clang crashes when compiling coroutine on Windows

[flode]

We observed a crash on Windows in coroutine code after upgrading to 19.1. Needs at least /O1.

Compiling the attached repro code, crashes.

Clang-cl 19.1
msvc-14.39.33519
windows sdk 10.0.22621.0

Stack dump:
0.      Program arguments: external\\clang_windows\\bin\\clang-cl.exe /O1 /c clangcl19windowscoroutinecrash.cpp /EHsc msvc /imsvc external/msvc/include /imsvc external/windows_sdk/Include/shared/ /imsvc external/windows_sdk/Include/ucrt/ /imsvc external/windows_sdk/Include/um/ -Xclang -std=c++23
1.      <eof> parser at end of file
2.      Optimizer
3.      Running pass "require<globals-aa>,function(invalidate<aa>),require<profile-summary>,cgscc(devirt<4>(inline,function-attrs<skip-non-recursive-function-attrs>,function<eager-inv;no-rerun>(sroa<modify-cfg>,early-cse<memssa>,speculative-execution<only-if-divergent-target>,jump-threading,correlated-propagation,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,aggressive-instcombine,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,constraint-elimination,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<no-nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,loop(loop-idiom,indvars,simple-loop-unswitch<no-nontrivial;trivial>,loop-deletion,loop-unroll-full),sroa<modify-cfg>,vector-combine,mldst-motion<no-split-footer-bb>,gvn<>,sccp,bdce,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,jump-threading,correlated-propagation,adce,memcpyopt,dse,move-auto-init,loop-mssa(licm<allowspeculation>),coro-elide,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;hoist-common-insts;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>),function-attrs,function(require<should-not-run-function-passes>),coro-split)),function(invalidate<should-not-run-function-passes>),cgscc(devirt<4>())" on module "C:\Users\fscheibner\hyper-db\clangcrashminimal.cpp"
4.      Running pass "cgscc(devirt<4>(inline,function-attrs<skip-non-recursive-function-attrs>,function<eager-inv;no-rerun>(sroa<modify-cfg>,early-cse<memssa>,speculative-execution<only-if-divergent-target>,jump-threading,correlated-propagation,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,aggressive-instcombine,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,constraint-elimination,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<no-nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,loop(loop-idiom,indvars,simple-loop-unswitch<no-nontrivial;trivial>,loop-deletion,loop-unroll-full),sroa<modify-cfg>,vector-combine,mldst-motion<no-split-footer-bb>,gvn<>,sccp,bdce,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,jump-threading,correlated-propagation,adce,memcpyopt,dse,move-auto-init,loop-mssa(licm<allowspeculation>),coro-elide,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;hoist-common-insts;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>),function-attrs,function(require<should-not-run-function-passes>),coro-split))" on module "clangcl19windowscoroutinecrashl.cpp"
5.      Running pass "jump-threading" on function "?asyncInit@@YA?AU?$AsyncFunction@H@@XZ.resume"
Exception Code: 0xC0000005

clang-cl: error: clang frontend command failed due to signal (use -v to see invocation)
hyper.salesforce.com clang version 19.1.0
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: external\clang_windows\bin
clang-cl: note: diagnostic msg:
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-cl: note: diagnostic msg: AppData\Local\Temp\2\clangcl19windowscoroutinecrash-c2ab57.cpp
clang-cl: note: diagnostic msg: AppData\Local\Temp\2\clangcl19windowscoroutinecrash-c2ab57.sh
clang-cl: note: diagnostic msg:

********************

clangcl19windowscoroutinecrash.zip

[vogelsgesang]

Note that this is a regression between 17.0.6 and 19.1.0 (we skipped the 18 release, and hence don't know if it also reproduces there)

[Endilll]

Confirmed on Clang 20.0 (trunk): https://godbolt.org/z/YxKseEGzv
Reduced by C-Reduce:

namespace std {
template <class _Ret>
struct coroutine_traits : _Ret {};

template <class = void>
struct coroutine_handle {
  static coroutine_handle from_address(void *);
  operator coroutine_handle<>();
};

struct suspend_always {
  int await_ready();
  void await_suspend(coroutine_handle<>);
  void await_resume();
};

struct ostream;

template <class _Ty2>
struct _Compressed_pair {
  _Ty2 _Myval2;
};

struct default_delete {
  void operator()(int *_Ptr) {
    delete _Ptr;
  }
};

struct _Get_deleter_pointer_type {
  using type = int *;
};

struct unique_ptr {
  using pointer = _Get_deleter_pointer_type::type;
  
  ~unique_ptr() {
    default_delete __trans_tmp_1;
    __trans_tmp_1(_Mypair._Myval2);
  }

