diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils')
| -rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp index 339d3a326d6..00c5f040020 100644 --- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -2322,8 +2322,18 @@ Value *FortifiedLibCallSimplifier::optimizeStrpNCpyChk(CallInst *CI, } Value *FortifiedLibCallSimplifier::optimizeCall(CallInst *CI) { - if (CI->isNoBuiltin()) - return nullptr; + // FIXME: We shouldn't be changing "nobuiltin" or TLI unavailable calls here. + // Some clang users checked for _chk libcall availability using: + // __has_builtin(__builtin___memcpy_chk) + // When compiling with -fno-builtin, this is always true. + // When passing -ffreestanding/-mkernel, which both imply -fno-builtin, we + // end up with fortified libcalls, which isn't acceptable in a freestanding + // environment which only provides their non-fortified counterparts. + // + // Until we change clang and/or teach external users to check for availability + // differently, disregard the "nobuiltin" attribute and TLI::has. + // + // PR23093. LibFunc::Func Func; Function *Callee = CI->getCalledFunction(); @@ -2332,7 +2342,7 @@ Value *FortifiedLibCallSimplifier::optimizeCall(CallInst *CI) { bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C; // First, check that this is a known library functions. - if (!TLI->getLibFunc(FuncName, Func) || !TLI->has(Func)) + if (!TLI->getLibFunc(FuncName, Func)) return nullptr; // We never change the calling convention. |
