[cfe-dev] libcxxabi cmake test problem on Linux x86-64

Eric Fiselier via cfe-dev cfe-dev at lists.llvm.org
Mon Dec 14 14:40:55 PST 2015


This should be fixed in r255559 and r255560.

@Ismail Please let me know if this broke something for you. I think I got
the library order I needed but I'm not 100% sure.

@Chandlerc The bootstrap should be clean now.

/Eric


On Thu, Dec 10, 2015 at 8:50 PM, Eric Fiselier <eric at efcs.ca> wrote:

> Alright, so the problem is that libgcc_eh.a marks most of the _Unwind
> symbols as hidden. This means that when libgcc_eh.a is linked into a shared
> library exceptions cannot be thrown beyond the library boundary. I think
> that both libgcc_s and libgcc_eh were being linked into lli causing the
> failures. Since we typically build libc++abi as a shared library we need to
> use libgcc_s.so instead. (I think we will still need to use libgcc_eh when
> creating a static libc++abi)
>
> I think that libc++abi should link the default libraries exactly as clang
> would if we didn't specify '-nodefaultlibs`.  This resulting link line for
> libc++abi.so should look something like:
>
>    -lm -lgcc_s -lpthread -lc -lgcc_s
>
> The resulting libc++abi.so will still have undefined references to
> libgcc.a's _Unwind symbols but libgcc.a should always be linked into the
> final executable.
> When using and testing libc++abi (via libc++) the link line should look
> something like:
>
>    -lc++ -lm -lgcc_s -lgcc -lpthread -lc -lgcc_s -lgcc
>
> When we want to use llvm's unwinder we will probably need to use -lunwind
> -lcompiler-rt instead but I'm not too familiar with this configuration.
>
> I'll put a patch together tonight.
>
> /Eric
>
> On Thu, Dec 10, 2015 at 6:26 PM, Eric Fiselier <eric at efcs.ca> wrote:
>
>> I've spent most of today looking into this and I still have no clue
>> what's going on. I think I need to know more about how lli provides libc++.
>>
>> I was able to reproduce the bug using the following steps:
>>
>> 1. export CC=clang CXX=clang++
>> 2. cmake --DLLVM_ENABLE_LIBCXX=ON -DLLVM_BUILD_PROJECTS=OFF../llvm
>> 3. ./bin/lli llvm/test/ExecutionEngine/MCJIT/eh.ll
>>
>> The above steps assume that you already have libc++.so installed
>> somewhere the linker can find it
>> and that libc++.so is a linker script that includes -lc++abi.
>>
>> I turned LLVM_BUILD_PROJECTS off so that we aren't contending with two
>> different libc++abi binaries.
>>
>> Any help with this bug would be appreciated.
>>
>> /Eric
>>
>> On Wed, Dec 9, 2015 at 12:27 PM, Chandler Carruth <chandlerc at google.com>
>> wrote:
>>
>>> Yep.
>>>
>>> On Wed, Dec 9, 2015 at 8:21 PM Eric Fiselier <eric at efcs.ca> wrote:
>>>
>>>> I don't remember what's going on here but alot has changed in a year. I
>>>> should be able to look into it later today.
>>>>
>>>> Chandler, I'm assuming your still able to reproduce the issue?
>>>>
>>>> /Eric
>>>>
>>>> On Wed, Dec 9, 2015 at 3:06 AM, Chandler Carruth <chandlerc at google.com>
>>>> wrote:
>>>>
>>>>> (Moving to the new mailing list)
>>>>>
>>>>> On Wed, Nov 26, 2014 at 10:09 PM Evgeniy Stepanov <
>>>>> eugeni.stepanov at gmail.com> wrote:
>>>>>
