#include C headers in D code

[John Colvin]

On Wednesday, 11 April 2018 at 18:36:56 UTC, Walter Bright wrote:
> On 4/11/2018 3:25 AM, Atila Neves wrote:
>> I did the best I could having seen some macros. It's likely 
>> there are cases I've missed, or that maybe the translation in 
>> the link above doesn't work even for what it's supposed to be 
>> doing (I have no confidence about catching all the C casts for 
>> instance).
>> 
>> If there are other cases, I'll fix them as they're 
>> encountered. It's possible some of them can't be fixed and the 
>> user will have to work around them. Right now I have a feeling 
>> it will probably be ok. Time will tell (assuming I have 
>> users!).
>
>
> That's right. There is no general solution. One can only look 
> for common patterns and do those. For example,
>
>   #define X 15
>
> is a common pattern and can be reliably rewritten as:
>
>   enum X = 15;

If I understand it correctly, dpp doesn't do that.

Instead, it runs the pre-processor on the source code, just like 
in C, so

// test.dpp
#define X 15
int foo() { return X; }

becomes

// test.d
int foo() { return 15; }

The upside of this approach: all macros just work, unless they 
use C (not C pre-processor, C proper) features that dpp can't 
handle. `sizeof(...)` is a special case that is handled in 
dpp.cursor.macro.translateToD and more could be added.

The downside: macros can't be directly used outside .dpp files.