title: Linking a shared library against a static library: must the static library be compiled differently than if an application were linking it?
body: <p>At least on Linux and Solaris, static libraries are really just a bunch of compiled .o's tossed into one big file. When compiling a static library, usually the -fpic flag is ommited, so the generated code is position dependent. </p>
  
  <p>Now say my static library is B. I've built it and have the resulting .a file which is really just a glob of all of the position dependent .o files. Now I have a shared library I'd like to build, A, and I want it to statically link B. When I build A, naturally I'll use the -fpic flag to make the generated code position independent. But if I link against B, aren't I mixing position dependent and position independent object files?</p>
  
  <p>I'm getting a lot of text relocation errors unless I also specify -mimpure-text, and I think this maybe the cause. It seems when I compile a library, I really need to compile it <em>3</em> times, a shared version, a static version, and a static-that-can-be-used-by-shared-libs version. Am I right? I could just keep using -mimpure-text but the g++ man page says that if you do that the object doesn't actually end up being shared (it's unclear if it's all unshared or just the statically linked parts though, does anyone know?). </p>