[all-commits] [llvm/llvm-project] da60b9: [flang] Fixed managing copy-in/copy-out temps.

[Slava Zakharin via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: da60b9e7dc6b217ecd8f422a71ee3aa4a4022015
      https://github.com/llvm/llvm-project/commit/da60b9e7dc6b217ecd8f422a71ee3aa4a4022015
  Author: Slava Zakharin <szakharin at nvidia.com>
  Date:   2023-05-23 (Tue, 23 May 2023)

  Changed paths:
    M flang/include/flang/Lower/CallInterface.h
    M flang/include/flang/Optimizer/Builder/Runtime/Assign.h
    M flang/include/flang/Optimizer/Builder/Runtime/Derived.h
    M flang/include/flang/Runtime/assign.h
    M flang/include/flang/Runtime/derived-api.h
    M flang/lib/Lower/CallInterface.cpp
    M flang/lib/Lower/ConvertCall.cpp
    M flang/lib/Lower/ConvertExpr.cpp
    M flang/lib/Optimizer/Builder/Runtime/Assign.cpp
    M flang/lib/Optimizer/Builder/Runtime/Derived.cpp
    M flang/lib/Optimizer/HLFIR/Transforms/ConvertToFIR.cpp
    M flang/runtime/assign.cpp
    M flang/runtime/derived-api.cpp
    M flang/test/HLFIR/copy-in-out-codegen.fir
    M flang/test/Lower/call-by-value-attr.f90
    M flang/test/Lower/call-copy-in-out.f90
    M flang/test/Lower/dummy-argument-assumed-shape-optional.f90
    M flang/test/Lower/dummy-argument-optional-2.f90
    M flang/test/Lower/optional-value-caller.f90

  Log Message:
  -----------
  [flang] Fixed managing copy-in/copy-out temps.

There are several observations regarding the copy-in/copy-out:
  * Actual argument associated with INTENT(OUT) dummy argument that
    requires finalization (7.5.6.3 p. 7) may be read by the finalization
    function, so a copy-in is required.
  * A temporary created for the copy-in/copy-out must be destroyed
    without finalization after the call (or after the corresponding copy-out),
    otherwise, memory leaks may occur.
  * The copy-out assignment must not perform finalization for the LHS.
  * The copy-out assignment from the temporary to the actual argument
    may or may not need to initialize the LHS.

This change-set introduces new runtime methods: CopyOutAssign and
DestroyWithoutFinalization. They are called by the compiler generated
code to match the behavior described above.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D151135