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find last iv TF fix#9
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@lukel97 lukel97 commented Apr 7, 2026 •
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@lukel97 lukel97 force-pushed the find-last-iv-TF-fix branch from 1e46c0f to e54cbc3 Compare April 7, 2026 09:03
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lukel97 commented Apr 7, 2026

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/test-suite

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test-suite diff from 399653cc81edd12e15d694cb945062f78136ab5b...cac250bea94984ba7f5e6ce0c13569bca6ade815: https://github.com/lukel97/llvm-project/actions/runs/24075280134/artifacts/6304250385

@ElvisWang123 @lukel97
Precommit tests.
1bafe27
@ElvisWang123 @lukel97
[LV] Fix cmp-select reduction phi backedge when fold tail.
53d88bb 
When folding tail, we need to make sure the there is a select after the
cmp-select reduction chain to make sure no poison in the phi backedge.

The original approach might works for targets other than RISCV. But in
RISCV, the last two iterations might not operate on full lanes. So the
`vec.phi` already contains poison value when try to select from middle
block.

This patch set the backedge of reduction phi to the original backedge
instead of the `%select`.

Before
```
vector.body:
  %vec.phi = [-1, %vector.ph], [%select, %vector.body]
  ...
  %cmp = icmp ...
  %select = %cmp, ...
  ...
middle.block
  %predicated.red.select = select %header-mask, %select, %vec.phi
  %red = compute-reduction-result(%predicated.red.select)
```
To
```
vector.body:
  %vec.phi = [-1, %vector.ph], [%predicated.red.select, %vector.body]
  ...
  %cmp = icmp ...
  %select = %cmp, ...
  %predicated.red.select = select %header-mask, %select, %vec.phi
  ...
middle.block
  %red = compute-reduction-result(%predicated.red.select)
@lukel97 lukel97 force-pushed the find-last-iv-TF-fix branch from e54cbc3 to 53d88bb Compare April 7, 2026 11:52
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test-suite diff from f7ba728...459fc44: https://github.com/lukel97/llvm-project/actions/runs/24079919524/artifacts/6306361357

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test-suite diff from f7ba728...459fc44: https://github.com/lukel97/llvm-project/actions/runs/24085263247/artifacts/6308995345

lukel97 pushed a commit that referenced this pull request Apr 16, 2026
@GeorgeHuyubo
[lldb] Fix stale Symbol pointer crash in statusline after 'target sym…
02fdc8f 
…bols add' (llvm#188377)

Context: 
lldb might crash when running to a debuggee crashing state and do a
target symbols add command.
Backtrace: 
```
 #0 0x000055ca6790dc65 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:848:11
 #1 0x000055ca6790e434 PrintStackTraceSignalHandler(void*) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:931:1
 #2 0x000055ca6790b839 llvm::sys::RunSignalHandlers() /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Signals.cpp:104:5
 #3 0x000055ca6790ff6b SignalHandler(int, siginfo_t*, void*) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:430:38
 #4 0x00007fe9e5e44560 __restore_rt /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/signal/../sysdeps/unix/sysv/linux/libc_sigaction.c:13:0
 #5 0x00007fe9e5f25649 syscall /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/misc/../sysdeps/unix/sysv/linux/x86_64/syscall.S:38:0
 #6 0x00007fe9ec649170 SignalHandler(int, siginfo_t*, void*) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:429:7
 #7 0x00007fe9e5e44560 __restore_rt /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/signal/../sysdeps/unix/sysv/linux/libc_sigaction.c:13:0
 #8 0x00007fe9ebb77bf0 lldb_private::operator<(lldb_private::StackID const&, lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/StackID.cpp:99:16
 #9 0x00007fe9ebb6863d CompareStackID(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/StackFrameList.cpp:683:3
