Re: Vala support for automake

[Jürg Billeter]

Hi Ralf,

On Wed, 2009-04-15 at 20:42 +0200, Ralf Wildenhues wrote:
> I'm looking at adding per-target flag support for vala sources.
> 
> Say I have baz.vala and want to create from that
>   foo-baz.c foo-baz.h
> 
> in one valac invocation, as well as
>   bar-baz.c bar-baz.h
> 
> in another 'valac -D BAR' invocation.  Is there some flag I can pass to
> valac that will use these output names for me?  If yes, does it do so
> without generating intermediate baz.c baz.h files or any other temporary
> files that have a name  which would conflict with parallel make -jN
> execution?

valac does not currently support any transformation on the output names
of the .c files. It's not as easy as a simple -o option because you have
multiple input and output files per invocation in general (see below).
If you think it would make sense to add a --suffix option or similar to
valac, I could certainly take a look at it.

> Also, I see that your vala compile passes all sources to valac.  Is that
> intentional (or just because that was good enough)?  I.e., if you have
>   bin_PROGRAMS = foo
>   foo_SOURCES = a.c b.vala c.l d.java e.vala
> 
> do you really want to invoke
>   valac -C a.c b.vala c.l d.java e.vala

That was not intentional. valac won't mind unnecessary .c files but will
reject files with other extensions.

> rather than
>   valac -C b.vala e.vala

This would be the correct commandline.

> or even
>   valac -C b.vala
>   valac -C e.vala

This would not work, valac requires all Vala source files of the same
program / library on the same commandline. The reason is that the source
files can depend on each other, but there is no header/include
mechanism.

> ?  And if per-target flags are used with multiple input files, how would
> I specify the renamed output files?

We'd probably need to add a new commandline option to valac as suggested
in the first paragraph.

Thanks,
Jürg