mruby-regexp, mruby-task: ask the build what it defines - #7171

Two GEMs read a build define out of build.cc.defines, which is the C compiler's list alone. A build that sets the define through conf.defines, which puts it on every compiler, compiles under the -D and is not seen here, so the GEM configures itself for a build it is not in. One symptom is a failing test, the other is a tool that never appears.

mruby-regexp hands mrbtest the wrong test file

MRuby::Build.new('probe') do |conf|
  conf.toolchain
  conf.gembox 'full-core'
  conf.defines << 'MRB_REGEXP_UNICODE_CASE'
  conf.enable_test
end

The engine is compiled with Unicode simple case folding, and the GEM hands mrbtest test/ascii_case.rb, the file that asserts /i refuses the very patterns the engine now folds. On master:

Fail: Regexp - /i refuses what ASCII folding cannot answer (mrbgems: mruby-regexp)
  Total: 2303
     KO: 1

mruby-task drops the tool the option asks for

MRB_TASK_BUILD_DEMO is a switch a build configuration throws to get bin/mruby_task_demo. Thrown through conf.defines, the GEM takes no binary, and nothing reports that the option went nowhere.

Both ask MRuby::Build#has_define? instead

a3513b6 added that reader for this and left it without a caller. It spans build.defines and every compiler's list, and matches on the name, so a define written as FOO=1 answers under FOO.

It has to be asked from spec.build_settings: a GEM contributes its defines while the GEMs are still being set up, so the answer during that phase depends on where the caller sits in the list, and has_define? refuses there rather than give one.

build_settings resets a GEM's build commands to the build's, so mruby-task's winmm library and its pkg-config query move into the block along with the question. Left outside they would be set during setup and then dropped. mruby-regexp sets no build command in its own block, so nothing moves there.

Verified

The conf.defines config above reports Total 2302 KO 0, one test fewer than the 2303 of the same config without the option, which is the ASCII file's two tests giving way to the Unicode file's one.

MRUBY_CONFIG=ci/gcc-clang rake -m test, four builds and the bintests, KO 0. full-debug sets the option through conf.cc.defines and still gets the Unicode file:

bintest       117 bintests
bintest       2303   Skip 10
byte-string   2239   Skip 29
cxx_abi       2303   Skip 10
full-debug    2302   Skip 2

MRUBY_CONFIG=default rake -m test, Total 2085 KO 0 plus 106 bintests, on each commit of this PR.

For mruby-task, build_config/glib_hal_test.rb sets the option through conf.cc.defines and builds under -fsanitize=address,undefined: it produces bin/mruby_task_demo, and the demo runs every scenario through to All scenarios completed. The same config without the demo passes rake -m test with Total 832 KO 0, so the glib port still compiles and links from the flags this block gathers.

Not fixed here

rake test on a build that turns the demo on cannot link mrbtest: MRuby::Gem::List#linker_attrs drops a GEM that owns a binary, and the glib libraries go with it. That is on master today and is a separate matter from which list the define is read out of.

Summary by CodeRabbit

• Bug Fixes
  • Improved build configuration so regular expression tests use the final Unicode case-folding settings.
  • Improved task-related builds by reliably detecting platform capabilities and demo requirements.
  • Preserved required Windows multimedia linking and GLib validation behavior.