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
  11 #include "nasmlib.h"
  12 #include "error.h"
  13
  14 #if !defined(HAVE_VSNPRINTF) && !defined(HAVE__VSNPRINTF)
  15
  16 #define BUFFER_SIZE     65536   /* Bigger than any string we might print... */
  17
  18 static char snprintf_buffer[BUFFER_SIZE];
  19
  20 int vsnprintf(char *str, size_t size, const char *format, va_list ap)
  21 {
  22     int rv, bytes;
  23
  24     if (size > BUFFER_SIZE) {
  25         nasm_panic("vsnprintf: size (%d) > BUFFER_SIZE (%d)",
  26                    size, BUFFER_SIZE);
  27         size = BUFFER_SIZE;
  28     }
  29
  30     rv = vsprintf(snprintf_buffer, format, ap);
  31     if (rv >= BUFFER_SIZE)
  32         nasm_panic("vsnprintf buffer overflow");
  33
  34     if (size > 0) {
  35         if ((size_t)rv < size-1)
  36             bytes = rv;
  37         else
  38             bytes = size-1;
  39         memcpy(str, snprintf_buffer, bytes);
  40         str[bytes] = '\0';
  41     }
  42
  43     return rv;
  44 }
  45
  46 #endif