>>>>>> #0  0x00007ffff62b5bb9 in __GI_raise (sig=sig at entry=6) at
>>>>>> ../nptl/sysdeps/unix/sysv/linux/raise.c:56
>>>>>> #1  0x00007ffff62b8fc8 in __GI_abort () at abort.c:89
>>>>>> #2  0x00007ffff7b60807 in abort_message (format=0x7ffff7bcdf13
>>>>>> "terminating with %s exception of type %s") at
>>>>>> ../projects/libcxxabi/src/abort_message.cpp:66
>>>>>> #3  0x00007ffff7b60ad6 in default_terminate_handler () at
>>>>>> ../projects/libcxxabi/src/cxa_default_handlers.cpp:68
>>>>>> #4  0x00007ffff7bc454e in std::__terminate (func=0x7ffff7b60900
>>>>>> <default_terminate_handler()>) at
>>>>>> ../projects/libcxxabi/src/cxa_handlers.cpp:68
>>>>>> #5  0x00007ffff7bc31dd in __cxxabiv1::failed_throw
>>>>>> (exception_header=0x1e87240) at
>>>>>> ../projects/libcxxabi/src/cxa_exception.cpp:149
>>>>>> #6  0x00007ffff7bc3136 in __cxa_throw (thrown_object=0x1e872b8,
>>>>>> tinfo=0x7ffff7dd83b0 <typeinfo for int>, dest=0x0) at
>>>>>> ../projects/libcxxabi/src/cxa_exception.cpp:244
>>>>>> #7  0x00007ffff7ff502d in throwException ()
>>>>>> #8  0x00007ffff7ff503d in main ()
>>>>>> #9  0x0000000000beef04 in llvm::MCJIT::runFunction (this=0x1e74c30,
>>>>>> F=0x1e6b4b0, ArgValues=...) at
>>>>>> ../lib/ExecutionEngine/MCJIT/MCJIT.cpp:500
>>>>>> #10 0x0000000000b26f90 in llvm::ExecutionEngine::runFunctionAsMain
>>>>>> (this=0x1e74c30, Fn=0x1e6b4b0, argv=..., envp=0x7fffffffe0d0)
>>>>>>     at ../lib/ExecutionEngine/ExecutionEngine.cpp:393
>>>>>> #11 0x0000000000567cc4 in main (argc=4, argv=0x7fffffffe0a8,
>>>>>> envp=0x7fffffffe0d0) at ../tools/lli/lli.cpp:613
>>>>>>
>>>>>
>>>>> Any update here Eric? Or others? Would really like to get the
>>>>> bootstrap clean with libc++abi.
>>>>>
>>>>>
>>>>>>
>>>>>> On Wed, Nov 26, 2014 at 11:37 PM, Eric Fiselier <eric at efcs.ca> wrote:
>>>>>> > Evgeniy,
>>>>>> >
>>>>>> > Would you be willing to reproduce this again but in debug mode
>>>>>> instead
>>>>>> > of release so we get a better stack trace?
>>>>>> >
>>>>>> > /Eric
>>>>>> >
>>>>>> > On Wed, Nov 26, 2014 at 5:20 AM, Evgeniy Stepanov
>>>>>> > <eugeni.stepanov at gmail.com> wrote:
>>>>>> >> I've got the same issue.
>>>>>> >> On Linux (Trusty/x86_64), build clang with libc++/libc++abi (just
>>>>>> >> plain ninja clang cxx cxxabi w/o any special cmake flags), then
>>>>>> use it
>>>>>> >> to bootstrap clang like this:
>>>>>> >>
>>>>>> >> CC=/code/llvm/build2/bin/clang \
>>>>>> >> CXX=/code/llvm/build2/bin/clang++ \
>>>>>> >> LDFLAGS="-lc++abi -L/code/llvm/build2/lib
>>>>>> -Wl,-rpath,/code/llvm/build2/lib" \
>>>>>> >> cmake \
>>>>>> >>   -GNinja \
>>>>>> >>   -DCMAKE_BUILD_TYPE=Release \
>>>>>> >>   -DLLVM_ENABLE_LIBCXX=ON  \
>>>>>> >>   ..
>>>>>> >>
>>>>>> >> In the second tree, MCJIT tests fail with the same error:
>>>>>> >>
>>>>>> >> ./bin/lli -relocation-model=pic -code-model=large
>>>>>> >> ../test/ExecutionEngine/MCJIT/eh-lg-pic.ll
>>>>>> >> terminating with uncaught exception of type int
>>>>>> >> 0  lli             0x0000000000a80a9a
>>>>>> >> _ZN4llvm3sys15PrintStackTraceEP8_IO_FILE + 42
>>>>>> >> 1  lli             0x0000000000a81eeb
>>>>>> >> 2  libpthread.so.0 0x00007f83baabf340
>>>>>> >> 3  libc.so.6       0x00007f83b9d2fbb9 gsignal + 57
