[llvm-dev] [cfe-dev] Orc Windows C++

Mon Oct 5 09:16:46 PDT 2015

It’s pretty intermittent at the moment…sometimes I get the relocation overflow issue, sometimes I get another issue about BSS sections having no contents.

The source code to reproduce either is simple:

#include <iostream>

int main (int argc, char* argv[])
{

}

I’ve managed to reproduce the BSS section issue in clang consistently, and since that comes before terms of where it happens in the compilation / JIT’ing process, I can’t get to the part where I see the relocation issue in clang.exe rather than my own program.

clang.exe -c "Y:\Documents\Visual Studio 2013\Projects\NewProject\Source\main.cpp"
llvm-rtdyld.exe" -execute main.o -dylib=C:\Windows\System32\msvcr120d.dll

It also occurs with -mcmodel=large specified.

The exact output of the second command, llvm-rtdyld, is as follows...

Assertion failed: (Sec->Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 && "BSS sections don't have contents!", file C:\llvm\llvm\lib\Object\COFFObjectFile.cpp, line 951
0x00007FF65EAA574C (0x0000000000000016 0x00007FFC73140648 0x0000007900000008 0x00000079E68EDC40), HandleAbort() + 0xC bytes(s), c:\llvm\llvm\lib\support\windows\signals.inc, line 296
0x00007FFC807B396F (0x00007FF600000016 0x0000000000000000 0x0000007900000004 0x0000000000000101), raise() + 0x35F bytes(s)
0x00007FFC807C2060 (0x00000079E68EE3F0 0x0000000000000240 0x00007FFC80888430 0x00007FF65F7BFF80), abort() + 0x40 bytes(s)
0x00007FFC807ABF78 (0x00007FF65F7BFF80 0x00007FF65F7BFEF0 0xCCCCCCCC000003B7 0xCCCCCCCCCCCCCCCC), _wassert() + 0x108 bytes(s)
0x00007FF65E9E7F57 (0x00000079E6A4AC40 0x00000079E68EE998 0x00000079E6A317FC 0x00000079E68EE968), llvm::object::COFFObjectFile::getSectionContents() + 0x77 bytes(s), c:\llvm\llvm\lib\object\coffobject
file.cpp, line 951 + 0x43 byte(s)
0x00007FF65E9E46E4 (0x00000079E6A4AC40 0x00000079E68EEE88 0x00000079E6A317FC 0x00000079E68EEC98), llvm::object::COFFObjectFile::getSectionContents() + 0x74 bytes(s), c:\llvm\llvm\lib\object\coffobject
file.cpp, line 293
0x00007FF65E8B2BC5 (0x00000079E68EEC48 0x00000079E68EEE88 0x00000079E68EEC98 0x00000079E68EEC78), llvm::object::SectionRef::getContents() + 0x55 bytes(s), c:\llvm\llvm\include\llvm\object\objectfile.h
, line 375 + 0x2D byte(s)
0x00007FF65EA1E516 (0x00000079E6A5DEA0 0x00000079E68EEFF0 0x00000079E6A4AC40 0xCCCCCCCCCCCCCCCC), llvm::RuntimeDyldImpl::loadObjectImpl() + 0x4D6 bytes(s), c:\llvm\llvm\lib\executionengine\runtimedyld
\runtimedyld.cpp, line 186 + 0x25 byte(s)
0x00007FF65EA431AC (0x00000079E6A5DEA0 0x00000079E68EF708 0x00000079E6A4AC40 0x00000079E68EF0C8), llvm::RuntimeDyldCOFF::loadObject() + 0x3C bytes(s), c:\llvm\llvm\lib\executionengine\runtimedyld\runt
imedyldcoff.cpp, line 57 + 0x14 byte(s)
0x00007FF65EA1B411 (0x00000079E68EF338 0x00000079E68EF708 0x00000079E6A4AC40 0xCCCCCCCCCCCCCCCC), llvm::RuntimeDyld::loadObject() + 0x221 bytes(s), c:\llvm\llvm\lib\executionengine\runtimedyld\runtime
dyld.cpp, line 928 + 0x2F byte(s)
0x00007FF65E6781A9 (0x00007FF65FB9AB70 0x00000079E6A45150 0x00007FF65F177408 0xCCCCCCCCCCCCCCCC), executeInput() + 0x419 bytes(s), c:\llvm\llvm\tools\llvm-rtdyld\llvm-rtdyld.cpp, line 365 + 0x1D byte(
s)
0x00007FF65E67A885 (0x00007FF600000004 0x00000079E6A45150 0x0000000000000000 0x0000000000000000), main() + 0xF5 bytes(s), c:\llvm\llvm\tools\llvm-rtdyld\llvm-rtdyld.cpp, line 687 + 0x5 byte(s)
0x00007FF65EE518CD (0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000), __tmainCRTStartup() + 0x19D bytes(s), f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c, line 626 + 0x19 byte
(s)
0x00007FF65EE519FE (0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000), mainCRTStartup() + 0xE bytes(s), f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c, line 466
0x00007FFC9C4F2D92 (0x00007FFC9C4F2D70 0x0000000000000000 0x0000000000000000 0x0000000000000000), BaseThreadInitThunk() + 0x22 bytes(s)
0x00007FFC9EE19F64 (0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000), RtlUserThreadStart() + 0x34 bytes(s)

…the stack trace of which looks semantically the same as when I have that assertion triggered in my own program.

