Trim down libcompat by removing <regexp.h>.

Erwin ran an exp-run with libcompat and <regexp.h> removed. It turns out
the regexp library is almost entirely unused. In fact, it looks like it
is sometimes used by accident. Because these function names clash with
libc's <regex.h>, some application use both <regex.h> and libcompat,
which means they link against the wrong regex library.

This commit removes the regexp library and reimplements re_comp() and
re_exec() using <regex.h>. It seems the grammar of the regular
expressions accepted by these functions is similar to POSIX EREs.

After this commit, 1 low-profile port will be broken, but the maintainer
already has a patch for it sitting in his mailbox.

2 files changed, 1 insertions, 71 deletions

diff --git a/include/Makefile b/include/Makefile
index 509bd47..96690ad 100644
--- a/include/Makefile
+++ b/include/Makefile
@@ -17,7 +17,7 @@ INCS=	a.out.h ar.h assert.h bitstring.h complex.h cpio.h _ctype.h ctype.h \
 	ndbm.h netconfig.h \
 	netdb.h nl_types.h nlist.h nss.h nsswitch.h paths.h \
 	printf.h proc_service.h pthread.h \
-	pthread_np.h pwd.h ranlib.h readpassphrase.h regex.h regexp.h \
+	pthread_np.h pwd.h ranlib.h readpassphrase.h regex.h \
 	res_update.h resolv.h runetype.h search.h semaphore.h setjmp.h \
 	signal.h spawn.h stab.h \
 	stdbool.h stddef.h stdio.h stdlib.h string.h stringlist.h \
diff --git a/include/regexp.h b/include/regexp.h
deleted file mode 100644
index 39cdf3a..0000000
--- a/include/regexp.h
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright (c) 1986 by University of Toronto.
- * Copyright (c) 1989, 1993
- *	The Regents of the University of California.  All rights reserved.
- *
- * This code is derived from software contributed to Berkeley
- * by Henry Spencer.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- *	@(#)regexp.h	8.1 (Berkeley) 6/2/93
- * $FreeBSD$
- */
-
-#ifndef	_REGEXP_H_
-#define	_REGEXP_H_
-
-#ifdef __GNUC__
-#warning "this file includes <regexp.h> which is deprecated, use <regex.h> instead"
-#endif
-
-/*
- * Definitions etc. for regexp(3) routines.
- *
- * Caveat:  this is V8 regexp(3) [actually, a reimplementation thereof],
- * not the System V one.
- */
-#define NSUBEXP  10
-typedef struct regexp {
-	char *startp[NSUBEXP];
-	char *endp[NSUBEXP];
-	char regstart;		/* Internal use only. */
-	char reganch;		/* Internal use only. */
-	char *regmust;		/* Internal use only. */
-	int regmlen;		/* Internal use only. */
-	char program[1];	/* Unwarranted chumminess with compiler. */
-} regexp;
-
-#include <sys/cdefs.h>
-
-__BEGIN_DECLS
-regexp *regcomp(const char *);
-int regexec(const  regexp *, const char *);
-void regsub(const  regexp *, const char *, char *);
-void regerror(const char *);
-__END_DECLS
-
-#endif /* !_REGEXP_H_ */