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-rw-r--r--include/features.h108
1 files changed, 84 insertions, 24 deletions
diff --git a/include/features.h b/include/features.h
index 9514d35718..5bed0a4996 100644
--- a/include/features.h
+++ b/include/features.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991-2016 Free Software Foundation, Inc.
+/* Copyright (C) 1991-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -24,6 +24,15 @@
__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_IEC_60559_TYPES_EXT__
+ Extensions to ISO C11 from TS 18661-3:2015.
+
_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;
@@ -41,10 +50,12 @@
_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
@@ -58,9 +69,14 @@
These are defined by this file and are used by the
header files to decide what to declare or define:
+ __GLIBC_USE (F) Define things from feature set F. This is defined
+ to 1 or 0; the subsequent macros are either defined
+ or undefined, and those tests should be moved to
+ __GLIBC_USE.
__USE_ISOC11 Define ISO C11 things.
__USE_ISOC99 Define ISO C99 things.
__USE_ISOC95 Define ISO C90 AMD1 (C95) things.
+ __USE_ISOCXX11 Define ISO C++11 things.
__USE_POSIX Define IEEE Std 1003.1 things.
__USE_POSIX2 Define IEEE Std 1003.2 things.
__USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
@@ -78,7 +94,6 @@
__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
@@ -90,7 +105,14 @@
explicitly undefined if they are not explicitly defined.
Feature-test macros that are not defined by the user or compiler
but are implied by the other feature-test macros defined (or by the
- lack of any definitions) are defined by the file. */
+ lack of any definitions) are defined by the file.
+
+ ISO C feature test macros depend on the definition of the macro
+ when an affected header is included, not when the first system
+ header is included, and so they are handled in
+ <bits/libc-header-start.h>, which does not have a multiple include
+ guard. Feature test macros that can be handled from the first
+ system header included are handled here. */
/* Undefine everything, so we get a clean slate. */
@@ -115,9 +137,9 @@
#undef __USE_MISC
#undef __USE_ATFILE
#undef __USE_GNU
-#undef __USE_REENTRANT
#undef __USE_FORTIFY_LEVEL
#undef __KERNEL_STRICT_NAMES
+#undef __GLIBC_USE_DEPRECATED_GETS
/* Suppress kernel-name space pollution unless user expressedly asks
for it. */
@@ -125,13 +147,13 @@
# define __KERNEL_STRICT_NAMES
#endif
-/* Convenience macros to test the versions of glibc and gcc.
- Use them like this:
+/* Convenience macro to test the version of gcc.
+ Use like this:
#if __GNUC_PREREQ (2,8)
... code requiring gcc 2.8 or later ...
#endif
- Note - they won't work for gcc1 or glibc1, since the _MINOR macros
- were not defined then. */
+ Note: only works for GCC 2.0 and later, because __GNUC_MINOR__ was
+ added in 2.0. */
#if defined __GNUC__ && defined __GNUC_MINOR__
# define __GNUC_PREREQ(maj, min) \
((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
@@ -139,6 +161,20 @@
# define __GNUC_PREREQ(maj, min) 0
#endif
+/* Similarly for clang. Features added to GCC after version 4.2 may
+ or may not also be available in clang, and clang's definitions of
+ __GNUC(_MINOR)__ are fixed at 4 and 2 respectively. Not all such
+ features can be queried via __has_extension/__has_feature. */
+#if defined __clang_major__ && defined __clang_minor__
+# define __glibc_clang_prereq(maj, min) \
+ ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
+#else
+# define __glibc_clang_prereq(maj, min) 0
+#endif
+
+/* Whether to use feature set F. */
+#define __GLIBC_USE(F) __GLIBC_USE_ ## F
+
/* _BSD_SOURCE and _SVID_SOURCE are deprecated aliases for
_DEFAULT_SOURCE. If _DEFAULT_SOURCE is present we do not
issue a warning; the expectation is that the source is being
@@ -178,7 +214,7 @@
define _DEFAULT_SOURCE. */
#if (defined _DEFAULT_SOURCE \
|| (!defined __STRICT_ANSI__ \
- && !defined _ISOC99_SOURCE \
+ && !defined _ISOC99_SOURCE && !defined _ISOC11_SOURCE \
&& !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE \
&& !defined _XOPEN_SOURCE))
# undef _DEFAULT_SOURCE
@@ -203,13 +239,17 @@
# define __USE_ISOC95 1
#endif
+#ifdef __cplusplus
+/* This is to enable compatibility for ISO C++17. */
+# if __cplusplus >= 201703L
+# define __USE_ISOC11 1
+# endif
/* This is to enable compatibility for ISO C++11.
-
- So far g++ does not provide a macro. Check the temporary macro for
- now, too. */
-#if ((defined __cplusplus && __cplusplus >= 201103L) \
- || defined __GXX_EXPERIMENTAL_CXX0X__)
-# define __USE_ISOCXX11 1
+ Check the temporary macro for now, too. */
+# if __cplusplus >= 201103L || defined __GXX_EXPERIMENTAL_CXX0X__
+# define __USE_ISOCXX11 1
+# define __USE_ISOC99 1
+# endif
#endif
/* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE
@@ -224,6 +264,7 @@
# 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)
@@ -240,6 +281,19 @@
# 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)
@@ -322,10 +376,6 @@
# 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)
@@ -341,6 +391,16 @@
# define __USE_FORTIFY_LEVEL 0
#endif
+/* The function 'gets' existed in C89, but is impossible to use
+ safely. It has been removed from ISO C11 and ISO C++14. Note: for
+ compatibility with various implementations of <cstdio>, this test
+ must consider only the value of __cplusplus when compiling C++. */
+#if defined __cplusplus ? __cplusplus >= 201402L : defined __USE_ISOC11
+# define __GLIBC_USE_DEPRECATED_GETS 0
+#else
+# define __GLIBC_USE_DEPRECATED_GETS 1
+#endif
+
/* Get definitions of __STDC_* predefined macros, if the compiler has
not preincluded this header automatically. */
#include <stdc-predef.h>
@@ -357,7 +417,7 @@
/* Major and minor version number of the GNU C library package. Use
these macros to test for features in specific releases. */
#define __GLIBC__ 2
-#define __GLIBC_MINOR__ 23
+#define __GLIBC_MINOR__ 28
#define __GLIBC_PREREQ(maj, min) \
((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))