  _Compressed_pair<pointer> _Mypair;
};

template <class>
unique_ptr make_unique();

template <class _Traits>
void operator<<(_Traits &, int);

extern ostream cerr;
} // namespace std

using namespace std;

struct AsyncFunctionPromise {
  auto initial_suspend() {
    return suspend_always();
  }

  struct FinalAwaitable {
    int await_ready() noexcept;
    void await_resume() noexcept;
    
    template <typename Promise>
    void await_suspend(Promise) noexcept;
  };

  auto final_suspend() noexcept {
    return FinalAwaitable();
  }

  auto get_return_object() {
    return coroutine_handle<AsyncFunctionPromise>();
  }

  void return_value(int);
  void unhandled_exception();
};

struct AsyncFunction {
  using promise_type = AsyncFunctionPromise;
  using Handle = coroutine_handle<promise_type>;
  AsyncFunction(Handle);
};

AsyncFunction asyncInit() {
  try {
    unique_ptr mem;
    try {
      mem = make_unique<int>();
    } catch (int) {
    }
    cerr << 0;
  } catch (int) {
  }
  co_return 0;
}

Clang 20.0 crash:

Instruction does not dominate all uses!
  %mem.sroa.0.0 = phi ptr [ %.try.cont1368, %"try.cont13.from.??1unique_ptr@std@@QEAA@XZ.exit" ], [ %.try.cont13, %try.cont13.from.catch11 ]
  %mem.sroa.0.0.ehcleanup15 = phi ptr [ %mem.sroa.0.0, %ehcleanup15.corodispatch ]
fatal error: error in backend: Broken function

PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++20 -O1 -target x86_64-pc-windows-msvc19.33.0 <source>
1.	<eof> parser at end of file
2.	Optimizer
3.	Running pass "require<globals-aa>,function(invalidate<aa>),require<profile-summary>,cgscc(devirt<4>(inline,function-attrs<skip-non-recursive-function-attrs>,function<eager-inv;no-rerun>(sroa<modify-cfg>,early-cse<memssa>,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,libcalls-shrinkwrap,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<no-nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,loop(loop-idiom,indvars,loop-deletion,loop-unroll-full),sroa<modify-cfg>,memcpyopt,sccp,bdce,instcombine<max-iterations=1;no-verify-fixpoint>,coro-elide,adce,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>),function-attrs,function(require<should-not-run-function-passes>),coro-split,function(coro-annotation-elide))),function(invalidate<should-not-run-function-passes>),cgscc(devirt<4>())" on module "<source>"
4.	Running pass "cgscc(devirt<4>(inline,function-attrs<skip-non-recursive-function-attrs>,function<eager-inv;no-rerun>(sroa<modify-cfg>,early-cse<memssa>,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,libcalls-shrinkwrap,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<no-nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,loop(loop-idiom,indvars,loop-deletion,loop-unroll-full),sroa<modify-cfg>,memcpyopt,sccp,bdce,instcombine<max-iterations=1;no-verify-fixpoint>,coro-elide,adce,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>),function-attrs,function(require<should-not-run-function-passes>),coro-split,function(coro-annotation-elide)))" on module "<source>"
5.	While splitting coroutine @"?asyncInit@@YA?AUAsyncFunction@@XZ"
 #0 0x0000000003b97db8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b97db8)
 #1 0x0000000003b95a7c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b95a7c)
 #2 0x0000000003ae4706 llvm::CrashRecoveryContext::HandleExit(int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3ae4706)
 #3 0x0000000003b8cd9e llvm::sys::Process::Exit(int, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b8cd9e)
 #4 0x0000000000cd6610 LLVMErrorHandler(void*, char const*, bool) cc1_main.cpp:0:0
 #5 0x0000000003aef723 llvm::report_fatal_error(llvm::Twine const&, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3aef723)
 #6 0x0000000003aef888 (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3aef888)
 #7 0x00000000052fca94 (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x52fca94)
 #8 0x000000000530c620 llvm::CoroSplitPass::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x530c620)
 #9 0x00000000051b5ece llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::CoroSplitPass, 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&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x51b5ece)
#10 0x0000000002a52362 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&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x2a52362)
#11 0x00000000051b4e0e llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>, 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&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x51b4e0e)
#12 0x0000000002a57c76 llvm::DevirtSCCRepeatedPass::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x2a57c76)
#13 0x00000000051b4e2e llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::DevirtSCCRepeatedPass, 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&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x51b4e2e)
#14 0x0000000002a55a06 llvm::ModuleToPostOrderCGSCCPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x2a55a06)
#15 0x00000000051b4dee llvm::detail::PassModel<llvm::Module, llvm::ModuleToPostOrderCGSCCPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x51b4dee)
#16 0x000000000354ed80 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x354ed80)
#17 0x00000000053b6775 llvm::ModuleInlinerWrapperPass::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x53b6775)
#18 0x00000000050531ee llvm::detail::PassModel<llvm::Module, llvm::ModuleInlinerWrapperPass, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x50531ee)
#19 0x000000000354ed80 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x354ed80)
#20 0x0000000003e4111b (anonymous namespace)::EmitAssemblyHelper::RunOptimizationPipeline(clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>&, std::unique_ptr<llvm::ToolOutputFile, std::default_delete<llvm::ToolOutputFile>>&, clang::BackendConsumer*) BackendUtil.cpp:0:0
#21 0x0000000003e446dd clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3e446dd)
#22 0x00000000044ee28e clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x44ee28e)
#23 0x000000000661746c clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x661746c)
#24 0x00000000044ee678 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x44ee678)
#25 0x00000000047a8169 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x47a8169)
#26 0x0000000004726e7e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4726e7e)
#27 0x000000000488dc0e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x488dc0e)
#28 0x0000000000cd8aff cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcd8aff)
#29 0x0000000000cd080a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#30 0x00000000045328f9 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#31 0x0000000003ae4644 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3ae4644)
#32 0x0000000004532eef clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#33 0x00000000044f827d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x44f827d)
#34 0x00000000044f936d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x44f936d)
#35 0x0000000004501025 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4501025)
#36 0x0000000000cd59cf clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcd59cf)
#37 0x0000000000ba5414 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xba5414)
#38 0x00007b1eb9829d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#39 0x00007b1eb9829e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#40 0x0000000000cd02be _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcd02be)
clang++: error: clang frontend command failed with exit code 70 (use -v to see invocation)
Compiler returned: 70