#10 0x00007fe9ebb6d049 bool __gnu_cxx::__ops::_Iter_comp_val<bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>::operator()<__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID const>(__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID const&) /mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/bits/predefined_ops.h:196:4
#11 0x00007fe9ebb6cefe __gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>> std::__lower_bound<__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID, __gnu_cxx::__ops::_Iter_comp_val<bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>>(__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, __gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID const&, __gnu_cxx::__ops::_Iter_comp_val<bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>) /mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/bits/stl_algobase.h:1464:8
#12 0x00007fe9ebb6cdfc __gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>> std::lower_bound<__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID, bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>(__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, __gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID const&, bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)) /mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/bits/stl_algo.h:2062:14
#13 0x00007fe9ebb685fa auto llvm::lower_bound<std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>&, lldb_private::StackID const&, bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>(std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>&, lldb_private::StackID const&, bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)) /home/hyubo/osmeta/external/llvm-project/llvm/include/llvm/ADT/STLExtras.h:2001:10
#14 0x00007fe9ebb68441 lldb_private::StackFrameList::GetFrameWithStackID(lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/StackFrameList.cpp:697:11
#15 0x00007fe9ebbee395 lldb_private::Thread::GetFrameWithStackID(lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/include/lldb/Target/Thread.h:459:7
#16 0x00007fe9ebac7cf7 lldb_private::ExecutionContextRef::GetFrameSP() const /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/ExecutionContext.cpp:643:25
llvm#17 0x00007fe9ebac80e1 lldb_private::GetStoppedExecutionContext(lldb_private::ExecutionContextRef const*) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/ExecutionContext.cpp:164:34
llvm#18 0x00007fe9eb8903fa lldb_private::Statusline::Redraw(std::optional<lldb_private::ExecutionContextRef>) /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/Statusline.cpp:139:7
llvm#19 0x00007fe9eb7ac8be lldb_private::Debugger::RedrawStatusline(std::optional<lldb_private::ExecutionContextRef>) /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/Debugger.cpp:1233:3
llvm#20 0x00007fe9eb804d1e lldb_private::IOHandlerEditline::RedrawCallback() /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/IOHandler.cpp:446:3
llvm#21 0x00007fe9eb80aa81 lldb_private::IOHandlerEditline::IOHandlerEditline(lldb_private::Debugger&, lldb_private::IOHandler::Type, std::shared_ptr<lldb_private::File> const&, std::shared_ptr<lldb_private::LockableStreamFile> const&, std::shared_ptr<lldb_private::LockableStreamFile> const&, unsigned int, char const*, llvm::StringRef, llvm::StringRef, bool, bool, unsigned int, lldb_private::IOHandlerDelegate&)::$_2::operator()() const /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/IOHandler.cpp:262:73
llvm#22 0x00007fe9eb80aa5d void llvm::detail::UniqueFunctionBase<void>::CallImpl<lldb_private::IOHandlerEditline::IOHandlerEditline(lldb_private::Debugger&, lldb_private::IOHandler::Type, std::shared_ptr<lldb_private::File> const&, std::shared_ptr<lldb_private::LockableStreamFile> const&, std::shared_ptr<lldb_private::LockableStreamFile> const&, unsigned int, char const*, llvm::StringRef, llvm::StringRef, bool, bool, unsigned int, lldb_private::IOHandlerDelegate&)::$_2>(void*) /home/hyubo/osmeta/external/llvm-project/llvm/include/llvm/ADT/FunctionExtras.h:213:5
