Support for asm-sources, cmm-sources, and js-sources in executable components

[hsyl20]

Describe the bug

Cabal doesn't support asm-sources, cmm-sources, and js-sources in executable components.

To Reproduce

$ mkdir cabal-foreign
$ cd cabal-foreign
$ cabal init --cabal-version=3.0
$ cabal build ; works fine
$ echo "    asm-sources: whatever.s" >> cabal-foreign.cabal
$ echo "    js-sources: whatever.js" >> cabal-foreign.cabal
$ echo "    cmm-sources: whatever.cmm" >> cabal-foreign.cabal
$ cabal clean && cabal build ; should fail because of the missing files, but doesn't

Expected behavior

Cabal should take into account the specified foreign files: link them when present, or fail when not present as in the reproducer above.

At the very least a warning that the fields are parsed but unused would be a better UX.

System information

• Linux
• cabal-install 3.6.2.0 and HEAD
• ghc 9.2.4

Additional context

I've noticed this bug while I was adapting the implementation of asm-sources to fix the support for js-sources in #8636.

As far as I can tell, the issue is in Distribution.Simple.GHC module. gbuildSources only returns C and C++ foreign sources (cf fields of BuildSources record). It should also return Cmm, asm, and js sources. Then BuildSources new fields must be handled properly in gbuild.

It looks like the code to build C/C++ sources for a library (in buildOrReplLib) is duplicated in gbuild to build an executable. I was reluctant to copy-paste the code handling asm/cmm/js sources from buildOrReplLib to gbuild too. It should probably be factorized instead. That's why I didn't do it as part of #8636.

[chreekat]

I just ran into this :D I'll see what I can slap together during Zurihac.

[mpickering]

It's pretty unclear why buildAndReplLib and gbuild are separate functions (for reasons like this).

[ysangkok]

can this be closed now since #9061 was merged?

[hsyl20]

Indeed!