[SimplifyLibCalls] Factor out signature checks for fortifiable libcalls.
The checks are the same for fortified counterparts to the libcalls, so
we might as well do them in a single place.
Differential Revision: http://reviews.llvm.org/D6539
llvm-svn: 225638
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 00d1ec6..930f666 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -116,6 +116,70 @@
}
}
+/// \brief Returns whether \p F matches the signature expected for the
+/// string/memory copying library function \p Func.
+/// Acceptable functions are st[rp][n]?cpy, memove, memcpy, and memset.
+/// Their fortified (_chk) counterparts are also accepted.
+static bool checkStringCopyLibFuncSignature(Function *F, LibFunc::Func Func,
+ const DataLayout *DL) {
+ FunctionType *FT = F->getFunctionType();
+ LLVMContext &Context = F->getContext();
+ Type *PCharTy = Type::getInt8PtrTy(Context);
+ Type *SizeTTy = DL ? DL->getIntPtrType(Context) : nullptr;
+ unsigned NumParams = FT->getNumParams();
+
+ // All string libfuncs return the same type as the first parameter.
+ if (FT->getReturnType() != FT->getParamType(0))
+ return false;
+
+ switch (Func) {
+ default:
+ llvm_unreachable("Can't check signature for non-string-copy libfunc.");
+ case LibFunc::stpncpy_chk:
+ case LibFunc::strncpy_chk:
+ --NumParams; // fallthrough
+ case LibFunc::stpncpy:
+ case LibFunc::strncpy: {
+ if (NumParams != 3 || FT->getParamType(0) != FT->getParamType(1) ||
+ FT->getParamType(0) != PCharTy || !FT->getParamType(2)->isIntegerTy())
+ return false;
+ break;
+ }
+ case LibFunc::strcpy_chk:
+ case LibFunc::stpcpy_chk:
+ --NumParams; // fallthrough
+ case LibFunc::stpcpy:
+ case LibFunc::strcpy: {
+ if (NumParams != 2 || FT->getParamType(0) != FT->getParamType(1) ||
+ FT->getParamType(0) != PCharTy)
+ return false;
+ break;
+ }
+ case LibFunc::memmove_chk:
+ case LibFunc::memcpy_chk:
+ --NumParams; // fallthrough
+ case LibFunc::memmove:
+ case LibFunc::memcpy: {
+ if (NumParams != 3 || !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isPointerTy() || FT->getParamType(2) != SizeTTy)
+ return false;
+ break;
+ }
+ case LibFunc::memset_chk:
+ --NumParams; // fallthrough
+ case LibFunc::memset: {
+ if (NumParams != 3 || !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isIntegerTy() || FT->getParamType(2) != SizeTTy)
+ return false;
+ break;
+ }
+ }
+ // If this is a fortified libcall, the last parameter is a size_t.
+ if (NumParams == FT->getNumParams() - 1)
+ return FT->getParamType(FT->getNumParams() - 1) == SizeTTy;
+ return true;
+}
+
//===----------------------------------------------------------------------===//
// Fortified Library Call Optimizations
//===----------------------------------------------------------------------===//
@@ -600,11 +664,8 @@
Value *LibCallSimplifier::optimizeStrCpy(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
- // Verify the "strcpy" function prototype.
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != B.getInt8PtrTy())
+
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::strcpy, DL))
return nullptr;
Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
@@ -631,9 +692,8 @@
Function *Callee = CI->getCalledFunction();
// Verify the "stpcpy" function prototype.
FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != B.getInt8PtrTy())
+
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::stpcpy, DL))
return nullptr;
// These optimizations require DataLayout.
@@ -665,10 +725,8 @@
Value *LibCallSimplifier::optimizeStrNCpy(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != B.getInt8PtrTy() ||
- !FT->getParamType(2)->isIntegerTy())
+
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::strncpy, DL))
return nullptr;
Value *Dst = CI->getArgOperand(0);
@@ -976,11 +1034,7 @@
if (!DL)
return nullptr;
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isPointerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(CI->getContext()))
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memcpy, DL))
return nullptr;
// memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
@@ -995,11 +1049,7 @@
if (!DL)
return nullptr;
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isPointerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(CI->getContext()))
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memmove, DL))
return nullptr;
// memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
@@ -1014,11 +1064,7 @@
if (!DL)
return nullptr;
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isIntegerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(FT->getParamType(0)))
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memset, DL))
return nullptr;
// memset(p, v, n) -> llvm.memset(p, v, n, 1)