halcompile - add extralib field to comp file

[ArcEye]

Added extralib field to comp file
Allows linking to custom libs and non-standard lib paths
with halcompile
For userspace components only, exits with error is used
with rt component

Signed-off-by: Mick Grant arceye@mgware.co.uk

[jepler]

While reviewing this pull request, I noticed that there was already an unfinished ability to do this, though with a different syntax and different limitations. I fixed it, and added a test and documentation. Starting in the next 2.6 release, you will be able to specify extra link-time arguments, such as additional libraries using the syntax

option extra_link_args "-lm";

[jepler]

(this in no way reflects negatively on your contribution; I hope you'll consider offering more contributions in the future)

[ArcEye]

jepler wrote:
"
While reviewing this pull request, I noticed that there was already an unfinished ability to do this, though with a different syntax and different limitations. I fixed it, and added a test and documentation. Starting in the next 2.6 release, you will be able to specify extra link-time arguments, such as additional libraries using the syntax

option extra_link_args "-lm"; "

That explains the presence of the extra_link_args. I searched high and low to see where they originated, as that was the obvious place to insert them, but could not find them.
Presumably python does not care and just creates a blank string which does nothing in the existing
(now superseded) version