These functions are used inside assertions; an example: ASSERT(abd_is_linear(abd)); They declared in headers as 'inline'd; probably, they should be staticized as well.
Created attachment 184171 [details] Add 'static' keyword to inline functions in abd.h I think this was (also) caused by 'CFLAGS=-O0'; anyway, the patch fixes this issue for me.
Committed in r322601.