<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/77420>77420</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Title: [mlir] --canonicalize causes the Segmentation Fault in eraseUnreachableBlocks.
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            mlir
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          anonymousMCS
      </td>
    </tr>
</table>

<pre>
    Similar to https://github.com/llvm/llvm-project/issues/74461, but with different content in the unreachable block.

git version: 6e90f13cc9bc9dbc5c2c248d95c6e18a5fb021b4

system: ```Ubuntu 20.04.6 LTS (Focal Fossa)```

reproduced with: ```mlir-opt --canonicalize a.mlir```

a.mlir:
```
func.func private @func1() {
  %false = arith.constant false
  %c0 = arith.constant 0 : index

  cf.cond_br %false, ^bb1, ^bb2
^bb1:  // pred: ^bb0
  omp.parallel {
 omp.wsloop for  (%arg0) : index = (%c0) to (%c0) step (%c0) {
      %189 = llvm.intr.stacksave : !llvm.ptr
      llvm.br ^bb1
    ^bb1:  // pred: ^bb0
      llvm.br ^bb2
    ^bb2:  // pred: ^bb1
      omp.yield
 }
    omp.terminator
  }
  cf.br ^bb2
^bb2:  // pred: ^bb0
 return
}
```

trace:
```
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /data1/bin-dev/llvm-project/build/bin/mlir-opt --canonicalize a.mlir
 #0 0x000055b186889e4f llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x1684e4f)
 #1 0x000055b186886ea4 SignalHandler(int) Signals.cpp:0:0
 #2 0x00007fd721788420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #3 0x000055b1896c0d6b mlir::SuccessorRange::SuccessorRange(mlir::Block*) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x44bbd6b)
 #4 0x000055b18942f71f llvm::po_iterator<mlir::Block*, llvm::SmallPtrSet<mlir::Block*, 8u>, false, llvm::GraphTraits<mlir::Block*>>::traverseChild() (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x422a71f)
 #5 0x000055b18942fdeb llvm::iterator_range<llvm::po_iterator<mlir::Block*, llvm::SmallPtrSet<llvm::GraphTraits<mlir::Block*>::NodeRef, 8u>, false, llvm::GraphTraits<mlir::Block*>>> llvm::post_order<mlir::Block*>(mlir::Block* const&) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x422adeb)
 #6 0x000055b1897a8feb mlir::RewriterBase::eraseOp(mlir::Operation*)::'lambda0'(mlir::Operation*)::operator()(mlir::Operation*) const (.isra.0) PatternMatch.cpp:0:0
 #7 0x000055b1897a911e mlir::RewriterBase::eraseOp(mlir::Operation*)::'lambda0'(mlir::Operation*)::operator()(mlir::Operation*) const (.isra.0) PatternMatch.cpp:0:0
 #8 0x000055b1897a9d36 mlir::RewriterBase::eraseOp(mlir::Operation*) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x45a4d36)
 #9 0x000055b1897a9c09 mlir::RewriterBase::eraseBlock(mlir::Block*) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x45a4c09)
#10 0x000055b18965cdbb mlir::eraseUnreachableBlocks(mlir::RewriterBase&, llvm::MutableArrayRef<mlir::Region>) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x4457dbb)
