[llvm-dev] Get the Metadata User of a Value

[José Wesley Magalhães via llvm-dev]

Hi Jeremy,

>There's a helper function "findDbgValues" in
>llvm/lib/Transforms/Utils/Local.cpp which should do exactly what you
>want, producing a collection of dbg.value intrinsics for a given
>Value.

Thanks a lot! This function does exactly what I need.

Best regards,

José Wesley de Souza Magalhães
Mestrando em Ciência da Computação
Belo Horizonte/MG - Brasil


Em seg., 2 de nov. de 2020 às 06:49, Jeremy Morse <
jeremy.morse.llvm at gmail.com> escreveu:

> Hi José,
>
> On Thu, Oct 29, 2020 at 2:41 PM José Wesley Magalhães via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> > If I iterate over the users of the value %2 (line 92), I cannot get the
> > debug instruction at line 94. Knowing that the value is used by metadata,
> > (method isUsedByMetadata returns true), is it possible to get the debug
> intrinsic
> > that uses value %2? Or this does not configure a Use of %2?
>
> There's a helper function "findDbgValues" in
> llvm/lib/Transforms/Utils/Local.cpp which should do exactly what you
> want, producing a collection of dbg.value intrinsics for a given
> Value.
>
> If you need to do something more complicated: as that function shows
> the extra step you're missing is calling MetadataAsValue::getIfExists.
> As far as I understand it, by design there's no mapping back from one
> metadata node to its users: debug info metadata hangs everything off a
> unique MetadataAsValue and tries to look it up directly. Value users
> of MetadataAsValue can then be looked up in the usual way.
>
> --
> Thanks,
> Jeremy
>
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