llvm#23 0x00007fe9eb93bfbf llvm::unique_function<void ()>::operator()() /home/hyubo/osmeta/external/llvm-project/llvm/include/llvm/ADT/FunctionExtras.h:365:5
llvm#24 0x00007fe9eb93bb80 lldb_private::Editline::GetCharacter(wchar_t*) /home/hyubo/osmeta/external/llvm-project/lldb/source/Host/common/Editline.cpp:0:5
llvm#25 0x00007fe9eb941a18 lldb_private::Editline::ConfigureEditor(bool)::$_0::operator()(editline*, wchar_t*) const /home/hyubo/osmeta/external/llvm-project/lldb/source/Host/common/Editline.cpp:1287:5
llvm#26 0x00007fe9eb9419e2 lldb_private::Editline::ConfigureEditor(bool)::$_0::__invoke(editline*, wchar_t*) /home/hyubo/osmeta/external/llvm-project/lldb/source/Host/common/Editline.cpp:1286:27
llvm#27 0x00007fe9f3384e26 el_getc /home/engshare/third-party2/libedit/3.1/src/libedit/src/read.c:439:14
llvm#28 0x00007fe9f3384e26 el_getc /home/engshare/third-party2/libedit/3.1/src/libedit/src/read.c:400:1
llvm#29 0x00007fe9f3384f90 read_getcmd /home/engshare/third-party2/libedit/3.1/src/libedit/src/read.c:247:14
llvm#30 0x00007fe9f3384f90 el_gets /home/engshare/third-party2/libedit/3.1/src/libedit/src/read.c:586:14
llvm#31 0x00007fe9eb9409f3 lldb_private::Editline::GetLine(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>&, bool&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Host/common/Editline.cpp:1636:16
llvm#32 0x00007fe9eb8044d7 lldb_private::IOHandlerEditline::GetLine(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>&, bool&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/IOHandler.cpp:339:5
llvm#33 0x00007fe9eb805609 lldb_private::IOHandlerEditline::Run() /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/IOHandler.cpp:600:11
llvm#34 0x00007fe9eb7b214c lldb_private::Debugger::RunIOHandlers() /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/Debugger.cpp:1280:16
llvm#35 0x00007fe9eb98f00f lldb_private::CommandInterpreter::RunCommandInterpreter(lldb_private::CommandInterpreterRunOptions&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:3620:16
llvm#36 0x00007fe9eb4f0e09 lldb::SBDebugger::RunCommandInterpreter(bool, bool) /home/hyubo/osmeta/external/llvm-project/lldb/source/API/SBDebugger.cpp:1234:42
llvm#37 0x000055ca6788d6b0 Driver::MainLoop() /home/hyubo/osmeta/external/llvm-project/lldb/tools/driver/Driver.cpp:677:3
llvm#38 0x000055ca6788e226 main /home/hyubo/osmeta/external/llvm-project/lldb/tools/driver/Driver.cpp:887:17
llvm#39 0x00007fe9e5e2c657 __libc_start_call_main /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/csu/../sysdeps/nptl/libc_start_call_main.h:58:16
llvm#40 0x00007fe9e5e2c718 call_init /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/csu/../csu/libc-start.c:128:20
llvm#41 0x00007fe9e5e2c718 __libc_start_main@GLIBC_2.2.5 /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/csu/../csu/libc-start.c:379:5
llvm#42 0x000055ca67889a11 _start /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/csu/../sysdeps/x86_64/start.S:118:0
Segmentation fault (core dumped)
```

When `target symbols add` is run, `Symtab::AddSymbol()` can reallocate
the underlying `std::vector<Symbol>` and resize it, invalidating all
existing Symbol* pointers. While `Process::Flush()` clears stale stack
frames, the statusline caches its own `ExecutionContextRef` containing a
`StackID` with a `SymbolContextScope*` (which can be a `Symbol*`). This
cached reference is not cleared by `Process::Flush()`, so the next
statusline redraw accesses a dangling pointer and crashes.

Fix this by adding `Statusline::Flush()` which clears the cached frame,
`Debugger::Flush()` which forwards to it under the statusline mutex, and
calling `Debugger::Flush()` from `Process::Flush()` so that all flush
paths (symbol add, exec, module load) also invalidate the statusline's
stale state.

