[GSoC] Header Generation for C/C++

[Manu]

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:
> > Great idea!
> > We can make the generated header emit this:
> >
> > #ifndef D_ENUM
> > # define D_ENUM(name, type) enum name
> > #endif
> > #ifndef D_ENUM_KEY
> > # define D_ENUM_KEY(key, enumType) enumType##_##key
> > #endif
> > #ifndef D_ENUM_KEY_VAL
> > # define D_ENUM_KEY_VAL(key, value, enumType) enumType##_##key
> > = value
> > #endif
> >
> > D_ENUM(DEnum, int)
> > {
> >   D_ENUM_KEY(A, DEnum),
> >   D_ENUM_KEY_VAL(B, 10, DEnum),
> > };
> >
> >
> >
> > And then someone can override those with:
> >
> > #define D_ENUM(name, type) enum class name : type
> > #define D_ENUM_KEY(name, enumType) name
> > #define D_ENUM_KEY_VAL(name, value, enumType) name = value
> >
> > #include "my_d_header.h"
> >
> >
> >
> > And for over-powered win, define the macros like this:
> >
> > # define D_ENUM(name, lower, upper, type) ...
> > # define D_ENUM_KEY(key, keyLower, keyUpper, type, typeLower,
> > typeUpper) ...
> >
> > And then the header emits:
> > D_ENUM(DEnum, denum, DENUM, int)
> > {
> >   D_ENUM_KEY(MyKey, mykey, MYKEY, DEnum, denum, DENUM),
> > }
> >
> > This allows maximum flexibility! It can support the D compilers
> > weird naming strategy without adding additional options to the
> > compiler.
>
> 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.