[Patch, Fortran] [RFC] PR fortran/36746 / missing part from PR 32095?

[Daniel Kraft]

Hi,

this is a proposed patch for PR fortran/36746.  There, code like

IMPLICIT TYPE(t) (x)
DIMENSION x(:)
PRINT *, x(1)%comp

is rejected because the parser does not yet know x is of a derived-type
when the component reference is encountered (because the type is
IMPLICIT).  At least it's something similar to this description...

I'm thinking if this is a missed part of PR 32095 where I introduced
code to check for symbols being used before they get a type.  Does the
DIMENSION statement count as such a "use"?  This way, my patch attaches
the IMPLICIT type on encountering x in the DIMENSION statement and the
code compiles just fine.  On the other hand, however, code that gets now
rejected is:

IMPLICIT TYPE(t) (x)
DIMENSION x(:)
INTEGER :: x ! 'x' already has a type (TYPE(t))!

Is code like that legal?  I don't know what the standard says about it,
but I would guess intuitively that it isn't and it is indeed a missed
part of PR 32095.  What do you think, is my patch legal?  And if it is,
are there other cases apart from DIMENSION where I should enable this
typing in attr_decl1 (POINTER, ALLOCATABLE or maybe INTENT come to mind)?

gfortran.fortran-torture/execute/equiv_[2/4].f90 use code like the 
above, though, where there's a DIMENSION before the type gets declared.

With my patch, I see some regressions apart from that one (in three 
files) at the moment, but those seem all to be invalid code that now 
gets "another" error, and with fine-tuning the patch and changing 
expected error messages that should go fine.

Yours,
Daniel

-- 
Done:     Arc-Bar-Cav-Sam-Val-Wiz, Dwa-Elf-Gno-Hum-Orc, Law-Neu-Cha, Fem-Mal
To go:    Hea-Kni-Mon-Pri-Ran-Rog-Tou



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