How to determine CLAP version from C(++) preprocessor?

[Arakula]

In 1.1.4, some draft extensions were obviously dropped (file-reference.h, quick-controls.h).

There's a bit of a problem with that, if host and PlugIn versions differ and (at least) one of them supports one of the draft extensions.
Since I try to support as much as possible in my hosts, I'd like to keep that support intact for pre-1.1.4 PlugIns. Normally, in this case, I would simply copy the contents of 1.1.3 file-reference.h and quick-controls.h into my code and surround them with a little #ifor #ifdef statement so that they are only used when needed ... but there's no way I can see to do that.

Unless I'm missing something, version.h doesn't include anything that can be used in a preprocessor statement to determine which CLAP version is in use. All nice and helpful for an if()statement in C(++), but not for the preprocessor.

Neither file-reference.h nor quick-controls.h contain any preprocessor definition, so I can't check for that either.

Of course, I could simply copy the two headers from 1.1.3 to my copy of CLAP 1.1.4 and add them to clap.h, but I'd prefer to leave CLAP intact.
Of course, I could simply copy the contents of the two headers to my CLAP glue code, shrug my shoulders thinking "Hey, I'll never step back to pre-1.1.4 anyway", and be done with it. I just don't like the idea.

Am I missing something here? Or can somebody show me how to cobble the required #if or ifdef statements together?

[baconpaul]

So the way JUCE does it is perhaps something we could follow. That is we can

#define CLAP_PREPROCESSOR_VERSION = ((CLAP_VERSION_MAJOR << 16) + (CLAP_VERSION_MINOR << 8) + CLAP_VERSION_REVISION)

then you can write things like

#if CLAP_PREPROCESSOR_VERSION < 0x010104

#else

#endif 

this exact JUCE_VERSINO strategy in juce headers allows us to make the clap juce extensions work with multiple juces

We may be hurt a bit by the clap versions having an explicit uint32_t in them so we need to be a bit careful

Thoughts?

[Arakula]

Here's a little sample program that shows that it unfortunately doesn't work in this simplicity.
This little program should compile as C or C++:

#include <stdint.h>
#include <stdio.h>

#if 0

#define CLAP_VERSION_MAJOR ((uint32_t)1)
#define CLAP_VERSION_MINOR ((uint32_t)1)
#define CLAP_VERSION_REVISION ((uint32_t)4)

#else

#define CLAP_VERSION_MAJOR 1
#define CLAP_VERSION_MINOR 1
#define CLAP_VERSION_REVISION 4

#endif

#define CLAP_PREPROCESSOR_VERSION ((CLAP_VERSION_MAJOR << 16) + (CLAP_VERSION_MINOR << 8) + CLAP_VERSION_REVISION)


#if CLAP_PREPROCESSOR_VERSION < 0x010105
#define CHK1 "<"
#else
#define CHK1 ">="
#endif

#if CLAP_PREPROCESSOR_VERSION > 0x010103
#define CHK2 ">"
#else
#define CHK2 "<="
#endif

#if CLAP_PREPROCESSOR_VERSION == 0x010104
#define CHK3 "=="
#else
#define CHK3 "!="
#endif


int main()
{
	printf("%d.%d.%d %s 1.1.5\n", CLAP_VERSION_MAJOR, CLAP_VERSION_MINOR, CLAP_VERSION_REVISION, CHK1);
	printf("%d.%d.%d %s 1.1.3\n", CLAP_VERSION_MAJOR, CLAP_VERSION_MINOR, CLAP_VERSION_REVISION, CHK2);
	printf("%d.%d.%d %s 1.1.4\n", CLAP_VERSION_MAJOR, CLAP_VERSION_MINOR, CLAP_VERSION_REVISION, CHK3);

	return 0;
}

If CLAP_VERSION_MAJOR/MINOR/REVISION were simple integer constants, it would work. In version.h, however, they are not - they are ((uint32_t)something). That's a bit too much for the preprocessor. Just change the #if 0 to #if 1 in the 4th line and see for yourself what happens.
Tried with VS2022; even with /std:c++20 it doesn't work.

[baconpaul]

Right so then the trick is

have a clap major version digit
Clap major version references that with the uint
Then add the shifted combo using digit

right?

@abique i think we should at least consider that for 1.1.5 (which is imminent) and then @Arakula can skip 114 and use the digit defined as 113 or earlier condition if needs be

[Arakula]

The method itself is tried and proven; Steinberg does it similarly:

https://github.com/steinbergmedia/vst3_pluginterfaces/blob/bc5ff0f87aaa3cd28c114810f4f03c384421ad2c/vst/vsttypes.h

[baconpaul]

yup i think #254 would do it also just doing some review work on it and fixing some of my silly bugs. Also some folks parse the .h file textually with custom software so theres one or two things we need to fix up.

[baconpaul]

(It also limits us to 256 makjor, minor or revision versions of CLAP before each breaks, so we couldn't do 1.13.257)

[baconpaul]

#254 this is roughly what it would look like if we changed this in 1.1.5 I think (but obviously that conflicts with next)

[robbert-vdh]

I think the 'is the current clap version less than' version has a lot more practical applications, and that's in line with how these kinds of version comparisons usually works. So my vote is for keeping the names as is and swapping the arguments. Noone's using these yet so that should be fine. 😉

[baconpaul]

Yeah I'll prep that as a PR.

Sigh.

[baconpaul]

#269

@abique @robbert-vdh can you peek?

[baconpaul]

Anyway @Arakula this is fixed in 1.1.6, which has the only difference between it and 1.1.5 correcting that macro.

Thanks

[Arakula]

Thank you!