llvm error: Assertion `IncMUD && "MemoryUseOrDef cannot be null, all preds processed."' failed.

[matthiaskrgr]

I tried this code:

pub fn fun(number: usize, decision: bool) {
    for _ in 0..2 {
        for _ in 0..number {
            let iter: Box<dyn Iterator<Item = ()>> = if decision {
                Box::new(std::iter::empty())
            } else {
                Box::new(std::iter::once(()))
            };
            for _ in iter {}
        }
    }
}

rustc -Copt-level=3

Meta

rustc --version --verbose:

rustc 1.77.0-dev
binary: rustc
commit-hash: unknown
commit-date: unknown
host: x86_64-unknown-linux-gnu
release: 1.77.0-dev
LLVM version: 17.0.6

rustc: /home/matthias/vcs/github/rust_debug_assertions/src/llvm-project/llvm/lib/Analysis/MemorySSAUpdater.cpp:703: auto llvm::MemorySSAUpdater::updateForClonedLoop(const LoopBlocksRPO &, ArrayRef<BasicBlock *>, const ValueToValueMapTy &, bool)::(anonymous class)::operator()(MemoryPhi *, MemoryPhi *) const: Assertion `IncMUD && "MemoryUseOrDef cannot be null, all preds processed."' failed.
[1]    862692 IOT instruction  ~/.rustup/toolchains/local-debug-assertions/bin/rustc -Copt-level=3   lib

