[Flang][OpenMP] omp declare variant match causes fatal internal error: CHECK(!dirContext_.empty()) failed

[k-arrows]

Reproducer:
https://godbolt.org/z/qjKj6nn8b

module m
contains
  integer function f1 (x, y)
    real, intent(in) :: x
    real, intent(out) :: y
  end function

  integer function f2 (x, y)
    real, intent(in) :: x
    real, intent(out) :: y
    !$omp declare variant (f1) match (construct={simd(uniform(y))})
  end function

end module

Backtrace:

fatal internal error: CHECK(!dirContext_.empty()) failed at /root/llvm-project/flang/lib/Semantics/resolve-directives.cpp(63)
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang -fc1 -triple x86_64-unknown-linux-gnu -S -mrelocation-model pic -pic-level 2 -pic-is-pie -target-cpu x86-64 -mllvm -x86-asm-syntax=intel -fopenmp -resource-dir /opt/compiler-explorer/clang-llvmflang-trunk-20250622/lib/clang/21 -mframe-pointer=all -o /app/output.s -x f95 /app/example.f90
 #0 0x0000000003e78268 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3e78268)
 #1 0x0000000003e75e24 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x0000734ad1442520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x0000734ad14969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #4 0x0000734ad1442476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #5 0x0000734ad14287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #6 0x0000000005c105e9 (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x5c105e9)
 #7 0x0000000004d16eb7 (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d16eb7)
 #8 0x0000000004d57755 (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d57755)
 #9 0x0000000004d57b89 void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::parser::OmpClause, Fortran::semantics::OmpAttributeVisitor>(std::__cxx11::list<Fortran::parser::OmpClause, std::allocator<Fortran::parser::OmpClause>> const&, Fortran::semantics::OmpAttributeVisitor&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d57b89)
#10 0x0000000004d5a8b1 void Fortran::parser::detail::ParseTreeVisitorLookupScope::ForEachInTuple<3ul, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::semantics::OmpAttributeVisitor, std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>>(std::tuple<std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>> const&, Fortran::semantics::OmpAttributeVisitor&)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&), std::tuple<std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>>>(std::tuple<std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>> const&, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::semantics::OmpAttributeVisitor, std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>>(std::tuple<std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>> const&, Fortran::semantics::OmpAttributeVisitor&)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&)) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d5a8b1)
#11 0x0000000004d5b395 void Fortran::parser::detail::ParseTreeVisitorLookupScope::ForEachInTuple<1ul, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::semantics::OmpAttributeVisitor, std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>>(std::tuple<std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>> const&, Fortran::semantics::OmpAttributeVisitor&)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&), std::tuple<std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>>>(std::tuple<std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>> const&, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::semantics::OmpAttributeVisitor, std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>>(std::tuple<std::__cxx11::list<Fortran::parser::OpenACCDeclarativeConstruct, std::allocator<Fortran::parser::OpenACCDeclarativeConstruct>>, std::__cxx11::list<Fortran::parser::OpenMPDeclarativeConstruct, std::allocator<Fortran::parser::OpenMPDeclarativeConstruct>>, std::__cxx11::list<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, std::allocator<Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::UseStmt, false>>>>, std::__cxx11::list<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>, std::allocator<Fortran::parser::Statement<Fortran::common::Indirection<Fortran::parser::ImportStmt, false>>>>, Fortran::parser::ImplicitPart, std::__cxx11::list<Fortran::parser::DeclarationConstruct, std::allocator<Fortran::parser::DeclarationConstruct>>> const&, Fortran::semantics::OmpAttributeVisitor&)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&)) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d5b395)
