Re: Help, zillions of undefined references

[Ian Lance Taylor <ian at wasabisystems dot com>]

Eric Evans <eje4@cornell.edu> writes:

> The programmer told me that I should use gcc 2.96 in order to ensure
> that it links in the jpeg libraries that are needed by the program.
> But unfortunately, although using 2.96 does cause the jpeg libraries
> to be linked in properly, it also results in many dozens of other
> undefined reference errors.

I don't understand why the version of gcc would affect whether it
links in any jpeg libraries.  Which libraries are linked in would seem
to be purely an effect of how the link phase is invoked.

> Is there some way of finding out what specific library files these
> missing functions belong to?  I would think that these missing
> functions, since the programmer himself has no knowledge of them and
> is not explicitly invoking them in his program code, must be some
> common system functions that perform some kind of basic system
> operations and so they ought to well-known to somebody, somewhere out
> there!  If anyone has any thoughts on this problem, I would appreciate
> hearing them.  Thanks very much.

I think the missing symbols you mentioned are mostly in libgcc.

This suggests the possibility that you are building with one version
of the compiler and linking with another.  You need to be consistent
in this regard.  Are you building all of your code with gcc 2.96?
Your code and also all statically linked libraries should be built
with the same compiler.

Ian