diff options
| author | Zack Weinberg <zackw@panix.com> | 2016-12-06 10:14:42 -0500 |
|---|---|---|
| committer | Zack Weinberg <zackw@panix.com> | 2016-12-08 15:45:33 -0500 |
| commit | c03073774f915fe7841c2b551fe304544143470f (patch) | |
| tree | 724d0dff62918aba70b4e4fc17c80f35f2e6eafa /posix/unistd.h | |
| parent | 3d6bfcace17a479c2e006a33567af80e6070583f (diff) | |
Make _REENTRANT and _THREAD_SAFE aliases for _POSIX_C_SOURCE=199506L.
For many years, the only effect of these macros has been to make
unistd.h declare getlogin_r. _POSIX_C_SOURCE >= 199506L also causes
this function to be declared. However, people who don't carefully
read all the headers might be confused into thinking they need to
define _REENTRANT for any threaded code (as was indeed the case a long
time ago).
Therefore, remove __USE_REENTRANT, and make _REENTRANT and _THREAD_SAFE
into synonyms for _POSIX_C_SOURCE=199506L. This will only affect
programs that don't select a higher conformance level some other way.
For instance, -std=c89 -D_REENTRANT will see a change in visible
declarations, but -std=c99 -D_POSIX_C_SOURCE=200809L -D_REENTRANT won't,
and -D_REENTRANT all by itself also won't, because _DEFAULT_SOURCE
implies _POSIX_C_SOURCE > 199506.
* include/features.h: Remove __USE_REENTRANT. Treat _REENTRANT
and _THREAD_SAFE the same as _POSIX_C_SOURCE=199506L, if a higher
POSIX conformance level has not been selected by other macros.
* NEWS, manual/creature.texi: Document this change.
* posix/unistd.h, posix/bits/unistd.h: Don't check __USE_REENTRANT.
* include/libc-symbols.h: Don't define _REENTRANT.
* scripts/check-installed-headers.sh: Don't undefine _REENTRANT.
Diffstat (limited to 'posix/unistd.h')
| -rw-r--r-- | posix/unistd.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/posix/unistd.h b/posix/unistd.h index 625ba77da7..392dc0e004 100644 --- a/posix/unistd.h +++ b/posix/unistd.h @@ -849,7 +849,7 @@ extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW; This function is a possible cancellation point and therefore not marked with __THROW. */ extern char *getlogin (void); -#if defined __USE_REENTRANT || defined __USE_POSIX199506 +#ifdef __USE_POSIX199506 /* Return at most NAME_LEN characters of the login name of the user in NAME. If it cannot be determined or some other error occurred, return the error code. Otherwise return 0. |