#12 0x0000000004d5fd7b void Fortran::parser::detail::ParseTreeVisitorLookupScope::ForEachInTuple<0ul, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::semantics::OmpAttributeVisitor, Fortran::parser::Statement<Fortran::parser::ContainsStmt>, std::__cxx11::list<Fortran::parser::ModuleSubprogram, std::allocator<Fortran::parser::ModuleSubprogram>>>(std::tuple<Fortran::parser::Statement<Fortran::parser::ContainsStmt>, std::__cxx11::list<Fortran::parser::ModuleSubprogram, std::allocator<Fortran::parser::ModuleSubprogram>>> const&, Fortran::semantics::OmpAttributeVisitor&)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&), std::tuple<Fortran::parser::Statement<Fortran::parser::ContainsStmt>, std::__cxx11::list<Fortran::parser::ModuleSubprogram, std::allocator<Fortran::parser::ModuleSubprogram>>>>(std::tuple<Fortran::parser::Statement<Fortran::parser::ContainsStmt>, std::__cxx11::list<Fortran::parser::ModuleSubprogram, std::allocator<Fortran::parser::ModuleSubprogram>>> const&, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::semantics::OmpAttributeVisitor, Fortran::parser::Statement<Fortran::parser::ContainsStmt>, std::__cxx11::list<Fortran::parser::ModuleSubprogram, std::allocator<Fortran::parser::ModuleSubprogram>>>(std::tuple<Fortran::parser::Statement<Fortran::parser::ContainsStmt>, std::__cxx11::list<Fortran::parser::ModuleSubprogram, std::allocator<Fortran::parser::ModuleSubprogram>>> const&, Fortran::semantics::OmpAttributeVisitor&)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&)) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d5fd7b)
#13 0x0000000004d607bc void Fortran::common::log2visit::Log2VisitHelper<0ul, 7ul, void, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::semantics::OmpAttributeVisitor, Fortran::common::Indirection<Fortran::parser::MainProgram, false>, Fortran::common::Indirection<Fortran::parser::FunctionSubprogram, false>, Fortran::common::Indirection<Fortran::parser::SubroutineSubprogram, false>, Fortran::common::Indirection<Fortran::parser::Module, false>, Fortran::common::Indirection<Fortran::parser::Submodule, false>, Fortran::common::Indirection<Fortran::parser::BlockData, false>, Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, Fortran::common::Indirection<Fortran::parser::OpenACCRoutineConstruct, false>>(std::variant<Fortran::common::Indirection<Fortran::parser::MainProgram, false>, Fortran::common::Indirection<Fortran::parser::FunctionSubprogram, false>, Fortran::common::Indirection<Fortran::parser::SubroutineSubprogram, false>, Fortran::common::Indirection<Fortran::parser::Module, false>, Fortran::common::Indirection<Fortran::parser::Submodule, false>, Fortran::common::Indirection<Fortran::parser::BlockData, false>, Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, Fortran::common::Indirection<Fortran::parser::OpenACCRoutineConstruct, false>> const&, Fortran::semantics::OmpAttributeVisitor&)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&), std::variant<Fortran::common::Indirection<Fortran::parser::MainProgram, false>, Fortran::common::Indirection<Fortran::parser::FunctionSubprogram, false>, Fortran::common::Indirection<Fortran::parser::SubroutineSubprogram, false>, Fortran::common::Indirection<Fortran::parser::Module, false>, Fortran::common::Indirection<Fortran::parser::Submodule, false>, Fortran::common::Indirection<Fortran::parser::BlockData, false>, Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, Fortran::common::Indirection<Fortran::parser::OpenACCRoutineConstruct, false>> const&>(void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk<Fortran::semantics::OmpAttributeVisitor, Fortran::common::Indirection<Fortran::parser::MainProgram, false>, Fortran::common::Indirection<Fortran::parser::FunctionSubprogram, false>