Re: [Vala] Question about valac symbols (-D, --define)

[Enrique Ocaña González <eocanha igalia com>]

On Thursday 07 October 2010 12:40:15 Tomasz Jankowski wrote:

> I'm new to Vala. I already integrated it with my project (I use Autotools).
> I have problem with defining preprocessor symbol, I want to do something
> like this:
> gcc -DDATA_DIRECTORY_PATH="../data" main.c -o app

The alternative I found to do that kind of things is to create a custom vapi 
file, such as:

  [CCode (cprefix = "", lower_case_cprefix = "")]
  namespace Config {
    public const string DATADIR;
    ...
  }

Use it in your program like this:

  using Config;
  ...
  const string UI_PATH = Config.DATADIR+"/myapp/ui";

And compile the program in two stages (Vala to C, C to executable), more or 
less like this (taken from a Makefile.am):

  valac -C --vapidir=. --pkg=config [...] program.vala
  gcc -DDATADIR=\""$(datadir)"\" [...] program.c

With the vapi, Vala just expects the defined string "to be there" and "to be 
of the proper type". Then you supply it via gcc parameter or via an 
additionally included C header.

Cheers.

-- 
Enrique Ocaña