<div dir="ltr"><div dir="ltr">On Wed, Feb 27, 2019 at 4:11 PM Shi, Steven <<a href="mailto:steven.shi@intel.com">steven.shi@intel.com</a>> wrote:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<p class="MsoNormal"><a name="m_-6464440701852042691__MailEndCompose">>Steven,<u></u><u></u></a></p>
<p class="MsoNormal">>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.<u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Yes, I need the LTO for the smallest code size. Without LTO, my firmware image will be +30% larger which is not competitive with MSVC.</span></p></div></div></blockquote><div><br></div><div>In the meantime you probably want to experiment clang-cl and lld without -flto. Once this issue is resolved, you can turn it on.</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div lang="EN-US"><div class="gmail-m_-6464440701852042691WordSection1">
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Thanks<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Steven
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<p class="MsoNormal"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u> <u></u></span></p>
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<p class="MsoNormal"><a name="m_-6464440701852042691______replyseparator"></a><b><span style="font-size:11pt;font-family:Calibri,sans-serif">From:</span></b><span style="font-size:11pt;font-family:Calibri,sans-serif"> Rui Ueyama [mailto:<a href="mailto:ruiu@google.com" target="_blank">ruiu@google.com</a>]
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<b>Sent:</b> Thursday, February 28, 2019 8:01 AM<br>
<b>To:</b> Shi, Steven <<a href="mailto:steven.shi@intel.com" target="_blank">steven.shi@intel.com</a>>; Peter Collingbourne <<a href="mailto:pcc@chromium.org" target="_blank">pcc@chromium.org</a>><br>
<b>Cc:</b> Peter Smith <<a href="mailto:peter.smith@linaro.org" target="_blank">peter.smith@linaro.org</a>>; Martin Storsjö <<a href="mailto:martin@martin.st" target="_blank">martin@martin.st</a>>; <a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a><br>
<b>Subject:</b> Re: lld-link crash when linking intrinsics lib<u></u><u></u></span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal"><a href="mailto:pcc@chromium.org" target="_blank">+Peter Collingbourne</a><u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">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?<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Steven,<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">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.<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">On Wed, Feb 27, 2019 at 3:00 PM Rui Ueyama <<a href="mailto:ruiu@google.com" target="_blank">ruiu@google.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">Hi Steven,<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">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.<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">On Tue, Feb 26, 2019 at 8:20 PM Shi, Steven <<a href="mailto:steven.shi@intel.com" target="_blank">steven.shi@intel.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">Hello Rui,<u></u><u></u></p>
<p class="MsoNormal">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).
<u></u><u></u></p>
<p class="MsoNormal">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.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">$ cat main.c<u></u><u></u></p>
<p class="MsoNormal">typedef struct {<u></u><u></u></p>
<p class="MsoNormal"> struct MAP_LIST {<u></u><u></u></p>
<p class="MsoNormal"> unsigned long long VirtualAddress;<u></u><u></u></p>
<p class="MsoNormal"> void *MapCookie;<u></u><u></u></p>
<p class="MsoNormal"> } MapList[100];<u></u><u></u></p>
<p class="MsoNormal">} SNP_DRIVER;<u></u><u></u></p>
<p class="MsoNormal">SNP_DRIVER snp_instance;<u></u><u></u></p>
<p class="MsoNormal">int main()<u></u><u></u></p>
<p class="MsoNormal">{<u></u><u></u></p>
<p class="MsoNormal"> SNP_DRIVER *Snp;<u></u><u></u></p>
<p class="MsoNormal"> Snp = &snp_instance;<u></u><u></u></p>
<p class="MsoNormal"> for (int Index = 0; Index < 100; Index++) {<u></u><u></u></p>
<p class="MsoNormal"> Snp->MapList[Index].VirtualAddress = 0;<u></u><u></u></p>
<p class="MsoNormal"> Snp->MapList[Index].MapCookie = 0;<u></u><u></u></p>
<p class="MsoNormal"> }<u></u><u></u></p>
<p class="MsoNormal"> return 0;<u></u><u></u></p>