[Endilll]

Well, the reduction above reproduces all the way to Clang 14, which appears to be the first supporting C++20 coroutines.

[llvmbot]

@llvm/issue-subscribers-coroutines

Author: Florian Scheibner (flode)

We observed a crash on Windows in coroutine code after upgrading to 19.1. Needs at least /O1.

Compiling the attached repro code, crashes.

Clang-cl 19.1
msvc-14.39.33519
windows sdk 10.0.22621.0

Stack dump:
0.      Program arguments: external\\clang_windows\\bin\\clang-cl.exe /O1 /c clangcl19windowscoroutinecrash.cpp /EHsc msvc /imsvc external/msvc/include /imsvc external/windows_sdk/Include/shared/ /imsvc external/windows_sdk/Include/ucrt/ /imsvc external/windows_sdk/Include/um/ -Xclang -std=c++23
1.      <eof> parser at end of file
2.      Optimizer
3.      Running pass "require<globals-aa>,function(invalidate<aa>),require<profile-summary>,cgscc(devirt<4>(inline,function-attrs<skip-non-recursive-function-attrs>,function<eager-inv;no-rerun>(sroa<modify-cfg>,early-cse<memssa>,speculative-execution<only-if-divergent-target>,jump-threading,correlated-propagation,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,aggressive-instcombine,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,constraint-elimination,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<no-nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,loop(loop-idiom,indvars,simple-loop-unswitch<no-nontrivial;trivial>,loop-deletion,loop-unroll-full),sroa<modify-cfg>,vector-combine,mldst-motion<no-split-footer-bb>,gvn<>,sccp,bdce,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,jump-threading,correlated-propagation,adce,memcpyopt,dse,move-auto-init,loop-mssa(licm<allowspeculation>),coro-elide,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;hoist-common-insts;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>),function-attrs,function(require<should-not-run-function-passes>),coro-split)),function(invalidate<should-not-run-function-passes>),cgscc(devirt<4>())" on module "C:\Users\fscheibner\hyper-db\clangcrashminimal.cpp"
4.      Running pass "cgscc(devirt<4>(inline,function-attrs<skip-non-recursive-function-attrs>,function<eager-inv;no-rerun>(sroa<modify-cfg>,early-cse<memssa>,speculative-execution<only-if-divergent-target>,jump-threading,correlated-propagation,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,aggressive-instcombine,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,constraint-elimination,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<no-nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,loop(loop-idiom,indvars,simple-loop-unswitch<no-nontrivial;trivial>,loop-deletion,loop-unroll-full),sroa<modify-cfg>,vector-combine,mldst-motion<no-split-footer-bb>,gvn<>,sccp,bdce,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>,jump-threading,correlated-propagation,adce,memcpyopt,dse,move-auto-init,loop-mssa(licm<allowspeculation>),coro-elide,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;hoist-common-insts;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-use-loop-info;no-verify-fixpoint>),function-attrs,function(require<should-not-run-function-passes>),coro-split))" on module "clangcl19windowscoroutinecrashl.cpp"
5.      Running pass "jump-threading" on function "?asyncInit@@<!-- -->YA?AU?$AsyncFunction@<!-- -->H@@<!-- -->XZ.resume"
Exception Code: 0xC0000005

clang-cl: error: clang frontend command failed due to signal (use -v to see invocation)
hyper.salesforce.com clang version 19.1.0
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: external\clang_windows\bin
clang-cl: note: diagnostic msg:
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PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-cl: note: diagnostic msg: AppData\Local\Temp\2\clangcl19windowscoroutinecrash-c2ab57.cpp
clang-cl: note: diagnostic msg: AppData\Local\Temp\2\clangcl19windowscoroutinecrash-c2ab57.sh
clang-cl: note: diagnostic msg:

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clangcl19windowscoroutinecrash.zip