fix(make): exclude makefile variable from completion and handle multiple targets in a rule

[braineo]

https://ftp.gnu.org/old-gnu/Manuals/make-3.79.1/html_chapter/make_6.html

Makefile variables can be defined as

red:=$(shell echo -e "\033[0;31m")

this change uses negative lookahead to exclude := patterns

also added support for multi-target case

https://www.gnu.org/software/make/manual/html_node/Multiple-Targets.html

bigoutput littleoutput : text.g
        generate text.g -$(subst output,,$@) > $@

[braineo]

@chitoku-k done, upgraded the regex to deal with one more case

[chitoku-k]

@braineo Seems good! Could you also update the test case (tests/make.zunit) rather than describing the patterns as comment?

[braineo]

@braineo Seems good! Could you also update the test case (tests/make.zunit) rather than describing the patterns as comment?

no problem. TIL. interesting behavior difference for gawk and mawk, i wrote 3 different versions of the same awk script

[braineo]

as for the comment that's my personal habit. i always forget why i wrote the (slightly
complicated) regexp in that way after 3 weeks.

[chitoku-k]

TIL. interesting behavior difference for gawk and mawk, i wrote 3 different versions of the same awk script

That’s why I set up CI to ensure the same behavior across the different implementations. It seemed like it helped debugging here.

Regarding the comment, I’m pretty fine with them as long as there are test cases that cover that. Thank you for your contribution!