Re: [boost] jam build problems

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2001-08-16 12:13:47

----- Original Message -----
From: "John Maddock" <John_Maddock_at_[hidden]>

> >Why wouldn't it? This arrangement seemed to raise alarm bells for Bill as
> >well, but I can't understand why. A static lib is just an archive of
> object
> >files. If you compile them with the right options, there's no reason they
> >can't be part of a shared lib.
>
> Because normally when you link to a static lib, only referenced code gets
> included in the output file.  Building dll's is different - you want all
> the code in the output file regardless of whether it's referenced or not.

It seems to me that you want all the code that's referenced by an exported
symbol.

> Now it may be that VC6 will automatically include anything that's tagged
as
> __declarspec(dllexport), but gcc will just link in what it needs (same
with
> other unix compilers I think).

...but it needs everything that is referenced by an exported symbol.

> I seem to remember seeing of ways in which
> a static lib can be converted to a shared lib (probably involves declaring
> the symbols you want as undefined/external to force their inclusion), but
> it's far from trivial or portable IMO.
>

In any case, doesn't the enclosed subproject (which works under the build
system with cygwin, BTW) sort of put the argument to rest? Or have I missed
something?

> The problem is quite easy to reproduce: it occures whenever there is a
> dependency to a lib that either doesn't exist, or Jam doesn't know how to
> build:
>
> exe bad_exe : bad_exe.cpp <lib>does_not_exist : ;

Ah, thank you! It looks to me as though two people have run into this
problem at the same time.

-Dave