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[Flang][OpenMP] Add Lowering support for lastprivate in taskloops#2

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[Flang][OpenMP] Add Lowering support for lastprivate in taskloops#2
Stylie777 wants to merge 1 commit into
11-05-_flang_openmp_add_lowering_support_for_taskloop_reductions_from
11-05-_flang_openmp_add_lowering_support_for_lastprivate_in_taskloops

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lastprivate support already exists within the DataSharingProcessor,
so this can be extended to include the use of taskloops to enable
AST->FIR lowering. The related error message has also been updated
to indicate that taskloops are now supported.

lastprivate support already exists within the DataSharingProcessor,
so this can be extended to include the use of taskloops to enable
AST->FIR lowering. The related error message has also been updated
to indicate that taskloops are now supported.

Stylie777 commented Nov 5, 2025

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@Stylie777 Stylie777 closed this Nov 5, 2025
Stylie777 pushed a commit that referenced this pull request Nov 6, 2025
llvm#159474

Another try of trying to land
llvm#166382
- Fix some leftover tests checking for specific  errnos
- Guard errno checking tests to not run on the GPU

@michaelrj-google
Stylie777 pushed a commit that referenced this pull request Nov 26, 2025
…am (llvm#167724)

This got exposed by `09262656f32ab3f2e1d82e5342ba37eecac52522`.

The underlying stream of `m_os` is referenced by the `TextDiagnostic`
member of `TextDiagnosticPrinter`. It got turned into a
`llvm::formatted_raw_ostream` in the commit above. When
`~TextDiagnosticPrinter` (and thus `~TextDiagnostic`) is invoked, we now
call `~formatted_raw_ostream`, which tries to access the underlying
stream. But `m_os` was already deleted because it is earlier in the
order of destruction in `TextDiagnosticPrinter`. Move the `m_os` member
before the `TextDiagnosticPrinter` to avoid a use-after-free.

Drive-by:
* Also move the `m_output` member which the `m_os` holds a reference to.
The fact it's a reference indicates the expectation is most likely that
the string outlives the stream.

