[llvm-dev] lld/lto/win32 crash on DIE code

[Evgeny Leviant via llvm-dev]

Hello Carlo,

I tried your reproducer and faced different problem from one you described
(I'm using MacOS Sierra and lld built from trunk on Mar, 15). The crash happens
when SelectionDAGBuilder::lowerInvokable tries to access EH info of this function:

ms_t26_RemObjects_d_Elements_d_EUnit_d_Runnerb_RunChildrennt2a_RemObjects_d_Elements_d_EUnit_d_RunContext

This happens because LLVM doesn't know your personality function (@_elements_exception_handler), so I suggest looking
at llvm::classifyEHPersonality function as well.

________________________________________
От: llvm-dev <llvm-dev-bounces at lists.llvm.org> от имени Carlo Kok via llvm-dev <llvm-dev at lists.llvm.org>
Отправлено: 14 марта 2018 г. 15:42
Кому: llvm-dev
Тема: [llvm-dev] lld/lto/win32 crash on DIE code

I have a fairly recent LLD/LTO llvm crashing on

DIE *ContextDIE = getOrCreateContextDIE(Context)
being null for a (local) variable. (Context is a DICompileUnit in this
case, but it's not present in MDNodeToDieMap so it returns null.
callstack is:

llc.exe!llvm::DwarfUnit::getOrCreateTypeDIE(const llvm::MDNode * TyNode)
Line 718        C++
llvm::DwarfUnit::addType(llvm::DIE & Entity, const llvm::DIType * Ty,
llvm::dwarf::Attribute Attribute) Line 768      C++
llvm::DwarfCompileUnit::applyVariableAttributes(const llvm::DbgVariable
& Var, llvm::DIE & VariableDie) Line 897        C++
llvm::DwarfCompileUnit::finishVariableDefinition(const llvm::DbgVariable
& Var) Line 725 C++
llvm::DwarfDebug::finishVariableDefinitions() Line 655  C++
llvm::DwarfDebug::finalizeModuleInfo() Line 677 C++
llvm::DwarfDebug::endModule() Line 768  C++
llvm::AsmPrinter::doFinalization(llvm::Module & M) Line 1348    C++
llvm::FPPassManager::doFinalization(llvm::Module & M) Line 1559 C++
`anonymous namespace'::MPPassManager::runOnModule(llvm::Module & M) Line
1615    C++
llvm::legacy::PassManagerImpl::run(llvm::Module & M) Line 1700  C++
llvm::legacy::PassManager::run(llvm::Module & M) Line 1732      C++
compileModule(char * * argv, llvm::LLVMContext & Context) Line 572      C++

The input of this testcase is huge, full repro.tar is here: (14mb)
https://www.dropbox.com/s/ugv9sfqouhlszff/repro.tar?dl=0

With lld /lldsavetemps I managed to narrow down what it actually fails
on, specifcally from the Island.Tests.Windows.exe.0.5.precodegen.bc
(which fails too when passed to llc -O1)

This is the pattern that it generates:
https://gist.github.com/carlokok/fb0f1bf213ee4599d8f2442e37b23f03

If I read this correctly it somehow ends up using two compile units at
once from the same type and failing because of that. I don't know if
that's a merging bug or something I'm doing, but none of my input bc
files has more than 1 compileunit per file, so I don't know how this
could have happened.

What can I do to solve this?


Thanks,

carlo Kok
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