How to exclude with GPRbuild some functions?

Question

I have an executable in Ada compiled with gprbuild.the executable use some simple function (like sin e cos).This executable is operating in a App binded to a POS (Partition Operating System) designed with vxwork. Once recompiled the whole process it appears a bunch of multiple function declaration errors between the POS_API.o and the ada executable (hello.o) . These functions (sin, cos, ...) are all in the same library. Unfortunately the most easy solution to de-reference all this function in POS is not permitted (bound of design).Any suggestions on how to compile or proceed? Is this any possibility to compile without a specific library or some function in order to avoid the multiple reference error?

Answer 1

I'm afraid this isn't really an answer: largely because it's more than ten years since I worked with VxWorks and Ada, and things have got a bit hazy. Also, it's a bit long for a comment on your question

As I used it, VxWorks comes with a whole suite of software that you configure to hold just the components you need into your kernel: in this case, that would presumably include the maths package, functions like sin(), as well as the OS functions like taskSpawn().

The Ada/VxWorks build process that we used generates a partially-linked object file, with references to sin(), taskSpawn() unresolved (I can't remember how this is achieved; if using GNU ld, maybe the -r or --relocatable switch?). When VxWorks loads this object file over the configured kernel, the unresolved references get resolved, and away we go.

Now, I don't know what sort of thing your POS_API does. Is it a skin over a configured VxWorks kernel? Does it load yoour Ada program itself? If it is itself a VxWorks program, how come it's exporting sin()?

I suspect that the problem is to do with the way you've linked your executable. Maybe you could show us your GPR file? Otherwise, I'm just whistling in the dark.