Hi, On Wed, 9 Aug 2017, H.J. Lu wrote:
> > OK, but then both -f[no-]omit-frame-pointer do not have clearly defined > > semantics and thus shouldn't be exposed to the user? > > -f[no-]omit-frame-pointer apply to cases where a new stack frame > is needed. -fno-omit-frame-pointer allows you to unwind each > stack frame, not necessarily each function, via frame pointer. > -fno-omit-frame-pointer may not create a new stack frame for > each function, similar to LTO or function inlining. But you can still > unwind via frame pointer. We never guarantee that we will create > a new stack frame for each function. Some functions are inlined > completely. Some just use the caller's stack frame. Maybe something along these lines should be added to the docu of fno-omit-frame-pointer then. At least "Note that -fno-omit-frame-pointer doesn't force a frame for all functions if it isn't otherwise needed, and hence doesn't guarantee a frame pointer for all functions." . Ciao, Michael.
