[Bug fortran/115315] New: valgrind error in gfc_simplify_expr

[Bug fortran/115315] New: valgrind error in gfc_simplify_expr

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115315

            Bug ID: 115315
           Summary: valgrind error in gfc_simplify_expr
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

For this Fortran source code:

! RUN: %python %S/test_errors.py %s %flang_fc1
! Test section subscript
subroutine p1
  real :: a(10,10)
  real :: b(5,5)
  real :: c
  integer :: n
  n = 2
  b = a(1:10:n,1:n+3)
end

! Test substring
subroutine p2
  type t1(n1,n2)
    integer,kind :: n1,n2
    integer :: c2(iachar('ABCDEFGHIJ'(n1:n1)))
  end type
  character :: a(10)
  character :: b(5)
  character :: c(0)
  integer :: n
  n = 3
  b = a(n:7)
  b = a(n+3:)
  b = a(:n+2)
  a(n:7) = b
  a(n+3:) = b
  a(:n+2) = b
  n = iachar(1_'ABCDEFGHIJ'(1:1))
  c = 'ABCDEFGHIJ'(1:0)
end

! Test pointer assignment with bounds
subroutine p3
  integer, pointer :: a(:,:)
  integer, target :: b(2,2)
  integer :: n
  n = 2
  a(n:,n:) => b
  a(1:n,1:n) => b
end

! Test pointer assignment to array element
subroutine p4
  type :: t
    real, pointer :: a
  end type
  type(t) :: x(10)
  integer :: i
  real, target :: y
  x(i)%a => y
end subroutine

A recent valgrind version of gfortran does this:

test $ ~/gcc/results.20240530.valgrind/bin/gfortran -c -w
./Semantics/resolve49.f90
==1331074== Invalid read of size 2
==1331074==    at 0x48513A0: memmove (vg_replace_strmem.c:1414)
==1331074==    by 0x74F69F: gfc_simplify_expr(gfc_expr*, int) (expr.cc:2305)
==1331074==    by 0x74F4FB: gfc_simplify_expr(gfc_expr*, int) (expr.cc:2265)

The source code file is from the flang testsuite at 

https://github.com/llvm/llvm-project/tree/main/flang/test

[Bug fortran/115315] [PDT] valgrind error in gfc_simplify_expr

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115315

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
            Summary|valgrind error in           |[PDT] valgrind error in
                   |gfc_simplify_expr           |gfc_simplify_expr
           Priority|P3                          |P4
   Last reconfirmed|                            |2024-06-01

--- Comment #1 from anlauf at gcc dot gnu.org ---
Reduced testcase:

subroutine p2
  type t1(n1,n2)
    integer,kind :: n1,n2
    integer :: c2(iachar('ABCDEFGHIJ'(n1:n1)))
  end type
end

The current implementation is known to be incomplete.