[Bug fortran/115150] New: [12/13/14/15 Regression] SHAPE of zero-sized array yields a negative value

[burnus at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115150

            Bug ID: 115150
           Summary: [12/13/14/15 Regression] SHAPE of zero-sized array
                    yields a negative value
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org
  Target Milestone: ---

GCC 11.4 has:
 Shape:           0           0
 Shape:           0           3           0

But since GCC 12:
 Shape:          -2           0
 Shape:          -3           3           0

Testcase:

implicit none
real,allocatable :: A(:),B(:,:)
allocate(a(3:0), b(5:1, 3))
print *, 'Shape:', shape(a), size(a)
print *, 'Shape:', shape(b), size(b)
end