<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/143229>143229</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [Flang][OpenMP] crashes on invalid goto inside OpenMP parallel/master block
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            crash-on-invalid,
            flang:openmp
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          k-arrows
      </td>
    </tr>
</table>

<pre>
    Reproducer:
https://godbolt.org/z/fvvGoP896
```f90
!$omp parallel
do i = 1, 2
  goto 10
end do
!$omp master
10 print *, i
!$omp end master
!$omp end parallel
end
```

Backtrace:
```console
flang-21: warning: OpenMP support in flang is still experimental [-Wexperimental-option]
/app/example.f90:5:7: warning: OpenMP directive MASTER has been deprecated, please use MASKED instead.
  !$omp master
 ^^^^^^
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-20250606/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-20250606/lib/clang/21 -mframe-pointer=all -o /app/output.s -x f95 /app/example.f90
 #0 0x0000000003eadc28 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x3eadc28)
 #1 0x0000000003eab7e4 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x000078f2e8e42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x000000000939f0c7 mlir::SuccessorRange::SuccessorRange(mlir::Block*) (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x939f0c7)
 #4 0x0000000007c7ecde mlir::eraseUnreachableBlocks(mlir::RewriterBase&, llvm::MutableArrayRef<mlir::Region>) (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x7c7ecde)
 #5 0x0000000004342421 (anonymous namespace)::FirConverter::lowerFunc(Fortran::lower::pft::FunctionLikeUnit&) Bridge.cpp:0:0
 #6 0x0000000004344174 Fortran::lower::LoweringBridge::lower(Fortran::parser::Program const&, Fortran::semantics::SemanticsContext const&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x4344174)
 #7 0x00000000041b8e86 Fortran::frontend::CodeGenAction::beginSourceFileAction() (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x41b8e86)
 #8 0x0000000003f050c5 Fortran::frontend::FrontendAction::beginSourceFile(Fortran::frontend::CompilerInstance&, Fortran::frontend::FrontendInputFile const&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x3f050c5)
 #9 0x0000000003ef3c77 Fortran::frontend::CompilerInstance::executeAction(Fortran::frontend::FrontendAction&) (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x3ef3c77)
#10 0x0000000003f0ea33 Fortran::frontend::executeCompilerInvocation(Fortran::frontend::CompilerInstance*) (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x3f0ea33)
#11 0x0000000002203cba fc1_main(llvm::ArrayRef<char const*>, char const*) (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x2203cba)
#12 0x00000000020b97e6 main (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x20b97e6)
