[llvm-dev] Dwarf - 5 features in clang and llvm

[Sourabh Singh Tomar via llvm-dev]

Hello Djordje, Vedant,

Thanks a lot for sharing information.

I have a doubt, please consider the following simple test case-
#include <iostream>
int func(int* ptr){
        std::cout << *ptr;
        return *ptr + 5;
}
int main(int argc, char** argv){
        int a = 4;
        int* ptr_a = &a;
        int b = func(ptr_a);
        return 0;
}
commandline used --
bash$ clang++ -Xclang -femit-debug-entry-values -O2 -ggdb test.cpp

For this case-- these Tags are not emitted
DW_TAG_call_site, DW_TAG_call_site_paramter ..
only DW_AT_GNU_all_call_sites attribute is present.

+ @Djorde DW_TAG_call_site are supported using late MIR approach, are the
new Call Site related development will be supported via MIR. or their will
be a frontend level debug metadata support will be added.

Thanks!
Sourabh.



On Wed, Sep 11, 2019 at 12:02 PM Djordje Todorovic <
djordje.todorovic at rt-rk.com> wrote:

> Great to see this! :)
>
> Best,
> Djordje
>
> On 10.9.19. 21:16, Vedant Kumar wrote:
> >
> >
> >> On Sep 10, 2019, at 6:15 AM, Djordje Todorovic via llvm-dev <
> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
> >>
> >> Hi Sourabh,
> >>
> >> Support for call-site related DWARF 5 tag/attributes is implemented
> very late, in the LLVM middle-end.
> >> Please note that there is also the IR-level flag
> (DIFlagAllCallsDescribed) that lowers to
> >> the DW_AT_call_all_calls.
> >>
> >> There is also support for call-site-parameter
> (DW_TAG_call_site_parameter) and the debug entry values
> >> (DW_OP_entry_value) related DWARF 5 symbols, but it is restricted by
> the CC1 option ‘-femit-debug-entry-values’,
> >> since the LLDB is still missing support for that.
> >
> > Not for too long ;)
> >
> > See https://reviews.llvm.org/D67410 & https://reviews.llvm.org/D67376
> >
> > best,
> > vedant
> >
> >>
> >> Best regards,
> >> Djordje
> >>
> >> On 10.9.19. 13:58, Sourabh Singh Tomar via llvm-dev wrote:
> >>> Hello All,
> >>>
> >>> I was working on some dwarf-5 features and debugging optimized code
> support in clang and llvm.
> >>>
> >>> Noticed that, DW_TAG_call_site is supported in llvm middle-end. but
> clang is not emitting these.
> >>>
> >>> I was hoping, if someone could provide current status of these
> features and current status of dwarf-5 features in clang and llvm.
> >>> That will be immensely helpful.
> >>>
> >>> Thanks!
> >>> Sourabh.
> >>>
> >>> _______________________________________________
> >>> LLVM Developers mailing list
> >>> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
> >>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >>>
> >> _______________________________________________
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> >
>
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