<p class="MsoNormal">}<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">$ cat intrinsics.c<u></u><u></u></p>
<p class="MsoNormal">void * memset (void *dest, int ch, size_t count)<u></u><u></u></p>
<p class="MsoNormal">{<u></u><u></u></p>
<p class="MsoNormal"> volatile char *Pointer;<u></u><u></u></p>
<p class="MsoNormal"> Pointer = (char *)dest;<u></u><u></u></p>
<p class="MsoNormal"> while (count-- != 0) {<u></u><u></u></p>
<p class="MsoNormal"> *(Pointer++) = (char)ch;<u></u><u></u></p>
<p class="MsoNormal"> }<u></u><u></u></p>
<p class="MsoNormal"> return dest;<u></u><u></u></p>
<p class="MsoNormal">}<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">$ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" /Fomain.obj /c --target=x86_64-pc-win32-coff -m64 /O1b2s -flto main.c<u></u><u></u></p>
<p class="MsoNormal">$ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" /Fointrinsics.obj /c --target=x86_64-pc-win32-coff -m64 /O1b2s -flto intrinsics.c<u></u><u></u></p>
<p class="MsoNormal">$ "/home/jshi19/llvm/releaseinstall/bin/llvm-lib" /OUT:intrinsics.lib intrinsics.obj<u></u><u></u></p>
<p class="MsoNormal">$ "/home/jshi19/llvm/releaseinstall/bin/lld-link" /NODEFAULTLIB /ENTRY:main main.obj intrinsics.lib<u></u><u></u></p>
<p class="MsoNormal">Stack dump:<u></u><u></u></p>
<p class="MsoNormal">0. Program arguments: /home/jshi19/llvm/releaseinstall/bin/lld-link /NODEFAULTLIB /ENTRY:main main.obj intrinsics.lib<u></u><u></u></p>
<p class="MsoNormal">#0 0x0000559a34ba5e4a llvm::sys::PrintStackTrace(llvm::raw_ostream&) (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x272e4a)<u></u><u></u></p>
<p class="MsoNormal">#1 0x0000559a34ba3d14 llvm::sys::RunSignalHandlers() (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x270d14)<u></u><u></u></p>
<p class="MsoNormal">#2 0x0000559a34ba3e52 SignalHandler(int) (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x270e52)<u></u><u></u></p>
<p class="MsoNormal">#3 0x00007f896c8ea890 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x12890)<u></u><u></u></p>
<p class="MsoNormal">#4 0x0000559a34c11325 lld::coff::markLive(llvm::ArrayRef<lld::coff::Chunk*>) (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2de325)<u></u><u></u></p>
<p class="MsoNormal">#5 0x0000559a34bf0220 lld::coff::LinkerDriver::link(llvm::ArrayRef<char const*>) (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2bd220)<u></u><u></u></p>
<p class="MsoNormal">#6 0x0000559a34bf0478 lld::coff::link(llvm::ArrayRef<char const*>, bool, llvm::raw_ostream&) (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2bd478)<u></u><u></u></p>
<p class="MsoNormal">#7 0x0000559a34b2a300 main (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x1f7300)<u></u><u></u></p>
<p class="MsoNormal">#8 0x00007f896b3c1b97 __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:344:0<u></u><u></u></p>
<p class="MsoNormal">#9 0x0000559a34b8c27a _start (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x25927a)<u></u><u></u></p>
<p class="MsoNormal">Segmentation fault (core dumped)<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">$ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" --version<u></u><u></u></p>
<p class="MsoNormal">clang version 9.0.0 (<a href="https://github.com/llvm-mirror/clang.git" target="_blank">https://github.com/llvm-mirror/clang.git</a> 1f02068469ff18f5fc5728cafe9d96ee5f66c5b9) (<a href="https://github.com/llvm-project/llvm.git" target="_blank">https://github.com/llvm-project/llvm.git</a>
330395ea4fce35b019b33797ff751be029a1f866)<u></u><u></u></p>
<p class="MsoNormal">Target: x86_64-pc-windows-msvc<u></u><u></u></p>
<p class="MsoNormal">Thread model: posix<u></u><u></u></p>
<p class="MsoNormal">InstalledDir: /home/jshi19/llvm/releaseinstall/bin<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">$ "/home/jshi19/llvm/releaseinstall/bin/lld-link" --version<u></u><u></u></p>
<p class="MsoNormal">LLD 9.0.0 (<a href="https://github.com/llvm-mirror/lld.git" target="_blank">https://github.com/llvm-mirror/lld.git</a> aa7adc0ec804b689771f11d52e39f83a16378f5f)<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Thanks<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:10pt;font-family:Arial,sans-serif">Steven Shi</span></b><u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:10pt;font-family:Arial,sans-serif">Intel\SSG\FID\Firmware Infrastructure</span></b><u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
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