[GSoC] Header Generation for C/C++

[Eduard Staniloiu]

On Tuesday, 30 July 2019 at 14:43:01 UTC, Eduard Staniloiu wrote:
> On Monday, 29 July 2019 at 01:19:36 UTC, Manu wrote:
>> On Sun, Jul 28, 2019 at 5:20 PM Gregor Mückl via Digitalmars-d 
>> <digitalmars-d at puremagic.com> wrote:
>>>
>>> On Monday, 22 July 2019 at 18:12:01 UTC, Manu wrote:
>>> > [...]
>>>
>>> That's a pretty neat hack!
>>>
>>> I'm just worried about two things:
>>> - it makes the generated code harder to read (not that big of 
>>> a
>>> deal)
>>
>> Barely... and a generated header is not really for human 
>> consumption either way.
>>
>>> - if you happen to include headers with conflicting D_ENUM* 
>>> defines (e.g. a potential 3rd party D wrapper), you might get 
>>> some nasty surprises :/
>>
>> C/C++ programmers now how to do macros and what to expect.
>
> So should we go ahead with generating code based on the 
> `-extern-std` value or by using defines?
>
> After sleeping a bit on this, I prefer `-extern-std`.

BTW, I went with `-extern-std` in the current implementation (on 
GH).

Another question is how should `align(n)` be generated. See the 
following two:

1) __attribute__((packed, aligned(n)))

or

2) __attribute__((aligned(n)))

Note the missing `packed` between 1) and 2)

Currently (on GH) the entire generated output looks like this

struct
#if defined(__GNUC__) || defined(__clang__)
     __attribute__((packed, aligned(8)))
#elif defined(_MSC_VER)
     __declspec(align(8))
#elif defined(__DMC__)
     #pragma pack(push, 8)
#endif
MyStruct
{
   /* fields */
}
#if defined(__DMC__)
     #pragma pack(pop)
#endif