[flang] Missing runtime error diagnostic when deallocate an unallocated object

[DanielCChen]

Consider the following code:

      integer, allocatable :: a
      deallocate(a)
      end

Flang executes it without error.
Is the omission of the runtime diagnostic intentional or under an option?

[llvmbot]

@llvm/issue-subscribers-flang-runtime

Author: Daniel Chen (DanielCChen)

Consider the following code: ``` integer, allocatable :: a deallocate(a) end ```

Flang executes it without error.
Is the omission of the runtime diagnostic intentional or under an option?

[klausler]

Deallocations with a simple type requiring no finalization or recursive deallocation are implemented by lowering with an LLVM operation that is generated as a call to free(3), which does not abort on a null pointer.