[llvm-dev] lld-link crash when linking intrinsics lib

[Peter Collingbourne via llvm-dev]

Hmm, you might need something like the ELF linker's r338434/r339301 in the
COFF linker.

Peter

On Wed, Feb 27, 2019 at 4:01 PM Rui Ueyama <ruiu at google.com> wrote:

> +Peter Collingbourne <pcc at chromium.org>
>
> LTO is used in this test case, and one source file defines its own
> `memset` function while the other file uses llvm.memset. Looks like LTO is
> confused by the user-defined memset. Could you take a look?
>
> Steven,
>
> Do you need to use LTO? I thought that LTO is a workaround to not produce
> an object file that cannot be handled by your ELF-to-COFF translation tool.
> If you are now doing a regular cross build, I guess you can remove -flto.
>
> On Wed, Feb 27, 2019 at 3:00 PM Rui Ueyama <ruiu at google.com> wrote:
>
>> Hi Steven,
>>
>> I confirmed that lld-link crashes with these inputs. That shouldn't
>> happen. I'll debug this and get back to you. Thank you for reporting.
>>
>> On Tue, Feb 26, 2019 at 8:20 PM Shi, Steven <steven.shi at intel.com> wrote:
>>
>>> Hello Rui,
>>>
>>> I met couples of lld-link crash when enable the clang-cl + lld-link
>>> build toolchain for Uefi firmware. Below is a simplified example (main.c
>>> and intrinsics.c).
>>>
>>> Uefi firmware is self-contained and doesn’t depend on the compiler
>>> intrinsics implementation, so we have our own intrinsics lib. It is weird
>>> that if I don’t use the llvm-lib but directly “lld-link /NODEFAULTLIB
>>> /ENTRY:main  main.obj intrinsics.obj”, the below example can pass link.
>>> Please advise what’s wrong in this example.
>>>
>>>
>>>
>>>
>>>
>>> $ cat main.c
>>>
>>> typedef struct {
>>>
>>>   struct MAP_LIST {
>>>
>>>     unsigned long long  VirtualAddress;
>>>
>>>     void              *MapCookie;
>>>
>>>   } MapList[100];
>>>
>>> } SNP_DRIVER;
>>>
>>> SNP_DRIVER snp_instance;
>>>
>>> int main()
>>>
>>> {
>>>
>>>   SNP_DRIVER  *Snp;
>>>
>>>   Snp = &snp_instance;
>>>
>>>   for (int Index = 0; Index < 100; Index++) {
>>>
>>>     Snp->MapList[Index].VirtualAddress = 0;
>>>
>>>     Snp->MapList[Index].MapCookie      = 0;
>>>
>>>   }
>>>
>>>   return 0;
>>>
>>> }
>>>
>>>
>>>
>>> $ cat intrinsics.c
>>>
>>> void * memset (void *dest, int ch, size_t count)
>>>
>>> {
>>>
>>>   volatile char  *Pointer;
>>>
>>>   Pointer = (char *)dest;
>>>
>>>   while (count-- != 0) {
>>>
>>>     *(Pointer++) = (char)ch;
>>>
>>>   }
>>>
>>>   return dest;
>>>
>>> }
>>>
>>>
>>>
>>>
>>>
>>> $ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" /Fomain.obj /c
>>> --target=x86_64-pc-win32-coff -m64 /O1b2s -flto main.c
>>>
>>> $ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" /Fointrinsics.obj /c
>>> --target=x86_64-pc-win32-coff -m64 /O1b2s -flto intrinsics.c
>>>
>>> $ "/home/jshi19/llvm/releaseinstall/bin/llvm-lib" /OUT:intrinsics.lib
>>> intrinsics.obj
>>>
>>> $ "/home/jshi19/llvm/releaseinstall/bin/lld-link" /NODEFAULTLIB
>>> /ENTRY:main  main.obj intrinsics.lib
>>>
>>> Stack dump:
>>>
>>> 0.      Program arguments: /home/jshi19/llvm/releaseinstall/bin/lld-link
>>> /NODEFAULTLIB /ENTRY:main main.obj intrinsics.lib
>>>
>>> #0 0x0000559a34ba5e4a llvm::sys::PrintStackTrace(llvm::raw_ostream&)
>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x272e4a)
>>>
>>> #1 0x0000559a34ba3d14 llvm::sys::RunSignalHandlers()
>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x270d14)
>>>
>>> #2 0x0000559a34ba3e52 SignalHandler(int)
>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x270e52)
>>>
>>> #3 0x00007f896c8ea890 __restore_rt
>>> (/lib/x86_64-linux-gnu/libpthread.so.0+0x12890)
>>>
>>> #4 0x0000559a34c11325
>>> lld::coff::markLive(llvm::ArrayRef<lld::coff::Chunk*>)
>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2de325)
>>>
>>> #5 0x0000559a34bf0220 lld::coff::LinkerDriver::link(llvm::ArrayRef<char
>>> const*>) (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2bd220)
>>>
>>> #6 0x0000559a34bf0478 lld::coff::link(llvm::ArrayRef<char const*>, bool,
>>> llvm::raw_ostream&) (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2bd478)
>>>
>>> #7 0x0000559a34b2a300 main
>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x1f7300)
>>>
>>> #8 0x00007f896b3c1b97 __libc_start_main
>>> /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:344:0
>>>
>>> #9 0x0000559a34b8c27a _start
>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x25927a)
>>>
>>> Segmentation fault (core dumped)
>>>
>>>
>>>
>>> $ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" --version
>>>
>>> clang version 9.0.0 (https://github.com/llvm-mirror/clang.git
>>> 1f02068469ff18f5fc5728cafe9d96ee5f66c5b9) (
>>> https://github.com/llvm-project/llvm.git
>>> 330395ea4fce35b019b33797ff751be029a1f866)
>>>
>>> Target: x86_64-pc-windows-msvc
>>>
>>> Thread model: posix
>>>
>>> InstalledDir: /home/jshi19/llvm/releaseinstall/bin
>>>
>>>
>>>
>>> $ "/home/jshi19/llvm/releaseinstall/bin/lld-link" --version
>>>
>>> LLD 9.0.0 (https://github.com/llvm-mirror/lld.git
>>> aa7adc0ec804b689771f11d52e39f83a16378f5f)
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> Thanks
>>>
>>>
>>>
>>> *Steven Shi*
>>>
>>> *Intel\SSG\FID\Firmware Infrastructure*
>>>
>>>
>>>
>>
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