Re: [Patch, fortran] PR37336 (Finalization) - [F03] Finish derived-type finalization

[Harald Anlauf <anlauf@gmx.de>]

Hi Paul,

Am 08.02.22 um 12:22 schrieb Paul Richard Thomas via Fortran:
> Hi Harald,
> 
> Thanks for giving the patch a whirl.
> 
> 
>> the parent components as an array. I strongly suspect that, from reading
>>> 7.5.6.2 paragraphs 2 and 3 closely, that ifort has it right. However,
>> this
>>> is another issue to come back to in the future.
>>
>> Could you specify which version of Intel you tried?
>>
> 
> ifort (IFORT) 2021.1 Beta 20201112

ok, that's good to know.

>>
>> Testcase finalize_38.f90 fails for me with ifort 2021.5.0 with:
>>
>> 131
>>
>> This test also fails with crayftn 11 & 12 and nagfor 7.0,
>> but in a different place.
>>

I have run your modified version of finalize_38.f90, and now I see
that you can get a bloody head just from scratching too much...

crayftn 12.0.2:

  1,  3,  1
  2,  21,  0
  11,  3,  2
  12,  21,  1
  21,  4,  3
  23,  21,  22 | 42,  43
  31,  6,  4
  41,  7,  5
  51,  9,  7
  61,  10,  8
  71,  13,  10
  101,  2,  1
  102,  4,  3
  111,  3,  2
  121,  4,  2
  122,  0,  4
  123,  5,  6 | 2*0
  131,  5,  2
  132,  0,  4
  133,  7,  8 | 2*0
  141,  6,  3
  151,  10,  5
  161,  16,  9
  171,  18,  11
  175,  0.,  20. | 10.,  20.

nagfor 7.0:

  1 0 1
  11 1 2
  23 21 22 | 42 43
  71 9 10
  72 11 99
  131 3 2
  132 5 4
  141 4 3
  151 6 5
  161 10 9
  171 12 11

Intel 2021.5.0:

          131           3           2
          132           0           4
          133           5           6 |           0           0
          141           4           3
          151           7           5
          152           3           0
          153           0           0 |           1           3
forrtl: severe (174): SIGSEGV, segmentation fault occurred
[...]


That got me reading 7.5.6.3, where is says in paragraph 1:

"When an intrinsic assignment statement is executed (10.2.1.3), if the
variable is not an unallocated allocatable variable, it is finalized
after evaluation of expr and before the definition of the variable.
..."

Looking at the beginning of the testcase code (abridged):

   type(simple), allocatable :: MyType, MyType2
   type(simple) :: ThyType = simple(21), ThyType2 = simple(22)

! The original PR - one finalization of 'var' before (re)allocation.
   MyType = ThyType
   call test(1, 0, [0,0], 0)


This is an intrinsic assignment.

Naively I would expect MyType to be initially unallocated.

ThyType is not allocatable and non-pointer and cannot become
undefined here and would not play any role in finalization.

I am probably too blind-sighted to see why there should be
a finalization here.  What am I missing?

> Could you use the attached version of finalize_38.f90 with crayftn and NAG?
> All the stop statements are replaced with prints. Ifort gives:
>           131           3           2
>           132           0           4
>           133           5           6 |           0           0
>           141           4           3
>           151           7           5
>           152           3           0
>           153           0           0 |           1           3
>           161          13           9
>           162          20           0
>           163           0           0 |          10          20
>           171          14          11

I think it is a good idea to have these prints in the testcase
whenever there is a departure from expectations.  So print&stop?

Furthermore, for the sake of health of people reading the testcases
later, I think it would not harm to add more explanations why we
expect a certain behavior... ;-)

> Best regards
> 
> Paul

Best regards,
Harald