[cfe-users] Get Source Location details from IR code (Function Pass)

[David Blaikie via cfe-users]

the location of composite types isn't stored in a DILocation - it's stored
in the 'file'/'line' attributes of the DICompositeType (similarly, the
members have a 'file' and 'line' attribute).

See for instance line 39 of the LLVM IR in https://godbolt.org/z/o3oce5 :

!12 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo",
file: !8, line: 1, size: 32, flags: DIFlagTypePassByValue, elements: !13,
identifier: "_ZTS3Foo")

Note the 'file:' and 'line: fields there. (the file field refers to !8
which is !8 = !DIFile(filename: "./example.cpp", directory: "/home/ce"))

On Tue, Jan 26, 2021 at 5:15 PM Bella V <bellavistaghome at gmail.com> wrote:

> Thanks for the answer.
> struct Foo
> {int x;};
>
> Void bar() {
> struct Foo f;
> f.x = 1;
> }
>
> I'm trying to access the DILocation for DICompositeType (Foo), that is the
> Source Location for struct Foo and struct members. Any pointers.
>
> Regards.
>
> On Sun, Jan 17, 2021 at 11:20 AM David Blaikie <dblaikie at gmail.com> wrote:
>
>> Not sure I understand the question - llvm.dbg.declare can be
>> queried/examined/etc through the usual LLVM IR APIs, yes - it's an
>> intrinsic call, with operands, etc. It's a DbgVariableIntrinsic (
>> https://llvm.org/doxygen/classllvm_1_1DbgVariableIntrinsic.html ) you
>> can interrogate for information.
>>
>> On Fri, Jan 15, 2021 at 7:17 PM Bella V <bellavistaghome at gmail.com>
>> wrote:
>> >
>> > Thank you. Also Is there a pragmatically way to access the metadata
>> info for local variables within the llvm.dbg.declare.
>> > ( llvm::Value does not have local variables).
>> >
>> > On Tue, Jan 12, 2021 at 1:55 PM David Blaikie <dblaikie at gmail.com>
>> wrote:
>> >>
>> >> You'd have to get IR from somewhere that has attached debug info -
>> such as clang -g
>> >>
>> >> On Tue, Jan 12, 2021 at 1:22 PM Bella V <bellavistaghome at gmail.com>
>> wrote:
>> >>>
>> >>> Do we have to initially attach some metadata to the Value? Because in
>> function pass, when I do F.getAllMetadata(MDs), i do not see any metadata
>> appending to MDS.
>> >>> F.hasMetadata() also returns false. What would be the way to get
>> debugLoc in these scenario?
>> >>>
>> >>> Thanks and Regards.
>> >>>
>> >>> On Mon, Jan 11, 2021 at 6:31 PM David Blaikie <dblaikie at gmail.com>
>> wrote:
>> >>>>
>> >>>>
>> >>>>
>> >>>> On Mon, Jan 11, 2021 at 4:33 PM Ayush Mittal via cfe-users <
>> cfe-users at lists.llvm.org> wrote:
>> >>>>>
>> >>>>> Hello Cfe Users,
>> >>>>>
>> >>>>> Could you please point to an effective way to get Source Location
>> details from an IR code.
>> >>>>> From the documentation, I think this could be a way:
>> >>>>> Function Pass-> LLVM Value-> MDN->DILocation-> Source Location.
>> >>>>
>> >>>>
>> >>>> Yep, that's about it (I mean, you can do it in a pass, or not - but
>> yes, find an llvm::Value and get the debugLoc from that)
>> >>>>
>> >>>>>
>> >>>>> Please include any example if the above approach is correct too.
>> >>>>>
>> >>>>> Thanks and Regards.
>> >>>>> _______________________________________________
>> >>>>> cfe-users mailing list
>> >>>>> cfe-users at lists.llvm.org
>> >>>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
>>
>
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