libexplain/getc.h

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/*
 * libexplain - Explain errno values returned by libc functions
 * Copyright (C) 2008, 2009, 2013, 2014 Peter Miller
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 3 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef LIBEXPLAIN_GETC_H
#define LIBEXPLAIN_GETC_H

#include <libexplain/gcc_attributes.h>
#include <libexplain/large_file_support.h>

#include <stdio.h>

#ifdef __cplusplus
extern "C" {
#endif

/*
 * FIXME: need a better inline-availability test,
 * but the defines in libexplain/config.h (generated by the ./configure
 * script generated by GNU Autoconf) are not suitable for inclusion in
 * the client API because they have no LIBEXPLAIN_ namespace prefix.
 */
#if __GNUC__ >= 3 || defined(__clang__)

void explain_getc_or_die_failed(FILE *fp);
#endif

#if __GNUC__ >= 3 || defined(__clang__)
static __inline__
#endif
int explain_getc_or_die(FILE *fp)
#if __GNUC__ >= 3 || defined(__clang__)
__attribute__((always_inline))
#endif
;

#if __GNUC__ >= 3 || defined(__clang__)

static __inline__ int
explain_getc_or_die(FILE *fp)
{
    /*
     * By using inline, the users dosn't have to pay a one-function-
     * call-per-character penalty for using libexplain, because getc is
     * usually a macro or an inline that only calls underflow when the
     * buffer is exhausted.
     */
    int c = getc(fp);
    if (c == EOF && ferror(fp))
        explain_getc_or_die_failed(fp);
    return c;
}

#endif

int explain_getc_on_error(FILE *fp)
                                                  LIBEXPLAIN_WARN_UNUSED_RESULT;

const char *explain_getc(FILE *fp)
                                                  LIBEXPLAIN_WARN_UNUSED_RESULT;

const char *explain_errno_getc(int errnum, FILE *fp)
                                                  LIBEXPLAIN_WARN_UNUSED_RESULT;

void explain_message_getc(char *message, int message_size, FILE *fp);

void explain_message_errno_getc(char *message, int message_size, int errnum,
    FILE *fp);

#ifdef __cplusplus
}
#endif

/* vim: set ts=8 sw=4 et : */
#endif /* LIBEXPLAIN_GETC_H */