[LLVMdev] Crash on invalid during LLVMContext destruction MDNode::dropAllReferences

Tue Jan 13 23:48:53 PST 2015

Not at a computer right now, but it looks like teardown isn't working correctly.  Do you have an asserts build?  Does an assertion fire there?

Looking at the stack trace, dropAllReferences() is being called on a node, so it sets its operands to nullptr, and some operand has RAUW support (so the tracking needs to be dropped) but looks like it might have been deleted or is otherwise corrupt.  Hard to tell though. 

Does this reproduce from preprocessed source?   Can you send it to me?

Or maybe that's a test case in your email.  I'll try it in the morning.

-- dpnes

> On Jan 13, 2015, at 10:30 PM, David Blaikie <dblaikie at gmail.com> wrote:
> 
> Hi Duncan,
> 
> I came across something like the following recently which I guess might be related to your recent work. Any ideas?
> 
> $ clang++-tot -cc1 crash_on_invalid.cpp -g -emit-obj -fexceptions -fcxx-exceptions
> crash_on_invalid.cpp:13:1: error: C++ requires a type specifier for all declarations
> x;
> ^
> 1 error generated.
> *** Error in `clang++-tot': corrupted double-linked list: 0x000000000754f340 ***
> ^C
> blaikie at blaikie-linux:/tmp/dbginfo$ cat crash_on_invalid.cpp
> // RUN: %clang_cc1 -fexceptions -fcxx-exceptions -g -std=c++11 -S -emit-llvm %s -o - | FileCheck %s
> 
> extern "C" __complex float complex_src();
> 
> struct foo {
>   __complex float k;
>   foo();
> };
> 
> foo::foo()
>     : k(complex_src()) {
> }
> x;
> 
> 
> In some nearby/related test cases rather than a vague corrupted double-linked list error, I get a stack something like:
> 
> #0 0x1efe5de llvm::sys::PrintStackTrace(_IO_FILE*) /usr/local/google/home/blaikie/dev/llvm/src/lib/Support/Unix/Signals.inc:422:15
> #1 0x1eff37b PrintStackTraceSignalHandler(void*) /usr/local/google/home/blaikie/dev/llvm/src/lib/Support/Unix/Signals.inc:481:1
> #2 0x1f01653 SignalHandler(int) /usr/local/google/home/blaikie/dev/llvm/src/lib/Support/Unix/Signals.inc:198:60
> #3 0x7f6893e22340 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x10340)
> #4 0x1ae3a9f bool llvm::DenseMapBase<llvm::SmallDenseMap<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long>, 4u, llvm::DenseMapInfo<void*>, llvm::detail::DenseMapPair<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long> > >, void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long>, llvm::DenseMapInfo<void*>, llvm::detail::DenseMapPair<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long> > >::LookupBucketFor<void*>(void* const&, llvm::detail::DenseMapPair<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long> > const*&) const /usr/local/google/home/blaikie/dev/llvm/src/include/llvm/ADT/DenseMap.h:495:34
> #5 0x1ae3968 bool llvm::DenseMapBase<llvm::SmallDenseMap<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long>, 4u, llvm::DenseMapInfo<void*>, llvm::detail::DenseMapPair<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long> > >, void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long>, llvm::DenseMapInfo<void*>, llvm::detail::DenseMapPair<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long> > >::LookupBucketFor<void*>(void* const&, llvm::detail::DenseMapPair<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long> >*&) /usr/local/google/home/blaikie/dev/llvm/src/include/llvm/ADT/DenseMap.h:525:10
