Implement -I option and M4PATH environment variable

7 files changed, 173 insertions, 14 deletions

diff --git a/usr.bin/m4/Makefile b/usr.bin/m4/Makefile
index b75b373c1ab..8c32123005c 100644
--- a/usr.bin/m4/Makefile
+++ b/usr.bin/m4/Makefile
@@ -1,11 +1,11 @@
-#	$OpenBSD: Makefile,v 1.3 1997/09/21 11:49:47 deraadt Exp $
+#	$OpenBSD: Makefile,v 1.4 1999/09/14 08:21:32 espie Exp $
 
 # -DEXTENDED 
 # 	if you want the paste & spaste macros.
 
 PROG=	m4
 CFLAGS+=-DEXTENDED
-SRCS=	eval.c expr.c look.c main.c misc.c
+SRCS=	eval.c expr.c look.c main.c misc.c gnum4.c
 MAN=	m4.1
 
 .include <bsd.prog.mk>
diff --git a/usr.bin/m4/eval.c b/usr.bin/m4/eval.c
index 6ada8da46b6..a83666a79fc 100644
--- a/usr.bin/m4/eval.c
+++ b/usr.bin/m4/eval.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: eval.c,v 1.14 1999/09/06 13:24:59 espie Exp $	*/
+/*	$OpenBSD: eval.c,v 1.15 1999/09/14 08:21:36 espie Exp $	*/
 /*	$NetBSD: eval.c,v 1.7 1996/11/10 21:21:29 pk Exp $	*/
 
 /*
@@ -41,7 +41,7 @@
 #if 0
 static char sccsid[] = "@(#)eval.c	8.2 (Berkeley) 4/27/95";
 #else
-static char rcsid[] = "$OpenBSD: eval.c,v 1.14 1999/09/06 13:24:59 espie Exp $";
+static char rcsid[] = "$OpenBSD: eval.c,v 1.15 1999/09/14 08:21:36 espie Exp $";
 #endif
 #endif /* not lint */
 
@@ -576,7 +576,7 @@ char *ifile;
 {
 	if (ilevel + 1 == MAXINP)
 		errx(1, "too many include files.");
-	if ((infile[ilevel + 1] = fopen(ifile, "r")) != NULL) {
+	if ((infile[ilevel + 1] = fopen_trypath(ifile)) != NULL) {
 		ilevel++;
 		bbase[ilevel] = bufbase = bp;
 		return (1);
diff --git a/usr.bin/m4/extern.h b/usr.bin/m4/extern.h
index 94908ff34f7..1d12c595f66 100644
--- a/usr.bin/m4/extern.h
+++ b/usr.bin/m4/extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: extern.h,v 1.8 1999/09/06 13:29:32 espie Exp $	*/
+/*	$OpenBSD: extern.h,v 1.9 1999/09/14 08:21:36 espie Exp $	*/
 /*	$NetBSD: extern.h,v 1.3 1996/01/13 23:25:24 pk Exp $	*/
 
