exerror.c

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/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
 
/*
 * Glenn Fowler
 * AT&T Research
 *
 * expression library
 */
 
#include <assert.h>
#include <cgraph/exit.h>
#include <expr/exlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
/*
 * library error handler
 */
 
static char *make_msg(const char *format, va_list ap) {
 
  // retrieve buffered message
  char buf[64];
  excontext(expr.program, buf, sizeof(buf));
 
  // how many bytes do we need to construct the message?
  size_t len = (size_t)snprintf(NULL, 0, "%s\n -- ", buf);
  {
    va_list ap2;
    va_copy(ap2, ap);
    int r = vsnprintf(NULL, 0, format, ap2);
    va_end(ap2);
    if (r < 0) {
      return strdup("malformed format");
    }
    len += (size_t)r + 1; // +1 for NUL
  }
 
  char *s = malloc(len);
  if (s == NULL) {
    return NULL;
  }
 
  int offset = snprintf(s, len, "%s\n -- ", buf);
  assert(offset > 0);
  vsnprintf(s + offset, len - (size_t)offset, format, ap);
 
  return s;
}
 
void
exerror(const char* format, ...)
{
        if (expr.program->disc->errorf && !expr.program->errors)
        {
                va_list ap;
 
                expr.program->errors = 1;
                va_start(ap, format);
                char *s = make_msg(format, ap);
                va_end(ap);
                expr.program->disc->errorf(expr.program, expr.program->disc, 2, "%s",
                  s ? s : "out of space");
    free(s);
        }
}
 
void 
exwarn(const char *format, ...)
{
        if (expr.program->disc->errorf) {
                va_list ap;
 
                va_start(ap, format);
                char *s = make_msg(format, ap);
                va_end(ap);
                expr.program->disc->errorf(expr.program, expr.program->disc,
                                       ERROR_WARNING, "%s", s ? s : "out of space");
                free(s);
        }
}