> I was disappointed that @KnarfB did not show any notion of acknowledeging that ST's approach of predefining mandatory callbacks as weak symbols is in fact problematic.
Actually you are the first person bringing this issue as problematic, in several years. This suggests that majority of users manage to use the software as is. (and they may be annoyed by change of such scale unless justified).
Removing weak functions from your lib can be done with existing GNU utilities, something like following:
# unpack the lib:
ar x your_library.a
# For each object list weak symbols:
nm -a your_object.o | grep ' W ' | awk '{print $3}' > functions.txt
# then remove these functions
objcopy --strip-symbol=functions.txt your_object.o
# Then re-assembly the o files into .a
ar cr new_library.a *.o
> There is no way to catch the error at build time
Hmm. Perhaps this can be done with a "canary" , like this:
// canary_lib.c
// Add this in the .a library:
extern void link_is_broken(void); // isn't defined anywhere
void __attribute__((weak)) build_canary()
{
link_is_broken();
}
// Add this in your main code
void build_canary() { /* nothing */ }
int main() {
.........
build_canary(); //use
.......
}
If the weak function is selected, build will fail because of unresolved symbol.