#11 0x000055b18966535a mlir::simplifyRegions(mlir::RewriterBase&, llvm::MutableArrayRef<mlir::Region>) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x446035a)
#12 0x000055b1896455b1 mlir::applyPatternsAndFoldGreedily(mlir::Region&, mlir::FrozenRewritePatternSet const&, mlir::GreedyRewriteConfig, bool*) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x44405b1)
#13 0x000055b1895adcda (anonymous namespace)::Canonicalizer::runOnOperation() Canonicalizer.cpp:0:0
#14 0x000055b18958e85e mlir::detail::OpToOpPassAdaptor::run(mlir::Pass*, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x438985e)
#15 0x000055b18958ed3a mlir::detail::OpToOpPassAdaptor::runPipeline(mlir::OpPassManager&, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int, mlir::PassInstrumentor*, mlir::PassInstrumentation::PipelineParentInfo const*) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x4389d3a)
#16 0x000055b18958f504 mlir::PassManager::run(mlir::Operation*) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x438a504)
#17 0x000055b1895801f3 performActions(llvm::raw_ostream&, std::shared_ptr<llvm::SourceMgr> const&, mlir::MLIRContext*, mlir::MlirOptMainConfig const&) MlirOptMain.cpp:0:0
#18 0x000055b189581774 processBuffer(llvm::raw_ostream&, std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, mlir::MlirOptMainConfig const&, mlir::DialectRegistry&, llvm::ThreadPool*) MlirOptMain.cpp:0:0
#19 0x000055b189581924 mlir::LogicalResult llvm::function_ref<mlir::LogicalResult (std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, llvm::raw_ostream&)>::callback_fn<mlir::MlirOptMain(llvm::raw_ostream&, std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, mlir::DialectRegistry&, mlir::MlirOptMainConfig const&)::'lambda'(std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, llvm::raw_ostream&)>(long, std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, llvm::raw_ostream&) MlirOptMain.cpp:0:0
#20 0x000055b18967df14 mlir::splitAndProcessBuffer(std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, llvm::function_ref<mlir::LogicalResult (std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, llvm::raw_ostream&)>, llvm::raw_ostream&, bool, bool) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x4478f14)
#21 0x000055b189579d87 mlir::MlirOptMain(llvm::raw_ostream&, std::unique_ptr<llvm::MemoryBuffer, std::default_delete<llvm::MemoryBuffer>>, mlir::DialectRegistry&, mlir::MlirOptMainConfig const&) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x4374d87)
#22 0x000055b189581a71 mlir::MlirOptMain(int, char**, llvm::StringRef, llvm::StringRef, mlir::DialectRegistry&) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x437ca71)
#23 0x000055b189581ef6 mlir::MlirOptMain(int, char**, llvm::StringRef, mlir::DialectRegistry&) (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x437cef6)
#24 0x000055b1867c05d3 main (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x15bb5d3)