After this fix, lldb is not crashing anymore, new symbols from a symbol
file are correctly loaded

---------

Co-authored-by: George Hu <georgehuyubo@gmail.com>
lukel97 pushed a commit that referenced this pull request May 11, 2026
@thurstond
Revert "[llvm-profgen] Support [buildid:]0xaddr format in perfscript …
1f83fdb 
…input" (llvm#195551)

Reverts llvm#190863 due to buildbot breakage e.g.,
https://lab.llvm.org/buildbot/#/builders/52/builds/16951

```
Failed Tests (1):
  LLVM :: tools/llvm-profgen/filter-build-id.test
```
```
==llvm-profgen==3809550==ERROR: AddressSanitizer: container-overflow on address 0x6e80441e1762 at pc 0x6216c3f2cdce bp 0x7fff3c3ddf60 sp 0x7fff3c3dd710
READ of size 8 at 0x6e80441e1762 thread T0
    #0 0x6216c3f2cdcd in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long), void const*, void const*, unsigned long) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:848:7
    #1 0x6216c3f2d25c in bcmp /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:894:10
    #2 0x6216c400b836 in operator== /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/include/llvm/ADT/StringRef.h:914:10
    #3 0x6216c400b836 in operator!= /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/include/llvm/ADT/StringRef.h:917:69
    #4 0x6216c400b836 in llvm::sampleprof::PerfScriptReader::extractCallstack(llvm::sampleprof::TraceStream&, llvm::SmallVectorImpl<unsigned long>&) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:801:36
    #5 0x6216c400d37a in llvm::sampleprof::HybridPerfReader::parseSample(llvm::sampleprof::TraceStream&, unsigned long) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:881:8
    #6 0x6216c40150d8 in parseSample /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1118:3
    #7 0x6216c40150d8 in llvm::sampleprof::PerfScriptReader::parseEventOrSample(llvm::sampleprof::TraceStream&) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1201:5
    #8 0x6216c401539a in llvm::sampleprof::PerfScriptReader::parseAndAggregateTrace() /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1210:5
    #9 0x6216c4018c88 in llvm::sampleprof::PerfScriptReader::parsePerfTraces() /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1457:3
    #10 0x6216c3ff2c7a in main /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/llvm-profgen.cpp:229:19
    #11 0x72404502a8c0  (/usr/lib/x86_64-linux-gnu/libc.so.6+0x2a8c0) (BuildId: ae327f26c123ea1374623c41e676a4bf00e5c1cb)
    #12 0x72404502a9d7 in __libc_start_main (/usr/lib/x86_64-linux-gnu/libc.so.6+0x2a9d7) (BuildId: ae327f26c123ea1374623c41e676a4bf00e5c1cb)
    #13 0x6216c3f0f3d4 in _start (/home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/llvm-profgen+0x2f083d4)
0x6e80441e1762 is located 18 bytes inside of 48-byte region [0x6e80441e1750,0x6e80441e1780)
allocated by thread T0 here:
    #0 0x6216c3feab0d in operator new(unsigned long) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/compiler-rt/lib/asan/asan_new_delete.cpp:109:35
    #1 0x724045511c07 in __libcpp_allocate<char> /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/libcxx/include/__new/allocate.h:42:28
    #2 0x724045511c07 in allocate /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/libcxx/include/__memory/allocator.h:92:14
    #3 0x724045511c07 in allocate_at_least /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/libcxx/include/__memory/allocator.h:99:13
    #4 0x724045511c07 in allocate_at_least<std::__1::allocator<char> > /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/libcxx/include/__memory/allocator_traits.h:340:22
    #5 0x724045511c07 in __allocate_at_least<std::__1::allocator<char> > /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/libcxx/include/__memory/allocate_at_least.h:36:16
    #6 0x724045511c07 in __allocate_long_buffer /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/libcxx/include/string:2259:21
    #7 0x724045511c07 in std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>::__grow_by(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/libcxx/include/string:2769:25
    #8 0x6216c401d90a in __grow_by_without_replace /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/libcxx_install_asan/include/c++/v1/string:2795:3
    #9 0x6216c401d90a in std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>& std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>::append[abi:sqn230000]<char const*, 0>(char const*, char const*) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/libcxx_install_asan/include/c++/v1/string:1431:9
