diff options
| author | Alejandro Colomar <[email protected]> | 2022-03-05 01:25:22 +0100 |
|---|---|---|
| committer | GitHub <[email protected]> | 2022-03-04 16:25:22 -0800 |
| commit | db7f1a91def6bbaf72dd3e9ad31255efb0bf81ab (patch) | |
| tree | 1817651092cca3f549bf229436993cb10736706d /config/always-compiler-options.m4 | |
| parent | 06b805067833902613de1871fa01e29fc80c8247 (diff) | |
Use _Noreturn (C11; GNU89) properly
A function that returns with no value is a different thing from a
function that doesn't return at all. Those are two orthogonal
concepts, commonly confused.
pthread_create(3) expects a pointer to a start routine that has a
very precise prototype:
void *(*start_routine)(void *);
However, other thread functions, such as kernel ones, expect:
void (*start_routine)(void *);
Providing a different one is incorrect, and has only been working
because the ABIs happen to produce a compatible function.
We should use '_Noreturn void', since it's the natural type, and
then provide a '_Noreturn void *' wrapper for pthread functions.
For consistency, replace most cases of __NORETURN or
__attribute__((noreturn)) by _Noreturn. _Noreturn is understood
by -std=gnu89, so it should be safe to use everywhere.
Ref: https://github.com/openzfs/zfs/pull/13110#discussion_r808450136
Ref: https://software.codidact.com/posts/285972
Reviewed-by: Brian Behlendorf <[email protected]>
Co-authored-by: Ahelenia Ziemiańska <[email protected]>
Signed-off-by: Alejandro Colomar <[email protected]>
Closes #13120
Diffstat (limited to 'config/always-compiler-options.m4')
| -rw-r--r-- | config/always-compiler-options.m4 | 26 |
1 files changed, 0 insertions, 26 deletions
diff --git a/config/always-compiler-options.m4 b/config/always-compiler-options.m4 index 9a0e83905..8cfd27535 100644 --- a/config/always-compiler-options.m4 +++ b/config/always-compiler-options.m4 @@ -182,32 +182,6 @@ AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_CC_NO_CLOBBERED], [ ]) dnl # -dnl # Check if cc supports -Wno-cast-function-type option. -dnl # -dnl # We actually invoke it with the --cast-function-type option -dnl # and infer the 'no-' version does or doesn't exist based upon -dnl # the results. This is required because when checking any of -dnl # no- prefixed options gcc always returns success. -dnl # -AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_CC_NO_CAST_FUNCTION_TYPE], [ - AC_MSG_CHECKING([whether $CC supports -Wno-cast-function-type]) - - saved_flags="$CFLAGS" - CFLAGS="$CFLAGS -Werror -Wcast-function-type" - - AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [])], [ - NO_CAST_FUNCTION_TYPE=-Wno-cast-function-type - AC_MSG_RESULT([yes]) - ], [ - NO_CAST_FUNCTION_TYPE= - AC_MSG_RESULT([no]) - ]) - - CFLAGS="$saved_flags" - AC_SUBST([NO_CAST_FUNCTION_TYPE]) -]) - -dnl # dnl # Check if cc supports -Wimplicit-fallthrough option. dnl # AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_CC_IMPLICIT_FALLTHROUGH], [ |