fpic

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. 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

I have some doubt about how do programs use shared library. When I build a shared library ( with -shared -fPIC switches) I make some functions available from an external program. Usually I do a dlopen() to load the library and then dlsym() to link the said functions to some function pointers. This approach does not involve including any .h file. Is there a way to avoid doing dlopen() & dlsym() and just including the .h of the shared library? I guess this may be how c++ programs uses code stored in system shared library. ie just including stdlib.h etc. Nick, I think all the other answers are

I've already read the gcc manpage, but I still can't understand the difference between -fpic and -fPIC . Can someone explain it, in a very simple and clear way? Related questions: What does -fPIC mean when building a shared library? What, if any, are the implications of compiling objects with gcc -fPIC flag if they get used in executables? Anycorn http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html Use -fPIC or -fpic to generate position independent code. Whether to use -fPIC or -fpic to generate position independent code is target-dependent. The -fPIC choice always works, but

I know the ' -fPIC ' option has something to do with resolving addresses and independence between individual modules, but I'm not sure what it really means. Can you explain? sean riley PIC stands for Position Independent Code and to quote man gcc : If supported for the target machine, emit position-independent code, suitable for dynamic linking and avoiding any limit on the size of the global offset table. This option makes a difference on the m68k, PowerPC and SPARC. Position-independent code requires special support, and therefore works only on certain machines. use this when building shared