Use Gnulib regex for lib-src

Emacs regular expressions forked from everyone else long ago.
This makes it official and should allow simplification later.
etags.c now uses the glibc regex API, falling back on a
Gnulib-supplied substitute lib/regex.c if necessary.
Emacs proper now uses its own regular expression module.
Although this patch may look dauntingly large, most of it
was generated automatically by admin/merge-gnulib
and contains an exact copy of the glibc regex source,
and the by-hand changes do not grow the Emacs source code.
* admin/merge-gnulib (GNULIB_MODULES): Add regex.
(AVOIDED_MODULES): Add btowc, langinfo, lock, mbrtowc, mbsinit,
nl_langinfo, wchar, wcrtomb, wctype-h.
* lib-src/Makefile.in (regex-emacs.o): Remove; Gnulib does it now.
(etags_deps, etags_libs): Remove regex-emacs.o.
* lib-src/etags.c: Go back to including regex.h.
(add_regex): Use unsigned char translation array,
since glibc regex requires that.
* lib/Makefile.in (not_emacs_OBJECTS, for_emacs_OBJECTS): New macros.
(libegnu_a_OBJECTS): Use them, to avoid building e-regex.o.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/regcomp.c, lib/regex.c, lib/regex.h, lib/regex_internal.c:
* lib/regex_internal.h, lib/regexec.c, m4/builtin-expect.m4:
* m4/eealloc.m4, m4/glibc21.m4, m4/mbstate_t.m4, m4/regex.m4:
New files, copied from Gnulib.
* src/regex-emacs.h, src/conf_post.h:
(RE_TRANSLATE_TYPE, RE_TRANSLATE, RE_TRANSLATE_P):
Move from src/conf_post.h to src/regex-emacs.h,
so that they don’t interfere with compiling lib/regex.c.

1 files changed, 34 insertions, 0 deletions

diff --git a/m4/glibc21.m4 b/m4/glibc21.m4
new file mode 100644
index 00000000000..126aa1a959e
--- /dev/null
+++ b/m4/glibc21.m4
@@ -0,0 +1,34 @@
+# glibc21.m4 serial 5
+dnl Copyright (C) 2000-2002, 2004, 2008, 2010-2018 Free Software Foundation,
+dnl Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Test for the GNU C Library, version 2.1 or newer, or uClibc.
+# From Bruno Haible.
+
+AC_DEFUN([gl_GLIBC21],
+  [
+    AC_CACHE_CHECK([whether we are using the GNU C Library >= 2.1 or uClibc],
+      [ac_cv_gnu_library_2_1],
+      [AC_EGREP_CPP([Lucky],
+        [
+#include <features.h>
+#ifdef __GNU_LIBRARY__
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1) || (__GLIBC__ > 2)
+  Lucky GNU user
+ #endif
+#endif
+#ifdef __UCLIBC__
+ Lucky user
+#endif
+        ],
+        [ac_cv_gnu_library_2_1=yes],
+        [ac_cv_gnu_library_2_1=no])
+      ]
+    )
+    AC_SUBST([GLIBC21])
+    GLIBC21="$ac_cv_gnu_library_2_1"
+  ]
+)