Q62703: Use of K&R Style Function Definitions May Generate Bad Code

Article: Q62703
Product(s): See article
Version(s): 6.00   | 6.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | buglist6.00 | mspl13_c
Last Modified: 15-AUG-1990

The following code should print out "ABCDEF". However, if compiled
with default optimizations it prints out "ACEGIK" in small model and
"  TLr" in large model. This is corrected by turning off optimizations or
converting the program to the ANSI style.

Sample Code
-----------

#define NULL ((char *) 0)

int var;
int *my_prog_var_table[] = {&var,&var,&var,&var,&var,&var,NULL};
char my_prog_suffix_table[] = "ABCDEFGHIJKLMNOP";

main()
{
   printf("Program should print \"ABCDEF\"\n");
   my_prog_init_files(my_prog_var_table,my_prog_suffix_table);
   printf("\n");
}

// #pragma optimize("tc",off) //Will Fix

my_prog_init_files(vars, suffix)
int *vars[];
char suffix[];
{
   int i;
   for (i = 0; vars[i]; i++)
   {
   my_prog_init_file(vars[i], suffix[i])
   }
}

// #pragma optimize("tc",on) //Will Fix

my_prog_init_file(var, suffix)
int *var;
char suffix;
{
   printf("%c", suffix);
}

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.