macro function with variable argument

napyonsen

Hi,

folllowing code compiles in Visual C++ compiler but cannot be compiled with c6000 compiler(v7.4.11, and gcc support enabled).

#define LogL2(f_, ...) printf((f_), __VA_ARGS__)
//#define LogL2(f_, ...) vrintf((f_), __VA_ARGS__) // vprintf did not make a difference

LogL2("Changing SystemMode to IBIT..\n"); // this gives compile error, but no error Visual C++ compiler

LogL2("Changing SystemMode to IBIT..\n",0); // this works in both

thanks..

over 9 years ago

0 Michel Solecki over 9 years ago

Mastermind 8415 points

Hi,

This is a known problem with gcc.
In fact, you Visual C++ preprocessor quietly gets rid of those commas so the compiler doesn't complain.

Here is a discussion about this:
stackoverflow.com/.../standard-alternative-to-gccs-va-args-trick

There is a workaround that will get rid of these errors. You would have to add a few macros as shown in this thread below:
stackoverflow.com/.../checking-if-an-argument-is-passed-in-variadic-macros-in-c

Hope this helps
Michel

0 Kenia Guinto over 9 years ago in reply to Michel Solecki

TI__Expert 7250 points

There was a suggested answer and since there has been no active on this thread for more than a week, the suggested answer was marked as verify. Please feel free to select the "Reject Answer" button and reply with more details.

0 napyonsen over 9 years ago in reply to Michel Solecki

Intellectual 370 points

Thank you.
#define LogL2(...) printf( __VA_ARGS__)
as in the first link, solved my problem.

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macro function with variable argument