From 155ac333945d7af507bb28dc6f2539300a4c0666 Mon Sep 17 00:00:00 2001 From: =?utf8?q?D=C3=A1vid=20Bolvansk=C3=BD?= Date: Sun, 27 Sep 2020 21:32:32 +0200 Subject: [PATCH] [BuildLibCalls] Add noalias for strcat and stpcpy strcat: destination and source shall not overlap. (http://www.cplusplus.com/reference/cstring/strcat/) stpcpy: The strings may not overlap, and the destination string dest must be large enough to receive the copy. (https://man7.org/linux/man-pages/man3/stpcpy.3.html) Reviewed By: jdoerfert Differential Revision: https://reviews.llvm.org/D88335 --- llvm/lib/Transforms/Utils/BuildLibCalls.cpp | 5 ++--- llvm/test/Transforms/InferFunctionAttrs/annotate.ll | 8 ++++---- 2 files changed, 6 insertions(+), 7 deletions(-) diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp index 09ed68a..64e168d 100644 --- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp +++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp @@ -203,9 +203,6 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) { return Changed; case LibFunc_strcpy: case LibFunc_strncpy: - Changed |= setDoesNotAlias(F, 0); - Changed |= setDoesNotAlias(F, 1); - LLVM_FALLTHROUGH; case LibFunc_strcat: case LibFunc_strncat: Changed |= setReturnedArg(F, 0); @@ -215,6 +212,8 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) { Changed |= setDoesNotThrow(F); Changed |= setDoesNotCapture(F, 1); Changed |= setOnlyReadsMemory(F, 1); + Changed |= setDoesNotAlias(F, 0); + Changed |= setDoesNotAlias(F, 1); return Changed; case LibFunc_strxfrm: Changed |= setDoesNotThrow(F); diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll index 7f52bf7..d4b0f0f 100644 --- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll +++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll @@ -825,16 +825,16 @@ declare i32 @statvfs(i8*, %opaque*) ; CHECK-LINUX: declare noundef i32 @statvfs64(i8* nocapture noundef readonly, %opaque* nocapture noundef) [[G1]] declare i32 @statvfs64(i8*, %opaque*) -; CHECK: declare i8* @stpcpy(i8*, i8* nocapture readonly) [[G1]] +; CHECK: declare i8* @stpcpy(i8* noalias, i8* noalias nocapture readonly) [[G1]] declare i8* @stpcpy(i8*, i8*) -; CHECK: declare i8* @stpncpy(i8*, i8* nocapture readonly, i64) [[G1]] +; CHECK: declare i8* @stpncpy(i8* noalias, i8* noalias nocapture readonly, i64) [[G1]] declare i8* @stpncpy(i8*, i8*, i64) ; CHECK: declare i32 @strcasecmp(i8* nocapture, i8* nocapture) [[G2]] declare i32 @strcasecmp(i8*, i8*) -; CHECK: declare i8* @strcat(i8* returned, i8* nocapture readonly) [[G1]] +; CHECK: declare i8* @strcat(i8* noalias returned, i8* noalias nocapture readonly) [[G1]] declare i8* @strcat(i8*, i8*) ; CHECK: declare i8* @strchr(i8*, i32) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]] @@ -861,7 +861,7 @@ declare i64 @strlen(i8*) ; CHECK: declare i32 @strncasecmp(i8* nocapture, i8* nocapture, i64) [[G2]] declare i32 @strncasecmp(i8*, i8*, i64) -; CHECK: declare i8* @strncat(i8* returned, i8* nocapture readonly, i64) [[G1]] +; CHECK: declare i8* @strncat(i8* noalias returned, i8* noalias nocapture readonly, i64) [[G1]] declare i8* @strncat(i8*, i8*, i64) ; CHECK: declare i32 @strncmp(i8* nocapture, i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]] -- 2.7.4