Le 15/03/2024 à 20:32, Harald Anlauf a écrit :
Dear all,
as there has been some good progress in the handling of optional dummy
arguments, I looked again at this PR and a patch for it that I withdrew
as it turned out incomplete.
It turned out that it now needs only a minor adjustment for optional
dummy arguments of procedures with bind(c) attribute so that ubsan
checking does not trigger.
Along this way I extended the previous testcase to exercise to some
extent combinations of bind(c) and non-bind(c) procedures and found
one failure (since at least gcc-9) that is genuine: passing a missing
optional from a bind(c) procedure to an assumed-rank dummy, see
PR114355. The corresponding test is commented in the testcase.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
Thanks,
Harald
(...)
From b3079a82a220477704f8156207239e4af4103ea9 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anl...@gmx.de>
Date: Fri, 15 Mar 2024 20:14:07 +0100
Subject: [PATCH] Fortran: fix for absent array argument passed to optional
dummy [PR101135]
gcc/fortran/ChangeLog:
PR fortran/101135
* trans-array.cc (gfc_get_dataptr_offset): Check for optional
arguments being present before dereferencing data pointer.
gcc/testsuite/ChangeLog:
PR fortran/101135
* gfortran.dg/missing_optional_dummy_6a.f90: Adjust diagnostic pattern.
* gfortran.dg/ubsan/missing_optional_dummy_8.f90: New test.
---
gcc/fortran/trans-array.cc | 11 ++
.../gfortran.dg/missing_optional_dummy_6a.f90 | 2 +-
.../ubsan/missing_optional_dummy_8.f90 | 108 ++++++++++++++++++
3 files changed, 120 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gfortran.dg/ubsan/missing_optional_dummy_8.f90
diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index 3673fa40720..a7717a8107e 100644
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -7526,6 +7526,17 @@ gfc_get_dataptr_offset (stmtblock_t *block, tree parm,
tree desc, tree offset,
/* Set the target data pointer. */
offset = gfc_build_addr_expr (gfc_array_dataptr_type (desc), tmp);
+
+ /* Check for optional dummy argument being present. Arguments of BIND(C)
+ procedures are excepted here since they are handled differently. */
+ if (expr->expr_type == EXPR_VARIABLE
+ && expr->symtree->n.sym->attr.dummy
+ && expr->symtree->n.sym->attr.optional
+ && !is_CFI_desc (NULL, expr))
I think the condition could additionally check the lack of subreferences.
But it's maybe not worth the trouble, and the patch is conservatively
correct as is, so OK.
Thanks for the patch.
+ offset = build3_loc (input_location, COND_EXPR, TREE_TYPE (offset),
+ gfc_conv_expr_present (expr->symtree->n.sym), offset,
+ fold_convert (TREE_TYPE (offset),
gfc_index_zero_node));
+
gfc_conv_descriptor_data_set (block, parm, offset);
}
