[llvm-dev] LLVM 10 ORC2 issue with symbol resolution

[Lang Hames via llvm-dev]

Hi Dibyendu,

I had a look - to be honest I am not sure where the error is being
> reported from. It looks like this:
> JIT session error: Symbols not found: [ luaV_tointeger_, luaG_runerror ]
> I don't think it is from any logging I am doing.


Errors in ORC may trigger cascading failures. E.g. if two different modules
M1 and M2 both reference a function "foo" which cannot be resolved, then
you have three errors: A failure to resolve "foo", A failure to materialize
the symbols in M1, and a failure to materialize the symbols in M2. When
such a cascade occurs ORC will usually report the original error(s) via
ExecutionSession::reportError (which logs them to stderr by default) and
return a derived error (e.g. failure-to-materialize) to callers. I believe
you're seeing the logged error, and you will see a failure-to-materialize
error if you log the result that reaches cantFail in your example above.

-- Lang.


On Mon, Apr 13, 2020 at 1:18 PM Dibyendu Majumdar <mobile at majumdar.org.uk>
wrote:

> Hi Lang,
>
>
> > > Can you share the specific errors that you're getting back? I would
> recommend replacing
> > >
> > > cantFail(callToFailingFunc(...));
> > >
> > > with
> > >
> > > logAllUnhandledErrors(callToFailingFunc(...), errs(),
> "callToFailingFunc(...) failed:");
> > >
> >
> > Okay thank you - I will do that and report back.
>
>
> I had a look - to be honest I am not sure where the error is being
> reported from. It looks like this:
>
> JIT session error: Symbols not found: [ luaV_tointeger_, luaG_runerror ]
>
> I don't think it is from any logging I am doing.
>
> >
> > > On Mon, Apr 13, 2020 at 10:06 AM Dibyendu Majumdar <
> mobile at majumdar.org.uk> wrote:
> > >>
> > >> Hi,
> > >>
> > >> I updated my project to LLVM 10.0 today and I am getting JIT symbol
> > >> resolution errors.
> > >> I could not find any example or updated tutorial or documentation that
> > >> describes the new api - as all documentation seems out of date.
> > >>
> > >> I paste below some code snippets that show what I am doing:
> > >>
> > >> /* global syms is a array mapping names to function addresses */
> > >>
> > >> ES->createJITDylib("<main>");
> > >> MainJD = ES->getJITDylibByName("<main>");
> > >> MainJD->addGenerator(
> > >>
>  cantFail(llvm::orc::DynamicLibrarySearchGenerator::GetForCurrentProcess(
> > >>         DL->getGlobalPrefix())));
> > >> auto &JD = *MainJD;
> > >> llvm::orc::MangleAndInterner mangle(*ES, *this->DL);
> > >> llvm::orc::SymbolMap Symbols;
> > >> for (int i = 0; global_syms[i].name != nullptr; i++) {
> > >>   Symbols.insert({mangle(global_syms[i].name),
> > >>
> > >>
> llvm::JITEvaluatedSymbol(llvm::pointerToJITTargetAddress(global_syms[i].address),
> > >>
> > >> llvm::JITSymbolFlags(llvm::JITSymbolFlags::FlagNames::Absolute))});
> > >> }
> > >> llvm::cantFail(JD.define(llvm::orc::absoluteSymbols(Symbols)), "Failed
> > >> to install extern symbols");
> > >>
> > >> FYI - my previous post on similar issue.
> > >> Basically I haven't been able to get ORC v2 working - tried in 8, 9
> and now 10.
> > >>
> > >>
> http://llvm.1065342.n5.nabble.com/llvm-dev-ORC-v2-question-tp130489p130601.html
> > >>
> > >> Thanks and Regards
> > >> Dibyendu
>
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