#13 0x000078f2e8e29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#14 0x000078f2e8e29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#15 0x0000000002202685 _start (/opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin/flang+0x2202685)
flang-21: error: unable to execute command: Segmentation fault (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 de3a9ea510fecd501b4dd57534cf300d1c9622c9)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/compiler-explorer/clang-llvmflang-trunk-20250606/bin
flang-21: warning: OpenMP support in flang is still experimental [-Wexperimental-option]
flang-21: note: diagnostic msg: 
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJy8WF-P4ygS_zT0S8kRxnYSP-TB3ensrW5HN5qe1T22MC47XGOwAKcz9-lPYKfzRz2jnbvpG2XUgCnq96sqCgrunOw04oYU96TY3vHR743dvCTcWvPq7mrTfNt8wcGaZhRoSVYRWu29H1xosh1hu840tVF-YWxH2O7fhO3aw-E383ldLgmtyJJOv7akoctSwnLTDzBwy5VCRWjVGJBAsi2khD0AI7QC6Iw3kAYR1A005kq2586jJbRKKQxWag-EVUFWXk0Lkm9Tr4cvtKNuLnGGNq3uuXjxlgucGL99FUY7o5DQqlVcdwlLSVbBK7da6i40_zGg_vQZ3DgMxnqQGuJEkA6cl0oBHge0skftuQJS3Cf_vBxJzOCl0aTYRsg7PgyE7fDI-0HhItgwqwqSVav31TbSovDygPCpevr6-AX23EGNqKHBwaLgHptgp0EhdwijixP__rgFqZ1H3iyi8d-xNJDi8fZHq89_PFZPj-DGupceONRjBxYjc2_gJk6k34_1QpiesJ1Sh9OfZLDmXyg8YTvp3IiOsB1w3YDUQo0Ngt8jCMvdHuqTVwLMJ8_FCzRjP0w-ogtCy8_WdJb3wG03BosG9UDYzgxhfWH6QSq0CR4HZSzaMBb9GIBMHvV21C8Jo6ygS7okbFdLHWI6ejFpRQqJt3JQCMf18nmZJ6N-0eZVJ0rq8Zh0eoTkCZLeojKCB2cmvWlQwSAFJIMUicIDKmBTR7pkkAiJ57ZDn4hhDOsmyxySPoCCJHS56xP3TXt-JNlWao8KktYMqPsBEovOjFZg0kj7P3JVsj5NI2zHUkj61vIek8EErZZkW64UJAbeYtOMfhj9wkFyhLYs4N2gDfHDMgr0SE__MuSNYGuIkZBVJKvcNzc1PoctHd37NW5Btj5Psvz12ThvkfeELeOe156wEghb_zI_E3ZPjzNAwsoZfnoDv15hDk-y01z9jetGBTXriOYBnOykbs2znxPTwcgmNstZwi3EEAKXxv-TAjYrWK1bhmvMWcHozGtyzBxxb5E2fRALZxbLiDmKnBFnl4jLrGypWEGvpJ1s-TQKgc4Z-4XrDt8dY-vz9HtlxMtM4pdbe0Z3xp5fYl-JFYoGL7Cj5Q7_1Ba52PNaYQTnrvB-wVcrPdp77nCOlXMcfRp9EKus5d--YEuyh0vBLuTg7PFDmM5czkyLS6Z5lrOcpUEt10Z_683oQPMe3RC3QjlB3En7YPQBrccZtDKvaHejFoStd8Z6y_XFh6k5tH4WH7UIqekP-YJ_aumjeUq4t7Lp8J3IXN5AzNNVDt_T8kdoSt1Nq11-vkE2cOtOQqfEHQ5YP3vrarLDnmsvxZwjnk7dB6M9Hv2F4Af4bKZ89tnqyiBpvcb18hpvawMw3Uy9B9Pgb6iraPVpqMZO6qeYuXdS4fwpJpwPIDBBPBNYXyWzlhZUFD8isJt7P2Bw695bC0w0ftfOcy3wPR-_r_J3PYw-KPhYH89GOJuovM73bSZWqx_7-IbhlKiOKEZ_du9ft_FH8ZyYTDzDsUZvQgF5lv2I58zoTPcwX3R-NgA-5iSZGZz5XZ3bjNFM1BxakT73PIheXC4uTgOx5_YUb1U8Ch7geuwjsM_oztjZFXZalytcQsD9Abqn1c-6s-vrCCub8ievI1HkvGB-uyDmFJ6fg8yz89z65wtmf1kF5hcqihtfs-W6gGnxD_FWWH_SflkPorUmnGsw6nDJCLXQvGlAmL7ncUvAE3ax6AtbB1o-qghRGIuxqgmV2ncXnsqR0wY7rQotlwobaMao08WbZlg0FHrJIY4hgrzYsW8a4IDWBSQsXdAF7WRE83Ml3CJINZjxEnmR0hZFU9C0zpumWBVZLtqM0iYV5ZIxUU66v8a6J1D6XjkVJu0t8gZiHRWmDsbJI6FVTCVKYbONV7dfUOj9X-r6SxXa-HBQQCN5p43zUkDvosbLZ4e7ZpM1ZVbyO9ykq7xkS7pe5Xf7Dc2zmlFRY5a2mNZNkTdFyinmddaysk3v5GZmuKJpviqyxTLLCyGKvM3ygi_LlOQUey7VIlhmYWx3F6vwTZpnjJV3iteoXHweYixW4YnRidQHrkJFwwh7IIxNeyKrppI0DBfbO7uJsVGPnSM5VdJ5d1bipVfx1WkXRYstKe4nG5NiO5X76MBomFVND0JSO9ngyRlvjzhsN71TQB2qgLvRqs1___YwEz9s2H8CAAD__6ZF9cE">