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AX_CC_ATTRCOMMON
Determine whether the C compiler supports C tentative defintions 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
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