#25 0x00007fd721254083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#26 0x000055b18685993e _start (/data1/bin-dev/llvm-project/build/bin/mlir-opt+0x165493e)
Segmentation fault (core dumped)
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzcWt1z4ygS_2uUFyouCX0_-MH58N5WTW5ScfbZhaBlc4NBB2gm3r_-CiTbkuIks7feubmdyvgDmub3a7qbRpgYwzcSYB6kN0F6d0Vau1V6TqSS-51qzcPt6qpSbD9f8R0XRCOr0NbaxgTxIsDLAC833G7bakbVLsBLIb4e3q4brf4F1AZ4yY1pwQR4mSdJFgX4FlWtRd-43SLG6xo0SIuokta9c4nsFlArNRC6JZUAVAlFv8yC8C4IF93rhlv0FbThSgbxAmVQhnUUU1pWtGQVTSmmOClYmdIMooKkdRXiqEqGKszeWNi50UEWdn-_Va20LcLhLExmGfr0vEIBLpaKEoGWyhgS4PIoPNSlodGKtRSYZzVSuhNcX6vGoutr6szKKRH8d0Bk5nrOquu74v7rRKZuJZ25F9Ro_pVYQEESuu9RgIsAlyjIbzpJhAKc1kQYQEF8h4jmdjujShpLpEW-YyBIw3NSrnGBuGTwMoSIEK2dEFtX-jiLW9kgva-q6PgJ94O61tjP5LwGNRqYt5PrCQ9K1a6ZNUQTIUAMeLjmb0Yo1aBaaaejCHBK9Cb0fA8APf6uj_oeq0ZfjYVm1DCwlPsX4DQqSq_FefCMS6tnxhL6xZCv4OcJcOS7GquHI32bs0TH89jzvbxf6cATHfhNHdFQhzPUnoNgfWOQ3526XacFveOSWHWEPxCh9XT-D-Y-4NdgWy37IQd9Z13bakLhLc9-_HS_WN0j01Y7bhFBVbtBGhql7Z9LO4hIhrikomXgkwvVxGxRRegXj6dPLSu30oi1u-YIMJx1dn3UaqPJDhG9aXcgrel8YcmIJVGAlxWX1wy-vsZQtVywTiDAyw9yQb9mOA5R-BKGYZimVVRkRVFCUnv_cMBil7q6D4-aS-thP3u74uIkpMm3tTJWA9kFOHMByaX1Tu8C4L9FHuCb8CXKigSS2mXDI-RoAjkDkqAV30gi_kEkE6ADXPQIumYzo42zdOj_HxXhXlFesxxHeVEkOETrtQZjlYa1tj0BwasAL1-KbJ0l14LL9uV6I9uuo7FbDYTNjJqFHeIkweEIbzzEW2Y0ZFmFDmk3XqxaSsEYpZ-I3MDZNlycxG_cDhXgxWXsmyRVxbJqhDcZ4U1wnUdDl2jUmlvQPrDj23PAbgfSqx0R4tHqFdg3pYs2iO_dh2NqP43_RZNm-6wJd4Fwbnx87_9cm9XE7dRwu_V8iwuZCGOSR2MXTKcmYlANQB_ss9bdkt5exnp_0Cqu4Z-KwRPUl7Ly_cgPjF0rzeANIm6yM36L_H7v88SlVofB2IGz0erkpKhhGHBP8E27Nbghpg830MTA52aE93PjVslVfT7WusYA54LsKkbCAOcfi6umX2nvi-_Jd1Zx9phxo8nM1wyPxFrQ8oFYuj2fwfIJ0zKK4O_JtJgyZXH2Z5lewv1SkrA4G7lfOYVKw_JjqH18_HWZPiUJDcsjUreRhuOdKaWsGgaKx_Xb6XTkAZkRxhGZbu8_ZYiH1rphC63J3iWhYZp4go0_Ud1fah9Lc1ZVI3bRmF2WxikZsDN81whe7zskPyutLIxTMqKFx7QS9z6gRZpG7Pt4MgvJlkqwXzQA42I_4eihduxOzUutfgfZG6DXswI7SNtDaa9530vfKlnzjT90KyUuWKMkYeoOegMjjGuqlDDKiJvq-DQBSbID0_hStc9Rt4M6uIevW_lZDrKCLxlGcq-zkZt-XCKlBRTpMO8ysISLQ855Vp-bR2LMgpHGb_v9zKPVcAL99v9Wvhr2LCQRe8PNA5Fk4wreg81vUSv9cxZ2uSI8iYuySGG0AOnUAiwmf9gCj7wBwSVMkrQTPRLLLm6S4SA31a_SWO3PWm7_Wrwn0M3cdfTYH4kGaX-VtTqEyKXcPi5KFo9jP5tYvU7DZAL2QP-sl_0FG2BckDRMRijzCcowqmPUgK6V3i2o7bPte-dHY1mfpLdEA1s3Vo_q35VqNYWHjXYl6fnM9PDp16dbJS282FeL-iC4_tzYB8Jll7NGRemg93z0FxN-UZ4nqNHKHdlu2rr2B9DvotdK_u8WXtF7gJ3S-4OqgTyDmrTCrhkIsPD2mK5c_27OQ7k7TgRQ63YHY_X-1e737M-7j6cE_6G5yqm5Sjx02k9q45LtE5hW2MFEdSu9r6z1ZI8dDwhw8ePM-failscjFyVCVIR-WddyBHtgp5_QPc4v-3eGzOTI0J0YfppVwYVQcvNjDfsOpA8DBk_K8pzV0TBgTCO4XUj2OMk4_wt2_4dB-q7EqWbo3i9Tv-ZFHY22SDw-m6R5yYr8fLT93XLFRWqOPGFFPjIonm4yJI_eNGhfBtIt6Qq-6VM3q7nc9I_N3mh-3xoXYklJPjr24HjKEursIix_DB2osxGd0TEqy2mYshjtCJeXuDlIqypl8Wi-dPTAH6dJWMRovRa8omtjibbrweTvPfWnM6NmmZ8HOyWjWbLx_URaljGgTv9FbkTSpIxPh7EVbI4nE-RD2k1ClQZ_vwTshO1wBXbF5jEr45JcwTzKwyQv0jzLrrbzMomKKI7KJExKWud5miVFUUBZ0rLMGa2v-ByHOAmjsAzzOAuzWU1SGkUlCzPAcZnmQRLCjnAx81eMSm-u_NXYPM8THF4JUoEw_gcAGHuXwzhI76703POv2o0JklBwY81JgeVWwPzZvXa3gTd-ZHo3vdqipDVg_K3byChLbxQu0fnnWbOrVov5n_ilgaP2nwAAAP__EJHrgg">