On Thu, May 10, 2018 at 6:06 PM, Khem Raj <[email protected]> wrote: > On Thu, May 10, 2018 at 6:00 PM, Andre McCurdy <[email protected]> wrote: >> On Thu, May 10, 2018 at 5:55 PM, Khem Raj <[email protected]> wrote: >>> On Thu, May 10, 2018 at 4:11 PM, Andre McCurdy <[email protected]> wrote: >>>> On Thu, May 10, 2018 at 3:50 PM, Martin Jansa <[email protected]> >>>> wrote: >>>>> On Thu, May 10, 2018 at 03:40:53PM -0700, Andre McCurdy wrote: >>>>>> On Thu, May 10, 2018 at 3:38 PM, Martin Jansa <[email protected]> >>>>>> wrote: >>>>>> > see >>>>>> > http://lists.openembedded.org/pipermail/openembedded-core/2018-May/150654.html >>>>>> >>>>>> Removing -fno-omit-frame-pointer isn't the same as adding >>>>>> -fomit-frame-pointer. Frame pointers may get enabled depending on the >>>>>> optimisation level etc (ie not only by -fno-omit-frame-pointer). >>>>> >>>>> Should I send v2 adding -fomit-frame-pointer instead of removing >>>>> -fno-omit-frame-pointer? >>>>> >>>>> The v1 fixes the issue for me with default config + DEBUG_BUILD. >>>> >>>> The v1 patch isn't wrong, it's just incomplete (the problem could come >>>> back if someone changes optimisation level or switches gcc to clang, >>>> etc). >>>> >>>> My choice would be a v2 patch which adds -fomit-frame-pointer to >>>> CFLAGS unconditionally for all ARM builds when Thumb is enabled. That >>>> should fix the problem for all optimisation levels etc and avoids >>>> building the main strace binary differently depending on whether or >>>> not ptest is enabled. >>> >>> explicitly adding this option is a poor choice especially for debug >>> builds where we should >>> let the -On level decide and not explicitly ask for either >>> enable/disable frame-pointers >>> that will also make it compiler proof. >> >> Of course, we should let the compiler decide whenever it's possible to do so. >> >> Unfortunately there are cases like this one where frame pointers clash >> with inline assembler and we need to over-rule the compiler's choice. > > Here we are adding -fno-omit-frame-pointer via global opt flags that > is the issue > where we have fallouts from default O options I agree we should teach > this to build > system and help the compiler
Since there's NO situation where enabling frame pointers is going to work for this code + ARM + Thumb, I don't see the advantage of leaving anything up to chance. Just explicitly disabling frame pointers is the safest and cleanest option. -- _______________________________________________ Openembedded-devel mailing list [email protected] http://lists.openembedded.org/mailman/listinfo/openembedded-devel
