From 0538372096e50d9cf0ab8bd413cf7b561a1b85d7 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 13 Feb 2019 13:50:13 +0000 Subject: Fix -Wempty-body warnings in glibc. One group of warnings seen building glibc with -Wextra is -Wempty-body warnings about an 'if' body (or in one case an 'else' body) that is just a semicolon, "warning: suggest braces around empty body in an 'if' statement [-Wempty-body]" - I think the point of the warning being to make it more visible whether an 'if' body is actually present or not. This patch fixes such warnings in glibc. There's one place, with a semicolon at the end of a comment, where this is clearly making the presence of an 'else' body more visible. The other cases involve macro definitions expanding to nothing. While there's no issue there with visibility at the call sites, I think it's still cleaner to have a macro that expands to something nonempty appropriate for the context - so do {} while (0) if it's only intended to be usable as a statement, or ((void) 0) where the macro definition is an alternative to a call to a function returning void, so this patch makes those changes. Tested for x86_64. * catgets/gencat.c (normalize_line): Use braces around empty 'else' body. * include/stap-probe.h [!USE_STAP_PROBE && !__ASSEMBLER__] (STAP_PROBE0): Use do {} while (0) for do-nothing definition. [!USE_STAP_PROBE && !__ASSEMBLER__] (STAP_PROBE1): Likewise. [!USE_STAP_PROBE && !__ASSEMBLER__] (STAP_PROBE2): Likewise. [!USE_STAP_PROBE && !__ASSEMBLER__] (STAP_PROBE3): Likewise. [!USE_STAP_PROBE && !__ASSEMBLER__] (STAP_PROBE4): Likewise. * libio/libio.h (_IO_funlockfile): Use ((void) 0) for do-nothing definition. --- libio/libio.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'libio') diff --git a/libio/libio.h b/libio/libio.h index d21162aab0..9c08c7eba1 100644 --- a/libio/libio.h +++ b/libio/libio.h @@ -240,7 +240,7 @@ extern int _IO_ftrylockfile (FILE *) __THROW; #define _IO_peekc(_fp) _IO_peekc_unlocked (_fp) #define _IO_flockfile(_fp) /**/ -#define _IO_funlockfile(_fp) /**/ +#define _IO_funlockfile(_fp) ((void) 0) #define _IO_ftrylockfile(_fp) /**/ #ifndef _IO_cleanup_region_start #define _IO_cleanup_region_start(_fct, _fp) /**/ -- cgit v1.2.1