Weird behavior with #def and -preprocess-def-macro

[Psteven5]

First off, I really like this project! I have given a whirl at an extended C myself but this is probably the best variant I've seen about.

So I don't know if this is intended behavior, but this code snippet:

#define CAT2_(A,...) A##__VA_ARGS__
#define CAT2(...) CAT2_(__VA_ARGS__)

#define STRINGIFY_(...) #__VA_ARGS__
#define STRINGIFY(...) STRINGIFY_(__VA_ARGS__)

#def IMPORT(Module)
    #ifndef CAT2(Module,_h)
    #define CAT2(Module,_h)
    #include STRINGIFY(CAT2(Module,.h))
    #endif
#enddef

IMPORT(stdio)
IMPORT(stdio)

int main(void)
{
}

leads to very cryptic errors:

Cake 0.14.00 (x86_x64_gcc)
main.c:8:28:
error 970: expected token 'identifier', got 'new line'

 8 |
   |~

main.c:9:28:
error 970: expected token 'identifier', got 'new line'

 9 |
   |~

While having only one IMPORT(stdio) compiles and includes <stdio.h> as one would expect.

[thradams]

Hi,
The C2Y #def proposal [1], doest not allow other directives inside def.
Cake put this extra step as extra experiment on the top of #def proposal.

I think # def is not moving forward in C2Y, so in cake it can remain as an extension or be removed.
Having this in mind I don't know if it is a good idea to invest time #def, but I can have a look on the expansions some day to see what is going on.

[1]
https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3524.txt

[thradams]

This reproduces a problem.

    
    #define F <stdio.h>
    #include F
    

cake is not preprocessing include. this is a bug.
I created #446

[Psteven5]

Understandable! I would put it low on the priority list as I do not particularly need the feature, and especially when it's likely to not end up in a C2y

[Psteven5]

I couldn't manage to solve this, but it looks like applying a #def macro with the -preprocess-def-macro flag clobbers the internal state of the macro, hence why it expands correctly the first time yet fails a second time. Interestingly enough though, it only seems to do this for the same argument; it does work twice when sending a different argument:

#include <stdio.h>

#def IMPORT(Module)
    #define Module 1
#enddef

IMPORT(stdio)
IMPORT(stddef)

int main(void)
{
    printf("%d\n", stdio + stddef);
}