re PR fortran/31725 ([4.1 only] substring bound evaluated multiple times: wrong code for string(function():) = 'X')

PR fortran/31725

	* trans-expr.c (gfc_conv_substring): Evaluate substring bounds
	only once.

	* gfortran.dg/substr_4.f: New test.

From-SVN: r124769

gcc/fortran/ChangeLog

@@ -1,3 +1,9 @@
+2007-05-16  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
+
+	PR fortran/31725
+	* trans-expr.c (gfc_conv_substring): Evaluate substring bounds
+	only once.
+
 2007-05-13  Release Manager
 
 	* GCC 4.2.0 released.

gcc/fortran/trans-expr.c

@@ -255,6 +255,10 @@ gfc_conv_substring (gfc_se * se, gfc_ref * ref, int kind)
     gfc_conv_string_parameter (se);
   else
     {
+      /* Avoid multiple evaluation of substring start.  */
+      if (!CONSTANT_CLASS_P (start.expr) && !DECL_P (start.expr))
+	start.expr = gfc_evaluate_now (start.expr, &se->pre);
+
       /* Change the start of the string.  */
       if (TYPE_STRING_FLAG (TREE_TYPE (se->expr)))
 	tmp = se->expr;
@@ -273,6 +277,10 @@ gfc_conv_substring (gfc_se * se, gfc_ref * ref, int kind)
       gfc_conv_expr_type (&end, ref->u.ss.end, gfc_charlen_type_node);
       gfc_add_block_to_block (&se->pre, &end.pre);
     }
+
+  if (!CONSTANT_CLASS_P (end.expr) && !DECL_P (end.expr))
+    end.expr = gfc_evaluate_now (end.expr, &se->pre);
+
   tmp = fold_build2 (MINUS_EXPR, gfc_charlen_type_node,
 		     build_int_cst (gfc_charlen_type_node, 1),
 		     start.expr);

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2007-05-16  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
+
+	PR fortran/31725
+	* gfortran.dg/substr_4.f: New test.
+
 2007-05-13  Release Manager
 
 	* GCC 4.2.0 released.

gcc/testsuite/gfortran.dg/substr_4.f

@@ -0,0 +1,69 @@
+! { dg-do run }
+      subroutine test_lower
+      implicit none
+      character(3), dimension(3) :: zsymel,zsymelr
+      common /xx/ zsymel, zsymelr
+      integer :: znsymelr
+      zsymel = (/ 'X', 'Y', ' ' /)
+      zsymelr= (/ 'X', 'Y', ' ' /)
+      znsymelr=2
+      call check_zsymel(zsymel,zsymelr,znsymelr)
+
+      contains
+
+      subroutine check_zsymel(zsymel,zsymelr,znsymelr)
+        implicit none
+        integer znsymelr, isym
+        character(*) zsymel(*),zsymelr(*)
+        character(len=80) buf
+        zsymel(3)(lenstr(zsymel(3))+1:)='X'
+        write (buf,10) (trim(zsymelr(isym)),isym=1,znsymelr)
+10      format(3(a,:,','))
+        if (trim(buf) /= 'X,Y') call abort
+      end subroutine check_zsymel
+
+      function lenstr(s)
+        character(len=*),intent(in) :: s
+        integer :: lenstr
+        if (len_trim(s) /= 0) call abort
+        lenstr = len_trim(s)
+      end function lenstr
+
+      end subroutine test_lower
+
+      subroutine test_upper
+      implicit none
+      character(3), dimension(3) :: zsymel,zsymelr
+      common /xx/ zsymel, zsymelr
+      integer :: znsymelr
+      zsymel = (/ 'X', 'Y', ' ' /)
+      zsymelr= (/ 'X', 'Y', ' ' /)
+      znsymelr=2
+      call check_zsymel(zsymel,zsymelr,znsymelr)
+
+      contains
+
+      subroutine check_zsymel(zsymel,zsymelr,znsymelr)
+        implicit none
+        integer znsymelr, isym
+        character(*) zsymel(*),zsymelr(*)
+        character(len=80) buf
+        zsymel(3)(:lenstr(zsymel(3))+1)='X'
+        write (buf,20) (trim(zsymelr(isym)),isym=1,znsymelr)
+20      format(3(a,:,','))
+        if (trim(buf) /= 'X,Y') call abort
+      end subroutine check_zsymel
+
+      function lenstr(s)
+        character(len=*),intent(in) :: s
+        integer :: lenstr
+        if (len_trim(s) /= 0) call abort
+        lenstr = len_trim(s)
+      end function lenstr
+
+      end subroutine test_upper
+
+      program test
+        call test_lower
+        call test_upper
+      end program test