Paul Eggert wrote:
> + AS_CASE([$gl_threads_api@$gl_use_threads@$gl_have_isoc_threads],
Three-dimensional pattern matching is more powerful than a sequence
of one-dimensional 'test' statements. But it's harder to understand.
Therefore, if we don't need it, I prefer the logically simpler one-
dimensional tests.
$ grep -rn 'AS_CASE[^]]*[$][^]]*[$]' *.m4
acl.m4:199:
AS_CASE([$enable_acl,$with_libsmack,$ac_cv_header_linux_xattr_h,$ac_cv_func_listxattr],
acl.m4:216:
AS_CASE([$enable_acl,$with_selinux,$ac_cv_header_linux_xattr_h,$ac_cv_func_listxattr],
acl.m4:224:
AS_CASE([$enable_acl,$gl_file_has_acl_uses_selinux,$gl_file_has_acl_uses_smack],
realloc.m4:80:
[AS_CASE([$gl_cv_func_realloc_sanitize,$gl_cv_malloc_ptrdiff,$gl_cv_func_malloc_posix,$host],
threadlib.m4:567:
AS_CASE([$gl_threads_api@$gl_use_threads@$gl_have_isoc_threads],
I'm fixing the case of threadlib.m4 only, at this point.
2025-04-28 Bruno Haible <br...@clisp.org>
threadlib: Avoid multi-dimensional pattern matching.
* m4/threadlib.m4: Change multi-dimensional AS_CASE back to several
one-dimensional tests.
diff --git a/m4/threadlib.m4 b/m4/threadlib.m4
index 37def278f6..85da2e6175 100644
--- a/m4/threadlib.m4
+++ b/m4/threadlib.m4
@@ -529,7 +529,7 @@ AC_DEFUN([gl_THREADLIB_BODY]
AS_IF([test $gl_pthread_api = yes], [
AS_IF([test "$gl_use_threads" = isoc+posix &&
test "$gl_have_isoc_threads" = yes], [
- gl_threads_api=isoc+posix
+ gl_threads_api="isoc+posix"
AC_DEFINE([USE_ISOC_AND_POSIX_THREADS], [1],
[Define if the combination of the ISO C and POSIX multithreading
APIs can be used.])
LIBTHREAD= LTLIBTHREAD=
@@ -564,16 +564,16 @@ AC_DEFUN([gl_THREADLIB_BODY]
])
])
])
- AS_CASE([$gl_threads_api@$gl_use_threads@$gl_have_isoc_threads],
- [none@isoc@yes],
- [
+ AS_IF([test $gl_threads_api = none], [
+ AS_IF([test "$gl_use_threads" = isoc && test "$gl_have_isoc_threads" =
yes], [
gl_STDTHREADLIB_BODY
LIBTHREAD=$LIBSTDTHREAD LTLIBTHREAD=$LIBSTDTHREAD
LIBMULTITHREAD=$LIBSTDTHREAD LTLIBMULTITHREAD=$LIBSTDTHREAD
gl_threads_api=isoc
AC_DEFINE([USE_ISOC_THREADS], [1],
[Define if the ISO C multithreading library can be used.])
- ])
+ ])
+ ])
AS_IF([test $gl_threads_api = none], [
# The "win32" is for backward compatibility.
AS_CASE([$gl_use_threads],