    #10 0x6216c401d1a6 in std::__1::basic_istream<char, std::__1::char_traits<char>>& std::__1::getline[abi:sqn230000]<char, std::__1::char_traits<char>, std::__1::allocator<char>>(std::__1::basic_istream<char, std::__1::char_traits<char>>&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>&, char) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/libcxx_install_asan/include/c++/v1/istream:1309:15
    #11 0x6216c4014a76 in getline<char, std::__1::char_traits<char>, std::__1::allocator<char> > /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/libcxx_install_asan/include/c++/v1/istream:1343:10
    #12 0x6216c4014a76 in advance /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.h:52:10
    #13 0x6216c4014a76 in llvm::sampleprof::PerfScriptReader::parseAggregatedCount(llvm::sampleprof::TraceStream&) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1110:13
    #14 0x6216c4015095 in parseSample /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1116:20
    #15 0x6216c4015095 in llvm::sampleprof::PerfScriptReader::parseEventOrSample(llvm::sampleprof::TraceStream&) /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1201:5
    #16 0x6216c401539a in llvm::sampleprof::PerfScriptReader::parseAndAggregateTrace() /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1210:5
    llvm#17 0x6216c4018c88 in llvm::sampleprof::PerfScriptReader::parsePerfTraces() /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp:1457:3
    llvm#18 0x6216c3ff2c7a in main /home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm-project/llvm/tools/llvm-profgen/llvm-profgen.cpp:229:19
    llvm#19 0x72404502a8c0  (/usr/lib/x86_64-linux-gnu/libc.so.6+0x2a8c0) (BuildId: ae327f26c123ea1374623c41e676a4bf00e5c1cb)
    llvm#20 0x72404502a9d7 in __libc_start_main (/usr/lib/x86_64-linux-gnu/libc.so.6+0x2a9d7) (BuildId: ae327f26c123ea1374623c41e676a4bf00e5c1cb)
    llvm#21 0x6216c3f0f3d4 in _start (/home/b/sanitizer-x86_64-linux-bootstrap-asan/build/llvm_build_asan/bin/llvm-profgen+0x2f083d4)
```
lukel97 pushed a commit that referenced this pull request May 11, 2026
@cakgok @tbaederr
[clang][bytecode] Don't evaluate bound member function expressions in…
f5c52a0 
… new constant interpreter (llvm#194851)

**Problem:**

A crash is triggered by clangd's hover feature when using C++23 and the
new bytecode interpreter, which calls `Expr::EvaluateAsRValue()` to
attempt constant folding on an expression under the cursor, even when it
is not a valid constant expression.

Tested versions: 22.1.3, Trunk (x86_64-pc-linux-gnu)

**How to reproduce:**
```cpp
struct S { void f(); };
void g() { S s; s.f(); }
```
Running `clangd --check=repro.cpp` 
(with `compile_flags.txt` containing `-std=c++23
-fexperimental-new-constant-interpreter`)
will crash. 

`Assertion ItemTypes.back() == toPrimType<T>() failed.`

You can observe the same crash by hovering over STL iterators like
`vec.begin()`.

**Relevant Stack Trace:**
```text
#8  clang::interp::InterpStack::pop<MemberPointer>()
#9  clang::interp::EvalEmitter::emitRet(PrimType, SourceInfo)
#10 clang::interp::Compiler<EvalEmitter>::visitExpr(Expr const*, bool)
#11 clang::interp::EvalEmitter::interpretExpr(Expr const*, bool, bool)
#12 clang::interp::Context::evaluateAsRValue(State&, Expr const*, APValue&)
#13 EvaluateAsRValue(EvalInfo&, Expr const*, APValue&)
#14 clang::Expr::EvaluateAsRValue(EvalResult&, ASTContext const&, bool) const
#15 clangd::(anon)::printExprValue(Expr const*, ASTContext const&)
#16 clangd::(anon)::printExprValue(SelectionTree::Node const*, ASTContext const&)
llvm#17 clangd::getHover(...)
```
*Basically: `textDocument/hover` → `getHover` → `EvaluateAsRValue` → new
constant interpreter → `MemberPointer` type mismatch on stack pop.*

When `Compiler<Emitter>::VisitMemberExpr()` encounters a non-static
`CXXMethodDecl` member (a bound member function expression such as `s.f`
in `s.f()`), it falls through to `visitDeclRef()`. This pushes a `FnPtr`
onto the interpreter stack. However, the caller expects a
`MemberPointer`, causing an assertion failure in `InterpStack::pop()`:

**Fix:**

* In `VisitMemberExpr()`, bail out early (`return false`) when the
member is a non-static `CXXMethodDecl`, before reaching
`visitDeclRef()`. This causes `EvaluateAsRValue()` to report failure
gracefully rather than crashing. Bound member function expressions
(`s.f`) are not valid constant expressions, so returning `false` should
be semantically correct.

**Testing:**
* Added AST unit test
(`EvaluateAsRValue.FailsGracefullyOnBoundMemberExpr`) that directly
isolates a bound `MemberExpr` and passes it to `EvaluateAsRValue()`,
asserting it returns `false` without crashing.

* Added clangd hover test
(Hover.NoCrashOnBoundMemberFunctionWithNewInterpreter)
  that reproduces the original crash scenario.

