Build portability

[bentley]

These three commits allow SameBoy to build on OpenBSD.

• On OpenBSD the compiler doesn’t look in /usr/local by default. pkg-config is used to provide whatever include directories are necessary for a library.
• SDL’s pkg-config files specify an include directory of ${prefix}/include/SDL2; its headers are meant to be included relative to this directory.
• POSIX specifies the head(1) utility, but doesn’t specify the -c flag, and OpenBSD doesn’t provide one. dd(1) is a portable alternative.

[orbea]

It would be nice if pkg-config wasn't hardcoded and supported alternative implementations like pkgconf.

[bentley]

It does; try make PKG_CONFIG=pkgconf.

[orbea]

Yes, you are right, sorry for the confusion.

[LIJI32]

I haven't tested this yet, but looking at the changes raises up a few questions/issues:

1. Looks like you're adding the SDL2 and GL CFLAGS even to non-SDL targets (Such as Cocoa and the tester)
2. SDL2/SDL.h vs SDL.h seems a bit problematic to me. First, I'm not sure this works on macOS without pkgconf. Second, How does this handle SDL1 vs SDL2 assuming both are installed?

[bentley]

There’s no ambiguity between SDL1 and SDL2, because they have separate include directories and separate pkg-config files.

I don’t know how macOS works. Does it come with pkg-config? If not, it could fall back to sdl2-config.

[LIJI32]

I'm talking about scenarios where pkg-config isn't available, I don't want to require it for targets that already work without it.

[bentley]

If pkg-config isn’t available it falls back to the original case.

[LIJI32]

But the include statements have changed, and are now ambiguous between SDL1 and 2.

[bentley]

Ah, I did overlook that. It’s not that they’re ambiguous, since ${prefix}/include/SDL and ${prefix}/include/SDL2 are not in compiler search paths by default. But by the same token the initial revision won’t build without pkg-config to set search paths; that was unintentional.

I’ve pushed a new revision that falls back to sdl2-config, which comes with SDL2, if pkg-config is not available, and only applies the flags to the SDL target.

[bentley]

Any thoughts on this version?

[LIJI32]

I kind of forgot about it... 😳

I'll give it a look this weekend.

[LIJI32]

It breaks the macOS SDL build when pkg-config is installed – it breaks all SDL includes and doesn't even find libgl (Package gl was not found in the pkg-config search path.)

[bentley]

That suggests that macOS doesn’t have gl.pc—surprising but not unbelievable.

This revision splits out GL build flags from SDL build flags, and sets them from pkg-config individually. If pkg-config isn’t present or fails to find one library, it falls back to -lGL or sdl2-config.

Note that even though GL_CFLAGS can be blank, it must exist for some systems. On OpenBSD, the libGL headers are under /usr/X11R6 which is not part of the default compiler search path; pkg-config adds that to GL_CFLAGS.

I tested this on OpenBSD with pkg-config and gl.pc present; pkg-config present but gl.pc absent; sdl2-config present but pkg-config absent; and got the results I expected.

I moved the bootrom trimming bits to #176 in case this part still needs fine tuning.

[inactive123]

Hi there @LIJI32, any resolution here?

[orbea]

@twinaphex I am not sure if you are aware, but this PR should only affect the standalone SameBoy and not libretro.

[bentley]

I’ve rebased against master.

If the previous macOS failure is from a missing gl.pc, then I believe this fixes it. Like I mentioned previously, I’ve tested with pkg-config and gl.pc present; pkg-config present but gl.pc absent; sdl2-config present but pkg-config absent. Would test on macOS but I don’t have access to any machines that run it.

Any issues with this revision?

[LIJI32]

It looks good. I'll test it and merge it.

[LIJI32]

It still fails on macOS because it adds -lGL in addition to -framework OpenGL (The former will not work). I'll fix it later and merge.

[bentley]

Thanks!