/* error.c -- error handler for noninteractive utilities
   Copyright (C) 1990-1992 Free Software Foundation, Inc.

   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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* David MacKenzie */
/* Brian Berliner added support for CVS */

#include "cvs.h"

#include <stdio.h>

/* If non-zero, error will use the CVS protocol to stdout to report error
   messages.  This will only be set in the CVS server parent process;
   most other code is run via do_cvs_command, which forks off a child
   process and packages up its stderr in the protocol.  */
int error_use_protocol; 

#ifdef HAVE_VPRINTF

#if __STDC__
#include <stdarg.h>
#define VA_START(args, lastarg) va_start(args, lastarg)
#else /* ! __STDC__ */
#include <varargs.h>
#define VA_START(args, lastarg) va_start(args)
#endif /* __STDC__ */

#else /* ! HAVE_VPRINTF */ 

#ifdef HAVE_DOPRNT
#define va_alist args
#define va_dcl int args;
#else /* ! HAVE_DOPRNT */
#define va_alist a1, a2, a3, a4, a5, a6, a7, a8
#define va_dcl char *a1, *a2, *a3, *a4, *a5, *a6, *a7, *a8;
#endif /* HAVE_DOPRNT */

#endif /* HAVE_VPRINTF */ 

#if STDC_HEADERS
#include <stdlib.h>
#include <string.h>
#else /* ! STDC_HEADERS */
#if __STDC__
void exit(int status);
#else /* ! __STDC__ */
void exit ();
#endif /* __STDC__ */
#endif /* STDC_HEADERS */

extern char *strerror ();

extern int vasprintf ();

typedef void (*fn_returning_void) PROTO((void));

/* Function to call before exiting.  */
static fn_returning_void cleanup_fn;

fn_returning_void
error_set_cleanup (arg)
     fn_returning_void arg;
{
    fn_returning_void retval = cleanup_fn;
    cleanup_fn = arg;
    return retval;
}

/* Print the program name and error message MESSAGE, which is a printf-style
   format string with optional args.
   If ERRNUM is nonzero, print its corresponding system error message.
   Exit with status EXIT_FAILURE if STATUS is nonzero.  */
/* VARARGS */
void
#if defined (HAVE_VPRINTF) && __STDC__
error (int status, int errnum, const char *message, ...)
#else
error (status, errnum, message, va_alist)
    int status;
    int errnum;
    const char *message;
    va_dcl
#endif
{
    FILE *out = stderr;
#ifdef HAVE_VPRINTF
    va_list args;
#endif

    if (error_use_protocol)
    {
	out = stdout;
	printf ("E ");
    }

#ifdef HAVE_VPRINTF
    {
	char *mess = NULL;
	char *entire;
	size_t len;

	VA_START (args, message);
	vasprintf (&mess, message, args);
	va_end (args);

	if (mess == NULL)
	{
	    entire = NULL;
	    status = 1;
	}
	else
	{
	    len = strlen (mess) + strlen (program_name) + 80;
	    if (command_name != NULL)
		len += strlen (command_name);
	    if (errnum != 0)
		len += strlen (strerror (errnum));
	    entire = malloc (len);
	    if (entire == NULL)
	    {
		free (mess);
		status = 1;
	    }
	    else
	    {
		strcpy (entire, program_name);
		if (command_name != NULL && command_name[0] != '\0')
		{
		    strcat (entire, " ");
		    if (status != 0)
			strcat (entire, "[");
		    strcat (entire, command_name);
		    if (status != 0)
			strcat (entire, " aborted]");
		}
		strcat (entire, ": ");
		strcat (entire, mess);
		if (errnum != 0)
		{
		    strcat (entire, ": ");
		    strcat (entire, strerror (errnum));
		}
		strcat (entire, "\n");
		free (mess);
	    }
	}
	if (error_use_protocol)
	    fputs (entire ? entire : "out of memory", out);
	else
	    cvs_outerr (entire ? entire : "out of memory", 0);
	if (entire != NULL)
	    free (entire);
    }

#else /* No HAVE_VPRINTF */
    /* I think that all relevant systems have vprintf these days.  But
       just in case, I'm leaving this code here.  */

    if (command_name && *command_name)
    {
	if (status)
	    fprintf (out, "%s [%s aborted]: ", program_name, command_name);
	else
	    fprintf (out, "%s %s: ", program_name, command_name);
    }
    else
	fprintf (out, "%s: ", program_name);

#ifdef HAVE_VPRINTF
    VA_START (args, message);
    vfprintf (out, message, args);
    va_end (args);
#else
#ifdef HAVE_DOPRNT
    _doprnt (message, &args, out);
#else
    fprintf (out, message, a1, a2, a3, a4, a5, a6, a7, a8);
#endif
#endif
    if (errnum)
	fprintf (out, ": %s", strerror (errnum));
    putc ('\n', out);

#endif /* No HAVE_VPRINTF */

    /* In the error_use_protocol case, this probably does something useful.
       In most other cases, I suspect it is a noop (either stderr is line
       buffered or we haven't written anything to stderr) or unnecessary
       (if stderr is not line buffered, maybe there is a reason....).  */
    fflush (out);

    if (status)
    {
	if (cleanup_fn)
	    (*cleanup_fn) ();
	exit (EXIT_FAILURE);
    }
}

/* Print the program name and error message MESSAGE, which is a printf-style
   format string with optional args to the file specified by FP.
   If ERRNUM is nonzero, print its corresponding system error message.
   Exit with status EXIT_FAILURE if STATUS is nonzero.  */
/* VARARGS */
void
#if defined (HAVE_VPRINTF) && __STDC__
fperror (FILE *fp, int status, int errnum, char *message, ...)
#else
fperror (fp, status, errnum, message, va_alist)
    FILE *fp;
    int status;
    int errnum;
    char *message;
    va_dcl
#endif
{
#ifdef HAVE_VPRINTF
    va_list args;
#endif

    fprintf (fp, "%s: ", program_name);
#ifdef HAVE_VPRINTF
    VA_START (args, message);
    vfprintf (fp, message, args);
    va_end (args);
#else
#ifdef HAVE_DOPRNT
    _doprnt (message, &args, fp);
#else
    fprintf (fp, message, a1, a2, a3, a4, a5, a6, a7, a8);
#endif
#endif
    if (errnum)
	fprintf (fp, ": %s", strerror (errnum));
    putc ('\n', fp);
    fflush (fp);
    if (status)
    {
	if (cleanup_fn)
	    (*cleanup_fn) ();
	exit (EXIT_FAILURE);
    }
}