[PATCH][gdb/symtab] Fix handling of DW_TAG_unspecified_type
Tom de Vries
tdevries@suse.de
Thu Sep 8 13:05:32 GMT 2022
Hi,
Currently, the test-case contained in this patch fails:
...
(gdb) p (int) foo ()^M
Invalid cast.^M
(gdb) FAIL: gdb.dwarf2/dw2-unspecified-type.exp: p (int) foo ()
...
because DW_TAG_unspecified_type is translated as void.
There's some code in read_unspecified_type that marks the type as stub, but
that's only active for ada:
...
if (cu->lang () == language_ada)
type->set_is_stub (true);
...
Fix this by:
- marking the type as a stub for all languages, and
- handling the stub return type case in call_function_by_hand_dummy.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29558
Any comments?
Thanks,
- Tom
[gdb/symtab] Fix handling of DW_TAG_unspecified_type
---
gdb/dwarf2/read.c | 6 +-
gdb/infcall.c | 2 +-
.../gdb.dwarf2/dw2-unspecified-type-foo.c | 22 +++++++
gdb/testsuite/gdb.dwarf2/dw2-unspecified-type.c | 25 ++++++++
gdb/testsuite/gdb.dwarf2/dw2-unspecified-type.exp | 72 ++++++++++++++++++++++
5 files changed, 123 insertions(+), 4 deletions(-)
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 3ca441c4cae..da99402cff0 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -17714,9 +17714,9 @@ read_unspecified_type (struct die_info *die, struct dwarf2_cu *cu)
/* In Ada, an unspecified type is typically used when the description
of the type is deferred to a different unit. When encountering
such a type, we treat it as a stub, and try to resolve it later on,
- when needed. */
- if (cu->lang () == language_ada)
- type->set_is_stub (true);
+ when needed.
+ Mark this as a stub type for all languages though. */
+ type->set_is_stub (true);
return set_die_type (die, type, cu);
}
diff --git a/gdb/infcall.c b/gdb/infcall.c
index 2acceed4b07..dd70682bc76 100644
--- a/gdb/infcall.c
+++ b/gdb/infcall.c
@@ -814,7 +814,7 @@ call_function_by_hand_dummy (struct value *function,
"target calling convention."),
get_function_name (funaddr, name_buf, sizeof (name_buf)));
- if (values_type == NULL)
+ if (values_type == NULL || values_type->is_stub ())
values_type = default_return_type;
if (values_type == NULL)
{
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type-foo.c b/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type-foo.c
new file mode 100644
index 00000000000..b1e3a8b98e4
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type-foo.c
@@ -0,0 +1,22 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2022 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/>. */
+
+int
+foo (void)
+{
+ asm ("foo_label: .globl foo_label");
+}
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type.c b/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type.c
new file mode 100644
index 00000000000..e3218205560
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type.c
@@ -0,0 +1,25 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2022 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/>. */
+
+extern int foo (void);
+
+int
+main (void)
+{
+ int res = foo ();
+ return res;
+}
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type.exp b/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type.exp
new file mode 100644
index 00000000000..20c31dc5740
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-unspecified-type.exp
@@ -0,0 +1,72 @@
+# Copyright 2022 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 dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+ return 0
+}
+
+standard_testfile .c -foo.c dwz.S
+
+set foo_res \
+ [function_range foo \
+ [list ${srcdir}/${subdir}/$srcfile ${srcdir}/${subdir}/$srcfile2]]
+lassign $foo_res \
+ foo_start foo_len
+set foo_end "$foo_start + $foo_len"
+
+# Create the DWARF.
+set asm_file [standard_output_file $srcfile3]
+Dwarf::assemble $asm_file {
+ global foo_start foo_end
+ declare_labels unspecified_type_label
+
+ cu {} {
+ compile_unit {
+ {language @DW_LANG_Mips_Assembler}
+ } {
+ unspecified_type_label: unspecified_type {}
+
+ DW_TAG_subprogram {
+ {name foo}
+ {low_pc $foo_start addr}
+ {high_pc $foo_end addr}
+ {type :$unspecified_type_label}
+ }
+
+ }
+ }
+}
+
+if [prepare_for_testing "failed to prepare" $testfile \
+ "${asm_file} ${srcfile} ${srcfile2}" {}] {
+ return -1
+}
+
+if ![runto_main] {
+ return -1
+}
+
+# Print the function type. Return type should be stub type, which is printed
+# as void.
+gdb_test "ptype foo" "type = void \\(void\\)"
+
+# Call the function, casting the function to the correct function type.
+gdb_test "p ((int (*) ()) foo) ()" " = 0"
+
+# Call the function, casting the function result to the correct type.
+gdb_test "p (int) foo ()" " = 0"
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