Hi Jerry,
Am 14.11.24 um 01:17 schrieb Jerry D:
On 11/13/24 2:26 PM, Harald Anlauf wrote:
Dear all,
the attached patch is the third part of a series to fix the handling of
NULL() passed to pointer dummy arguments. This one addresses character
dummy arguments (scalar, assumed-shape, assumed-rank) for various
uses in the caller.
The patch is a little larger than I expected, due to corner cases
(MOLD present or not, assumed-rank or other). If someone finds a
more clever version, I would be happy to learn about it.
Especially the treatment of assumed-rank dummy could certainly
be done differently.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
As this fixes wrong code on the one hand, and is very localized,
I would like to backport this to 14-branch after some waiting.
Is this ok?
Thanks,
Harald
OK for mainline and backport.
Food for thought at another time:
gfc_conv_procedure_call contains about 2100 lines of code. One can read
through this fairly directly and the comments are very helpful. It begs
for some refactoring into a set of smaller functions.
you are absolutely right! I keep telling that to others, but didn't
follow my own recommendations...
Refactored and pushed the attached version as r15-5295-gf70c1d517e09c4.
Kind and Type regards,
Jerry
Thanks for the review!
Harald
From f70c1d517e09c4dde421774a8cec591ca3c479a0 Mon Sep 17 00:00:00 2001
From: Harald Anlauf
Date: Thu, 14 Nov 2024 21:38:04 +0100
Subject: [PATCH] Fortran: fix passing of NULL() actual argument to character
dummy [PR104819]
Ensure that character length is set and passed by the call to a procedure
when its dummy argument is NULL() with MOLD argument present, or set length
to either 0 or the callee's expected character length. For assumed-rank
dummies, use the rank of the MOLD argument. Generate temporaries for
passed arguments when needed.
PR fortran/104819
gcc/fortran/ChangeLog:
* trans-expr.cc (conv_null_actual): Helper function to handle
passing of NULL() to non-optional dummy arguments of non-bind(c)
procedures.
(gfc_conv_procedure_call): Use it for character dummies.
gcc/testsuite/ChangeLog:
* gfortran.dg/null_actual_6.f90: New test.
---
gcc/fortran/trans-expr.cc | 79 +++
gcc/testsuite/gfortran.dg/null_actual_6.f90 | 221
2 files changed, 300 insertions(+)
create mode 100644 gcc/testsuite/gfortran.dg/null_actual_6.f90
diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index ddbb5ecf068..f004af71334 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -6378,6 +6378,76 @@ conv_dummy_value (gfc_se * parmse, gfc_expr * e, gfc_symbol * fsym,
}
+/* Helper function for the handling of NULL() actual arguments associated with
+ non-optional dummy variables. Argument parmse should already be set up. */
+static void
+conv_null_actual (gfc_se * parmse, gfc_expr * e, gfc_symbol * fsym)
+{
+ gcc_assert (fsym && !fsym->attr.optional);
+
+ /* Obtain the character length for a NULL() actual with a character
+ MOLD argument. Otherwise substitute a suitable dummy length.
+ Here we handle only non-optional dummies of non-bind(c) procedures. */
+ if (fsym->ts.type == BT_CHARACTER)
+{
+ if (e->ts.type == BT_CHARACTER
+ && e->symtree->n.sym->ts.type == BT_CHARACTER)
+ {
+ /* MOLD is present. Substitute a temporary character NULL pointer.
+ For an assumed-rank dummy we need a descriptor that passes the
+ correct rank. */
+ if (fsym->as && fsym->as->type == AS_ASSUMED_RANK)
+ {
+ tree rank;
+ tree tmp = parmse->expr;
+ tmp = gfc_conv_scalar_to_descriptor (parmse, tmp, fsym->attr);
+ rank = gfc_conv_descriptor_rank (tmp);
+ gfc_add_modify (&parmse->pre, rank,
+ build_int_cst (TREE_TYPE (rank), e->rank));
+ parmse->expr = gfc_build_addr_expr (NULL_TREE, tmp);
+ }
+ else
+ {
+ tree tmp = gfc_create_var (TREE_TYPE (parmse->expr), "null");
+ gfc_add_modify (&parmse->pre, tmp,
+ build_zero_cst (TREE_TYPE (tmp)));
+ parmse->expr = gfc_build_addr_expr (NULL_TREE, tmp);
+ }
+
+ /* Ensure that a usable length is available. */
+ if (parmse->string_length == NULL_TREE)
+ {
+ gfc_typespec *ts = &e->symtree->n.sym->ts;
+
+ if (ts->u.cl->length != NULL
+ && ts->u.cl->length->expr_type == EXPR_CONSTANT)
+ gfc_conv_const_charlen (ts->u.cl);
+
+ if (ts->u.cl->backend_decl)
+ parmse->string_length = ts->u.cl->backend_decl;
+ }
+ }
+ else if (e->ts.type == BT_UNKNOWN && parmse->string_length == NULL_TREE)
+ {
+ /* MOLD is not present. Pass length of associated dummy character
+ argument if constant, or zero. */
+ if (fsym->ts.u.cl->length != NULL
+ && fsym->ts.u.cl->length->expr_type == EXPR_CONSTANT)
+ {
+ gfc_conv_const_charlen (fsym->ts.u.cl);
+ parmse->string_length = fsym->ts.u.cl->backend_decl;
+ }
+ else
+ {
+ parm
