Dear all,
the attached patch fixes issues exhibited by the testcase in comment#19 of
PR55978.
First, when passing an allocatable optional dummy array to an optional dummy,
we need to prevent accessing the data component of the array when the argument
is not present, and pass a null pointer instead. This is straightforward.
Second, the case of a missing pointer optional dummy array should have worked,
but the presence check surprisingly did not work as expected at -O0 or -Og,
but at higher optimization levels. Interestingly, the dump-tree looked right,
but running under gdb or investigating the assembler revealed that the order
of tests in a logical AND expression was opposed to what the tree-dump looked
like. Replacing TRUTH_AND_EXPR by TRUTH_ANDIF_EXPR and checking the optimized
dump confirmed that this does fix the issue.
Note that the tree-dump is not changed by this replacement. Does this mean
thar AND and ANDIF currently are not differentiated at this level?
Regtested on x86_64-pc-linux-gnu. OK for mainline?
Would it be ok to backport this to 14-branch, too?
Thanks,
Harald
From 94e4c66d8374a12be38637620f362acf1fba5343 Mon Sep 17 00:00:00 2001
From: Harald Anlauf
Date: Sun, 23 Jun 2024 22:36:43 +0200
Subject: [PATCH] Fortran: fix passing of optional dummy as actual to optional
argument [PR55978]
gcc/fortran/ChangeLog:
PR fortran/55978
* trans-array.cc (gfc_conv_array_parameter): Do not dereference
data component of a missing allocatable dummy array argument for
passing as actual to optional dummy. Harden logic of presence
check for optional pointer dummy by using TRUTH_ANDIF_EXPR instead
of TRUTH_AND_EXPR.
gcc/testsuite/ChangeLog:
PR fortran/55978
* gfortran.dg/optional_absent_12.f90: New test.
---
gcc/fortran/trans-array.cc| 20 ++---
.../gfortran.dg/optional_absent_12.f90| 30 +++
2 files changed, 46 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/optional_absent_12.f90
diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index 19d69aec9c0..26237f43bec 100644
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -8703,6 +8703,10 @@ gfc_conv_array_parameter (gfc_se * se, gfc_expr * expr, bool g77,
&& (sym->backend_decl != parent))
this_array_result = false;
+ /* Passing an optional dummy argument as actual to an optional dummy? */
+ bool pass_optional;
+ pass_optional = fsym && fsym->attr.optional && sym && sym->attr.optional;
+
/* Passing address of the array if it is not pointer or assumed-shape. */
if (full_array_var && g77 && !this_array_result
&& sym->ts.type != BT_DERIVED && sym->ts.type != BT_CLASS)
@@ -8740,6 +8744,14 @@ gfc_conv_array_parameter (gfc_se * se, gfc_expr * expr, bool g77,
if (size)
array_parameter_size (&se->pre, tmp, expr, size);
se->expr = gfc_conv_array_data (tmp);
+ if (pass_optional)
+ {
+ tree cond = gfc_conv_expr_present (sym);
+ se->expr = build3_loc (input_location, COND_EXPR,
+ TREE_TYPE (se->expr), cond, se->expr,
+ fold_convert (TREE_TYPE (se->expr),
+ null_pointer_node));
+ }
return;
}
}
@@ -8989,8 +9001,8 @@ gfc_conv_array_parameter (gfc_se * se, gfc_expr * expr, bool g77,
tmp = fold_build2_loc (input_location, NE_EXPR, logical_type_node,
fold_convert (TREE_TYPE (tmp), ptr), tmp);
- if (fsym && fsym->attr.optional && sym && sym->attr.optional)
- tmp = fold_build2_loc (input_location, TRUTH_AND_EXPR,
+ if (pass_optional)
+ tmp = fold_build2_loc (input_location, TRUTH_ANDIF_EXPR,
logical_type_node,
gfc_conv_expr_present (sym), tmp);
@@ -9024,8 +9036,8 @@ gfc_conv_array_parameter (gfc_se * se, gfc_expr * expr, bool g77,
tmp = fold_build2_loc (input_location, NE_EXPR, logical_type_node,
fold_convert (TREE_TYPE (tmp), ptr), tmp);
- if (fsym && fsym->attr.optional && sym && sym->attr.optional)
- tmp = fold_build2_loc (input_location, TRUTH_AND_EXPR,
+ if (pass_optional)
+ tmp = fold_build2_loc (input_location, TRUTH_ANDIF_EXPR,
logical_type_node,
gfc_conv_expr_present (sym), tmp);
diff --git a/gcc/testsuite/gfortran.dg/optional_absent_12.f90 b/gcc/testsuite/gfortran.dg/optional_absent_12.f90
new file mode 100644
index 000..1e61d91fb6d
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/optional_absent_12.f90
@@ -0,0 +1,30 @@
+! { dg-do run }
+! { dg-additional-options "-fcheck=array-temps" }
+!
+! PR fortran/55978 - comment#19
+!
+! Test passing of (missing) optional dummy to optional array argument
+
+program test
+ implicit none
+ integer, pointer :: p(:) => null()
+ call one (p)
+ call one (null())
+ call one ()
+ call three ()
+contains
+ subroutin
