--target rollup option effect on linked libraries (--link-library option)

[greenhat]

I was quite surprised that --target rollup only adds -link-library for std and base only if no other --link-library option is specified. As soon as I add custom library linking via --link-library the std and base disappear and I have to add them manually. Is it a bug or intended behavior?

[greenhat]

I believe that it happens at

compiler/midenc-debug/src/cli.rs

Lines 72 to 74 in 17aa362

	default_value_ifs([
	("target", "base", "std"),
	("target", "rollup", "std,base"),

[bitwalker]

Yeah, setting link-library options when specifying certain --target options is a bit of a hack, I'm not sure we can make the combination of flags additive. We probably need to explicitly check if both options are provided, and if so, ensure that all of the implied link libraries for the given --target are still present (adding them if not).