, Fortran::common::Indirection<Fortran::parser::SubroutineSubprogram, false>, Fortran::common::Indirection<Fortran::parser::Module, false>, Fortran::common::Indirection<Fortran::parser::Submodule, false>, Fortran::common::Indirection<Fortran::parser::BlockData, false>, Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, Fortran::common::Indirection<Fortran::parser::OpenACCRoutineConstruct, false>>(std::variant<Fortran::common::Indirection<Fortran::parser::MainProgram, false>, Fortran::common::Indirection<Fortran::parser::FunctionSubprogram, false>, Fortran::common::Indirection<Fortran::parser::SubroutineSubprogram, false>, Fortran::common::Indirection<Fortran::parser::Module, false>, Fortran::common::Indirection<Fortran::parser::Submodule, false>, Fortran::common::Indirection<Fortran::parser::BlockData, false>, Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, Fortran::common::Indirection<Fortran::parser::OpenACCRoutineConstruct, false>> const&, Fortran::semantics::OmpAttributeVisitor&)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&)&&, unsigned long, std::variant<Fortran::common::Indirection<Fortran::parser::MainProgram, false>, Fortran::common::Indirection<Fortran::parser::FunctionSubprogram, false>, Fortran::common::Indirection<Fortran::parser::SubroutineSubprogram, false>, Fortran::common::Indirection<Fortran::parser::Module, false>, Fortran::common::Indirection<Fortran::parser::Submodule, false>, Fortran::common::Indirection<Fortran::parser::BlockData, false>, Fortran::common::Indirection<Fortran::parser::CompilerDirective, false>, Fortran::common::Indirection<Fortran::parser::OpenACCRoutineConstruct, false>> const&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d607bc)
#14 0x0000000004d60b8f Fortran::semantics::ResolveOmpParts(Fortran::semantics::SemanticsContext&, Fortran::parser::ProgramUnit const&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d60b8f)
#15 0x000000000498726f Fortran::semantics::ResolveNamesVisitor::Pre(Fortran::parser::ProgramUnit const&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x498726f)
#16 0x00000000049887e9 Fortran::semantics::ResolveNames(Fortran::semantics::SemanticsContext&, Fortran::parser::Program const&, Fortran::semantics::Scope&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x49887e9)
#17 0x00000000049f4206 Fortran::semantics::Semantics::Perform() (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x49f4206)
#18 0x0000000003ed1338 Fortran::frontend::FrontendAction::runSemanticChecks() (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3ed1338)
#19 0x0000000004188030 Fortran::frontend::CodeGenAction::beginSourceFileAction() (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4188030)
#20 0x0000000003ecff75 Fortran::frontend::FrontendAction::beginSourceFile(Fortran::frontend::CompilerInstance&, Fortran::frontend::FrontendInputFile const&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3ecff75)
#21 0x0000000003ebea67 Fortran::frontend::CompilerInstance::executeAction(Fortran::frontend::FrontendAction&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3ebea67)
#22 0x0000000003eda0d3 Fortran::frontend::executeCompilerInvocation(Fortran::frontend::CompilerInstance*) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3eda0d3)
#23 0x0000000002216b3a fc1_main(llvm::ArrayRef<char const*>, char const*) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x2216b3a)
#24 0x00000000020c5846 main (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x20c5846)
#25 0x0000734ad1429d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#26 0x0000734ad1429e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#27 0x0000000002215505 _start (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x2215505)
flang-21: error: unable to execute command: Aborted (core dumped)
flang-21: error: flang frontend command failed due to signal (use -v to see invocation)
flang version 21.0.0git (https://github.com/llvm/llvm-project.git f280d3b705de7f94ef9756e3ef2842b415a7c038)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin
flang-21: warning: OpenMP support in flang is still experimental [-Wexperimental-option]
flang-21: note: diagnostic msg: 

