[LLVMdev] Exception handling question

[James Williams]

2010/1/22 James Williams <junk at giantblob.com>

>
>
> 2010/1/22 Duncan Sands <baldrick at free.fr>
>
>> Hi James,
>>
>>
>>     want to send us your testcase code?  Then we can give it a whirl.
>>>
>>>
>>> Test code is at http://giantblob.com/ehtest.tar.gz
>>>
>>> Thanks for the help. I apologize in advance if it turns out I'm doing
>>> something stupid!
>>>
>>
>> I hope you realise that by running llvm-ld without -native you are
>> actually
>> executing your program from the JIT.  I did a native compilation as
>> follows:
>> used llvm-link to link all of the bitcode into "total.bc"; ran llc on
>> total.bc,
>> producing "total.s"; did "g++ -o total total.s"; ran ./total.  It seems to
>> work:
>>
>> $ ./total
>> __l_personality called$
>>
>> Of course it is probably supposed to work from the JIT too (I don't know
>> anything about the JIT), but it clearly doesn't: when I tried I got:
>>
>> lli: lib/ExecutionEngine/JIT/JIT.cpp:624: void
>> llvm::JIT::runJITOnFunctionUnlocked(llvm::Function*, const
>> llvm::MutexGuard&): Assertion `!isAlreadyCodeGenerating && "Error: Recursive
>> compilation detected!"' failed.
>> ...
>> 6  lli       0x0000000000d3f5e2
>> llvm::JIT::runJITOnFunctionUnlocked(llvm::Function*, llvm::MutexGuard
>> const&) + 62
>> 7  lli       0x0000000000d3f9c6
>> llvm::JIT::getPointerToFunction(llvm::Function*) + 686
>> 8  lli       0x0000000000d67c86
>> llvm::ExecutionEngine::getPointerToGlobal(llvm::GlobalValue const*) + 70
>> 9  lli       0x0000000000d62805
>> llvm::JITDwarfEmitter::EmitCommonEHFrame(llvm::Function const*) const + 613
>> 10 lli       0x0000000000d60ac3
>> llvm::JITDwarfEmitter::EmitDwarfTable(llvm::MachineFunction&,
>> llvm::JITCodeEmitter&, unsigned char*, unsigned char*, unsigned char*&) +
>> 335
>> ...
>>
> Thanks for looking at this.
>
> Yes, I realise this will link to bitcode and that the result is a script
> that runs lli. I kind of just expected JIT to work, particularly since the
> example code on the wiki uses JIT.
>
> The JIT is what my project will eventually target (goal is an out of
> process compiler will incrementally generate bitcode on disk combined with
> an application server that will run resulting bitcode via JIT) and hence
> I've only been testing on the JIT.
>
> I'll see if I can work around the recursive compilation problem.
>
> -- James
>

Sorry - t's only just sunk in that the JIT must use a completely different
mechanism to load the eh tables versus having  as + ld and the ELF loader do
it and that posting the assembler when I was seeing the JIT fail was
probably unhelpful. I apologise for the confusion.

-- James

>
>
>> Ciao,
>>
>> Duncan.
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20100122/d5700562/attachment.html>