On Thu, Aug 19, 2021 at 12:12 PM Harald Anlauf via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > Hi Tobias, > > > I am inclined to say that the Intel compiler has a bug by not > > accepting it – but as written before, I regard sub-string length > > (esp. with const expr) inquiries as an odd corner case which > > is unlikely to occur in real-world code. > > ok. > > > Still does not work – or rather: ...%t(:)(3:4) [i.e. substring with array > > section] > > and ...%str(3:4) [i.e. substring of deferred-length scalar] both do work > > but if one combines the two (→ ...%str2(:)(3:4), i.e. substring of > > deferred-length > > array section), it does not: > > > > Array ‘r’ at (1) is a variable, which does not reduce to a constant > > expression > > > > for: > > > > --- a/gcc/testsuite/gfortran.dg/pr100950.f90 > > +++ b/gcc/testsuite/gfortran.dg/pr100950.f90 > > @@ -15,2 +15,3 @@ program p > > character(len=:), allocatable :: str > > + character(len=:), allocatable :: str2(:) > > end type t_ > > @@ -24,2 +25,4 @@ program p > > integer, parameter :: l6 = len (r(1)%str (3:4)) > > + integer, parameter :: l7 = len (r(1)%str2(1)(3:4)) > > + integer, parameter :: l8 = len (r(1)%str2(:)(3:4)) > > > > > > which feels odd. > > I agree. I have revised the code slightly to accept substrings > of deferred-length. Your suggested variants now work correctly. > > > In principle, LGTM – except I wonder what we do about the > > len(r(1)%str(1)(3:4)); > > I think we really do handle most code available and I would like to > > close this > > topic – but still it feels a bit odd to leave this bit out. > > That is handle now as discussed, see attached final patch. > Regtested again. > > > I was also wondering whether we should check that the > > compile-time simplification works – i.e. use -fdump-tree-original for this; > > I attached a patch for this. > > I added this to the final patch and taken the liberty to push the result > to master as d881460deb1f0bdfc3e8fa2d391a03a9763cbff4. > > Thanks for your patience, given the rather extensive review... > > Harald
This may have broken bootstrap on 32-bit hosts: https://gcc.gnu.org/pipermail/gcc-regression/2021-August/075209.html -- H.J.