[llvmbot]

@llvm/issue-subscribers-flang-frontend

Author: None (k-arrows)

Reproducer: https://godbolt.org/z/qjKj6nn8b ```f90 module m contains integer function f1 (x, y) real, intent(in) :: x real, intent(out) :: y end function

integer function f2 (x, y)
real, intent(in) :: x
real, intent(out) :: y
!$omp declare variant (f1) match (construct={simd(uniform(y))})
end function

end module

Backtrace:
```console
fatal internal error: CHECK(!dirContext_.empty()) failed at /root/llvm-project/flang/lib/Semantics/resolve-directives.cpp(63)
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang -fc1 -triple x86_64-unknown-linux-gnu -S -mrelocation-model pic -pic-level 2 -pic-is-pie -target-cpu x86-64 -mllvm -x86-asm-syntax=intel -fopenmp -resource-dir /opt/compiler-explorer/clang-llvmflang-trunk-20250622/lib/clang/21 -mframe-pointer=all -o /app/output.s -x f95 /app/example.f90
 #<!-- -->0 0x0000000003e78268 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3e78268)
 #<!-- -->1 0x0000000003e75e24 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #<!-- -->2 0x0000734ad1442520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #<!-- -->3 0x0000734ad14969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #<!-- -->4 0x0000734ad1442476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #<!-- -->5 0x0000734ad14287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #<!-- -->6 0x0000000005c105e9 (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x5c105e9)
 #<!-- -->7 0x0000000004d16eb7 (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d16eb7)
 #<!-- -->8 0x0000000004d57755 (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d57755)
 #<!-- -->9 0x0000000004d57b89 void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::parser::OmpClause, Fortran::semantics::OmpAttributeVisitor&gt;(std::__cxx11::list&lt;Fortran::parser::OmpClause, std::allocator&lt;Fortran::parser::OmpClause&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d57b89)
#<!-- -->10 0x0000000004d5a8b1 void Fortran::parser::detail::ParseTreeVisitorLookupScope::ForEachInTuple&lt;3ul, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::semantics::OmpAttributeVisitor, std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt;(std::tuple&lt;std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&amp;), std::tuple&lt;std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt;&gt;(std::tuple&lt;std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt; const&amp;, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::semantics::OmpAttributeVisitor, std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt;(std::tuple&lt;std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&amp;)) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d5a8b1)
#<!-- -->11 0x0000000004d5b395 void Fortran::parser::detail::ParseTreeVisitorLookupScope::ForEachInTuple&lt;1ul, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::semantics::OmpAttributeVisitor, std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt;(std::tuple&lt;std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&amp;), std::tuple&lt;std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt;&gt;(std::tuple&lt;std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt; const&amp;, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::semantics::OmpAttributeVisitor, std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt;(std::tuple&lt;std::__cxx11::list&lt;Fortran::parser::OpenACCDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenACCDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::OpenMPDeclarativeConstruct, std::allocator&lt;Fortran::parser::OpenMPDeclarativeConstruct&gt;&gt;, std::__cxx11::list&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, std::allocator&lt;Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::UseStmt, false&gt;&gt;&gt;&gt;, std::__cxx11::list&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;, std::allocator&lt;Fortran::parser::Statement&lt;Fortran::common::Indirection&lt;Fortran::parser::ImportStmt, false&gt;&gt;&gt;&gt;, Fortran::parser::ImplicitPart, std::__cxx11::list&lt;Fortran::parser::DeclarationConstruct, std::allocator&lt;Fortran::parser::DeclarationConstruct&gt;&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&amp;)) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d5b395)
#<!-- -->12 0x0000000004d5fd7b void Fortran::parser::detail::ParseTreeVisitorLookupScope::ForEachInTuple&lt;0ul, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::semantics::OmpAttributeVisitor, Fortran::parser::Statement&lt;Fortran::parser::ContainsStmt&gt;, std::__cxx11::list&lt;Fortran::parser::ModuleSubprogram, std::allocator&lt;Fortran::parser::ModuleSubprogram&gt;&gt;&gt;(std::tuple&lt;Fortran::parser::Statement&lt;Fortran::parser::ContainsStmt&gt;, std::__cxx11::list&lt;Fortran::parser::ModuleSubprogram, std::allocator&lt;Fortran::parser::ModuleSubprogram&gt;&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&amp;), std::tuple&lt;Fortran::parser::Statement&lt;Fortran::parser::ContainsStmt&gt;, std::__cxx11::list&lt;Fortran::parser::ModuleSubprogram, std::allocator&lt;Fortran::parser::ModuleSubprogram&gt;&gt;&gt;&gt;(std::tuple&lt;Fortran::parser::Statement&lt;Fortran::parser::ContainsStmt&gt;, std::__cxx11::list&lt;Fortran::parser::ModuleSubprogram, std::allocator&lt;Fortran::parser::ModuleSubprogram&gt;&gt;&gt; const&amp;, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::semantics::OmpAttributeVisitor, Fortran::parser::Statement&lt;Fortran::parser::ContainsStmt&gt;, std::__cxx11::list&lt;Fortran::parser::ModuleSubprogram, std::allocator&lt;Fortran::parser::ModuleSubprogram&gt;&gt;&gt;(std::tuple&lt;Fortran::parser::Statement&lt;Fortran::parser::ContainsStmt&gt;, std::__cxx11::list&lt;Fortran::parser::ModuleSubprogram, std::allocator&lt;Fortran::parser::ModuleSubprogram&gt;&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&amp;)) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d5fd7b)
