CVS commit: src/usr.bin/m4

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

Module Name:    src
Committed By:   lukem
Date:           Wed May 24 21:58:19 UTC 2023

Modified Files:
        src/usr.bin/m4: gnum4.c

Log Message:
m4 -g: { and } aren't supported in patsubst() or regexp()

When running in -g (GNU m4) emulation, patsubst() and regexp()
use the GNU m4 emacs-like regexes as implemented by gnulib,
which don't support {..} intervals.
When converting a GNU m4 regex to a POSIX ERE, escape raw { and }.

Autoconf relies on the GNU m4 regex behaviour.

See:
- https://www.gnu.org/software/autoconf/manual/autoconf-2.69/html_node/Redefined-M4-Macros.html
- https://www.gnu.org/software/gnulib/manual/html_node/emacs-regular-expression-syntax.html

This fixes the tools/compat/configure regen.

PR toolchain/57431


To generate a diff of this commit:
cvs rdiff -u -r1.11 -r1.12 src/usr.bin/m4/gnum4.c

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