https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85130
Bug ID: 85130
Summary: Substrings out of range are not rejected
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: tkoenig at gcc dot gnu.org
Target Milestone: ---
F2003, 6.1.1:
Let the characters in the parent string be numbered 1, 2, 3, ..., n, where n is
the length of the parent
string. Then the characters in the substring are those from the parent string
from the starting point and
proceeding in sequence up to and including the ending point. Both the starting
point and the ending
point shall be within the range 1, 2, ..., n unless the starting point exceeds
the ending point, in which
case the substring has length zero. If the starting point is not specified, the
default value is 1. If the
ending point is not specified, the default value is n.
We correctly reject this for simple cases, but not for all. For example,
substr_6.f90 has
! { dg-do run }
! { dg-options "-std=legacy" }
!
! Check that NULs don't mess up constant substring simplification
CHARACTER(5), parameter :: c0(1) = (/ "123" // ACHAR(0) // "5" /)
CHARACTER*5 c(1)
CHARACTER(1), parameter :: c1(5) = (/ "1", "2", "3", ACHAR(0), "5" /)
c = c0(1)(-5:-8)
if (c(1) /= " ") STOP 1
