[flang-commits] [flang] [llvm] [flang][runtime] Replace recursion with iterative work queue (PR #137727)

Tue Jun 10 19:26:03 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64-flang-aix` running on `ppc64-flang-aix-test` while building `flang-rt,flang` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/201/builds/5016

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (build-unified-tree) failure: build (failure)
...
10.687 [2/22/150] Building CXX object flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/io-api-minimal.cpp.o
10.861 [2/21/151] Building CXX object openmp/runtime/src/CMakeFiles/omp.dir/kmp_settings.cpp.o
clang++: warning: argument unused during compilation: '-fno-semantic-interposition' [-Wunused-command-line-argument]
In file included from /home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/openmp/runtime/src/kmp_settings.cpp:14:
/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/openmp/runtime/src/kmp_affinity.h:447:11: warning: unused variable 'gtid' [-Wunused-variable]
  447 |       int gtid = __kmp_entry_gtid();
      |           ^~~~
1 warning generated.
11.150 [2/20/152] Building CXX object flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/assign.cpp.o
11.248 [2/19/153] Building CXX object flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/unit.cpp.o
FAILED: flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/unit.cpp.o 
/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/build/./bin/clang++ --target=powerpc64-ibm-aix -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_LARGE_FILE_API -D_XOPEN_SOURCE=700 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/flang-rt/include -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/flang-rt/../flang/include -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/build/runtimes/runtimes-bins/flang-rt -mcmodel=large -fPIC -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -std=gnu++17 -UNDEBUG -fno-lto -fno-exceptions -fno-rtti -funwind-tables -fno-asynchronous-unwind-tables -U_GLIBCXX_ASSERTIONS -U_LIBCPP_ENABLE_ASSERTIONS -MD -MT flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/unit.cpp.o -MF flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/unit.cpp.o.d -o flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/unit.cpp.o -c /home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/flang-rt/lib/runtime/unit.cpp
PHI nodes not grouped at top of basic block!
  %niter = phi i64 [ 0, %for.cond2.preheader.us.i.new ], [ %niter.next.3, %for.body5.us.i ]
label %for.body5.us.i
in function _ZN7Fortran7runtime2io16ExternalFileUnit4EmitEPKcmmRNS1_14IoErrorHandlerE
fatal error: error in backend: Broken function found, compilation aborted!
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: /home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/build/./bin/clang++ --target=powerpc64-ibm-aix -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_LARGE_FILE_API -D_XOPEN_SOURCE=700 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/flang-rt/include -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/flang-rt/../flang/include -I/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/build/runtimes/runtimes-bins/flang-rt -mcmodel=large -fPIC -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -std=gnu++17 -UNDEBUG -fno-lto -fno-exceptions -fno-rtti -funwind-tables -fno-asynchronous-unwind-tables -U_GLIBCXX_ASSERTIONS -U_LIBCPP_ENABLE_ASSERTIONS -MD -MT flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/unit.cpp.o -MF flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/unit.cpp.o.d -o flang-rt/lib/runtime/CMakeFiles/flang_rt.runtime.static.dir/unit.cpp.o -c /home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/flang-rt/lib/runtime/unit.cpp
1.	<eof> parser at end of file
2.	Code generation
3.	Running pass 'Function Pass Manager' on module '/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/flang-rt/lib/runtime/unit.cpp'.
4.	Running pass 'Module Verifier' on function '@_ZN7Fortran7runtime2io16ExternalFileUnit4EmitEPKcmmRNS1_14IoErrorHandlerE'
clang++: error: clang frontend command failed with exit code 70 (use -v to see invocation)
clang version 21.0.0git
Target: powerpc64-ibm-aix
Thread model: posix
InstalledDir: /home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/build/bin
Build config: +assertions
clang++: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang++: note: diagnostic msg: /tmp/unit-9ef362.cpp
clang++: note: diagnostic msg: /tmp/unit-9ef362.sh
clang++: note: diagnostic msg: 

********************
12.071 [2/18/154] Building CXX object openmp/runtime/src/CMakeFiles/omp.dir/kmp_affinity.cpp.o
clang++: warning: argument unused during compilation: '-fno-semantic-interposition' [-Wunused-command-line-argument]
In file included from /home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/openmp/runtime/src/kmp_affinity.cpp:14:
/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/openmp/runtime/src/kmp_affinity.h:447:11: warning: unused variable 'gtid' [-Wunused-variable]
  447 |       int gtid = __kmp_entry_gtid();
      |           ^~~~
/home/llvm/llvm-external-buildbots/workers/ppc64-flang-aix-test/ppc64-flang-aix-build/llvm-project/openmp/runtime/src/kmp_affinity.cpp:3316:23: warning: unused variable 'cpuinfo' [-Wunused-variable]
 3316 |   lpar_info_format1_t cpuinfo;
      |                       ^~~~~~~

```

</details>

https://github.com/llvm/llvm-project/pull/137727