Using C X macros in combination with #ifdef -

assuming code looks in following snippet:

#ifdef cond1     extern int func1(void); #endif ... #ifdef condn     extern int funcn(void); #endif  my_struct funcs[] = { #ifdef cond1     {"func1 description", func1}, #endif ... #ifdef condn     {"funcn description", funcn}, #endif     {null, null}, }; 

is possible replace x macros in order minimize repetition of function names , conditions in both parts?

without #ifdef condx conditions, appears quite straight forward. however, have no idea how include them in x macro, because not allowed use #ifdef in #define.

not sure whether x macros solution here. can, however, use bit of preprocessor magic reduce typing. problem remains conditional compilation (#ifdefs) in example. without knowing these conditions difficult reduce amount of typing further.

condider following:

#define d(n) extern int func ## n(void); #define a(n) {"func" #n " description", func ## n},  #ifdef cond1   d(1) #endif #ifdef cond2   d(2) #endif  my_struct funcs[] = { #ifdef cond1   a(1) #endif #ifdef cond2   a(2) #endif }; 

this is, think, step in direction aiming for. see does, can try

gcc -e -dcond1 <file-with-contents-above>.c 

(if on unix) or

cl -e -dcond1 <file-with-contents-above>.c 

(if on windows using visual studio).