[Patch, fortran] PR87477 - (associate) - [meta-bug] [F03] issues concerning the ASSOCIATE statement

[Harald Anlauf]

Hi Paul!

On 6/7/23 18:10, Paul Richard Thomas via Gcc-patches wrote:
> Hi All,
>
> Three more fixes for PR87477. Please note that PR99350 was a blocker
> but, as pointed out in comment #5 of the PR, this has nothing to do
> with the associate construct.
>
> All three fixes are straight forward and the .diff + ChangeLog suffice
> to explain them. 'rankguessed' was made redundant by the last PR87477
> fix.
>
> Regtests on x86_64 - good for mainline?
>
> Paul
>
> Fortran: Fix some more blockers in associate meta-bug [PR87477]
>
> 2023-06-07  Paul Thomas  <pault@gcc.gnu.org>
>
> gcc/fortran
> PR fortran/99350
> * decl.cc (char_len_param_value): Simplify a copy of the expr
> and replace the original if there is no error.

This seems to lack a gfc_free_expr (p) in case the gfc_replace_expr
is not executed, leading to a possible memleak.  Can you check?

@@ -1081,10 +1082,10 @@ char_len_param_value (gfc_expr **expr, bool
*deferred)
    if (!gfc_expr_check_typed (*expr, gfc_current_ns, false))
      return MATCH_ERROR;

-  /* If gfortran gets an EXPR_OP, try to simplify it.  This catches things
-     like CHARACTER(([1])).   */
-  if ((*expr)->expr_type == EXPR_OP)
-    gfc_simplify_expr (*expr, 1);
+  /* Try to simplify the expression to catch things like
CHARACTER(([1])).   */
+  p = gfc_copy_expr (*expr);
+  if (gfc_is_constant_expr (p) && gfc_simplify_expr (p, 1))
+    gfc_replace_expr (*expr, p);
    else
      gfc_free_expr (p);

> * gfortran.h : Remove the redundant field 'rankguessed' from
> 'gfc_association_list'.
> * resolve.cc (resolve_assoc_var): Remove refs to 'rankguessed'.
>
> PR fortran/107281
> * resolve.cc (resolve_variable): Associate names with constant
> or structure constructor targets cannot have array refs.
>
> PR fortran/109451
> * trans-array.cc (gfc_conv_expr_descriptor): Guard expression
> character length backend decl before using it. Suppress the
> assignment if lhs equals rhs.
> * trans-io.cc (gfc_trans_transfer): Scalarize transfer of
> associate variables pointing to a variable. Add comment.
> * trans-stmt.cc (trans_associate_var): Remove requirement that
> the character length be deferred before assigning the value
> returned by gfc_conv_expr_descriptor. Also, guard the backend
> decl before testing with VAR_P.
>
> gcc/testsuite/
> PR fortran/99350
> * gfortran.dg/pr99350.f90 : New test.
>
> PR fortran/107281
> * gfortran.dg/associate_5.f03 : Changed error message.
> * gfortran.dg/pr107281.f90 : New test.
>
> PR fortran/109451
> * gfortran.dg/associate_61.f90 : New test

Otherwise LGTM.

Thanks for the patch!

Harald