traceenv.c

distcc编译器的源代码.好像是readhat公司开发的.

/* -*- c-file-style: "java"; indent-tabs-mode: nil -*-
 * 
 * distcc -- A simple distributed compiler system
 *
 * Copyright (C) 2002, 2003 by Martin Pool <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */


#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>

#include "distcc.h"
#include "trace.h"
#include "exitcode.h"
#include "util.h"


/**
 * Setup client error/trace output.
 *
 * Trace goes to the file specified by DISTCC_LOG, if any.  Otherwise, it goes
 * to stderr, except that UNCACHED_ERR_FD can redirect it elsewhere, for use
 * under ccache.
 *
 * The exact setting of log level is a little strange, but for a good
 * reason: if you ask for verbose, you get everything.  Otherwise, if
 * you set a file, you get INFO and above.  Otherwise, you only get
 * WARNING messages.  In practice this seems to be a nice balance.
 **/
void dcc_set_trace_from_env(void)
{
    const char *logfile, *logfd_name;
    int fd;

    if ((logfile = getenv("DISTCC_LOG")) && logfile[0]) {
        rs_trace_set_level(RS_LOG_INFO);

        fd = open(logfile, O_WRONLY|O_APPEND|O_CREAT, 0666);
        if (fd == -1) {
            /* use stderr instead */
            int save_errno = errno;
            
            rs_trace_set_level(RS_LOG_WARNING);
            rs_add_logger(rs_logger_file, RS_LOG_DEBUG, NULL, STDERR_FILENO);

            rs_log_error("failed to open logfile %s: %s",
                         logfile, strerror(save_errno));
        } else {
            rs_add_logger(rs_logger_file, RS_LOG_DEBUG, NULL, fd);
            rs_trace_set_level(RS_LOG_INFO);
        }
    } else {
        if ((logfd_name = getenv("UNCACHED_ERR_FD")) == NULL ||
            (fd = atoi(logfd_name)) == 0) {
            fd = STDERR_FILENO;
        }
            
        rs_trace_set_level(RS_LOG_WARNING);
        rs_add_logger(rs_logger_file, RS_LOG_DEBUG, NULL, fd);
    }

    if (dcc_getenv_bool("DISTCC_VERBOSE", 0)) {
        rs_trace_set_level(RS_LOG_DEBUG);
    }
}