stdlib/vsnprintf.c

   1 /*
   2  * vsnprintf()
   3  *
   4  * Poor substitute for a real vsnprintf() function for systems
   5  * that don't have them...
   6  */
   7
   8 #include "compiler.h"
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <stdarg.h>
  13 #include <string.h>
  14
  15 #include "nasmlib.h"
  16
  17 #if !defined(HAVE_VSNPRINTF) && !defined(HAVE__VSNPRINTF)
  18
  19 #define BUFFER_SIZE     65536   /* Bigger than any string we might print... */
  20
  21 static char snprintf_buffer[BUFFER_SIZE];
  22
  23 int vsnprintf(char *str, size_t size, const char *format, va_list ap)
  24 {
  25     int rv, bytes;
  26
  27     if (size > BUFFER_SIZE) {
  28         nasm_panic(ERR_NOFILE,
  29                    "vsnprintf: size (%d) > BUFFER_SIZE (%d)",
  30                    size, BUFFER_SIZE);
  31         size = BUFFER_SIZE;
  32     }
  33
  34     rv = vsprintf(snprintf_buffer, format, ap);
  35     if (rv >= BUFFER_SIZE)
  36         nasm_panic(ERR_NOFILE, "vsnprintf buffer overflow");
  37
  38     if (size > 0) {
  39         if ((size_t)rv < size-1)
  40             bytes = rv;
  41         else
  42             bytes = size-1;
  43         memcpy(str, snprintf_buffer, bytes);
  44         str[bytes] = '\0';
  45     }
  46
  47     return rv;
  48 }
  49
  50 #endif