Hi Harald and Jerry, I am reworking my way through, line by line wit F2018 in hand. Up to test with offset 70, NAG looks to be right. I introduced an assignment with a direct by ref function call, which doesn't finalise at the moment. Class entities are yet to come. I'll report back early next week.
Thanks for all the help. I have (re)learned to read the standard very carefully. Best regards Paul On Fri, 11 Feb 2022, 21:08 Harald Anlauf, <anl...@gmx.de> wrote: > Hi Paul, > > Am 11.02.22 um 10:08 schrieb Paul Richard Thomas via Fortran: > > Your "stupid questions" are not at all stupid. The finalization of > > 'variable' that occurs in your testcase demonstrates that the > finalization > > with my patch is occurring at the wrong time. I now see that NAG is > correct > > on this. > > > > Please press on with the questions! > > Jerry's suggestion to add lots of prints turned out to be really > enlightening with regard to observable behavior. I rewrote the > testcase again and placed the interesting stuff into a subroutine. > This way one can distinguish what actually happens during program > start, entering and leaving a subroutine. > > I encountered the least surprises (= none) with NAG 7.0 here. > For reference this is the output: > > At start of program : 0 > > Enter sub : 0 > After 1st allocation: 0 > After 2nd allocation: 0 > Checking MyType% ind: 21 > Checking MyType2%ind: 22 > Deallocate MyType : 0 > # Leave desctructor1: 1 21 > * MyType deallocated: 1 > (kept MyType2 for automatic deallocation on return from sub) > Leave sub : 1 > # Leave desctructor1: 2 22 > > After sub : 2 > > To make it short: the destructor is called only when deallocation > occurs, either explicitly or automatically. > > > Intel 2021.5.0: > > At start of program : 0 > > Enter sub : 0 > # Leave desctructor1: 1 0 > After 1st allocation: 1 > # Leave desctructor1: 2 0 > After 2nd allocation: 2 > Checking MyType% ind: 21 > Checking MyType2%ind: 22 > Deallocate MyType : 2 > # Leave desctructor1: 3 21 > * MyType deallocated: 3 > (kept MyType2 for automatic deallocation on return from sub) > Leave sub : 3 > # Leave desctructor1: 4 21 > # Leave desctructor1: 5 22 > # Leave desctructor1: 6 22 > > After sub : 6 > > So after entering the subroutine, the destructor is called twice, > but for unknown reasons element ind, which I had expected to be > either default-initialized to -1, or explicitly to 21 or 22, is 0. > The places where this happens seem to be the assignments of > MyType and MyType2. > > Furthermore, variable MyType is finalized on return from sub, > although it is already deallocated, and MyType2 appears to > get finalized twice automatically. > > I have no idea how this can get justified... > > > Crayftn 12.0.2: in order to make the output easier to understand, > I chose to reset final_count twice. This will become clear soon. > > # Leave desctructor1: 1, 20 > > At start of program : 1 > +++ Resetting final_count for Cray Fortran : Version 12.0.2 > > # Leave desctructor1: 1, 21 > # Leave desctructor1: 2, 22 > Enter sub : 2 > +++ Resetting final_count for Cray Fortran : Version 12.0.2 > After 1st allocation: 0 > After 2nd allocation: 0 > Checking MyType% ind: -21 > Checking MyType2%ind: 22 > Deallocate MyType : 0 > # Leave desctructor1: 1, -21 > * MyType deallocated: 1 > (kept MyType2 for automatic deallocation on return from sub) > Leave sub : 1 > # Leave desctructor1: 2, 22 > > After sub : 2 > > So it appears that Cray is calling the destructor for each declaration > where a constructor is involved, or the like. Even if this is a > parameter declaration, like in the main. Resetting the counter for > the first time. > > On entering sub, I see now two finalizations before the first print. > Resetting the counter for the second time. > > But then the assignments do not invoke finalization, where Intel did. > So this part appears more like NAG, but... > > ... something is strange here: component ind is wrong after the > first assignment. Looks clearly like a really bad bug. > > Explicit and automatic deallocation seems fine. > > > Nvidia 22.2: > > At start of program : 0 > > Enter sub : 0 > After 1st allocation: 0 > After 2nd allocation: 0 > Checking MyType% ind: 21 > Checking MyType2%ind: 22 > Deallocate MyType : 0 > # Leave desctructor1: 1 21 > * MyType deallocated: 1 > (kept MyType2 for automatic deallocation on return from sub) > Leave sub : 1 > # Leave desctructor1: 2 1590094384 > # Leave desctructor1: 3 22 > > After sub : 3 > > OK, that is really odd. Although valgrind does not report > invalid accesses, there is something really fishy here. > I have not investigated further. Nvidia is out for now. > > > One of the lessons learned is that it might be hard to write a > portable testcase that works for all compilers that rightfully(?) > can claim to implement finalization correctly... And I have only > scratched the surface so far. > > Paul: do you think you can enhance your much more comprehensive > testcase to ease debugging further? > > Cheers, > Harald >
