[llvm] r273585 - Preserve DebugInfo when replacing values in DAGCombiner

Thu Jul 21 12:37:47 PDT 2016

Ismall:

I'm still having problems finding reproducing this corruption locally, but
I may have a patch. Can you check if this works?
If it doesn't, maybe you can spot what I'm doing wrong in my reproduction
steps.

Thanks,

-Nirav

1.

export MALLOC_CHECK_=3
export MALLOC_PERTURB_=69

2. Run clang -cc1 internal call from llvm-symbolizer.cpp compilation from
CMake

gdb --args
 /usr/local/google/home/niravd/build/llvm/build_debug/bin/clang-3.9 -cc1
-triple x86_64-unknown-linux-gnu -emit-obj -disable-free -g -main-file-name
llvm-symbolizer.cpp -mrelocation-model pic -pic-level 2 -mthread-model
posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables
-fuse-init-array -target-cpu x86-64 -momit-leaf-frame-pointer -v
-dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections
-D GTEST_HAS_RTTI=0 -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D
__STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/llvm-symbolizer -I
/usr/local/google/home/niravd/build/llvm_alt/llvm/tools/llvm-symbolizer -I
include -I /usr/local/google/home/niravd/build/llvm_alt/llvm/include -D
NDEBUG -internal-isystem
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8
-internal-isystem
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/x86_64-linux-gnu/c++/4.8
-internal-isystem
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/x86_64-linux-gnu/c++/4.8
-internal-isystem
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/backward
-internal-isystem /usr/local/include -internal-isystem
/usr/local/google/home/niravd/build/llvm/build_debug/bin/../lib/clang/4.0.0/include
-internal-externc-isystem /usr/include/x86_64-linux-gnu
-internal-externc-isystem /include -internal-externc-isystem /usr/include
-O3 -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual
-Wmissing-field-initializers -Wno-long-long -Wcovered-switch-default
-Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Werror=date-time -pedantic
-std=c++11 -fdeprecated-macro -fdebug-compilation-dir
/usr/local/google/home/niravd/build/llvm_alt/llvm -ferror-limit 19
-fmessage-length 211 -fvisibility-inlines-hidden -fno-rtti
-fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics
-vectorize-loops -vectorize-slp -o /tmp/llvm-symbolizer.cpp.o -x c++
/usr/local/google/home/niravd/build/llvm_alt/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp

3. Initialize mcheck(0)

break main
commands
call mcheck(0)
continue
end

4. Inspect in llvm::SelectionDAG::TransferDbgValues checking that the
values of Dbg are reasonable.

On Fri, Jul 15, 2016 at 5:20 AM, Ismail Donmez <ismail at i10z.com> wrote:

