RE: [PATCH 20/20] tools lib: Fix builds when glibc contains strlcpy()

From: David Laight
Date: Mon Jan 06 2020 - 12:03:35 EST

From: Arnaldo Carvalho de Melo
> Sent: 06 January 2020 16:07
> From: Vitaly Chikunov <vt@xxxxxxxxxxxx>
> 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 âstrlcpyâ [-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,

Why not just always use the local version by renaming it?


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