Multi-line C strings and macros

[Rakehellion]

I'm including a GLSL shader in my C program using macros

#define TO_STRING(A) #A

const char* source = TO_STRING(
void main (void)
{
// do stuff
}	
 );

Which works fine, until I declare several variables at once:

const char* source = TO_STRING(
void main (void)
{
float a, b, c, d; // this line generates an error
}	
 );

The compiler gives me an error and says I'm passing too many arguments to the TO_STRING() macro. Is there some way around this? Are there a lot of special cases where multi-line strings can't be handled in this way?

 

[nickbits]

You can't have raw new line chars in a string macro or not.

 

[Rakehellion]

You can't have raw new line chars in a string macro or not.

My compiler isn't complaining. I'm using Xcode and LLVM.

I guess I'll just have to avoid doing certain things in GLSL until I can find a workable solution.

 

[Ken g6]

The multi-linedness isn't the problem. The problem is that you have commas in your argument. That's parsed as:

const char* source = TO_STRING("void main (void){float a"," b"," c"," d;}");

You probably don't see this in other cases because commas within parentheses are not counted. I don't see an easy way around this without doing just one declaration per line.

 

[Rakehellion]

So I can use anything but a comma? That isn't too bad. Thanks.

 

[Schmide]

All you have to do is do an escape sequence.

http://en.wikipedia.org/wiki/Escape_sequences_in_C

 

[randname]

Variadiac macros will get you around this I think... This works for me.

#include <stdio.h>
#define TO_STRING(...) #__VA_ARGS__
int main(int argc, char* argv[])
{
   const char* str = TO_STRING(
                               int main(int argc, char* argv[]){
                               int a,b,c,d;
                               return 0;
                               });


  printf("%s", str);
  return 0;
}