llvm dev - Jun 2008 - [LLVMdev] ExecutionEngine::create returns 0

What does it mean when ExecutionEngine::create returns 0?

Here's a simplified example:

#include "llvm/Module.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"

main()
{
  llvm::Module * module = new llvm::Module("the module");
  llvm::ExecutionEngine *ee = llvm::ExecutionEngine::create(module);
  fprintf(stdout, "pointer is %x.\n", ee);
}

I discovered this with a more complicated example in which I got
a segmentation fault the moment I tried to use the created execution
engine for anything.


In case they are relevant, here are the commands I used to comile the thing

g++ -o broken.o -c -I/farhome/hendrik/dv/llvm/llvm/include
-I/farhome/hendrik/dv/llvm/obj/include -D_DEBUG -D_GNU_SOURCE
-D__STDC_LIMIT_MACROS -g -Woverloaded-virtual broken.cpp
g++ -o broken broken.o
/farhome/hendrik/dv/llvm/obj/Debug/lib/LLVMExecutionEngine.o
/farhome/hendrik/dv/llvm/obj/Debug/lib/LLVMJIT.o
-L/farhome/hendrik/dv/llvm/obj/Debug/lib -lpthread -ldl -lm -lLLVMCore
-lLLVMSupport -lLLVMSystem -lLLVMAnalysis -lLLVMTarget -lLLVMSystem
-lLLVMAsmParser -lLLVMCodeGen -lLLVMCore -lLLVMSupport

-- hendrik

On Sat, 07 Jun 2008 15:24:41 +0000, Hendrik Boom wrote:
> What does it mean when ExecutionEngine::create returns 0?
> 
> Here's a simplified example:
> 
> #include "llvm/Module.h"
> #include "llvm/ExecutionEngine/ExecutionEngine.h"
> 
> main()
> {
>   llvm::Module * module = new llvm::Module("the module");
>   llvm::ExecutionEngine *ee = llvm::ExecutionEngine::create(module);
>   fprintf(stdout, "pointer is %x.\n", ee);
> }
> 
> I discovered this with a more complicated example in which I got a
> segmentation fault the moment I tried to use the created execution
> engine for anything.
I got the toy.cpp program from Chapter 4 of the tutorial to compile, after
one change to line 359  from
   return ConstantFP::get(Type::DoubleTy, APFloat(Val));
to
   return ConstantFP::get(APFloat(Val));

Now to compare it in detail with the much smaller program I've got and
maybe I'll figure out what's wrong with my call to
ExecutionEngine::create.

-- hendrik

> Now to compare it in detail with the much smaller program I've got and
> maybe I'll figure out what's wrong with my call to
> ExecutionEngine::create.
That call is perfectly valid, actually. It works for me when linked with:

g++ -o b b.o `llvm-config --ldflags` `llvm-config --libs engine jit`

Cheers,
-Mahadevan.