#<!-- -->13 0x0000000004d607bc void Fortran::common::log2visit::Log2VisitHelper&lt;0ul, 7ul, void, void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::semantics::OmpAttributeVisitor, Fortran::common::Indirection&lt;Fortran::parser::MainProgram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::FunctionSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::SubroutineSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Module, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Submodule, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::BlockData, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::OpenACCRoutineConstruct, false&gt;&gt;(std::variant&lt;Fortran::common::Indirection&lt;Fortran::parser::MainProgram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::FunctionSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::SubroutineSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Module, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Submodule, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::BlockData, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::OpenACCRoutineConstruct, false&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&amp;), std::variant&lt;Fortran::common::Indirection&lt;Fortran::parser::MainProgram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::FunctionSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::SubroutineSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Module, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Submodule, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::BlockData, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::OpenACCRoutineConstruct, false&gt;&gt; const&amp;&gt;(void Fortran::parser::detail::ParseTreeVisitorLookupScope::Walk&lt;Fortran::semantics::OmpAttributeVisitor, Fortran::common::Indirection&lt;Fortran::parser::MainProgram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::FunctionSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::SubroutineSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Module, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Submodule, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::BlockData, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::OpenACCRoutineConstruct, false&gt;&gt;(std::variant&lt;Fortran::common::Indirection&lt;Fortran::parser::MainProgram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::FunctionSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::SubroutineSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Module, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Submodule, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::BlockData, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::OpenACCRoutineConstruct, false&gt;&gt; const&amp;, Fortran::semantics::OmpAttributeVisitor&amp;)::'lambda'(Fortran::semantics::OmpAttributeVisitor const&amp;)&amp;&amp;, unsigned long, std::variant&lt;Fortran::common::Indirection&lt;Fortran::parser::MainProgram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::FunctionSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::SubroutineSubprogram, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Module, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::Submodule, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::BlockData, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::CompilerDirective, false&gt;, Fortran::common::Indirection&lt;Fortran::parser::OpenACCRoutineConstruct, false&gt;&gt; const&amp;) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d607bc)
#<!-- -->14 0x0000000004d60b8f Fortran::semantics::ResolveOmpParts(Fortran::semantics::SemanticsContext&amp;, Fortran::parser::ProgramUnit const&amp;) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4d60b8f)
#<!-- -->15 0x000000000498726f Fortran::semantics::ResolveNamesVisitor::Pre(Fortran::parser::ProgramUnit const&amp;) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x498726f)
#<!-- -->16 0x00000000049887e9 Fortran::semantics::ResolveNames(Fortran::semantics::SemanticsContext&amp;, Fortran::parser::Program const&amp;, Fortran::semantics::Scope&amp;) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x49887e9)
#<!-- -->17 0x00000000049f4206 Fortran::semantics::Semantics::Perform() (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x49f4206)
#<!-- -->18 0x0000000003ed1338 Fortran::frontend::FrontendAction::runSemanticChecks() (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3ed1338)
#<!-- -->19 0x0000000004188030 Fortran::frontend::CodeGenAction::beginSourceFileAction() (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x4188030)
#<!-- -->20 0x0000000003ecff75 Fortran::frontend::FrontendAction::beginSourceFile(Fortran::frontend::CompilerInstance&amp;, Fortran::frontend::FrontendInputFile const&amp;) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3ecff75)
#<!-- -->21 0x0000000003ebea67 Fortran::frontend::CompilerInstance::executeAction(Fortran::frontend::FrontendAction&amp;) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3ebea67)
#<!-- -->22 0x0000000003eda0d3 Fortran::frontend::executeCompilerInvocation(Fortran::frontend::CompilerInstance*) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x3eda0d3)
#<!-- -->23 0x0000000002216b3a fc1_main(llvm::ArrayRef&lt;char const*&gt;, char const*) (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x2216b3a)
#<!-- -->24 0x00000000020c5846 main (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x20c5846)
#<!-- -->25 0x0000734ad1429d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#<!-- -->26 0x0000734ad1429e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#<!-- -->27 0x0000000002215505 _start (/opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin/flang+0x2215505)
flang-21: error: unable to execute command: Aborted (core dumped)
flang-21: error: flang frontend command failed due to signal (use -v to see invocation)
flang version 21.0.0git (https://github.com/llvm/llvm-project.git f280d3b705de7f94ef9756e3ef2842b415a7c038)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/compiler-explorer/clang-llvmflang-trunk-20250622/bin
flang-21: warning: OpenMP support in flang is still experimental [-Wexperimental-option]
flang-21: note: diagnostic msg: