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author | Eric Christopher <echristo@apple.com> | 2010-01-29 01:37:11 +0000 |
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committer | Eric Christopher <echristo@apple.com> | 2010-01-29 01:37:11 +0000 |
commit | 407e47c21ea201292adf978e06d6b7c1dc62cda9 (patch) | |
tree | e07bee5b786900e923c9a5a12128341de280a5cd /lib/Transforms/Scalar | |
parent | 9988ab04961c5bdb8fd622e2ceff4407493cd15e (diff) | |
download | external_llvm-407e47c21ea201292adf978e06d6b7c1dc62cda9.zip external_llvm-407e47c21ea201292adf978e06d6b7c1dc62cda9.tar.gz external_llvm-407e47c21ea201292adf978e06d6b7c1dc62cda9.tar.bz2 |
Make strcpy_chk lower to strcpy if we have a safe size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94783 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Scalar')
-rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index a49da9c..fc23c42 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -1203,9 +1203,6 @@ struct MemMoveChkOpt : public LibCallOptimization { struct StrCpyChkOpt : public LibCallOptimization { virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) { - // These optimizations require TargetData. - if (!TD) return 0; - const FunctionType *FT = Callee->getFunctionType(); if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) || !isa<PointerType>(FT->getParamType(0)) || @@ -1217,8 +1214,13 @@ struct StrCpyChkOpt : public LibCallOptimization { if (!SizeCI) return 0; - // We don't have any length information, just lower to a plain strcpy. - if (SizeCI->isAllOnesValue()) + // If a) we don't have any length information, or b) we know this will + // fit then just lower to a plain strcpy. Otherwise we'll keep our + // strcpy_chk call which may fail at runtime if the size is too long. + // TODO: It might be nice to get a maximum length out of the possible + // string lengths for varying. + if (SizeCI->isAllOnesValue() || + SizeCI->getZExtValue() >= GetStringLength(CI->getOperand(2))) return EmitStrCpy(CI->getOperand(1), CI->getOperand(2), B); return 0; |