* *Note:* I could not add a Lit test because I believe this is
unreachable via normal `clang` invocations. `Sema` strictly catches
isolated bound member functions before constant evaluation. `clangd` has
a unique path to triggering this.

**Root cause:**

This is exposed by C++23 specifically due to (I think P2280R4 /
P2448R2):

- Relaxing the rules around "unknown" objects in constant evaluation,
allowing `s` in `s.f()` to proceed past the base object check even
though `s` is not constexpr and deferring failures to bytecode execution
rather than rejecting them structurally.

Assisted-by: gemini-cli

@tbaederr

---------

Co-authored-by: Timm Baeder <tbaeder@redhat.com>
@lukel97 lukel97 closed this May 12, 2026
lukel97 pushed a commit that referenced this pull request May 14, 2026
@thurstond
[AArch64][test] Fix use-after-scope in createInstrInfo (llvm#197622)
13a6287 
llvm#183506 revealed a pre-existing
use-after-scope in createInstrInfo (MSan bot:
https://lab.llvm.org/buildbot/#/builders/164/builds/21562 [*]).

This patch fixes the issue by changing the stack-allocated
AArch64Subtarget (which goes out of scope once createInstrInfo()
returns) into heap-allocated, allowing it to be safely stored in the
returned AArch64InstrInfo.

-----

[*] WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x55555666fabd in
llvm::AArch64InstrInfo::getInstSizeInBytes(llvm::MachineInstr const&)
const
/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp:247:5
...

/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/unittests/Target/AArch64/InstSizes.cpp:85:3
#9 0x555556508559 in InstSizes_MOVaddrTagged_Test::TestBody()
/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/unittests/Target/AArch64/InstSizes.cpp:301:3
...

  Member fields were destroyed
#0 0x555556498a1d in __sanitizer_dtor_callback_fields
/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1074:5
#1 0x5555564fbda6 in ~Triple
/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/include/llvm/TargetParser/Triple.h:348:12
#2 0x5555564fbda6 in ~Triple
/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/include/llvm/TargetParser/Triple.h:47:7
#3 0x5555564fbda6 in llvm::AArch64Subtarget::~AArch64Subtarget()
/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/lib/Target/AArch64/AArch64Subtarget.h:38:7
#4 0x555556503396 in (anonymous
namespace)::createInstrInfo(llvm::TargetMachine*)
/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/unittests/Target/AArch64/InstSizes.cpp:38:1
#5 0x5555565084cb in InstSizes_MOVaddrTagged_Test::TestBody()
/home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/unittests/Target/AArch64/InstSizes.cpp:299:42
lukel97 pushed a commit that referenced this pull request Jun 9, 2026
@DrSergei
[lldb] Add nullptr check in GetBroadcaster (llvm#201769)
731dd05 
I recently noticed LLDB crash during execution of `script
print(lldb.SBDebugger().GetBroadcaster().GetName())` command:
```
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /home/sergei/llvm-project/build/bin/lldb-dap
 #0 0x000062735c3403d2 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/sergei/llvm-project/build/bin/lldb-dap+0x7c3d2)
 #1 0x000062735c33d7ec llvm::sys::RunSignalHandlers() (/home/sergei/llvm-project/build/bin/lldb-dap+0x797ec)
 #2 0x000062735c33d94c SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x00007eaa6aa45330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
 #4 0x00007eaa6bb0c092 lldb::SBBroadcaster::GetName() const (/home/sergei/llvm-project/build/bin/../lib/liblldb.so.23.0git+0x90c092)
