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 #include "error.h"
  17
  18 #if !defined(HAVE_VSNPRINTF) && !defined(HAVE__VSNPRINTF)
  19
  20 #define BUFFER_SIZE     65536   /* Bigger than any string we might print... */
  21
  22 static char snprintf_buffer[BUFFER_SIZE];
  23
  24 int vsnprintf(char *str, size_t size, const char *format, va_list ap)
  25 {
  26     int rv, bytes;
  27
  28     if (size > BUFFER_SIZE) {
  29         nasm_panic(ERR_NOFILE,
  30                    "vsnprintf: size (%d) > BUFFER_SIZE (%d)",
  31                    size, BUFFER_SIZE);
  32         size = BUFFER_SIZE;
  33     }
  34
  35     rv = vsprintf(snprintf_buffer, format, ap);
  36     if (rv >= BUFFER_SIZE)
  37         nasm_panic(ERR_NOFILE, "vsnprintf buffer overflow");
  38
  39     if (size > 0) {
  40         if ((size_t)rv < size-1)
  41             bytes = rv;
  42         else
  43             bytes = size-1;
  44         memcpy(str, snprintf_buffer, bytes);
  45         str[bytes] = '\0';
  46     }
  47
  48     return rv;
  49 }
  50
  51 #endif