File: [local] / src / usr.bin / m4 / gnum4.c (download)
Revision 1.4, Wed Jan 12 17:49:53 2000 UTC (24 years, 5 months ago) by espie
Branch: MAIN
Changes since 1.3: +18 -14 lines
Use a proper abstract interface for file accesses, so that we can record
the file name and line number.
This yields more meaningful error messages, and the possibility for yet
more.
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/* $OpenBSD: gnum4.c,v 1.4 2000/01/12 17:49:53 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 __P((const char *));
static void ensure_m4path __P((void));
static struct input_file *dopath __P((struct input_file *, const char *));
static struct path_entry *
new_path_entry(dirname)
const 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
struct input_file *
dopath(i, filename)
struct input_file *i;
const char *filename;
{
char path[MAXPATHLEN];
struct path_entry *pe;
FILE *f;
for (pe = first; pe; pe = pe->next) {
snprintf(path, sizeof(path), "%s/%s", pe->name, filename);
if ((f = fopen(path, "r")) != 0) {
set_input(i, f, path);
return i;
}
}
return NULL;
}
struct input_file *
fopen_trypath(i, filename)
struct input_file *i;
const char *filename;
{
FILE *f;
f = fopen(filename, "r");
if (f != NULL) {
set_input(i, f, filename);
return i;
}
if (filename[0] == '/')
return NULL;
ensure_m4path();
return dopath(i, filename);
}