diff options
| -rw-r--r-- | NEWS | 13 | ||||
| -rw-r--r-- | include/features.h | 41 | ||||
| -rw-r--r-- | include/libc-symbols.h | 2 | ||||
| -rw-r--r-- | manual/creature.texi | 14 | ||||
| -rw-r--r-- | posix/bits/unistd.h | 2 | ||||
| -rw-r--r-- | posix/unistd.h | 2 | ||||
| -rw-r--r-- | scripts/check-installed-headers.sh | 1 |
7 files changed, 47 insertions, 28 deletions
@@ -22,6 +22,19 @@ Version 2.25 from that TS. Note that most features from that TS are not supported by the GNU C Library. +* The nonstandard feature selection macros _REENTRANT and _THREAD_SAFE are + now treated as compatibility synonyms for _POSIX_C_SOURCE=199506L. + Since the GNU C Library defaults to a much newer revision of POSIX, this + will only affect programs that specifically request an old conformance + mode. For instance, a program compiled with -std=c89 -D_REENTRANT will + see a change in the visible declarations, but a program compiled with + just -D_REENTRANT, or -std=c99 -D_POSIX_C_SOURCE=200809L -D_REENTRANT, + will not. + + Some C libraries once required _REENTRANT and/or _THREAD_SAFE to be + defined by all multithreaded code, but glibc has not required this for + many years. + * The inclusion of <sys/sysmacros.h> by <sys/types.h> is deprecated. This means that in a future release, the macros “major”, “minor”, and “makedev” will only be available from <sys/sysmacros.h>. diff --git a/include/features.h b/include/features.h index 650d4c5e12..4d8bda1bc6 100644 --- a/include/features.h +++ b/include/features.h @@ -24,10 +24,13 @@ __STRICT_ANSI__ ISO Standard C. _ISOC99_SOURCE Extensions to ISO C89 from ISO C99. _ISOC11_SOURCE Extensions to ISO C99 from ISO C11. - __STDC_WANT_LIB_EXT2__ Extensions to ISO C99 from TR 27431-2:2010. - __STDC_WANT_IEC_60559_BFP_EXT__ Extensions to ISO C11 from TS 18661-1:2014. - __STDC_WANT_IEC_60559_FUNCS_EXT__ Extensions to ISO C11 from - TS 18661-4:2015. + __STDC_WANT_LIB_EXT2__ + Extensions to ISO C99 from TR 27431-2:2010. + __STDC_WANT_IEC_60559_BFP_EXT__ + Extensions to ISO C11 from TS 18661-1:2014. + __STDC_WANT_IEC_60559_FUNCS_EXT__ + Extensions to ISO C11 from TS 18661-4:2015. + _POSIX_SOURCE IEEE Std 1003.1. _POSIX_C_SOURCE If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2; if >=199309L, add IEEE Std 1003.1b-1993; @@ -45,10 +48,12 @@ _GNU_SOURCE All of the above, plus GNU extensions. _DEFAULT_SOURCE The default set of features (taking precedence over __STRICT_ANSI__). - _REENTRANT Select additionally reentrant object. - _THREAD_SAFE Same as _REENTRANT, often used by other systems. - _FORTIFY_SOURCE If set to numeric value > 0 additional security - measures are defined, according to level. + + _FORTIFY_SOURCE Add security hardening to many library functions. + Set to 1 or 2; 2 performs stricter checks than 1. + + _REENTRANT, _THREAD_SAFE + Obsolete; equivalent to _POSIX_C_SOURCE=199506L. The `-ansi' switch to the GNU C compiler, and standards conformance options such as `-std=c99', define __STRICT_ANSI__. If none of @@ -86,7 +91,6 @@ __USE_MISC Define things from 4.3BSD or System V Unix. __USE_ATFILE Define *at interfaces and AT_* constants for them. __USE_GNU Define GNU extensions. - __USE_REENTRANT Define reentrant/thread-safe *_r functions. __USE_FORTIFY_LEVEL Additional security measures used, according to level. The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are @@ -130,7 +134,6 @@ #undef __USE_MISC #undef __USE_ATFILE #undef __USE_GNU -#undef __USE_REENTRANT #undef __USE_FORTIFY_LEVEL #undef __KERNEL_STRICT_NAMES @@ -253,6 +256,7 @@ # undef _POSIX_C_SOURCE # define _POSIX_C_SOURCE 200809L #endif + #if ((!defined __STRICT_ANSI__ \ || (defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) >= 500)) \ && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE) @@ -269,6 +273,19 @@ # define __USE_POSIX_IMPLICITLY 1 #endif +/* Some C libraries once required _REENTRANT and/or _THREAD_SAFE to be + defined in all multithreaded code. GNU libc has not required this + for many years. We now treat them as compatibility synonyms for + _POSIX_C_SOURCE=199506L, which is the earliest level of POSIX with + comprehensive support for multithreaded code. Using them never + lowers the selected level of POSIX conformance, only raises it. */ +#if ((!defined _POSIX_C_SOURCE || (_POSIX_C_SOURCE - 0) < 199506L) \ + && (defined _REENTRANT || defined _THREAD_SAFE)) +# define _POSIX_SOURCE 1 +# undef _POSIX_C_SOURCE +# define _POSIX_C_SOURCE 199506L +#endif + #if (defined _POSIX_SOURCE \ || (defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 1) \ || defined _XOPEN_SOURCE) @@ -351,10 +368,6 @@ # define __USE_GNU 1 #endif -#if defined _REENTRANT || defined _THREAD_SAFE -# define __USE_REENTRANT 1 -#endif - #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 # if !defined __OPTIMIZE__ || __OPTIMIZE__ <= 0 # warning _FORTIFY_SOURCE requires compiling with optimization (-O) diff --git a/include/libc-symbols.h b/include/libc-symbols.h index 1c91f2e6a3..4238d7930b 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -52,8 +52,6 @@ /* Enable declarations of GNU extensions, since we are compiling them. */ #define _GNU_SOURCE 1 -/* And we also need the data for the reentrant functions. */ -#define _REENTRANT 1 #include <config.h> diff --git a/manual/creature.texi b/manual/creature.texi index 257f8718b1..5048886292 100644 --- a/manual/creature.texi +++ b/manual/creature.texi @@ -219,15 +219,11 @@ cause them to be disabled. @comment GNU @defvr Macro _REENTRANT @defvrx Macro _THREAD_SAFE -If you define one of these macros, reentrant versions of several functions get -declared. Some of the functions are specified in POSIX.1c but many others -are only available on a few other systems or are unique to @theglibc{}. -The problem is the delay in the standardization of the thread safe C library -interface. - -Unlike on some other systems, no special version of the C library must be -used for linking. There is only one version but while compiling this -it must have been specified to compile as thread safe. +These macros are obsolete. They have the same effect as defining +@code{_POSIX_C_SOURCE} with the value @code{199506L}. + +Some very old C libraries required one of these macros to be defined +for basic functionality (e.g.@: @code{getchar}) to be thread-safe. @end defvr We recommend you use @code{_GNU_SOURCE} in new programs. If you don't diff --git a/posix/bits/unistd.h b/posix/bits/unistd.h index 0105f04f20..4a5f42e120 100644 --- a/posix/bits/unistd.h +++ b/posix/bits/unistd.h @@ -302,7 +302,7 @@ __NTH (ttyname_r (int __fd, char *__buf, size_t __buflen)) } -#if defined __USE_REENTRANT || defined __USE_POSIX199506 +#ifdef __USE_POSIX199506 extern int __getlogin_r_chk (char *__buf, size_t __buflen, size_t __nreal) __nonnull ((1)); extern int __REDIRECT (__getlogin_r_alias, (char *__buf, size_t __buflen), 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. diff --git a/scripts/check-installed-headers.sh b/scripts/check-installed-headers.sh index a245fe6be2..89e1514c7b 100644 --- a/scripts/check-installed-headers.sh +++ b/scripts/check-installed-headers.sh @@ -143,7 +143,6 @@ EOF inappropriate for this test. */ #undef _LIBC #undef _GNU_SOURCE -#undef _REENTRANT /* The library mode is selected here rather than on the command line to ensure that this selection wins. */ $expanded_lib_mode |