Currently, the Ada expression parser treats 'null' as an integer 0.
However, this causes overloading to fail in certain cases.
This patch changes the Ada expression parser to use a special type for
'null'. I chose pointer-to-int0, because I think that's not likely to
be needed for any other Ada expression. Note this works because a
"mod 1" type has an underlying non-zero byte size; the test includes a
check for this.
The output is changed so that "print null", by default, shows "null".
And, ada_type_match is changed both to recognize the special null type
and to remove a bit of weird code related to how pointers are treated
for overload type matching.
Tested on x86-64 Fedora 32. Because this only touches Ada, and Joel
already approved it internally at AdaCore, I am checking it in.
gdb/ChangeLog
2021-04-28 Tom Tromey <tromey@adacore.com>
* ada-exp.y (primary): Use new type for null pointer.
* ada-lang.c (ada_type_match): Remove "may_deref"
parameter. Handle null pointer.
(ada_args_match): Update.
* ada-valprint.c (ada_value_print_ptr, ada_value_print):
Handle null pointer.
gdb/testsuite/ChangeLog
2021-04-28 Tom Tromey <tromey@adacore.com>
* gdb.ada/null_overload.exp: New file.
* gdb.ada/null_overload/foo.adb: New file.
+2021-04-28 Tom Tromey <tromey@adacore.com>
+
+ * ada-exp.y (primary): Use new type for null pointer.
+ * ada-lang.c (ada_type_match): Remove "may_deref"
+ parameter. Handle null pointer.
+ (ada_args_match): Update.
+ * ada-valprint.c (ada_value_print_ptr, ada_value_print):
+ Handle null pointer.
+
2021-04-28 Andrew Burgess <andrew.burgess@embecosm.com>
* NEWS: Mention new commands.
;
primary : NULL_PTR
- { write_int (pstate, 0, type_int (pstate)); }
+ {
+ struct type *null_ptr_type
+ = lookup_pointer_type (parse_type (pstate)->builtin_int0);
+ write_int (pstate, 0, null_ptr_type);
+ }
;
primary : STRING
static int desc_arity (struct type *);
-static int ada_type_match (struct type *, struct type *, int);
-
static int ada_args_match (struct symbol *, struct value **, int);
static struct value *make_array_descriptor (struct type *, struct value *);
return candidates[i];
}
-/* Return non-zero if formal type FTYPE matches actual type ATYPE. If
- MAY_DEREF is non-zero, the formal may be a pointer and the actual
- a non-pointer. */
+/* Return non-zero if formal type FTYPE matches actual type ATYPE. */
/* The term "match" here is rather loose. The match is heuristic and
liberal. */
static int
-ada_type_match (struct type *ftype, struct type *atype, int may_deref)
+ada_type_match (struct type *ftype, struct type *atype)
{
ftype = ada_check_typedef (ftype);
atype = ada_check_typedef (atype);
default:
return ftype->code () == atype->code ();
case TYPE_CODE_PTR:
- if (atype->code () == TYPE_CODE_PTR)
- return ada_type_match (TYPE_TARGET_TYPE (ftype),
- TYPE_TARGET_TYPE (atype), 0);
- else
- return (may_deref
- && ada_type_match (TYPE_TARGET_TYPE (ftype), atype, 0));
+ if (atype->code () != TYPE_CODE_PTR)
+ return 0;
+ atype = TYPE_TARGET_TYPE (atype);
+ /* This can only happen if the actual argument is 'null'. */
+ if (atype->code () == TYPE_CODE_INT && TYPE_LENGTH (atype) == 0)
+ return 1;
+ return ada_type_match (TYPE_TARGET_TYPE (ftype), atype);
case TYPE_CODE_INT:
case TYPE_CODE_ENUM:
case TYPE_CODE_RANGE:
struct type *ftype = ada_check_typedef (func_type->field (i).type ());
struct type *atype = ada_check_typedef (value_type (actuals[i]));
- if (!ada_type_match (ftype, atype, 1))
+ if (!ada_type_match (ftype, atype))
return 0;
}
}
struct ui_file *stream, int recurse,
const struct value_print_options *options)
{
+ if (!options->format
+ && TYPE_TARGET_TYPE (value_type (val))->code () == TYPE_CODE_INT
+ && TYPE_LENGTH (TYPE_TARGET_TYPE (value_type (val))) == 0)
+ {
+ fputs_filtered ("null", stream);
+ return;
+ }
+
common_val_print (val, stream, recurse, options, language_def (language_c));
struct type *type = ada_check_typedef (value_type (val));
struct type *type = ada_check_typedef (value_type (val));
struct value_print_options opts;
- /* If it is a pointer, indicate what it points to. */
- if (type->code () == TYPE_CODE_PTR)
+ /* If it is a pointer, indicate what it points to; but not for
+ "void *" pointers. */
+ if (type->code () == TYPE_CODE_PTR
+ && !(TYPE_TARGET_TYPE (type)->code () == TYPE_CODE_INT
+ && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) == 0))
{
/* Hack: don't print (char *) for char strings. Their
type is indicated by the quoted string anyway. */
+2021-04-28 Tom Tromey <tromey@adacore.com>
+
+ * gdb.ada/null_overload.exp: New file.
+ * gdb.ada/null_overload/foo.adb: New file.
+
2021-04-28 Andrew Burgess <andrew.burgess@embecosm.com>
* gdb.python/py-startup-opt.exp: New file.
--- /dev/null
+# Copyright 2021 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+load_lib "ada.exp"
+
+if { [skip_ada_tests] } { return -1 }
+
+standard_ada_testfile foo
+
+if {[gdb_compile_ada "${srcfile}" "${binfile}" executable {debug}] != ""} {
+ return -1
+}
+
+clean_restart ${testfile}
+
+set bp_location [gdb_get_line_number "START" ${testdir}/foo.adb]
+runto "foo.adb:$bp_location"
+
+gdb_test "print f(null)" " = true"
+gdb_test "print f(r_access'(null))" " = true"
+gdb_test "print f(0)" " = false"
+
+gdb_test "print null" " = null"
+gdb_test "print/d null" " = 0"
+gdb_test "print U_Ptr" " = \\\(access foo\\.u_0\\\) 0x0"
--- /dev/null
+-- Copyright 2021 Free Software Foundation, Inc.
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+procedure Foo is
+
+ type R_Type is null record;
+ type R_Access is access R_Type;
+
+ type U_0 is mod 1;
+ type U_P_T is access all U_0;
+
+ function F (R : R_Access) return Boolean is
+ begin
+ return True;
+ end F;
+
+ function F (I : Integer) return Boolean is
+ begin
+ return False;
+ end F;
+
+ B1 : constant Boolean := F (null);
+ B2 : constant Boolean := F (0);
+
+ U : U_0 := 0;
+ U_Ptr : U_P_T := null;
+
+begin
+ null; -- START
+end Foo;
projects / binutils-gdb.git / commitdiff