On 16/12/15 19:48, Dave Johansen wrote:
On Wed, Dec 16, 2015 at 12:32 PM, Richard Shaw <hobbes1069@xxxxxxxxx <mailto:hobbes1069@xxxxxxxxx>> wrote: On Wed, Dec 16, 2015 at 1:15 PM, Dave Johansen <davejohansen@xxxxxxxxx <mailto:davejohansen@xxxxxxxxx>> wrote: I'm running into a linker issue when moving code that builds on RHEL 6 to Fedora or RHEL 7. Here's a simple reproducer: Download simple.c from https://github.com/markkilgard/glut/blob/master/progs/examples/simple.c and then run: g++ simple.c -lglut -o simple My SWG would be that for some reason on EL 6 you're getting the symbols for free perhaps due to the transitive nature of linking dynamic libraries? Since all you need to add is "-lGL" and it won't hurt anything on EL 6, seems like a pretty straight forward fix. Yes, in this simple example the fix is easy, but in our actual code it would mean changing the build command for hundreds of programs and several of them depend on multiple libraries which depend on multiple libraries, so it would be pretty time consuming. Plus, that's not even to mention the complexity and confusion that will be added when everyone wonders why a program is linking against a library it doesn't use.
It is using it, or you wouldn't get that error. The reference is in the .o file that the compiler has generated in /tmp for your input, not in a library you are linking to.
The cause of the change in behaviour will be this: https://fedoraproject.org/wiki/UnderstandingDSOLinkChange Tom -- Tom Hughes (tom@xxxxxxxxxx) http://compton.nu/ -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx http://lists.fedoraproject.org/admin/lists/devel@xxxxxxxxxxxxxxxxxxxxxxx