The ASAN macOS bot is currently failing with this:
```
08:15:39  =================================================================
08:15:39  ==61103==ERROR: AddressSanitizer: heap-use-after-free on address 0x60600012cf40 at pc 0x00012140d304 bp 0x00016eecc850 sp 0x00016eecc848
08:15:39  READ of size 8 at 0x60600012cf40 thread T0
08:15:39      #0 0x00012140d300 in llvm::formatted_raw_ostream::releaseStream() FormattedStream.h:205
08:15:39      #1 0x00012140d3a4 in llvm::formatted_raw_ostream::~formatted_raw_ostream() FormattedStream.h:145
08:15:39      #2 0x00012604abf8 in clang::TextDiagnostic::~TextDiagnostic() TextDiagnostic.cpp:721
08:15:39      #3 0x00012605dc80 in clang::TextDiagnosticPrinter::~TextDiagnosticPrinter() TextDiagnosticPrinter.cpp:30
08:15:39      llvm#4 0x00012605dd5c in clang::TextDiagnosticPrinter::~TextDiagnosticPrinter() TextDiagnosticPrinter.cpp:27
08:15:39      llvm#5 0x0001231fb210 in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47
08:15:39      llvm#6 0x0001231fb3bc in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47
08:15:39      llvm#7 0x000129aa9d70 in clang::DiagnosticsEngine::~DiagnosticsEngine() Diagnostic.cpp:91
08:15:39      llvm#8 0x0001230436b8 in llvm::RefCountedBase<clang::DiagnosticsEngine>::Release() const IntrusiveRefCntPtr.h:103
08:15:39      llvm#9 0x0001231fe6c8 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93
08:15:39      llvm#10 0x0001231fe858 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93
...
08:15:39
08:15:39  0x60600012cf40 is located 32 bytes inside of 56-byte region [0x60600012cf20,0x60600012cf58)
08:15:39  freed by thread T0 here:
08:15:39      #0 0x0001018abb88 in _ZdlPv+0x74 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x4bb88)
08:15:39      #1 0x0001231fb1c0 in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47
08:15:39      #2 0x0001231fb3bc in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47
08:15:39      #3 0x000129aa9d70 in clang::DiagnosticsEngine::~DiagnosticsEngine() Diagnostic.cpp:91
08:15:39      llvm#4 0x0001230436b8 in llvm::RefCountedBase<clang::DiagnosticsEngine>::Release() const IntrusiveRefCntPtr.h:103
08:15:39      llvm#5 0x0001231fe6c8 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93
08:15:39      llvm#6 0x0001231fe858 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93
...
08:15:39
08:15:39  previously allocated by thread T0 here:
08:15:39      #0 0x0001018ab760 in _Znwm+0x74 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x4b760)
08:15:39      #1 0x0001231f8dec in lldb_private::ClangModulesDeclVendor::Create(lldb_private::Target&) ClangModulesDeclVendor.cpp:732
08:15:39      #2 0x00012320af58 in lldb_private::ClangPersistentVariables::GetClangModulesDeclVendor() ClangPersistentVariables.cpp:124
08:15:39      #3 0x0001232111f0 in lldb_private::ClangUserExpression::PrepareForParsing(lldb_private::DiagnosticManager&, lldb_private::ExecutionContext&, bool) ClangUserExpression.cpp:536
08:15:39      llvm#4 0x000123213790 in lldb_private::ClangUserExpression::Parse(lldb_private::DiagnosticManager&, lldb_private::ExecutionContext&, lldb_private::ExecutionPolicy, bool, bool) ClangUserExpression.cpp:647
08:15:39      llvm#5 0x00012032b258 in lldb_private::UserExpression::Evaluate(lldb_private::ExecutionContext&, lldb_private::EvaluateExpressionOptions const&, llvm::StringRef, llvm::StringRef, std::__1::shared_ptr<lldb_private::ValueObject>&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*, lldb_private::ValueObject*) UserExpression.cpp:280
08:15:39      llvm#6 0x000120724010 in lldb_private::Target::EvaluateExpression(llvm::StringRef, lldb_private::ExecutionContextScope*, std::__1::shared_ptr<lldb_private::ValueObject>&, lldb_private::EvaluateExpressionOptions const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*, lldb_private::ValueObject*) Target.cpp:2905
08:15:39      llvm#7 0x00011fc7bde0 in lldb::SBTarget::EvaluateExpression(char const*, lldb::SBExpressionOptions const&) SBTarget.cpp:2305
08:15:39  ==61103==ABORTING
...
```
Stylie777 pushed a commit that referenced this pull request Mar 4, 2026
Using code/ideas from the x86 backend to optimize a select on a bitcast
integer. The previous aarch64 approach was to individually extract the
bits from the mask, which is kind of terrible.

https://rust.godbolt.org/z/576sndT66

```llvm
define void @if_then_else8(ptr %out, i8 %mask, ptr %if_true, ptr %if_false) {
start:
  %t = load <8 x i32>, ptr %if_true, align 4
  %f = load <8 x i32>, ptr %if_false, align 4
  %m = bitcast i8 %mask to <8 x i1>
  %s = select <8 x i1> %m, <8 x i32> %t, <8 x i32> %f
  store <8 x i32> %s, ptr %out, align 4
  ret void
}
```

turned into 

```asm
if_then_else8:                          // @if_then_else8
        sub     sp, sp, llvm#16
        ubfx    w8, w1, llvm#4, #1
        and     w11, w1, #0x1
        ubfx    w9, w1, llvm#5, #1
        fmov    s1, w11
        ubfx    w10, w1, #1, #1
        fmov    s0, w8
        ubfx    w8, w1, llvm#6, #1
        ldp     q5, q2, [x3]
        mov     v1.h[1], w10
        ldp     q4, q3, [x2]
        mov     v0.h[1], w9
        ubfx    w9, w1, #2, #1
        mov     v1.h[2], w9
        ubfx    w9, w1, #3, #1
        mov     v0.h[2], w8
        ubfx    w8, w1, llvm#7, #1
        mov     v1.h[3], w9
        mov     v0.h[3], w8
        ushll   v1.4s, v1.4h, #0
        ushll   v0.4s, v0.4h, #0
        shl     v1.4s, v1.4s, llvm#31
        shl     v0.4s, v0.4s, llvm#31
        cmlt    v1.4s, v1.4s, #0
        cmlt    v0.4s, v0.4s, #0
        bsl     v1.16b, v4.16b, v5.16b
        bsl     v0.16b, v3.16b, v2.16b
        stp     q1, q0, [x0]
        add     sp, sp, llvm#16
        ret
```