> #6 0x1ad2453 llvm::DenseMapBase<llvm::SmallDenseMap<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long>, 4u, llvm::DenseMapInfo<void*>, llvm::detail::DenseMapPair<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long> > >, void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long>, llvm::DenseMapInfo<void*>, llvm::detail::DenseMapPair<void*, std::pair<llvm::PointerUnion<llvm::MetadataAsValue*, llvm::Metadata*>, unsigned long> > >::erase(void* const&) /usr/local/google/home/blaikie/dev/llvm/src/include/llvm/ADT/DenseMap.h:200:10
> #7 0x1ad23da llvm::ReplaceableMetadataImpl::dropRef(void*) /usr/local/google/home/blaikie/dev/llvm/src/lib/IR/Metadata.cpp:134:8
> #8 0x1ae5c6a llvm::MetadataTracking::untrack(void*, llvm::Metadata&) /usr/local/google/home/blaikie/dev/llvm/src/lib/IR/MetadataTracking.cpp:43:1
> #9 0xa1282c llvm::MetadataTracking::untrack(llvm::Metadata*&) /usr/local/google/home/blaikie/dev/llvm/src/include/llvm/IR/MetadataTracking.h:69:59
> #10 0x1ae5221 llvm::MDOperand::untrack() /usr/local/google/home/blaikie/dev/llvm/src/include/llvm/IR/Metadata.h:562:3
> #11 0x1ad6d84 llvm::MDOperand::reset(llvm::Metadata*, llvm::Metadata*) /usr/local/google/home/blaikie/dev/llvm/src/include/llvm/IR/Metadata.h:545:5
> #12 0x1ad4efd llvm::MDNode::setOperand(unsigned int, llvm::Metadata*) /usr/local/google/home/blaikie/dev/llvm/src/lib/IR/Metadata.cpp:764:1
> #13 0x1ad58cd llvm::MDNode::dropAllReferences() /usr/local/google/home/blaikie/dev/llvm/src/lib/IR/Metadata.cpp:492:49
> #14 0x1aaccc9 llvm::LLVMContextImpl::~LLVMContextImpl() /usr/local/google/home/blaikie/dev/llvm/src/lib/IR/LLVMContextImpl.cpp:142:5
> #15 0x1aaa24d llvm::LLVMContext::~LLVMContext() /usr/local/google/home/blaikie/dev/llvm/src/lib/IR/LLVMContext.cpp:97:31
> #16 0x2555d3b clang::CodeGenAction::~CodeGenAction() /usr/local/google/home/blaikie/dev/llvm/src/tools/clang/lib/CodeGen/CodeGenAction.cpp:578:5
> #17 0x2558295 clang::EmitLLVMAction::~EmitLLVMAction() /usr/local/google/home/blaikie/dev/llvm/src/tools/clang/include/clang/CodeGen/CodeGenAction.h:77:7
> #18 0x25582b9 clang::EmitLLVMAction::~EmitLLVMAction() /usr/local/google/home/blaikie/dev/llvm/src/tools/clang/include/clang/CodeGen/CodeGenAction.h:77:7
> #19 0x213a2e2 std::default_delete<clang::FrontendAction>::operator()(clang::FrontendAction*) const /usr/local/google/home/blaikie/install/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.9.0/../../../../include/c++/4.9.0/bits/unique_ptr.h:77:7
> #20 0x213a256 std::unique_ptr<clang::FrontendAction, std::default_delete<clang::FrontendAction> >::~unique_ptr() /usr/local/google/home/blaikie/install/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.9.0/../../../../include/c++/4.9.0/bits/unique_ptr.h:237:2
> #21 0x228a7c1 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) /usr/local/google/home/blaikie/dev/llvm/src/tools/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:226:1
> #22 0x9f8a47 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) /usr/local/google/home/blaikie/dev/llvm/src/tools/clang/tools/driver/cc1_main.cpp:110:3
> #23 0x9ee003 ExecuteCC1Tool(llvm::ArrayRef<char const*>, llvm::StringRef) /usr/local/google/home/blaikie/dev/llvm/src/tools/clang/tools/driver/driver.cpp:369:12
> #24 0x9ed057 main /usr/local/google/home/blaikie/dev/llvm/src/tools/clang/tools/driver/driver.cpp:415:12
> #25 0x7f689354eec5 __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:321:0
> #26 0x9ecaf4 _start (/mnt/fast/dev/llvm/build/clang/debug/split/notypes/nostandalone/bin/clang-3.5+0x9ecaf4)