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Diffstat (limited to 'include/libc-diag.h')
| -rw-r--r-- | include/libc-diag.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/include/libc-diag.h b/include/libc-diag.h new file mode 100644 index 0000000000..db138c63b1 --- /dev/null +++ b/include/libc-diag.h @@ -0,0 +1,74 @@ +/* Macros for controlling diagnostic output from the compiler. + Copyright (C) 2014-2017 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 + <http://www.gnu.org/licenses/>. */ + +#ifndef _LIBC_DIAG_H +#define _LIBC_DIAG_H 1 + +/* Ignore the value of an expression when a cast to void does not + suffice (in particular, for a call to a function declared with + attribute warn_unused_result). */ +#define ignore_value(x) \ + ({ __typeof__ (x) __ignored_value = (x); (void) __ignored_value; }) + +/* The macros to control diagnostics are structured like this, rather + than a single macro that both pushes and pops diagnostic state and + takes the affected code as an argument, because the GCC pragmas + work by disabling the diagnostic for a range of source locations + and do not work when all the pragmas and the affected code are in a + single macro expansion. */ + +/* Push diagnostic state. */ +#define DIAG_PUSH_NEEDS_COMMENT _Pragma ("GCC diagnostic push") + +/* Pop diagnostic state. */ +#define DIAG_POP_NEEDS_COMMENT _Pragma ("GCC diagnostic pop") + +#define _DIAG_STR1(s) #s +#define _DIAG_STR(s) _DIAG_STR1(s) + +/* Ignore the diagnostic OPTION. VERSION is the most recent GCC + version for which the diagnostic has been confirmed to appear in + the absence of the pragma (in the form MAJOR.MINOR for GCC 4.x, + just MAJOR for GCC 5 and later). Uses of this pragma should be + reviewed when the GCC version given is no longer supported for + building glibc; the version number should always be on the same + source line as the macro name, so such uses can be found with grep. + Uses should come with a comment giving more details of the + diagnostic, and an architecture on which it is seen if possibly + optimization-related and not in architecture-specific code. This + macro should only be used if the diagnostic seems hard to fix (for + example, optimization-related false positives). */ +#define DIAG_IGNORE_NEEDS_COMMENT(version, option) \ + _Pragma (_DIAG_STR (GCC diagnostic ignored option)) + +/* Similar to DIAG_IGNORE_NEEDS_COMMENT the following macro ignores the + diagnostic OPTION but only if optimizations for size are enabled. + This is required because different warnings may be generated for + different optimization levels. For example a key piece of code may + only generate a warning when compiled at -Os, but at -O2 you could + still want the warning to be enabled to catch errors. In this case + you would use DIAG_IGNORE_Os_NEEDS_COMMENT to disable the warning + only for -Os. */ +#ifdef __OPTIMIZE_SIZE__ +# define DIAG_IGNORE_Os_NEEDS_COMMENT(version, option) \ + _Pragma (_DIAG_STR (GCC diagnostic ignored option)) +#else +# define DIAG_IGNORE_Os_NEEDS_COMMENT(version, option) +#endif + +#endif /* libc-diag.h */ |