 #5 0x00007eaa6bcb9a5d _wrap_SBBroadcaster_GetName LLDBWrapPython.cpp:0:0
 #6 0x00007eaa6a1df5f5 (/lib/x86_64-linux-gnu/libpython3.12.so.1.0+0x1df5f5)
 #7 0x00007eaa6a182b2c PyObject_Vectorcall (/lib/x86_64-linux-gnu/libpython3.12.so.1.0+0x182b2c)
 #8 0x00007eaa6a11d5ee _PyEval_EvalFrameDefault (/lib/x86_64-linux-gnu/libpython3.12.so.1.0+0x11d5ee)
 #9 0x00007eaa6a2a091f PyEval_EvalCode (/lib/x86_64-linux-gnu/libpython3.12.so.1.0+0x2a091f)
#10 0x00007eaa6a29c8b0 (/lib/x86_64-linux-gnu/libpython3.12.so.1.0+0x29c8b0)
#11 0x00007eaa6a11fbd3 _PyEval_EvalFrameDefault (/lib/x86_64-linux-gnu/libpython3.12.so.1.0+0x11fbd3)
#12 0x00007eaa6c4891b7 lldb_private::ScriptInterpreterPythonImpl::ExecuteOneLine(llvm::StringRef, lldb_private::CommandReturnObject*, lldb_private::ExecuteScriptOptions const&) (/home/sergei/llvm-project/build/bin/../lib/liblldb.so.23.0git+0x12891b7)
#13 0x00007eaa70326ff5 CommandObjectScriptingRun::DoExecute(llvm::StringRef, lldb_private::CommandReturnObject&) (/home/sergei/llvm-project/build/bin/../lib/liblldb.so.23.0git+0x5126ff5)
#14 0x00007eaa6bee3739 lldb_private::CommandObjectRaw::Execute(char const*, lldb_private::CommandReturnObject&) (/home/sergei/llvm-project/build/bin/../lib/liblldb.so.23.0git+0xce3739)
#15 0x00007eaa6bede09a lldb_private::CommandInterpreter::HandleCommand(char const*, lldb_private::LazyBool, lldb_private::CommandReturnObject&, bool) (/home/sergei/llvm-project/build/bin/../lib/liblldb.so.23.0git+0xcde09a)
#16 0x00007eaa6bb0f0f8 lldb::SBCommandInterpreter::HandleCommand(char const*, lldb::SBExecutionContext&, lldb::SBCommandReturnObject&, bool) (/home/sergei/llvm-project/build/bin/../lib/liblldb.so.23.0git+0x90f0f8)
llvm#17 0x00007eaa6bb0f265 lldb::SBCommandInterpreter::HandleCommand(char const*, lldb::SBCommandReturnObject&, bool) (/home/sergei/llvm-project/build/bin/../lib/liblldb.so.23.0git+0x90f265)
llvm#18 0x000062735c3707f3 lldb_dap::RunLLDBCommands[abi:cxx11](lldb::SBDebugger&, lldb::SBMutex, llvm::StringRef, llvm::ArrayRef<lldb_dap::protocol::String> const&, bool&, bool, bool) (/home/sergei/llvm-project/build/bin/lldb-dap+0xac7f3)
llvm#19 0x000062735c3a8019 lldb_dap::EvaluateRequestHandler::Run(lldb_dap::protocol::EvaluateArguments const&) const (/home/sergei/llvm-project/build/bin/lldb-dap+0xe4019)
llvm#20 0x000062735c3aba78 lldb_dap::RequestHandler<lldb_dap::protocol::EvaluateArguments, llvm::Expected<lldb_dap::protocol::EvaluateResponseBody>>::operator()(lldb_dap::protocol::Request const&) const (/home/sergei/llvm-project/build/bin/lldb-dap+0xe7a78)
llvm#21 0x000062735c3ce1bf lldb_dap::BaseRequestHandler::Run(lldb_dap::protocol::Request const&) (/home/sergei/llvm-project/build/bin/lldb-dap+0x10a1bf)
llvm#22 0x000062735c3577e7 lldb_dap::DAP::HandleObject(std::variant<lldb_dap::protocol::Request, lldb_dap::protocol::Response, lldb_dap::protocol::Event> const&) (/home/sergei/llvm-project/build/bin/lldb-dap+0x937e7)
llvm#23 0x000062735c358705 lldb_dap::DAP::Loop() (/home/sergei/llvm-project/build/bin/lldb-dap+0x94705)
llvm#24 0x000062735c2ed0c7 main (/home/sergei/llvm-project/build/bin/lldb-dap+0x290c7)
llvm#25 0x00007eaa6aa2a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
```
As far as I understand default constuctors should be covered by fuzzing
tests, so I don't know how to write test for that patch.
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2 participants

@lukel97 @ElvisWang123