With this PR that instead emits

```asm
if_then_else8:
   adrp x8, .LCPI0_1
   dup v0.4s, w1
   ldr q1, [x8, :lo12:.LCPI0_1]
   adrp x8, .LCPI0_0
   ldr q2, [x8, :lo12:.LCPI0_0]
   ldp q4, q3, [x2]
   and v1.16b, v0.16b, v1.16b
   and v0.16b, v0.16b, v2.16b
   ldp q5, q2, [x3]
   cmeq v1.4s, v1.4s, #0
   cmeq v0.4s, v0.4s, #0
   bsl v1.16b, v2.16b, v3.16b
   bsl v0.16b, v5.16b, v4.16b
   stp q0, q1, [x0]
   ret
```

So substantially shorter. Instead of building the mask
element-by-element, this approach (by virtue of not splitting) instead
splats the mask value into all vector lanes, performs a bitwise and with
powers of 2, and compares with zero to construct the mask vector.

cc rust-lang/rust#122376
cc llvm#175769
Stylie777 pushed a commit that referenced this pull request Mar 13, 2026
`SE.getUMaxExpr` causes assertion failure due to type mismatch here:


https://github.com/llvm/llvm-project/blob/main/llvm/lib/Analysis/LoopAccessAnalysis.cpp#L253

