https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83271
--- Comment #2 from Alexey Salmin <alexey.salmin at gmail dot com> --- (In reply to Jakub Jelinek from comment #1) > I must say I fail to see usefulness of adding the attribute to the > definition rather than declaration though. Here's my case. There's a const bool flag in a static library that should be reliably available before the main() entry point, therefore the static initialization is used (see C++11 3.6.2.2). By default the flag is set to true but it's overridden to false in a custom build. flag.h: extern const bool flag; enabled.cpp: #include "flag.h" const bool flag __attribute__((weak)) = true; disabled.cpp: #include "flag.h" const bool flag = false; // strong override Library behaves differently depending on whether the "disabled.o" was provided to the linker or not, while the "enabled.o" is always ar-ed into the static library. I include the same header file in both cpp files to make sure both definitions correspond to the same declaration. Let me know if there's a better way to achieve this behavior. The one I can think of involves a macro and two different builds of the library but it's not welcome in our build system. Another option would be to keep both "enabled.o" and "disabled.o" out of the static library and don't use weak symbols at all, but that breaks the compatibility.
