Q59439: C4071 Can Be Caused by Missing "void" in Function Prototype

Article: Q59439
Product(s): See article
Version(s): 5.00 5.10 6.00 | 5.00 5.10 6.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | s_quickc | mspl13_c
Last Modified: 18-APR-1990

Function prototypes must have parameter lists. If no arguments are to
be passed to a function, the parameter list must contain the keyword
"void". At warning level three (/W3), leaving the "void" out of such a
prototype parameter list leads to the following warning message in C
Versions 5.00 and 6.00 and QuickC Versions 2.00, 2.01, 2.50, and 2.51:

   C4071 'name' : no function prototype given

In C Version 5.10, the following additional warning message occurs:

   C4103 Function definition used as prototype

The following code demonstrates the problem:

/* myfunc is not prototyped correctly */

#include <stdio.h>
void myfunc();          /* missing void in parameter list */
void main(void)
{
  myfunc();             /* myfunc still not prototyped */
}

void myfunc()    /* function definition doesn't need void */
{
  printf("Hello\n");
}

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