glibc/assert/assert.h
Joseph Myers b8cc607f3c Do not define static_assert or thread_local in headers for C2x
C2x makes static_assert and thread_local into keywords, removing the
definitions as macros in assert.h and threads.h.  Thus, disable those
macros in those glibc headers for C2x.

The disabling is done based on a combination of language version and
__GNUC_PREREQ, *not* based on __GLIBC_USE (ISOC2X), on the principle
that users of the header (when requesting C11 or later APIs - not
assert.h for C99 and older API versions) should always have the names
static_assert or thread_local available after inclusion of the header,
whether as a keyword or as a macro.  Thus, when using a compiler
without the keywords (whether an older compiler, possibly in C2x mode,
or _GNU_SOURCE with any compiler but in an older language mode, for
example) the macros should be defined, even when C2x APIs have been
requested.  The __GNUC_PREREQ conditionals here may well need updating
with the versions of other compilers that gained support for these
keywords in C2x mode.

Tested for x86_64.
2022-09-07 18:39:28 +00:00

146 lines
4.6 KiB
C

/* Copyright (C) 1991-2022 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 defined __cplusplus && __GNUC_PREREQ (2,95)
# define __ASSERT_VOID_CAST static_cast<void>
#else
# define __ASSERT_VOID_CAST (void)
#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
# define assert(expr) (__ASSERT_VOID_CAST (0))
/* 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__));
/* 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__));
/* 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__));
__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
# define assert(expr) \
(static_cast <bool> (expr) \
? void (0) \
: __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION))
# elif !defined __GNUC__ || defined __STRICT_ANSI__
# define assert(expr) \
((expr) \
? __ASSERT_VOID_CAST (0) \
: __assert_fail (#expr, __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
# 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