[flang] Allow host-associated INTENT(OUT) in specification expr. (#135426)

Nearly, but not all, other compilers have a blanket prohibition against
the use of an INTENT(OUT) dummy argument in a specification expression.
Some compilers, however, permit an INTENT(OUT) dummy argument to appear
in a specification expression in a BLOCK construct or inner procedure
via host association.

The argument some have put forth to accept this usage comes from a
reading of 10.1.11 (specification expressions) in Fortran 2023 that, if
followed consistently, would also require host-associated OPTIONAL dummy
argument to be allowed. That would be dangerous for reasons that should
be obvious.

However, I can agree that a non-OPTIONAL dummy argument can't be assumed
to remain undefined on entry to a BLOCK construct or inner procedure, so
we can accept host-associated INTENT(OUT) in specification expressions
with a portability warning.
5 files changed
tree: d70bff79b9c19119d4e731053401c64311765c3e
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-tidy
  30. .git-blame-ignore-revs
  31. .gitattributes
  32. .gitignore
  33. .mailmap
  34. CODE_OF_CONDUCT.md
  35. CONTRIBUTING.md
  36. LICENSE.TXT
  37. pyproject.toml
  38. README.md
  39. SECURITY.md
README.md

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