Alessandro Rubini wrote:

...

...

+#define SMC_insb(r,b,l) ({ int __i ; \

• 			byte *__b2;  \
  

• 	    		__b2 = (byte *) b;  \
  

• 	    		for (__i = 0; __i < l; __i++) {  \
  

• 			  *(__b2 + __i) = SMC_inb(r);  \
  

• 			  SMC_inb(0);  \
  

• 			};  \
  

• 		})
  
  

...

[...] it's generally considered good form to wrap multi-line macros with do {...} while(0) in order to avoid compiler issues.

But this is the "expression statement" gcc slang. the do/while0 thing avoids if/else problems but isn't an expression, it is a statement. This has no issue with if/else (no trailing semicolon or brace) and moreover it is an expression.

Oh, I see. Thanks for taking the time Alessandro. I'm putting this back on list so others can be educated too.

regards, Ben