importC error: _Builtin_stddef

[Lance Bachmeier]

On Friday, 30 August 2024 at 04:49:48 UTC, Dakota wrote:
> get this error:
>
>
> ```sh
> In file included from /llvm/lib/clang/18/include/stddef.h:77,
>                  from /usr/include/time.h:29,
>                  from /llvm/include/clang-c/CXFile.h:17,
>                  from 
> /llvm/include/clang-c/CXSourceLocation.h:17,
>                  from /llvm/include/clang-c/CXDiagnostic.h:17,
>                  from /llvm/include/clang-c/Index.h:20,
>                  from /opt/d/D/c2d/src/c2di.c:1:
> /llvm/lib/clang/18/include/__stddef_size_t.h:15:50: error: 
> missing binary operator before token "("
>    15 |     (__has_feature(modules) && 
> !__building_module(_Builtin_stddef))
>       |                                                  ^
> In file included from /llvm/lib/clang/18/include/stddef.h:92:
> /llvm/lib/clang/18/include/__stddef_null.h:10:41: error: 
> missing binary operator before token "("
>    10 | #if !defined(NULL) || 
> !__building_module(_Builtin_stddef)
>
> ```

It's hard to say further without having the code you're 
compiling, but my best guess is that the C preprocessor is stuck 
on this or similar: 
https://clang.llvm.org/doxygen/____stddef__size__t_8h_source.html


```
/*
  * When -fbuiltin-headers-in-system-modules is set this is a 
non-modular header
  * and needs to behave as if it was textual.
  */
#if !defined(_SIZE_T) ||                                          
              \
     (__has_feature(modules) && 
!__building_module(_Builtin_stddef))
#define _SIZE_T
```

Without more information I can't give any specific advice, but 
the answer may be to pass something to the preprocessor using -P 
in your compilation command as described here: 
https://dlang.org/spec/importc.html#auto-cpp