From: Vitaly Chikunov vt@altlinux.org
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 vt@altlinux.org Reviewed-by: Dmitry Levin ldv@altlinux.org Cc: Dmitry Levin ldv@altlinux.org Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: kbuild test robot lkp@intel.com Cc: Peter Zijlstra peterz@infradead.org Cc: stable@vger.kernel.org Cc: Vineet Gupta vineet.gupta1@synopsys.com Link: http://lore.kernel.org/lkml/20191224172029.19690-1-vt@altlinux.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/include/linux/string.h | 8 ++++++++ tools/lib/string.c | 7 +++++++ 2 files changed, 15 insertions(+)
--- a/tools/include/linux/string.h +++ b/tools/include/linux/string.h @@ -14,7 +14,15 @@ int strtobool(const char *s, bool *res); * However uClibc headers also define __GLIBC__ hence the hack below */ #if defined(__GLIBC__) && !defined(__UCLIBC__) +// pragma diagnostic was introduced in gcc 4.6 +#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wredundant-decls" +#endif extern size_t strlcpy(char *dest, const char *src, size_t size); +#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) +#pragma GCC diagnostic pop +#endif #endif
char *str_error_r(int errnum, char *buf, size_t buflen); --- 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 } return ret; } +#ifdef __clang__ +#pragma clang diagnostic pop +#endif