Generate and use a config.h header

[eregon]

Useful for #1041

Related to #1051

[eregon]

This works with TruffleRuby with oracle/truffleruby#3140, so let's wait that merges and then we can merge this.

[kddnewton]

Yeah this looks good. I actually changed my mind on the src/yarp.c changes though, would you be able to revert those only? Other than that, I think this is good to go. Let me know when the truffleruby PR is merged.

[eregon]

I actually changed my mind on the src/yarp.c changes though, would you be able to revert those only?

Do you mean defining YP_VERSION_MAJOR in include/yarp.h instead of in config.h (via autoconf)? What's the rationale?

(BTW this PR should remove those YP_VERSION* from include/yarp.h if we keep it in autoconf, it seems #1051 missed that cleanup)

[kddnewton]

Specifically I mean using the PACKAGE_VERSION macro. I'm nervous about it conflicting since it's not prefixed with anything.

[eregon]

Ah sure, happy to change that back to YP_VERSION

[eregon]

Should I remove the arguments to AC_INIT as well then to not define any PACKAGE_* macros?

[kddnewton]

Should I remove the arguments to AC_INIT as well then to not define any PACKAGE_* macros?

I think they get defined as empty in that case. But yeah feel free.

[eregon]

Ah sure, happy to change that back to YP_VERSION

Done.

I think they get defined as empty in that case. But yeah feel free.

Indeed, so I left them in, otherwise they are empty strings.

[kddnewton]

Yeah this looks good

[kddnewton]

@eregon is this good to go or are we waiting on truffleruby?

[eregon]

Let's wait the TruffleRuby PR merges to not break the CI here.

[eregon]

https://github.com/oracle/truffleruby/actions/runs/5415357250/jobs/9843509793?pr=3140

src/enc/unicode.c: In function ‘utf_8_codepoint’:
src/enc/unicode.c:2233:28: error: conversion to ‘uint32_t’ {aka ‘unsigned int’} from ‘int’ may change the sign of the result [-Werror=sign-conversion]
 2233 |             (0xff >> type) & (byte);
      |                            ^

Not sure why it this error happens there and not in other places. I'll try a trivial fix.

[kddnewton]

@eregon strange - probably needs to be 0xffu

[eregon]

Yeah, that goes further, but there are more errors: https://github.com/oracle/truffleruby/actions/runs/5416543973/jobs/9846399623?pr=3140
I'm just using make all-no-debug, so really weird it doesn't happen in YARP's CI.
One difference is that job runs on Ubuntu 20.04 vs 22.04 here.
I'll try to add a 20.04 job here to see if that repros.

[eregon]

OK it repros on 20.04: https://github.com/ruby/yarp/actions/runs/5416596186/jobs/9846527321?pr=1088
@kddnewton Could you address these warnings?

[kddnewton]

@eregon yeah can you rebase off #1103

[eregon]

Thanks!
We'll need a bit longer before merging the TruffleRuby PR, because that needs a small change in mx, and that's currently blocked due to some unrelated CI issue.

[eregon]

The TruffleRuby PR merged, CI is green on rerun, I'll merge