> Hi,
>
> This is most certainly a memory corruption:
>
> #0  llvm::SelectionDAG::TransferDbgValues (this=<optimized out>,
> From=..., To=...)
>     at ../lib/CodeGen/SelectionDAG/SelectionDAG.cpp:6666
> 6666        if (Dbg->getKind() == SDDbgValue::SDNODE &&
> (gdb) print Dbg
> $1 = (llvm::SDDbgValue *) 0x4545454545454545
>
>
> The value 0x45 is what I set as MALLOC_PERTURB_ [0] value. You can
> easily reproduce this on Linux with malloc debugging, just do
>
> export MALLOC_CHECK_=3
> export MALLOC_PERTURB_=69
>
> See
> https://www.gnu.org/software/libc/manual/html_node/Heap-Consistency-Checking.html
> for more details.
>
> On Thu, Jul 14, 2016 at 8:02 PM, Ismail Donmez <ismail at i10z.com> wrote:
> > Hi,
> >
> > On Thu, Jun 23, 2016 at 8:52 PM, Nirav Dave via llvm-commits
> > <llvm-commits at lists.llvm.org> wrote:
> >> Author: niravd
> >> Date: Thu Jun 23 12:52:57 2016
> >> New Revision: 273585
> >>
> >> URL: http://llvm.org/viewvc/llvm-project?rev=273585&view=rev
> >> Log:
> >> Preserve DebugInfo when replacing values in DAGCombiner
> >>
> >> Recommiting after correcting over-eager Debug Value transfer fixing
> PR28270.
> >>
> >> [DAG] Previously debug values would transfer debuginfo for the selected
> >> start node for a replacement which allows for debug to be dropped.
> >>
> >> Push debug value transfer to occur with node/value replacement in
> >> SelectionDAG, remove now extraneous transfers of debug values.
> >>
> >> This refixes PR9817 which was being incompletely checked in the
> >> testsuite.
> >
> > Can't get a reproducer easily yet but this is crashing clang in stage2
> > bootstrap while compiling llvm-symbolizer.cpp  with a backtrace like:
> >
> > #0 0x00007ff3a922cec8 llvm::sys::PrintStackTrace(llvm::raw_ostream&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/Support/Unix/Signals.inc:402:13
> > #1 0x00007ff3a922ad26 bool std::__1::operator!=<std::__1::pair<void
> > (*)(void*), void*>*>(std::__1::__wrap_iter<std::__1::pair<void
> > (*)(void*), void*>*> const&, std::__1::__wrap_iter<std::__1::pair<void
> > (*)(void*), void*>*> const&)
> > /usr/bin/../include/c++/v1/iterator:1364:12
> > #2 0x00007ff3a922ad26 llvm::sys::RunSignalHandlers()
> > /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/Support/Signals.cpp:44:0
> > #3 0x00007ff3a922d501 SignalHandler(int)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/Support/Unix/Signals.inc:256:1
> > #4 0x00007ff3a8ce4ef0 __restore_rt (/lib64/libpthread.so.0+0x10ef0)
> > #5 0x00007ff3a779d7b3
> > llvm::SelectionDAG::TransferDbgValues(llvm::SDValue, llvm::SDValue)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/SelectionDAG/SelectionDAG.cpp:6666:46
> > #6 0x00007ff3a779d551 llvm::SDValue::operator==(llvm::SDValue const&)
> > const
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../include/llvm/CodeGen/SelectionDAGNodes.h:126:27
> > #7 0x00007ff3a779d551
> > llvm::SelectionDAG::ReplaceAllUsesWith(llvm::SDValue, llvm::SDValue)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/SelectionDAG/SelectionDAG.cpp:6312:0
> > #8 0x00007ff3a768d6e0 (anonymous
> > namespace)::SelectionDAGLegalize::ReplaceNode(llvm::SDValue,
> > llvm::SDValue)
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/SelectionDAG/LegalizeDAG.cpp:190:9
> > #9 0x00007ff3a768b21f (anonymous
> > namespace)::SelectionDAGLegalize::LegalizeOp(llvm::SDNode*)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/SelectionDAG/LegalizeDAG.cpp:1128:11
> > #10 0x00007ff3a768a585 llvm::SelectionDAG::Legalize()
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/SelectionDAG/LegalizeDAG.cpp:4428:28
> > #11 0x00007ff3a77b1d34 llvm::TimeRegion::~TimeRegion()
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../include/llvm/Support/Timer.h:148:9
> > #12 0x00007ff3a77b1d34 llvm::SelectionDAGISel::CodeGenAndEmitDAG()
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:824:0
> > #13 0x00007ff3a77b027d
> > llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1482:7
> > #14 0x00007ff3a77ac88b
> > llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:505:36
> > #15 0x00007ff3aa6a4451 (anonymous
> > namespace)::X86DAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/Target/X86/X86ISelDAGToDAG.cpp:176:7
> > #16 0x00007ff3a9ca0aa5
> > llvm::MachineFunctionPass::runOnFunction(llvm::Function&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/CodeGen/MachineFunctionPass.cpp:60:13
> > #17 0x00007ff3a995df04
> > llvm::FPPassManager::runOnFunction(llvm::Function&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/IR/LegacyPassManager.cpp:1526:23
> > #18 0x00007ff3a995e14b llvm::FPPassManager::runOnModule(llvm::Module&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/IR/LegacyPassManager.cpp:1547:13
> > #19 0x00007ff3a995e5b3 (anonymous
> > namespace)::MPPassManager::runOnModule(llvm::Module&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/IR/LegacyPassManager.cpp:1603:23
> > #20 0x00007ff3a995e5b3
> > llvm::legacy::PassManagerImpl::run(llvm::Module&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../lib/IR/LegacyPassManager.cpp:1706:0
> > #21 0x00007ff3a86332ed (anonymous
> > namespace)::EmitAssemblyHelper::EmitAssembly(clang::BackendAction,
> > llvm::raw_pwrite_stream*)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/lib/CodeGen/BackendUtil.cpp:767:3
> > #22 0x00007ff3a86332ed
> > clang::EmitBackendOutput(clang::DiagnosticsEngine&,
> > clang::CodeGenOptions const&, clang::TargetOptions const&,
> > clang::LangOptions const&, llvm::DataLayout const&, llvm::Module*,
> > clang::BackendAction, llvm::raw_pwrite_stream*)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/lib/CodeGen/BackendUtil.cpp:778:0
> > #23 0x00007ff3a88317dd
> > clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/lib/CodeGen/CodeGenAction.cpp:178:7
> > #24 0x00007ff3a661d376
> > std::__1::enable_if<(is_move_constructible<bool>::value) &&
> > (is_move_assignable<bool>::value), void>::type
> > std::__1::swap<bool>(bool&, bool&)
> > /usr/bin/../include/c++/v1/type_traits:4206:9
> > #25 0x00007ff3a661d376 clang::ParseAST(clang::Sema&, bool, bool)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/lib/Parse/ParseAST.cpp:169:0
> > #26 0x00007ff3a83b3ee6 clang::FrontendAction::Execute()
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/lib/Frontend/FrontendAction.cpp:461:7
> > #27 0x00007ff3a8377c21
> > clang::CompilerInstance::ExecuteAction(clang::FrontendAction&)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/lib/Frontend/CompilerInstance.cpp:877:7
> > #28 0x00007ff3aa8c3bb9
> > clang::ExecuteCompilerInvocation(clang::CompilerInstance*)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:241:18
> > #29 0x000000000040ec2a cc1_main(llvm::ArrayRef<char const*>, char
> > const*, void*)
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/tools/driver/cc1_main.cpp:116:13
> > #30 0x000000000040d895 ExecuteCC1Tool(llvm::ArrayRef<char const*>,
> > llvm::StringRef)
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/tools/driver/driver.cpp:301:12
> > #31 0x000000000040d895 main
> >
> /home/abuild/rpmbuild/BUILD/llvm/stage1/../tools/clang/tools/driver/driver.cpp:382:0
> > #32 0x00007ff3a795d741 __libc_start_main (/lib64/libc.so.6+0x20741)
> > #33 0x000000000040a829 _start
> >
> /home/abuild/rpmbuild/BUILD/glibc-2.23/csu/../sysdeps/x86_64/start.S:121:0
> >
> > Hopefully will have more ideas later on.
>
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