1
0
mirror of https://sourceware.org/git/glibc.git synced 2025-11-30 11:41:39 +03:00
Files
glibc/assert/assert.h
Joseph Myers e535fb910c Define C23 header version macros
C23 defines library macros __STDC_VERSION_<header>_H__ to indicate
that a header has support for new / changed features from C23.  Now
that all the required library features are implemented in glibc,
define these macros.  I'm not sure this is sufficiently much of a
user-visible feature to be worth a mention in NEWS.

Tested for x86_64.

There are various optional C23 features we don't yet have, of which I
might look at the Annex H ones (floating-point encoding conversion
functions and _Float16 functions) next.

* Optional time bases TIME_MONOTONIC, TIME_ACTIVE, TIME_THREAD_ACTIVE.
  See
  <https://sourceware.org/pipermail/libc-alpha/2023-June/149264.html>
  - we need to review / update that patch.  (I think patch 2/2,
  inventing new names for all the nonstandard CLOCK_* supported by the
  Linux kernel, is rather more dubious.)

* Updating conform/ tests for C23.

* Defining the rounding mode macro FE_TONEARESTFROMZERO for RISC-V (as
  far as I know, the only architecture supported by glibc that has
  hardware support for this rounding mode for binary floating point)
  and supporting it throughout glibc and its tests (especially the
  string/numeric conversions in both directions that explicitly handle
  each possible rounding mode, and various tests that do likewise).

* Annex H floating-point encoding conversion functions.  (It's not
  entirely clear which are optional even given support for Annex H;
  there's some wording applied inconsistently about only being
  required when non-arithmetic interchange formats are supported; see
  the comments I raised on the WG14 reflector on 23 Oct 2025.)

* _Float16 functions (and other header and testcase support for this
  type).

* Decimal floating-point support.

* Fully supporting __int128 and unsigned __int128 as integer types
  wider than intmax_t, as permitted by C23.  Would need doing in
  coordination with GCC, see GCC bug 113887 for more discussion of
  what's involved.
2025-11-27 19:32:49 +00:00

