I have a static lib A, which also uses static libs B, C and D.
I then have applications X and Y which both use A, but not B, C or D.
Is there some way to make it so X and Y will automatically see that A used B, C and D and link them, so that I don't need to keep track for the entire dependency tree so I can explicitly pass every static lib (quite a lot with things like Windows, Boost, etc)?
The easy way is to always offer the particular libraries A, B, C, and D to be linked. For a true library, the linker only retrieves the modules needed.
The key problem with A having some implicit linkage to other libraries is that they aren't necessarily uniquely identifiable. For example, should it use version 2.0 or 3.1? The one in /usr/share/lib or the one in /usr/lib/X11/xdm/share/lib? Etc.
Static libraries do not link with other static libraries. Only when building the executable (or shared library/DLL) is linkage performed, and the way to keep track of this is (of course) to use make.
I think, conceptually, you might be able to merge libs together to achieve what you want - they are after simply collections of symbols ready made for the linker. Having said that, I've never seen a tool to do it. The binary format of a lib is a compiler matter, so it would have to be a mingw or gcc specific tool.
In terms of knowing which version of Boost lib A uses, there isn't really much for it but to find the documentation for A.