/* $NetBSD: findcc.c,v 1.10 2021/08/20 06:36:10 rillig Exp $ */

/*-
* Copyright (c) 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matthias Scheler.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
#if !defined(lint)
__COPYRIGHT("@(#) Copyright (c) 1999 The NetBSD Foundation, Inc.\
All rights reserved.");
__RCSID("$NetBSD: findcc.c,v 1.10 2021/08/20 06:36:10 rillig Exp $");
#endif /* not lint */

#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "findcc.h"

char *
findcc(const char *progname)
{
       char *cc;
       const char *path, *dir;
       char buffer[MAXPATHLEN];
       size_t progname_len, dir_len;

       progname_len = strcspn(progname, " ");

       if (memchr(progname, '/', progname_len) != NULL) {
               if ((cc = strndup(progname, progname_len)) == NULL)
                       return NULL;
               if (access(cc, X_OK) == 0)
                       return cc;
               free(cc);
               return NULL;
       }

       if ((path = getenv("PATH")) == NULL)
               return NULL;

       for (dir = path; *dir != '\0'; ) {
               dir_len = strcspn(dir, ":");

               if ((size_t)snprintf(buffer, sizeof(buffer), "%.*s/%.*s",
                       (int)dir_len, dir, (int)progname_len, progname)
                   < sizeof(buffer)
                   && access(buffer, X_OK) == 0)
                       return strdup(buffer);

               dir += dir_len;
               if (*dir == ':')
                       dir++;
       }

       return NULL;
}