Problem linking to wrong class

[Brian Peschel <brianp at occinc dot com>]

This is the oddest problem I have ever seen. I am using Fedora 8 and gcc 
(GCC) 4.1.2 20070925 (Red Hat 4.1.2-33). I have two classes with the 
same name SqlQuery. One is in a static library (libone.a) and one is in 
a shared library (libtwo.so).

I have a class that is in the shared library only (DBI), that calls a 
method in SqlQuery. There is a method of the same name and parameters in 
the shared and static library: void clear(std::string& query).

I build the shared library without any reference to static library. I 
build the static library without any reference to the shared library. My 
program links both the shared and the static library into them without 
any errors or warnings about symbol clashes.

When I run my program calls a method in the DBI class (which is in the 
shared library), it crashes. Using gdb, the crash appears to be in the 
SqlQuery in the static library, not the shared library. Which makes no 
sense to me, as the libraries were built without any reference to each 
other. I can repoduce this every time with 2 different code paths, both 
eventually calling a common method.

If I add a namespace to the SqlQuery class in the shared library, the 
crash does not occur. But my code base is well over a millions lines of 
code and trying to do this everywhere a potential issue may be a is a 
daunting task. I have other common class names (and method definitions) 
that aren't causing crashes, but at this point, I am not sure they are 
calling the correct methods either.

Any ever heard of something like this? I am assuming it is some sort of 
linker problem. But I don't understand why I am not getting warnings 
about shared symbols.

- B