Hi Paul, Paul Eggert wrote: > > Thanks; I installed the attached somewhat fancier patch into Gnulib. > > ... and then installed the attach further patch to fix a thinko in the > previously-mentioned one.
These changes have the effect that even on glibc systems, gnulib's regex code is now used instead of glibc's. This is what happens at configure time: configure:29480: checking for working re_compile_pattern configure:29802: clang -fsanitize=address,undefined,signed-integer-overflow,shift,integer-divide-by-zero -fno-sanitize-recover=undefined -o conftest -O0 -fno-omit-frame-pointer -ggdb -Wall -Wthread-safety conftest.c >&5 conftest.c:207:15: error: "RE_SYNTAX_EMACS does not match Emacs behavior" 207 | # error "RE_SYNTAX_EMACS does not match Emacs behavior" | ^ And, in fact, this is not necessary, because - Application code sees the gnulib regex.h (due to -I options). Things would be different if the 'regex' module would be using a regex.in.h from which a regex.h is conditionally generated. But the way things are, gnulib regex.h is used unconditionally. - Nothing in the reg*.c files uses RE_SYNTAX_EMACS. It is just added baggage for applications. I therefore suggest to revert the changes to m4/regex.m4. Bruno