AX_CC_ATTRCOMMON
Determine whether the C compiler supports C tentative definitions with __attribute((__common__)) See K&R book Appendix A10.2 on ’extern’ and tentative definitions. Some compilers use a ’strict definition-reference model’ Traditionally most UNIX C compilers support C tentative definitions. GCC 10 switched from default fcommon to fnocommon and will need __attribute__ ((__common__)) for tentative definitions.
The $ac_cv_attrcommon variable will be either yes or no, and can be overridden on the command line with using –with-attrcommon
See also: ax_cc_tentdef.m4 for a test on C tentative definitions
Download the latest version of ax_cc_attrcommon.m4 or browse the macro’s revision history.
Copyright © 1996-2023 David Stes
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>.