>>>>>> >> 4  libc.so.6       0x00007f83b9d32fc8 abort + 328
>>>>>> >> 5  libc++abi.so.1  0x00007f83bb5121a7
>>>>>> >> 6  libc++abi.so.1  0x00007f83bb512355
>>>>>> >> 7  libc++abi.so.1  0x00007f83bb55c3b3
>>>>>> >> 8  libc++abi.so.1  0x00007f83bb55bb66 __cxa_throw + 166
>>>>>> >> 9  libc++abi.so.1  0x00007f83bb98802d __cxa_throw + 4375917
>>>>>> >> 10 libc++abi.so.1  0x00007f83bb98803d __cxa_throw + 4375933
>>>>>> >> 11 lli             0x0000000000849649
>>>>>> >>
>>>>>> _ZN4llvm5MCJIT11runFunctionEPNS_8FunctionERKNSt3__16vectorINS_12GenericValueENS3_9allocatorIS5_EEEE
>>>>>> >> + 1209
>>>>>> >> 12 lli             0x00000000007ecd08
>>>>>> >>
>>>>>> _ZN4llvm15ExecutionEngine17runFunctionAsMainEPNS_8FunctionERKNSt3__16vectorINS3_12basic_stringIcNS3_11char_traitsIcEENS3_9allocatorIcEEEENS8_ISA_EEEEPKPKc
>>>>>> >> + 1192
>>>>>> >> 13 lli             0x000000000050c434 main + 10404
>>>>>> >> 14 libc.so.6       0x00007f83b9d1aec5 __libc_start_main + 245
>>>>>> >> 15 lli             0x00000000005092fb
>>>>>> >> Stack dump:
>>>>>> >> 0. Program arguments: ./bin/lli -relocation-model=pic
>>>>>> >> -code-model=large ../test/ExecutionEngine/MCJIT/eh-lg-pic.ll
>>>>>> >> Aborted (core dumped)
>>>>>> >>
>>>>>> >> On Sat, Aug 16, 2014 at 9:24 AM, İsmail Dönmez <ismail at donmez.ws>
>>>>>> wrote:
>>>>>> >>> Ping?
>>>>>> >>>
>>>>>> >>> On Jul 17, 2014 11:05 AM, "İsmail Dönmez" <ismail at donmez.ws>
>>>>>> wrote:
>>>>>> >>>>
>>>>>> >>>> Hi,
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>> On Wed, Jul 16, 2014 at 6:43 PM, Nico Weber <thakis at chromium.org>
>>>>>> wrote:
>>>>>> >>>>>
>>>>>> >>>>> On Wed, Jul 16, 2014 at 4:10 AM, İsmail Dönmez <
>>>>>> ismail at donmez.ws> wrote:
>>>>>> >>>>>>
>>>>>> >>>>>> Hi,
>>>>>> >>>>>>
>>>>>> >>>>>>
>>>>>> >>>>>> On Mon, Jul 14, 2014 at 8:10 PM, Dan Albert <
>>>>>> danalbert at google.com>
>>>>>> >>>>>> wrote:
>>>>>> >>>>>>>
>>>>>> >>>>>>> Submitted (with some slight modifications,
>>>>>> s/libgcc_s/libgcc_eh/) as
>>>>>> >>>>>>> r212958. Tested with and without the LLVM unwinder, and
>>>>>> things look good.
>>>>>> >>>>>>> Thanks again!
>>>>>> >>>>>>
>>>>>> >>>>>>
>>>>>> >>>>>> Changing gcc_s with gcc_eh doesn't look good. libcxxabi tests
>>>>>> pass but
>>>>>> >>>>>> llvm MCJIT exception tests fail with:
>>>>>> >>>>>>
>>>>>> >>>>>> "terminating with uncaught exception of type int"
>>>>>> >>>>>
>>>>>> >>>>>
>>>>>> >>>>> Can you try to make a reduced test case for libcxxabi from this?
>>>>>> >>>>>
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>> Smallest test cases are
>>>>>> >>>> test/ExecutionEngine/MCJIT/{eh-sm-pic,eh-lg-pic}.ll
>>>>>> >>>>
>>>>>> >>>> Both fail the same way:
>>>>>> >>>>
>>>>>> >>>>  /home/abuild/rpmbuild/BUILD/llvm/stage2/./bin/lli -use-mcjit
>>>>>> >>>> -relocation-model=pic -code-model=small
>>>>>> >>>>
>>>>>> /home/abuild/rpmbuild/BUILD/llvm/test/ExecutionEngine/MCJIT/eh-sm-pic.ll
>>>>>> >>>>  --
>>>>>> >>>>  Exit Code: 134
>>>>>> >>>>
>>>>>> >>>>  Command Output (stderr):
>>>>>> >>>>  --
>>>>>> >>>>  terminating with uncaught exception of type int
>>>>>> >>>>  0  libLLVMSupport.so         0x00007f9c6ddf7d85
