+1));
+ if (Idx == nullptr || Idx->getZExtValue() > StructTy->getNumElements())
+ continue;
+ GlobalVariable *CounterArray = StructTyMap[StructTy];
+ if (CounterArray == nullptr)
+ return false;
+ IRBuilder<> IRB(I);
+ Constant *Indices[2];
+ // Xref http://llvm.org/docs/LangRef.html#i-getelementptr and
+ // http://llvm.org/docs/GetElementPtr.html.
+ // The first index of the GEP instruction steps through the first operand,
+ // i.e., the array itself.
+ Indices[0] = ConstantInt::get(IRB.getInt32Ty(), 0);
+ // The second index is the index within the array.
+ Indices[1] = ConstantInt::get(IRB.getInt32Ty(), Idx->getZExtValue());
+ Constant *Counter =
+ ConstantExpr::getGetElementPtr(
+ ArrayType::get(IRB.getInt64Ty(), StructTy->getNumElements()),
+ CounterArray, Indices);
+ Value *Load = IRB.CreateLoad(Counter);
+ IRB.CreateStore(IRB.CreateAdd(Load, ConstantInt::get(IRB.getInt64Ty(), 1)),
+ Counter);
+ Res = true;
}
- ++NumInstrumentedGEPs;
- // Use the last index as the index within the struct.
- ConstantInt *Idx = dyn_cast<ConstantInt>(GepInst->getOperand(2));
- if (Idx == nullptr || Idx->getZExtValue() > StructTy->getNumElements())
- return false;
-
- GlobalVariable *CounterArray = StructTyMap[StructTy];
- if (CounterArray == nullptr)
- return false;
- IRBuilder<> IRB(I);
- Constant *Indices[2];
- // Xref http://llvm.org/docs/LangRef.html#i-getelementptr and
- // http://llvm.org/docs/GetElementPtr.html.
- // The first index of the GEP instruction steps through the first operand,
- // i.e., the array itself.
- Indices[0] = ConstantInt::get(IRB.getInt32Ty(), 0);
- // The second index is the index within the array.
- Indices[1] = ConstantInt::get(IRB.getInt32Ty(), Idx->getZExtValue());
- Constant *Counter =
- ConstantExpr::getGetElementPtr(ArrayType::get(IRB.getInt64Ty(),
- StructTy->getNumElements()),
- CounterArray, Indices);
- Value *Load = IRB.CreateLoad(Counter);
- IRB.CreateStore(IRB.CreateAdd(Load, ConstantInt::get(IRB.getInt64Ty(), 1)),
- Counter);
- return true;
+ if (Res)
+ ++NumInstrumentedGEPs;
+ else
+ ++NumIgnoredGEPs;
+ return Res;
}
int EfficiencySanitizer::getMemoryAccessFuncIndex(Value *Addr,