Running `opt -S -p loop-vectorize -debug-only=loop-vectorize
llvm/test/Analysis/LoopAccessAnalysis/type-mismatch-in-scalar-evolution.ll
` without the changes made in LoopAccessAnalysis.cpp causes assertion
failure.
Attaching the stack dump for reference:
```
LV: Checking a loop in 'loop_contains_store_assumed_bounds' from input.ll
LV: Loop hints: force=? width=4 interleave=0
LV: Found a loop: for.body
LV: Found an induction variable.
opt: /home/kshitij/llvm-project/llvm/lib/Analysis/ScalarEvolution.cpp:3918: const llvm::SCEV* llvm::ScalarEvolution::getMinMaxExpr(llvm::SCEVTypes, llvm::SmallVectorImpl<const llvm::SCEV*>&): Assertion `getEffectiveSCEVType(Ops[i]->getType()) == ETy && "Operand types don't match!"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0.	Program arguments: opt -S -passes=loop-vectorize -debug-only=loop-vectorize -force-vector-width=4 -disable-output input.ll
1.	Running pass "function(loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>)" on module "input.ll"
2.	Running pass "loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>" on function "loop_contains_store_assumed_bounds"
 #0 0x000058ee97c5e652 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/local/bin/opt+0x4f44652)
 #1 0x000058ee97c5af0f llvm::sys::RunSignalHandlers() (/usr/local/bin/opt+0x4f40f0f)
 #2 0x000058ee97c5b05c SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x00007c49d4c45330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
 llvm#4 0x00007c49d4c9eb2c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 llvm#5 0x00007c49d4c9eb2c __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 llvm#6 0x00007c49d4c9eb2c pthread_kill ./nptl/pthread_kill.c:89:10
 llvm#7 0x00007c49d4c4527e raise ./signal/../sysdeps/posix/raise.c:27:6
 llvm#8 0x00007c49d4c288ff abort ./stdlib/abort.c:81:7
 llvm#9 0x00007c49d4c2881b _nl_load_domain ./intl/loadmsgcat.c:1177:9
llvm#10 0x00007c49d4c3b517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517)
llvm#11 0x000058ee98003fdb llvm::ScalarEvolution::getMinMaxExpr(llvm::SCEVTypes, llvm::SmallVectorImpl<llvm::SCEV const*>&) (/usr/local/bin/opt+0x52e9fdb)
llvm#12 0x000058ee98004507 llvm::ScalarEvolution::getUMaxExpr(llvm::SCEV const*, llvm::SCEV const*) (/usr/local/bin/opt+0x52ea507)
llvm#13 0x000058ee980dc728 llvm::getStartAndEndForAccess(llvm::Loop const*, llvm::SCEV const*, llvm::Type*, llvm::SCEV const*, llvm::SCEV const*, llvm::ScalarEvolution*, llvm::DenseMap<std::pair<llvm::SCEV const*, llvm::Type*>, std::pair<llvm::SCEV const*, llvm::SCEV const*>, llvm::DenseMapInfo<std::pair<llvm::SCEV const*, llvm::Type*>, void>, llvm::detail::DenseMapPair<std::pair<llvm::SCEV const*, llvm::Type*>, std::pair<llvm::SCEV const*, llvm::SCEV const*>>>*, llvm::DominatorTree*, llvm::AssumptionCache*, std::optional<llvm::ScalarEvolution::LoopGuards>&) (/usr/local/bin/opt+0x53c2728)
llvm#14 0x000058ee9814008b llvm::isDereferenceableAndAlignedInLoop(llvm::LoadInst*, llvm::Loop*, llvm::ScalarEvolution&, llvm::DominatorTree&, llvm::AssumptionCache*, llvm::SmallVectorImpl<llvm::SCEVPredicate const*>*) (/usr/local/bin/opt+0x542608b)
llvm#15 0x000058ee9a0fa1ca llvm::LoopVectorizationLegality::canUncountableExitConditionLoadBeMoved(llvm::BasicBlock*) (/usr/local/bin/opt+0x73e01ca)
llvm#16 0x000058ee9a0faee0 llvm::LoopVectorizationLegality::isVectorizableEarlyExitLoop() (/usr/local/bin/opt+0x73e0ee0)
llvm#17 0x000058ee9a104678 llvm::LoopVectorizationLegality::canVectorize(bool) (/usr/local/bin/opt+0x73ea678)
llvm#18 0x000058ee9a08c953 llvm::LoopVectorizePass::processLoop(llvm::Loop*) (/usr/local/bin/opt+0x7372953)
llvm#19 0x000058ee9a090e21 llvm::LoopVectorizePass::runImpl(llvm::Function&) (/usr/local/bin/opt+0x7376e21)
llvm#20 0x000058ee9a0914e0 llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/usr/local/bin/opt+0x73774e0)
llvm#21 0x000058ee99e419a5 llvm::detail::PassModel<llvm::Function, llvm::LoopVectorizePass, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) PassBuilderPipelines.cpp:0:0
llvm#22 0x000058ee97f18905 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/usr/local/bin/opt+0x51fe905)
llvm#23 0x000058ee995d70d5 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) AMDGPUTargetMachine.cpp:0:0
llvm#24 0x000058ee97f17051 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/usr/local/bin/opt+0x51fd051)
llvm#25 0x000058ee995d7775 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) AMDGPUTargetMachine.cpp:0:0
llvm#26 0x000058ee97f1783d llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/usr/local/bin/opt+0x51fd83d)
llvm#27 0x000058ee9c153909 llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::ArrayRef<std::function<void (llvm::PassBuilder&)>>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool, bool) (/usr/local/bin/opt+0x9439909)
llvm#28 0x000058ee97c3f380 optMain (/usr/local/bin/opt+0x4f25380)
llvm#29 0x00007c49d4c2a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
llvm#30 0x00007c49d4c2a28b call_init ./csu/../csu/libc-start.c:128:20
llvm#31 0x00007c49d4c2a28b __libc_start_main ./csu/../csu/libc-start.c:347:5
llvm#32 0x000058ee97c309a5 _start (/usr/local/bin/opt+0x4f169a5)
```

This is caused by a type mismatch between
`SE.getSCEV(DerefRK.IRArgValue)` and `DerefBytesSCEV`.
Fixing this by extending them to the wider type.
Stylie777 pushed a commit that referenced this pull request Apr 17, 2026
…D tensor.extract (llvm#187085)

Vectorizing a rank-0 `linalg.generic` whose body contains
`tensor.extract` with data-dependent indices hits the Gather
classification in `getTensorExtractMemoryAccessPattern` because
`isOutput1DVector` returns false for a 0-D result. This produces an
invalid `vector.gather` where operand #2 must be a vector of index
values but gets a scalar `index` instead.