Backtrace

44	      return INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO (ret) : 0;
(gdb) bt
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007ffff1d238a3 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78
#2  0x00007ffff1cd3668 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007ffff1cbb4b8 in __GI_abort () at abort.c:79
#4  0x00007ffff1cbb3dc in __assert_fail_base (fmt=0x7ffff1e34ae8 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x7fffed24f5d1 "IncMUD && \"MemoryUseOrDef cannot be null, all preds processed.\"",
    file=file@entry=0x7fffed393f26 <str.2.llvm> "/home/matthias/vcs/github/rust_debug_assertions/src/llvm-project/llvm/lib/Analysis/MemorySSAUpdater.cpp", line=line@entry=703,
    function=function@entry=0x7fffed992c7c "auto llvm::MemorySSAUpdater::updateForClonedLoop(const LoopBlocksRPO &, ArrayRef<BasicBlock *>, const ValueToValueMapTy &, bool)::(anonymous class)::operator()(MemoryPhi *, MemoryPhi *) const") at assert.c:92
#5  0x00007ffff1ccbd26 in __assert_fail (assertion=0x7fffed24f5d1 "IncMUD && \"MemoryUseOrDef cannot be null, all preds processed.\"", file=0x7fffed393f26 <str.2.llvm> "/home/matthias/vcs/github/rust_debug_assertions/src/llvm-project/llvm/lib/Analysis/MemorySSAUpdater.cpp", line=703,
    function=0x7fffed992c7c "auto llvm::MemorySSAUpdater::updateForClonedLoop(const LoopBlocksRPO &, ArrayRef<BasicBlock *>, const ValueToValueMapTy &, bool)::(anonymous class)::operator()(MemoryPhi *, MemoryPhi *) const") at assert.c:101
#6  0x00007ffff06d7793 in llvm::MemorySSAUpdater::updateForClonedLoop(llvm::LoopBlocksRPO const&, llvm::ArrayRef<llvm::BasicBlock*>, llvm::ValueMap<llvm::Value const*, llvm::WeakTrackingVH, llvm::ValueMapConfig<llvm::Value const*, llvm::sys::SmartMutex<false> > > const&, bool) ()
   from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#7  0x00007fffeff26132 in unswitchNontrivialInvariants(llvm::Loop&, llvm::Instruction&, llvm::ArrayRef<llvm::Value*>, llvm::IVConditionInfo&, llvm::DominatorTree&, llvm::LoopInfo&, llvm::AssumptionCache&, llvm::function_ref<void (bool, bool, bool, llvm::ArrayRef<llvm::Loop*>)>, llvm::ScalarEvolution*, llvm::MemoryS--T--Type <RET> for more, q to quit, c to continue without paging--
SAUpdater*, llvm::function_ref<void (llvm::Loop&, llvm::StringRef)>, bool, bool) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#8  0x00007fffeff1b0b8 in unswitchBestCondition(llvm::Loop&, llvm::DominatorTree&, llvm::LoopInfo&, llvm::AssumptionCache&, llvm::AAResults&, llvm::TargetTransformInfo&, llvm::function_ref<void (bool, bool, bool, llvm::ArrayRef<llvm::Loop*>)>, llvm::ScalarEvolution*, llvm::MemorySSAUpdater*, llvm::function_ref<void (llvm::Loop&, llvm::StringRef)>) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#9  0x00007fffeff0dc69 in unswitchLoop(llvm::Loop&, llvm::DominatorTree&, llvm::LoopInfo&, llvm::AssumptionCache&, llvm::AAResults&, llvm::TargetTransformInfo&, bool, bool, llvm::function_ref<void (bool, bool, bool, llvm::ArrayRef<llvm::Loop*>)>, llvm::ScalarEvolution*, llvm::MemorySSAUpdater*, llvm::ProfileSummaryInfo*, llvm::BlockFrequencyInfo*, llvm::function_ref<void (llvm::Loop&, llvm::StringRef)>) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#10 0x00007fffeff0d242 in llvm::SimpleLoopUnswitchPass::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#11 0x00007ffff18937ed in llvm::detail::PassModel<llvm::Loop, llvm::SimpleLoopUnswitchPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#12 0x00007fffefd87277 in std::optional<llvm::PreservedAnalyses> llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runSinglePass<llvm::Loop, std::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&> > > >(llvm::Loop&, std::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&> > >&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&, llvm::PassInstrumentation&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#13 0x00007fffefd86e1f in llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runWithoutLoopNestPasses(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#14 0x00007fffefd85c96 in llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#15 0x00007ffff186e07d in llvm::detail::PassModel<llvm::Loop, llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#16 0x00007fffefd88223 in llvm::FunctionToLoopPassAdaptor::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#17 0x00007ffff189266d in llvm::detail::PassModel<llvm::Function, llvm::FunctionToLoopPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) ()
   from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#18 0x00007fffee843244 in llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#19 0x00007ffff187723d in llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) ()
   from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#20 0x00007ffff04dfb4f in llvm::CGSCCToFunctionPassAdaptor::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#21 0x00007ffff1893e7d in llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::CGSCCToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#22 0x00007ffff04d97f0 in llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#23 0x00007ffff00cd1bd in llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) ()
   from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#24 0x00007ffff04dd903 in llvm::DevirtSCCRepeatedPass::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#25 0x00007ffff00cda5d in llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::DevirtSCCRepeatedPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#26 0x00007ffff04dbb97 in llvm::ModuleToPostOrderCGSCCPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#27 0x00007ffff00cd74d in llvm::detail::PassModel<llvm::Module, llvm::ModuleToPostOrderCGSCCPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) ()
   from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#28 0x00007fffee841a44 in llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#29 0x00007ffff00c9cc6 in llvm::ModuleInlinerWrapperPass::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#30 0x00007ffff187e7ed in llvm::detail::PassModel<llvm::Module, llvm::ModuleInlinerWrapperPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) ()
   from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#31 0x00007fffee841a44 in llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/../lib/libLLVM-17-rust-dev.so
#32 0x00007ffff79c178c in LLVMRustOptimize () from /home/matthias/.rustup/toolchains/local-debug-assertions/bin/../lib/librustc_driver-953ad79e60e3aede.so
#33 0x00007ffff4650794 in rustc_codegen_llvm::back::write::llvm_optimize () at compiler/rustc_codegen_llvm/src/back/write.rs:559
#34 0x00007ffff465101f in rustc_codegen_llvm::back::write::optimize () at compiler/rustc_codegen_llvm/src/back/write.rs:622
#35 0x00007ffff45fda38 in rustc_codegen_llvm::{impl#3}::optimize () at compiler/rustc_codegen_llvm/src/lib.rs:227
#36 rustc_codegen_ssa::back::write::execute_optimize_work_item<rustc_codegen_llvm::LlvmCodegenBackend> () at compiler/rustc_codegen_ssa/src/back/write.rs:843
#37 0x00007ffff453358c in rustc_codegen_ssa::back::write::spawn_work::{closure#0}<rustc_codegen_llvm::LlvmCodegenBackend> () at compiler/rustc_codegen_ssa/src/back/write.rs:1744
#38 rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()> () at compiler/rustc_codegen_llvm/src/lib.rs:162
#39 std::sys_common::backtrace::__rust_begin_short_backtrace<rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure_env#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()>, ()> () at library/std/src/sys_common/backtrace.rs:155
#40 0x00007ffff45373ca in std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure#0}<rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure_env#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()>, ()> () at library/std/src/thread/mod.rs:529
#41 core::panic::unwind_safe::{impl#23}::call_once<(), std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure_env#0}<rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure_env#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()>, ()>> ()
    at library/core/src/panic/unwind_safe.rs:272
#42 std::panicking::try::do_call<core::panic::unwind_safe::AssertUnwindSafe<std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure_env#0}<rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure_env#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()>, ()>>, ()> () at library/std/src/panicking.rs:554
#43 std::panicking::try<(), core::panic::unwind_safe::AssertUnwindSafe<std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure_env#0}<rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure_env#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()>, ()>>>
    () at library/std/src/panicking.rs:518
#44 std::panic::catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure_env#0}<rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure_env#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()>, ()>>, ()> () at library/std/src/panic.rs:142
#45 std::thread::{impl#0}::spawn_unchecked_::{closure#1}<rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure_env#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()>, ()> () at library/std/src/thread/mod.rs:528
#46 core::ops::function::FnOnce::call_once<std::thread::{impl#0}::spawn_unchecked_::{closure_env#1}<rustc_codegen_llvm::{impl#2}::spawn_named_thread::{closure_env#0}<rustc_codegen_ssa::back::write::spawn_work::{closure_env#0}<rustc_codegen_llvm::LlvmCodegenBackend>, ()>, ()>, ()> ()
    at library/core/src/ops/function.rs:250
#47 0x00007ffff1f2a32c in alloc::boxed::{impl#47}::call_once<(), dyn core::ops::function::FnOnce<(), Output=()>, alloc::alloc::Global> () at library/alloc/src/boxed.rs:2016
#48 alloc::boxed::{impl#47}::call_once<(), alloc::boxed::Box<dyn core::ops::function::FnOnce<(), Output=()>, alloc::alloc::Global>, alloc::alloc::Global> () at library/alloc/src/boxed.rs:2016
#49 0x00007ffff1f4b955 in std::sys::pal::unix::thread::{impl#2}::new::thread_start () at library/std/src/sys/pal/unix/thread.rs:108
#50 0x00007ffff1d219eb in start_thread (arg=<optimized out>) at pthread_create.c:444
#51 0x00007ffff1da57cc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78