 /*-
@@ -93,3 +93,7 @@ extern char *m4wraps;		/* m4wrap string default. */
 extern char *null;		/* as it says.. just a null. */
 extern char rquote[];		/* right quote character (') */
 extern char scommt[];		/* start character for comment */
+
+/* gnum4.c */
+extern FILE *fopen_trypath __P((const char *filename));
+extern void addtoincludepath __P((const char *dirname));
diff --git a/usr.bin/m4/gnum4.c b/usr.bin/m4/gnum4.c
new file mode 100644
index 00000000000..366a3bbc2e7
--- /dev/null
+++ b/usr.bin/m4/gnum4.c
@@ -0,0 +1,145 @@
+/* $OpenBSD: gnum4.c,v 1.1 1999/09/14 08:21:36 espie Exp $ */
+
+/*
+ * Copyright (c) 1999 Marc Espie
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+/* 
+ * functions needed to support gnu-m4 extensions, including a fake freezing
+ */
+
+#include <sys/param.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <err.h>
+#include "mdef.h"
+#include "stdd.h"
+#include "extern.h"
+
+/*
+ * Support for include path search
+ * First search in the the current directory.
+ * If not found, and the path is not absolute, include path kicks in.
+ * First, -I options, in the order found on the command line.
+ * Then M4PATH env variable
+ */
+
+struct path_entry {
+	char *name;
+	struct path_entry *next;
+} *first, *last;
+
+static struct path_entry *
+new_path_entry(dirname)
+	char *dirname;
+{
+	struct path_entry *n;
+
+	n = malloc(sizeof(struct path_entry));
+	if (!n)
+		errx(1, "out of memory");
+	n->name = strdup(dirname);
+	if (!n->name)
+		errx(1, "out of memory");
+	n->next = 0;
+	return n;
+}
+	
+void 
+addtoincludepath(dirname)
+	const char *dirname;
+{
+	struct path_entry *n;
+
+	n = new_path_entry(dirname);
+
+	if (last) {
+		last->next = n;
+		last = n;
+	}
+	else
+		last = first = n;
+}
+
+static void
+ensure_m4path()
+{
+	static int envpathdone = 0;
+	char *envpath;
+	char *sweep;
+	char *path;
+
+	if (envpathdone)
+		return;
+	envpathdone = TRUE;
+	envpath = getenv("M4PATH");
+	if (!envpath) 
+		return;
+	/* for portability: getenv result is read-only */
+	envpath = strdup(envpath);
+	if (!envpath)
+		errx(1, "out of memory");
+	for (sweep = envpath; 
+	    (path = strsep(&sweep, ":")) != NULL;)
+	    addtoincludepath(path);
+	free(envpath);
+}
+
+static
+FILE *
+dopath(const char *filename)
+{
+	char path[MAXPATHLEN];
+	struct path_entry *pe;
+	FILE *file;
+
+	for (pe = first; pe; pe = pe->next) {
+		snprintf(path, sizeof(path), "%s/%s", pe->name, filename);
+		if ((file = fopen(path, "r")) != 0)
+			return file;
+	}
+	return NULL;
+}
+
+FILE *
+fopen_trypath(filename)
+	const char *filename;
+{
+	FILE *f;
+
+	f = fopen(filename, "r");
+	if (f)
+		return f;
+	if (filename[0] == '/')
+		return NULL;
+
+	ensure_m4path();
+
+	return dopath(filename);
+}
+
+
+
diff --git a/usr.bin/m4/m4.1 b/usr.bin/m4/m4.1
index e0b541d0d44..c01f5fea377 100644
--- a/usr.bin/m4/m4.1
+++ b/usr.bin/m4/m4.1
@@ -1,4 +1,4 @@
-.\"	@(#) $OpenBSD: m4.1,v 1.6 1999/09/06 13:07:17 espie Exp $
+.\"	@(#) $OpenBSD: m4.1,v 1.7 1999/09/14 08:21:37 espie Exp $
 .\"
 .\"
 .Dd January 26, 1993
@@ -13,6 +13,7 @@
 .Fl D Ns Ar name Ns Op Ar =value
 .Oc
 .Op Fl U Ns Ar name
+.Op Fl I Ar dirname
 .Sh DESCRIPTION
 The
 .Nm m4
@@ -50,7 +51,10 @@ to have some value (or NULL).
 .It Fl "U" Ns Ar "name"
 Undefine the symbol
 .Ar name .
-.El
+.It Fl I Ar "dirname"
+Add directory 
+.Ar dirname
+to the include path.
 .Sh SYNTAX
 .Nm m4
 provides the following built-in macros.  They may be
@@ -120,6 +124,12 @@ zero or one arguments left, either this last argument or NULL is
 returned if no other matches were found.
 .It Ic include
 Returns the contents of the file specified in the first argument.
+If the file is not found as is, look through the include path:
+first the directories specified with
+.Fl I
+on the command line, then the environment variable
+.Va M4PATH ,
+as a colon-separated list of directories.
 Include aborts with an error message if the file cannot be included.
 .It Ic incr
 Increments the argument by 1.  The argument must be a valid numeric string.
diff --git a/usr.bin/m4/main.c b/usr.bin/m4/main.c
index a2a6b39d3df..d613c29d818 100644
--- a/usr.bin/m4/main.c
+++ b/usr.bin/m4/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.14 1999/09/06 13:29:32 espie Exp $	*/
+/*	$OpenBSD: main.c,v 1.15 1999/09/14 08:21:37 espie Exp $	*/
 /*	$NetBSD: main.c,v 1.12 1997/02/08 23:54:49 cgd Exp $	*/
 
 /*-
@@ -47,7 +47,7 @@ static char copyright[] =
 #if 0
 static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/6/93";
 #else
-static char rcsid[] = "$OpenBSD: main.c,v 1.14 1999/09/06 13:29:32 espie Exp $";
+static char rcsid[] = "$OpenBSD: main.c,v 1.15 1999/09/14 08:21:37 espie Exp $";
 #endif
 #endif /* not lint */
 
@@ -192,7 +192,7 @@ main(argc,argv)
 			p = *argv;
 			if (p[0] == '-' && p[1] == EOS)
 				ifp = stdin;
-			else if ((ifp = fopen(p, "r")) == NULL)
+			else if ((ifp = fopen_trypath(p)) == NULL)
 				err(1, "%s", p);
 			sp = -1;
 			fp = 0; 
diff --git a/usr.bin/m4/misc.c b/usr.bin/m4/misc.c
index b130293d6b2..568a1028cb6 100644
--- a/usr.bin/m4/misc.c
+++ b/usr.bin/m4/misc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: misc.c,v 1.10 1999/09/09 22:18:19 espie Exp $	*/
+/*	$OpenBSD: misc.c,v 1.11 1999/09/14 08:21:37 espie Exp $	*/
 /*	$NetBSD: misc.c,v 1.6 1995/09/28 05:37:41 tls Exp $	*/
 
 /*
@@ -41,7 +41,7 @@
 #if 0
 static char sccsid[] = "@(#)misc.c	8.1 (Berkeley) 6/6/93";
 #else
-static char rcsid[] = "$OpenBSD: misc.c,v 1.10 1999/09/09 22:18:19 espie Exp $";
+static char rcsid[] = "$OpenBSD: misc.c,v 1.11 1999/09/14 08:21:37 espie Exp $";
 #endif
 #endif /* not lint */
 
@@ -290,7 +290,7 @@ const char *s;
 void
 usage()
 {
-	fprintf(stderr, "usage: m4 [-Dname[=val]] [-Uname]\n");
+	fprintf(stderr, "usage: m4 [-Dname[=val]] [-Uname] [-I dirname...]\n");
 	exit(1);
 }