Relevant information:
- llvm, clang and compiler-rt revision 249038 from trunk
- built with the command (where ../llvm is the llvm source root) cmake -G "Visual Studio 12 2013 Win64" -DLLVM_INCLUDE_EXAMPLES=OFF -DLLVM_INCLUDE_TESTS=OFF -DLLVM_INCLUDE_DOCS=OFF -DLLVM_USE_CRT_DEBUG=MDd -DLLVM_USE_CRT_RELEASE=MD ../llvm
- VS2013 version 12.0.40629.00 Update 5

Running the same code without llvm-rtdyld.exe (i.e. non-JIT) does so without error.

Thanks very much for any response!

(Sorry for the slow reply, was trying to get something as minimal as possible for you to look at)

> On 2 Oct 2015, at 19:45, Andy Ayers <andya at microsoft.com> wrote:
> 
> If LLVM is generating the x64 code and you have specified a large code model, you should not see any 32 bit relocations.
> 
> So it would be interesting to determine what kind of relocation you are seeing and where it came from.
> 
> -----Original Message-----
> From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Joshua Gerrard via llvm-dev
> Sent: Friday, October 2, 2015 1:18 AM
> To: Hayden Livingston <halivingston at gmail.com>
> Cc: llvm-dev <llvm-dev at lists.llvm.org>
> Subject: Re: [llvm-dev] [cfe-dev] Orc Windows C++
> 
> Thanks for the link!
> There’s some code there that looks extremely relevant to say the least.
> 
>> On 1 Oct 2015, at 19:00, Hayden Livingston <halivingston at gmail.com> wrote:
>> 
>> Maybe looking at their code might help:
>> 
>> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fgithu
>> b.com%2fdotnet%2fllilc%2fblob%2fdd12743f9cdb5418f1c39b2cd756da1e8396a9
>> 22%2flib%2fJit%2fLLILCJit.cpp%23L299&data=01%7c01%7candya%40microsoft.
>> com%7ce71168aad7ca4c98ee1f08d2cb024bf8%7c72f988bf86f141af91ab2d7cd011d
>> b47%7c1&sdata=4LCM5dPAFSQZYdEV2jNoXbtIg79%2foS5%2bB8O2Nl3ZqT4%3d
>> 
>> On Thu, Oct 1, 2015 at 10:45 AM, David Blaikie via llvm-dev 
>> <llvm-dev at lists.llvm.org> wrote:
>>> Moving to the LLVM Dev list & cc'ing Lang.
>>> 
>>> On Thu, Oct 1, 2015 at 4:23 AM, Joshua Gerrard via cfe-dev 
>>> <cfe-dev at lists.llvm.org> wrote:
>>>> 
>>>> Hello folks,
>>>> 
>>>> I’m developing an application that uses Orc JIT for C++, which works 
>>>> swimmingly on Mac OS X. However, the Windows version has been a 
>>>> battle and a half, and it’s now at the point where I need some assistance to progress.
>>>> 
>>>> The problem I’m having is “Relocation overflow” (related:
>>>> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fllv
>>>> m.org%2fbugs%2fshow_bug.cgi%3fid%3d23228%23c8%2c&data=01%7c01%7candy
>>>> a%40microsoft.com%7ce71168aad7ca4c98ee1f08d2cb024bf8%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=SnxHR5RzKhzNYFDeryATV0MSpqTcjZauHtTG2GTEazA%3d see #8) … so I spoke to some clang developers who focussed on Windows at CppCon last week, and they gave me the following advice:
>>>> - Use ELF
>>>>   - Using this results in another issue about comdat sections, see here:
>>>> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2froo
>>>> t.cern.ch%2fphpBB3%2fviewtopic.php%3ft%3d19808&data=01%7c01%7candya%
>>>> 40microsoft.com%7ce71168aad7ca4c98ee1f08d2cb024bf8%7c72f988bf86f141a
>>>> f91ab2d7cd011db47%7c1&sdata=DxCUHFZFW7SxfN6pHlHDfT3yY4DrE5DZTyLCVDWv
>>>> 3Yw%3d
>>>> - Stick with COFF, but use the large code model
>>>>   - No observed difference, seems to be the case because JITDefault 
>>>> is being used in the same way as Large, which would make sense
>>>>   - According to the clang developers I spoke to, Lang and Andy 
>>>> might have an interest in fixing this (would seem likely, as they’re 
>>>> the two commenters on the first issue I linked), since it’s better 
>>>> to use COFF on Windows than keep trying to work around it
>>>> 
>>>> Any ideas?
>>>> 
>>>> Thanks in advance!
>>>> 
>>>> _______________________________________________
>>>> cfe-dev mailing list
>>>> cfe-dev at lists.llvm.org
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>>>> s.llvm.org%2fcgi-bin%2fmailman%2flistinfo%2fcfe-dev&data=01%7c01%7ca
>>>> ndya%40microsoft.com%7ce71168aad7ca4c98ee1f08d2cb024bf8%7c72f988bf86
>>>> f141af91ab2d7cd011db47%7c1&sdata=9uOfIMd1%2b2DesS3Bne%2f2jkbDpV5REzk
>>>> VYj33rujvMGY%3d
>>>> 
>>> 
>>> 
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> 
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