>>>>>> >>>> llvm::sys::PrintStackTrace(_IO_FILE*) + 37
>>>>>> >>>>  1  libLLVMSupport.so         0x00007f9c6ddf83f3
>>>>>> >>>>  2  libpthread.so.0           0x00007f9c6d0d79f0
>>>>>> >>>>  3  libc.so.6                 0x00007f9c6c806849 gsignal + 57
>>>>>> >>>>  4  libc.so.6                 0x00007f9c6c807cd8 abort + 328
>>>>>> >>>>  5  libc++abi.so.1            0x00007f9c6cb89237
>>>>>> >>>>  6  libc++abi.so.1            0x00007f9c6cb894b6
>>>>>> >>>>  7  libc++abi.so.1            0x00007f9c6cbeda7e
>>>>>> >>>>  8  libc++abi.so.1            0x00007f9c6cbec6ed
>>>>>> >>>>  9  libc++abi.so.1            0x00007f9c6cbec646
>>>>>> >>>>  10 libc++abi.so.1            0x00007f9c6ff3001c
>>>>>> >>>>  11 libc++abi.so.1            0x00007f9c6ff30026
>>>>>> >>>>  12 libLLVMMCJIT.so           0x00007f9c6e61fd27
>>>>>> >>>> llvm::MCJIT::runFunction(llvm::Function*,
>>>>>> >>>> std::__1::vector<llvm::GenericValue,
>>>>>> std::__1::allocator<llvm::GenericValue>
>>>>>> >>>> > const&) + 919
>>>>>> >>>>  13 libLLVMExecutionEngine.so 0x00007f9c6f34fa65
>>>>>> >>>> llvm::ExecutionEngine::runFunctionAsMain(llvm::Function*,
>>>>>> >>>> std::__1::vector<std::__1::basic_string<char,
>>>>>> std::__1::char_traits<char>,
>>>>>> >>>> std::__1::allocator<char> >,
>>>>>> >>>> std::__1::allocator<std::__1::basic_string<char,
>>>>>> >>>> std::__1::char_traits<char>, std::__1::allocator<char> > > >
>>>>>> const&, char
>>>>>> >>>> const* const*) + 1221
>>>>>> >>>>  14 lli                       0x000000000040c8b7 main + 6599
>>>>>> >>>>  15 libc.so.6                 0x00007f9c6c7f2be5
>>>>>> __libc_start_main + 245
>>>>>> >>>>  16 lli                       0x000000000040a6d1
>>>>>> >>>>  Stack dump:
>>>>>> >>>>  0. Program arguments:
>>>>>> /home/abuild/rpmbuild/BUILD/llvm/stage2/./bin/lli
>>>>>> >>>> -use-mcjit -relocation-model=pic -code-model=small
>>>>>> >>>>
>>>>>> /home/abuild/rpmbuild/BUILD/llvm/test/ExecutionEngine/MCJIT/eh-sm-pic.ll
>>>>>> >>>>
>>>>>> >>>>
>>>>>> /home/abuild/rpmbuild/BUILD/llvm/stage2/test/ExecutionEngine/MCJIT/Output/eh-sm-pic.ll.script:
>>>>>> >>>> line 1: 30636 Aborted
>>>>>> >>>> /home/abuild/rpmbuild/BUILD/llvm/stage2/./bin/lli -use-mcjit
>>>>>> >>>> -relocation-model=pic -code-model=small
>>>>>> >>>>
>>>>>> /home/abuild/rpmbuild/BUILD/llvm/test/ExecutionEngine/MCJIT/eh-sm-pic.ll
>>>>>> >>>>
>>>>>> >>>> Note that this clang is hardcoded to use libc++
>>>>>> (-stdlibc=libc++). Is this
>>>>>> >>>> good enough?
>>>>>> >>>>
>>>>>> >>>> Thanks!
>>>>>> >>>>
>>>>>> >>>
>>>>>> >>> _______________________________________________
>>>>>> >>> cfe-dev mailing list
>>>>>> >>> cfe-dev at cs.uiuc.edu
>>>>>> >>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>>> >>>
>>>>>> >>
>>>>>> >> _______________________________________________
>>>>>> >> cfe-dev mailing list
>>>>>> >> cfe-dev at cs.uiuc.edu
>>>>>> >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>>>
>>>>>> _______________________________________________
>>>>>> cfe-dev mailing list
>>>>>> cfe-dev at cs.uiuc.edu
>>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>>>
>>>>>
>>>>
>>
>
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