Problem with macro expansion removing ? characters from macros

Question

Hi,
When compiling the following code (CC ex.cpp), we always receive the error line 28: Error: Unexpected ":" found.
ex.cpp
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#define ONE 1
#define MCheck(n) (n == ONE ? "One" : "???")
#define F1(buff, size, ...) func(buff, size, __VA_ARGS__)
#define F(...) F1(acBuff, sizeof(acBuff), __VA_ARGS__)
void func(char* buff, size_t len, const char* fmt, ...) {
    va_list args;
    va_start(args, fmt);
    size_t nWrote = vsnprintf(buff, len, fmt, args);
    va_end(args);
int main(void) {
    char acBuff[10];
    // Parsed OK
    F1(acBuff, sizeof(acBuff), "%s\n", MCheck(1));
    printf("%s", acBuff);
    // Causes error
    F("%s\n", MCheck(1));
    printf("%s", acBuff);
    return 0;
}This appears to be because the pre-processed code (found using CC -E ex.cpp) has removed the '?' characters from the parsed macro 'F' expansion as shown:
(Code inserted from headers)
#13 "ex.cpp"
void func ( char * buff , size_t len , const char * fmt , ... ) {
va_list args ;
( void ) ( args = ( __va_list ) & __builtin_va_alist ) ;
size_t nWrote = vsnprintf ( buff , len , fmt , args ) ;
( void ) 0 ;
int main ( void ) {
char acBuff [ 10 ] ;
func ( acBuff , sizeof ( acBuff ) , "%s\n" , ( 1 == 1 ? "One" : "???" ) ) ;
printf ( "%s" , acBuff ) ;
func ( acBuff , sizeof ( acBuff ) , "%s\n" , ( 1 == 1 "One" : "???" ) ) ;
printf ( "%s" , acBuff ) ;
return 0 ;
}Is this an error with the compiler, or is there some flag we need to set to ensure the macros are expanded to the correct level?

Answer 1

Bwadly wrote:
Hi Maxim,
Thanks for the feedback.
We are using Solaris 8, so I'm guessing we should use Sun Studio 11? Correct, the latest release that supports Solaris 8 is Sun Studio 11. Be sure to patch both Solaris and Sun Studio once you install it.
BTW, I was able to reproduce the problem using Studio 9 compiler (CC 5.6). Apparently, it got fixed in later versions of compiler - patched version of CC 5.6 does not have it.
Edited by: MaximKartashev on 15.08.2008 12:55