CVS commit: src/tools/compat

["Luke Mewburn" <lukem%netbsd.org@localhost>]

Module Name:    src
Committed By:   lukem
Date:           Tue May 30 18:39:19 UTC 2023

Modified Files:
        src/tools/compat: configure.ac defs.mk.in

Log Message:
tools/compat: detect supported host compiler flags

Define NB_CC_FLAG(FLAG) to use AX_CHECK_COMPILE_FLAG
to determine if the host compiler supports FLAG
and define and AC_SUBST CC_FLAG if so.

Use workarounds to force clang to hard-fail on unknown -Wwarning,
and gcc to use -WWARN to check unknown -Wno-WARN because the
latter doesn't cause an error in gcc.

In the future we could use NB_CC_FLAG([-fcommon]) for
older NetBSD release branches compiled with host gcc 10+.

Rework Darwin -no-cpp-precomp check to use NB_CC_FLAG().
Note: this flag probably hasn't been required on macOS (Darwin)
for a long time, but serves as a good example on how to use this.

Display varaibles at the end of configure to show what was detected.


To generate a diff of this commit:
cvs rdiff -u -r1.102 -r1.103 src/tools/compat/configure.ac
cvs rdiff -u -r1.13 -r1.14 src/tools/compat/defs.mk.in

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.