Q59490: Errors When Space Exists Between Macro Name and Parameters

Article: Q59490
Product(s): See article
Version(s): 4.x 5.00 5.10 | 5.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | s_quickc s_quickasm | mspl13_c
Last Modified: 17-DEC-1990

If you put a space between a macro name and the left parenthesis that
begins the parameter list for a macro, you will receive multiple
compiler errors because the preprocessor is designed to accept any
code after the first space after the macro name as the code definition
for the macro.

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

#define incr (x) x+1      /* Change to incr(x) to correct. */
#include <stdio.h>

void main ( void )
{
    int f1, f2;

    f2 = 0 ;

    f1 = incr(f2);

    printf ( "%d %d ", f1, f2 ) ;
}

Compiling this program under C Versions 4.x, 5.00, and 5.10, or QuickC
Version 1.00, 1.01, 2.00, or 2.01, returns the following error
messages:

   macro.c
   macro.c(10) : error C2065: 'x' : undefined
   macro.c(10) : error C2146: syntax error : missing ';' before
                 identifier 'x'
   macro.c(10) : error C2064: term does not evaluate to a
                 function

Removing the space between the macro name and the left parenthesis
eliminates the errors.

The following error and warning messages are returned by C Version
6.00 under warning level 2 and above:

   macro.c
   macro.c(10) : error C2065: 'x' : undefined
   macro.c(10) : error C2146: syntax error : missing ';'
                 before identifier 'x'
   macro.c(10) : error C2064: term does not evaluate to a
                 function
   macro.c(10) : warning C4071: 'function through ptr' : no
                 function prototype given

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