209 lines
6.7 KiB
C

/* Copyright (C) 1991-2025 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
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/*
* ISO C99 Standard: 7.2 Diagnostics <assert.h>
*/
#ifdef _ASSERT_H
# undef _ASSERT_H
# undef assert
# undef __ASSERT_VOID_CAST
# ifdef __USE_GNU
# undef assert_perror
# endif
#endif /* assert.h */
#define _ASSERT_H 1
#include <features.h>
#if __GLIBC_USE (ISOC23)
# ifndef __STDC_VERSION_ASSERT_H__
# define __STDC_VERSION_ASSERT_H__ 202311L
# endif
#endif
#if defined __cplusplus && __GNUC_PREREQ (2,95)
# define __ASSERT_VOID_CAST static_cast<void>
#else
# define __ASSERT_VOID_CAST (void)
#endif
/* C23 makes assert a variadic macro so that expressions with a comma
not between parentheses, but that would still be valid as a single
function argument, such as those involving compound literals with a
comma in the initializer list, can be passed to assert. This
depends on support for variadic macros (added in C99 and GCC 2.95),
and on support for _Bool (added in C99 and GCC 3.0) in order to
validate that only a single expression is passed as an argument,
and is currently implemented only for C. */
#if (__GLIBC_USE (ISOC23) \
&& (defined __GNUC__ \
? __GNUC_PREREQ (3, 0) \
: defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L) \
&& !defined __cplusplus)
# define __ASSERT_VARIADIC 1
#else
# define __ASSERT_VARIADIC 0
#endif
/* void assert (int expression);
If NDEBUG is defined, do nothing.
If not, and EXPRESSION is zero, print an error message and abort. */
#ifdef NDEBUG
# if __ASSERT_VARIADIC
# define assert(...) (__ASSERT_VOID_CAST (0))
# else
# define assert(expr) (__ASSERT_VOID_CAST (0))
# endif
/* void assert_perror (int errnum);
If NDEBUG is defined, do nothing. If not, and ERRNUM is not zero, print an
error message with the error text for ERRNUM and abort.
(This is a GNU extension.) */
# ifdef __USE_GNU
# define assert_perror(errnum) (__ASSERT_VOID_CAST (0))
# endif
#else /* Not NDEBUG. */
__BEGIN_DECLS
/* This prints an "Assertion failed" message and aborts. */
extern void __assert_fail (const char *__assertion, const char *__file,
unsigned int __line, const char *__function)
__THROW __attribute__ ((__noreturn__)) __COLD;
/* Likewise, but prints the error text for ERRNUM. */
extern void __assert_perror_fail (int __errnum, const char *__file,
unsigned int __line, const char *__function)
__THROW __attribute__ ((__noreturn__)) __COLD;
/* The following is not at all used here but needed for standard
compliance. */
extern void __assert (const char *__assertion, const char *__file, int __line)
__THROW __attribute__ ((__noreturn__)) __COLD;
# if __ASSERT_VARIADIC
/* This function is not defined and is not called outside of an
unevaluated sizeof, but serves to verify that the argument to
assert is a single expression. */
extern _Bool __assert_single_arg (_Bool);
# endif
__END_DECLS
/* When possible, define assert so that it does not add extra
parentheses around EXPR. Otherwise, those added parentheses would
suppress warnings we'd expect to be detected by gcc's -Wparentheses. */
# if defined __cplusplus
# if defined __has_builtin
# if __has_builtin (__builtin_FILE)
# define __ASSERT_FILE __builtin_FILE ()
# define __ASSERT_LINE __builtin_LINE ()
# endif
# endif
# if !defined __ASSERT_FILE
# define __ASSERT_FILE __FILE__
# define __ASSERT_LINE __LINE__
# endif
# define assert(expr) \
(static_cast <bool> (expr) \
? void (0) \
: __assert_fail (#expr, __ASSERT_FILE, __ASSERT_LINE, \
__ASSERT_FUNCTION))
# elif !defined __GNUC__ || defined __STRICT_ANSI__
# if __ASSERT_VARIADIC
# define assert(...) \
(((void) sizeof (__assert_single_arg (__VA_ARGS__)), __VA_ARGS__) \
? __ASSERT_VOID_CAST (0) \
: __assert_fail (#__VA_ARGS__, __FILE__, __LINE__, __ASSERT_FUNCTION))
# else
# define assert(expr) \
((expr) \
? __ASSERT_VOID_CAST (0) \
: __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION))
# endif
# else
# if __ASSERT_VARIADIC
# define assert(...) \
((void) sizeof (__assert_single_arg (__VA_ARGS__)), __extension__ ({ \
if (__VA_ARGS__) \
; /* empty */ \
else \
__assert_fail (#__VA_ARGS__, __FILE__, __LINE__, __ASSERT_FUNCTION); \
}))
# else
/* The first occurrence of EXPR is not evaluated due to the sizeof,
but will trigger any pedantic warnings masked by the __extension__
for the second occurrence. The ternary operator is required to
support function pointers and bit fields in this context, and to
suppress the evaluation of variable length arrays. */
# define assert(expr) \
((void) sizeof ((expr) ? 1 : 0), __extension__ ({ \
if (expr) \
; /* empty */ \
else \
__assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION); \
}))
# endif
# endif
# ifdef __USE_GNU
# define assert_perror(errnum) \
(!(errnum) \
? __ASSERT_VOID_CAST (0) \
: __assert_perror_fail ((errnum), __FILE__, __LINE__, __ASSERT_FUNCTION))
# endif
/* Version 2.4 and later of GCC define a magical variable `__PRETTY_FUNCTION__'
which contains the name of the function currently being defined.
This is broken in G++ before version 2.6.
C9x has a similar variable called __func__, but prefer the GCC one since
it demangles C++ function names. */
# if defined __cplusplus ? __GNUC_PREREQ (2, 6) : __GNUC_PREREQ (2, 4)
# define __ASSERT_FUNCTION __extension__ __PRETTY_FUNCTION__
# else
# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
# define __ASSERT_FUNCTION __func__
# else
# define __ASSERT_FUNCTION ((const char *) 0)
# endif
# endif
#endif /* NDEBUG. */
#if (defined __USE_ISOC11 \
&& (!defined __STDC_VERSION__ \
|| __STDC_VERSION__ <= 201710L \
|| !__GNUC_PREREQ (13, 0)) \
&& !defined __cplusplus)
# undef static_assert
# define static_assert _Static_assert
#endif