fix(emacs): only use vfiles in etags action

[Alizter]

@jdchristensen This should work better.

[jdchristensen]

This still has the extra quoting around the regular expression arguments. This is how I see the command

rm -f TAGS _build/default/TAGS; dune build --verbose --cache=disabled -f --always-show-command-line TAGS

and in a correctly built TAGS file, grep functor_join TAGS should show output.

[Alizter]

@jdchristensen The command that dune outputs with --verbose and --always-show-command-line isn't always accurate, especially when it comes to quoting. I will play around with etags myself to see what might be going wrong.

[Alizter]

The reason I say that is because I wrote my own etags executable in order to echo out the arguments being passed:

Argument 1: ../install/default/bin/etags
Argument 2: --language=none
Argument 3: -r '/^[ \t]*\(\(Local\|Global\|Cumulative\|NonCumulative\|Monomorphic\|Polymorphic\|Private\)[ \t]+\)*\(Axiom\|Theorem\|Class\|Instance\|Let\|Ltac\|Definition\|Lemma\|Record\|Remark\|Structure\|Fixpoint\|Fact\|Corollary\|Inductive\|CoInductive\|Proposition\)[ \t]+\([a-zA-Z0-9_'\'']+\)/\4/'
Argument 4: -r '/^[ \t]*\([a-zA-Z0-9_'\'']+\)[ \t]*:/\1/'
Argument 5: theories/Algebra/AbGroups.v
Argument 6: theories/Algebra/AbGroups/AbHom.v
Argument 7: theories/Algebra/AbGroups/AbProjective.v
Argument 8: theories/Algebra/AbGroups/AbPullback.v
Argument 9: theories/Algebra/AbGroups/AbPushout.v

It looks to me as the regex is being passed fine. The quotation you see is an artefact of how dune serialises its internal commands to shell commands.

[jdchristensen]

No, what etags is getting as "Argument 3" is supposed to be two arguments. The quoting that dune inserts combines them into one argument. But maybe just inserting line breaks in the etags-args file would fix it?

[Alizter]

OK I've managed to fix it. The issue is that we were running the etags program directly essentially using the unix exec. The shell scripting magic that was being done is actually quite essential before being passed into etags. Therefore switching the action to use the (system) shell fixes the issues. I've checked by hand and dune and make agree here.

[jdchristensen]

Also, Argument 3 has some single quote characters in it that shouldn't be there.

[Alizter]

I've also removed the %{bin:etags} from the deps and put it directly in the (system) action. Dune will automatically add the dependency there so we don't need to be explicit about it. This also allows us to avoid having to bind a name to a subset of the deps and go back to using %{deps}.

@jdchristensen Can you give this push a go?

[jdchristensen]

This seems to be working, but I don't see how. There are still extra single quote characters being passed to etags, which should mess it up. It must have some internal code that deletes them. But I think it would be cleaner to not rely on this behaviour. Can dune literally put the contents of a file on the command line? If not, maybe it's cleaner to put the etags command and its args into a script?

[jdchristensen]

I can try the script method if dune can't create the right command line.

[Alizter]

@jdchristensen The removal of the quote characters is standard shell expansion (i.e. what happens when you shove that expression thorugh sh or bash). This is the same behaviour that the makefile relies on. Feel free to remove any shell behaviours if they are not to your liking. I don't mind keeping them in for something like TAGS however.

[jdchristensen]

@Alizter I'm going to PR a different method that I think is easier to understand. You can let me know what you think.