[llvm-dev] setDataLayout segfault

[Frank Winter via llvm-dev]

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So I conclude that any type of operation on the module is no longer valid.

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

Frank


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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