Fix classifies a 0-D result as ScalarBroadcast rather than Gather, and
skips mask generation for 0-D in that path.
Stylie777 pushed a commit that referenced this pull request Apr 17, 2026
…8271)

Example:

    int foo(int a, int b) { return a - 1 + ~b; }

Before, on AArch64:

    mvn w8, w1
    add w8, w0, w8
    sub w0, w8, #1

After (matches gcc):

    sub w0, w0, w1
    sub w0, w0, #2

Proof: https://alive2.llvm.org/ce/z/g_bV01
Stylie777 pushed a commit that referenced this pull request Apr 17, 2026
…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
 llvm#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
 llvm#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
 llvm#6 0x00007fe9ec649170 SignalHandler(int, siginfo_t*, void*) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:429:7
 llvm#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
 llvm#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
 llvm#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
llvm#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
llvm#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
llvm#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
llvm#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
llvm#14 0x00007fe9ebb68441 lldb_private::StackFrameList::GetFrameWithStackID(lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/StackFrameList.cpp:697:11
llvm#15 0x00007fe9ebbee395 lldb_private::Thread::GetFrameWithStackID(lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/include/lldb/Target/Thread.h:459:7
llvm#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>
Stylie777 pushed a commit that referenced this pull request Apr 23, 2026
When Control Flow Integrity (CFI) is enabled, jump tables are used to
redirect indirect calls. Previously, these jump table entries lacked
debug information, making it difficult for profilers and debuggers to
attribute execution time correctly.

Now stack trace, when stopped on jump table entry will looks like this:
```
#0: __ubsan_check_cfi_icall_jt at sanitizer/ubsan_interface.h:0
#1: c::c() (.cfi_jt) at sanitizer/ubsan_interface.h:0:0
#2: .cfi.jumptable.81 at sanitizer/ubsan_interface.h:0:0
```
Stylie777 pushed a commit that referenced this pull request Apr 23, 2026
…93670)

When Control Flow Integrity (CFI) is enabled, jump tables are used to
redirect indirect calls. Previously, these jump table entries lacked
debug information, making it difficult for profilers and debuggers to
attribute execution time correctly.

Now stack trace, when stopped on jump table entry will looks like this:
```
#0: __ubsan_check_cfi_icall_jt at sanitizer/ubsan_interface.h:0
#1: c::c() (.cfi_jt) at sanitizer/ubsan_interface.h:0:0
#2: .cfi.jumptable.81 at sanitizer/ubsan_interface.h:0:0
```

This is reland of llvm#192736, reverted with llvm#193663.
This version don't update debug info for "Cross-DSO CFI" mode.
Stylie777 pushed a commit that referenced this pull request May 26, 2026
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
llvm#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
llvm#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
llvm#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
Stylie777 pushed a commit that referenced this pull request May 26, 2026
…198548)

When an MCP client disconnects (EOF), `IOTransport::OnRead` called
`handler.OnClosed()` before resetting `m_read_handle`. The MCP server's
`OnClosed` handler erases the client from `m_instances`, destroying both
  the transport (`this`) and the binder (`handler`). The subsequent
`m_read_handle.reset()` then accessed the destroyed transport's member,
  causing a use-after-free (SIGSEGV).

* thread #1, stop reason = signal SIGSEGV: address not mapped to object
(fault address=0x28)
* frame #0: 0x00007ff5d4d5afda
liblldb.so.23.2`lldb_private::transport::IOTransport<lldb_protocol::mcp::ProtocolDescriptor>::OnRead(lldb_private::MainLoopBase&,
lldb_private::transport::JSONTransport<lldb_protocol::mcp::ProtocolDescriptor>::MessageHandler&)
+ 1274
frame #1: 0x00007ff5d1140ad8
liblldb.so.23.0`lldb_private::MainLoopPosix::Run() + 408
frame #2: 0x00007ff5d1760c1c
liblldb.so.23.0`std::thread::_State_impl<std::thre

  Fix by resetting the read handle before calling `OnClosed()`, so no
  transport members are accessed after the handler potentially destroys
  the transport.

Then when the scope is left, the destructor is called for the new
read_handle local variable and it is cleaned up.

New unit tests added that fail without this change. With the change, the
custom 'ai' script (allows end user locally to communicate lldb context
to agent backend via a spun up MCP server: "protocol-server start MCP
listen://localhost:{port}") now successfully concludes without this
crash

Assisted with: claude
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