[flang-commits] [flang] [Flang OpenMP] Add semantics checks for cray pointer usage in DSA list (PR #121028)

[LLVM Continuous Integration via flang-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-aarch64-libcxx` running on `linaro-flang-aarch64-libcxx` while building `flang` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/89/builds/14474

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
92.842 [157/6/7173] Creating library symlink lib/libFIRTestAnalysis.so
93.413 [157/5/7174] Linking CXX shared library lib/libHLFIRTransforms.so.20.0git
93.419 [156/5/7175] Creating library symlink lib/libHLFIRTransforms.so
93.908 [154/6/7176] Linking CXX shared library lib/libflangPasses.so.20.0git
93.914 [153/6/7177] Creating library symlink lib/libflangPasses.so
94.325 [152/6/7178] Linking CXX executable bin/fir-opt
94.712 [152/5/7179] Linking CXX shared library lib/libclang-cpp.so.20.0git
94.718 [151/5/7180] Creating library symlink lib/libclang-cpp.so
94.766 [151/4/7181] Linking CXX executable bin/tco
199.898 [151/3/7182] Building CXX object tools/flang/lib/Semantics/CMakeFiles/FortranSemantics.dir/resolve-directives.cpp.o
FAILED: tools/flang/lib/Semantics/CMakeFiles/FortranSemantics.dir/resolve-directives.cpp.o 
/usr/local/bin/c++ -DFLANG_INCLUDE_TESTS=1 -DFLANG_LITTLE_ENDIAN=1 -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/tools/flang/lib/Semantics -I/home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/flang/lib/Semantics -I/home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/flang/include -I/home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/tools/flang/include -I/home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/llvm/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/llvm/../mlir/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/tools/mlir/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/tools/clang/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/llvm/../clang/include -stdlib=libc++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -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 -Werror -Wno-deprecated-copy -Wno-string-conversion -Wno-ctad-maybe-unsupported -Wno-unused-command-line-argument -Wstring-conversion           -Wcovered-switch-default -Wno-nested-anon-types -O3 -DNDEBUG -std=c++17 -fPIC  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT tools/flang/lib/Semantics/CMakeFiles/FortranSemantics.dir/resolve-directives.cpp.o -MF tools/flang/lib/Semantics/CMakeFiles/FortranSemantics.dir/resolve-directives.cpp.o.d -o tools/flang/lib/Semantics/CMakeFiles/FortranSemantics.dir/resolve-directives.cpp.o -c /home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/flang/lib/Semantics/resolve-directives.cpp
../llvm-project/flang/lib/Semantics/resolve-directives.cpp:2123:16: error: reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true [-Werror,-Wundefined-bool-conversion]
 2120 |           (sym->test(Symbol::Flag::CrayPointee) &&
      |                                                 ~~
 2121 |               // If CrayPointer is among the DSA list then the
 2122 |               // CrayPointee is Privatizable
 2123 |               &semantics::GetCrayPointer(*sym))) &&
      |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../llvm-project/flang/include/flang/Semantics/tools.h:315:15: note: 'GetCrayPointer' returns a reference
  315 | const Symbol &GetCrayPointer(const Symbol &crayPointee);
      |               ^
1 error generated.
228.603 [151/2/7183] Building CXX object tools/flang/lib/Semantics/CMakeFiles/FortranSemantics.dir/semantics.cpp.o
371.786 [151/1/7184] Building CXX object tools/flang/lib/Semantics/CMakeFiles/FortranSemantics.dir/check-omp-structure.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/121028