Fortran: reject invalid non-constant pointer initialization targets

gcc/fortran/ChangeLog:

	PR fortran/101762
	* expr.c (gfc_check_pointer_assign): For pointer initialization
	targets, check that subscripts and substring indices in
	specifications are constant expressions.

gcc/testsuite/ChangeLog:

	PR fortran/101762
	* gfortran.dg/pr101762.f90: New test.

diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index 96a2cd7..a87686d 100644 (file)
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -4343,6 +4343,7 @@ gfc_check_pointer_assign (gfc_expr *lvalue, gfc_expr *rvalue,
     {
       gfc_symbol *sym;
       bool target;
+      gfc_ref *ref;
 
       if (gfc_is_size_zero_array (rvalue))
        {
@@ -4372,6 +4373,39 @@ gfc_check_pointer_assign (gfc_expr *lvalue, gfc_expr *rvalue,
                     &rvalue->where);
          return false;
        }
+
+      for (ref = rvalue->ref; ref; ref = ref->next)
+       {
+         switch (ref->type)
+           {
+           case REF_ARRAY:
+             for (int n = 0; n < ref->u.ar.dimen; n++)
+               if (!gfc_is_constant_expr (ref->u.ar.start[n])
+                   || !gfc_is_constant_expr (ref->u.ar.end[n])
+                   || !gfc_is_constant_expr (ref->u.ar.stride[n]))
+                 {
+                   gfc_error ("Every subscript of target specification "
+                              "at %L must be a constant expression",
+                              &ref->u.ar.where);
+                   return false;
+                 }
+             break;
+
+           case REF_SUBSTRING:
+             if (!gfc_is_constant_expr (ref->u.ss.start)
+                 || !gfc_is_constant_expr (ref->u.ss.end))
+               {
+                 gfc_error ("Substring starting and ending points of target "
+                            "specification at %L must be constant expressions",
+                            &ref->u.ss.start->where);
+                 return false;
+               }
+             break;
+
+           default:
+             break;
+           }
+       }
     }
   else
     {

diff --git a/gcc/testsuite/gfortran.dg/pr101762.f90 b/gcc/testsuite/gfortran.dg/pr101762.f90
new file mode 100644 (file)
index 0000000..9ffd754
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr101762.f90
@@ -0,0 +1,23 @@
+! { dg-do compile }
+! PR fortran/101762 - ICE on non-constant pointer initialization targets
+! Contributed by G.Steinmetz
+
+program p
+  integer,      target  :: a(3) = [7, 8, 9]
+  integer,      pointer :: x    => a(3)
+  integer,      pointer :: y    => a(n())  ! { dg-error "constant expression" }
+  integer,      pointer :: z(:) => a(:n()) ! { dg-error "constant expression" }
+  character(7), target  :: c    = "abcdefg"
+  character(3), pointer :: c0   => c(2:4)
+  character(3), pointer :: c1   => c(m():) ! { dg-error "constant expression" }
+  character(3), pointer :: c2   => c(:m()) ! { dg-error "constant expression" }
+  print *, x, y
+contains
+  pure integer function k ()
+    k = 2
+  end function k
+  subroutine s ()
+    integer, pointer :: yy => a(k()) ! { dg-error "constant expression" }
+    print *, yy
+  end subroutine s
+end