Re: [PATCH][Ada] Add option to gnatlink to fix gnat.dg on some platforms

[Dave Korn <dave dot korn dot cygwin at googlemail dot com>]

Laurent GUERBY wrote:

> What we want if a way to turn off the following behaviour:
> 
> "If the compiler executable is different from the default one (gcc or
> <prefix>-gcc), then the back-end switches in the ALI file are not used
> to compile the binder generated source."

  Perhaps it would work if we changed its idea of the "default" compiler to
include any found through a -B option?  That would resolve the bootstrapping
issue (well, I assume there are -B options passed during building the ada
stuff, I haven't actually verified that statement).

> As an alternative I can add a switch, eg something like
> "--from-ali" (anyone with a better name?) which when present changes the
> behaviour of --GCC in the same way that --XCC from my original patch
> does.

  Or even unconditionally disable the behaviour if any -B option is present.
It's not an everyday thing to use and it might be reasonable to infer that the
user is doing something special and doesn't need the compiler trying to
second-guess them.

> PS: for reference I've always been opposed to in-tree testing. I wonder
> how many hundred of lines of dubious stuff would go away if we just
> tested what we want to test: an installed tree instead of something
> the user will never see.

  Speaking for myself, I would always want to have the option to test stuff
before I install it.

    cheers,
      DaveK