[llvm-dev] setDataLayout segfault

[Mehdi Amini via llvm-dev]

> On Sep 14, 2016, at 9:11 AM, Frank Winter via llvm-dev <llvm-dev at lists.llvm.org> wrote:
> 
> I am constructing the engine builder in the following way:
> 
> llvm::SMDiagnostic Err;
> unique_ptr<Module> Mod = getLazyIRFileModule("f.ll", Err, TheContext);
> llvm::EngineBuilder engineBuilder(std::move(Mod));
> 
> However, after moving the pointer to the constructor it is no longer retrievable from the unique_ptr object.
> 
> Mod.get()->dump();   // this segfaults after the move, but not before
> 
> So I conclude that any type of operation on the module is no longer valid.


Oh it seems you already figured, my previous email was not helpful :)


> 
> Am I constructing the engine builder as it is supposed to?

CC: +Lang

— 
Mehdi


> 
> 
> 
> On 09/14/2016 10:59 AM, Frank Winter via llvm-dev wrote:
>> I get a segfault with this code when setting the data layout:
>> 
>> 
>> 
>> int main(int argc, char** argv)
>> {
>>  llvm::InitializeNativeTarget();
>> 
>>  llvm::LLVMContext TheContext;
>>  unique_ptr<Module> Mod(new Module("A",TheContext));
>> 
>>  llvm::EngineBuilder engineBuilder(std::move(Mod));
>>  std::string mcjit_error;
>> 
>>  engineBuilder.setMCPU(llvm::sys::getHostCPUName());
>> 
>>  engineBuilder.setEngineKind(llvm::EngineKind::JIT);
>>  engineBuilder.setOptLevel(llvm::CodeGenOpt::Aggressive);
>>  engineBuilder.setErrorStr(&mcjit_error);
>> 
>>  llvm::TargetOptions targetOptions;
>>  targetOptions.AllowFPOpFusion = llvm::FPOpFusion::Fast;
>>  engineBuilder.setTargetOptions( targetOptions );
>> 
>>  TargetMachine *targetMachine = engineBuilder.selectTarget();
>> 
>>  assert(targetMachine && "failed to create target machine");
>> 
>>  std::cout << targetMachine->createDataLayout().getStringRepresentation() << "\n";
>> 
>>  Mod.get()->setDataLayout( targetMachine->createDataLayout().getStringRepresentation() ); // this segfaults
>>  Mod.get()->setDataLayout( targetMachine->createDataLayout()  ); // as well as this
>> }
>> 
>> 
>> Backtrace:
>> 
>> 
>> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
>> e-m:e-i64:64-f80:128-n8:16:32:64-S128
>> 
>> Program received signal SIGSEGV, Segmentation fault.
>> 0x00007ffff5f65832 in llvm::SmallVectorTemplateCommon<unsigned char, void>::end (this=0x148) at /home/fwinter/svn/llvm-3.9/include/llvm/ADT/SmallVector.h:117
>> 117      iterator end() { return (iterator)this->EndX; }
>> (gdb) bt
>> #0  0x00007ffff5f65832 in llvm::SmallVectorTemplateCommon<unsigned char, void>::end (this=0x148) at /home/fwinter/svn/llvm-3.9/include/llvm/ADT/SmallVector.h:117
>> #1  llvm::SmallVectorImpl<unsigned char>::clear (this=0x148) at /home/fwinter/svn/llvm-3.9/include/llvm/ADT/SmallVector.h:345
>> #2  0x00007ffff5fa13b5 in llvm::DataLayout::clear (this=0x138) at /home/fwinter/svn/llvm-3.9/lib/IR/DataLayout.cpp:545
>> #3  0x00007ffff5f9f561 in llvm::DataLayout::reset (this=0x138, Desc=...) at /home/fwinter/svn/llvm-3.9/lib/IR/DataLayout.cpp:179
>> #4  0x00007ffff60b25ca in llvm::Module::setDataLayout (this=0x0, Desc=...) at /home/fwinter/svn/llvm-3.9/lib/IR/Module.cpp:377
>> #5  0x0000000000406c46 in main (argc=1, argv=0x7fffffffde68) at main.cc:95
>> 
>> 
>> Any idea?
>> 
>> Frank
>> 
>> 
>> 
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>> llvm-dev at lists.llvm.org
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> 
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