missing symbols of inline functions

Question

missing symbols of inline functions

piotrszulcaptiv opened this issue 7 years ago · comments

Hi,
Another issue we have found: when compiling without optimization the compiler complains about missing symbols that are defined in metric.h. Shouldn't these be defined in the .c file?

Piotr Szulc

Brian Armstrong · Answer 1 · Tue Jan 09 2018 01:23:56 GMT+0800 (China Standard Time)

Which compiler? What's the warning?

Brian Armstrong · Answer 2 · Tue Jan 09 2018 03:24:18 GMT+0800 (China Standard Time)

It looks like those functions should be static inline, not just inline.

Piotr Szulc · Answer 3 · Tue Jan 09 2018 17:08:32 GMT+0800 (China Standard Time)

The compiler was clang.

I don't have the build log right now, but the linker error was simply as if the functions were defined but not implemented. I solved this by moving the implementation to .c file (but of course they are no longer inline). Seems like this is the same issue:
https://stackoverflow.com/questions/16740515/simple-c-inline-linker-error
http://clang.llvm.org/compatibility.html#inline

Brian Armstrong · Answer 4 · Tue Jan 09 2018 17:25:47 GMT+0800 (China Standard Time)

Thanks for the report. I was able to reproduce and believe I have now fixed it. I'm actually surprised it worked in higher optimization levels.

For performance reasons, it's fairly important those metrics be defined inline. I could just put them in the decoder file, but this allows the code to be shared, and the separation feels a little cleaner.