From 6d6c4c1bb569edc88624d8f6894928064363d9d5 Mon Sep 17 00:00:00 2001 From: Vitaly Chikunov Date: Tue, 24 Dec 2019 20:20:29 +0300 Subject: tools lib: Fix builds when glibc contains strlcpy() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 6c4798d3f08b81c2c52936b10e0fa872590c96ae upstream. Disable a couple of compilation warnings (which are treated as errors) on strlcpy() definition and declaration, allowing users to compile perf and kernel (objtool) when: 1. glibc have strlcpy() (such as in ALT Linux since 2004) objtool and perf build fails with this (in gcc): In file included from exec-cmd.c:3: tools/include/linux/string.h:20:15: error: redundant redeclaration of ‘strlcpy’ [-Werror=redundant-decls] 20 | extern size_t strlcpy(char *dest, const char *src, size_t size); 2. clang ignores `-Wredundant-decls', but produces another warning when building perf: CC util/string.o ../lib/string.c:99:8: error: attribute declaration must precede definition [-Werror,-Wignored-attributes] size_t __weak strlcpy(char *dest, const char *src, size_t size) ../../tools/include/linux/compiler.h:66:34: note: expanded from macro '__weak' # define __weak __attribute__((weak)) /usr/include/bits/string_fortified.h:151:8: note: previous definition is here __NTH (strlcpy (char *__restrict __dest, const char *__restrict __src, Committer notes: The #pragma GCC diagnostic directive was introduced in gcc 4.6, so check for that as well. Fixes: ce99091 ("perf tools: Move strlcpy() from perf to tools/lib/string.c") Fixes: 0215d59 ("tools lib: Reinstate strlcpy() header guard with __UCLIBC__") Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=118481 Signed-off-by: Vitaly Chikunov Reviewed-by: Dmitry Levin Cc: Dmitry Levin Cc: Josh Poimboeuf Cc: kbuild test robot Cc: Peter Zijlstra Cc: stable@vger.kernel.org Cc: Vineet Gupta Link: http://lore.kernel.org/lkml/20191224172029.19690-1-vt@altlinux.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/lib/string.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'tools/lib') diff --git a/tools/lib/string.c b/tools/lib/string.c index 93b3d4b6feac..ee0afcbdd696 100644 --- a/tools/lib/string.c +++ b/tools/lib/string.c @@ -95,6 +95,10 @@ int strtobool(const char *s, bool *res) * If libc has strlcpy() then that version will override this * implementation: */ +#ifdef __clang__ +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Wignored-attributes" +#endif size_t __weak strlcpy(char *dest, const char *src, size_t size) { size_t ret = strlen(src); @@ -106,3 +110,6 @@ size_t __weak strlcpy(char *dest, const char *src, size_t size) } return ret; } +#ifdef __clang__ +#pragma clang diagnostic pop +#endif -- cgit v1.2.3