[PATCH][gdb/symtab] Support .gdb_index section with TUs in .debug_info

[Tom de Vries]

Hi,

The .gdb_index variant of commit d878bb39e41 ("[gdb/symtab] Support
.debug_names section with TUs in .debug_info").

Tested on x86_64-linux.

Any comments?

Thanks,
- Tom

[gdb/symtab] Support .gdb_index section with TUs in .debug_info

---
 gdb/dwarf2/read.c                                  |  7 ++--
 gdb/testsuite/gdb.dwarf2/gdb-index-types-dwarf5.c  | 29 +++++++++++++++
 .../gdb.dwarf2/gdb-index-types-dwarf5.exp          | 41 ++++++++++++++++++++++
 3 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 3ca441c4cae..d9fadd796a2 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -2707,13 +2707,16 @@ dwarf2_read_gdb_index
     {
       /* We can only handle a single .debug_types when we have an
 	 index.  */
-      if (per_bfd->types.size () != 1)
+      if (per_bfd->types.size () > 1)
 	{
 	  per_bfd->all_comp_units.clear ();
 	  return 0;
 	}
 
-      dwarf2_section_info *section = &per_bfd->types[0];
+      dwarf2_section_info *section
+	= (per_bfd->types.size () == 1
+	   ? &per_bfd->types[0]
+	   : &per_bfd->info);
 
       create_signatured_type_table_from_index (per_bfd, section, types_list,
 					       types_list_elements);
diff --git a/gdb/testsuite/gdb.dwarf2/gdb-index-types-dwarf5.c b/gdb/testsuite/gdb.dwarf2/gdb-index-types-dwarf5.c
new file mode 100644
index 00000000000..f568c82917e
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/gdb-index-types-dwarf5.c
@@ -0,0 +1,29 @@
+/* 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/>.  */
+
+struct struct_with_int_member {
+  int member;
+};
+
+struct struct_with_int_member var;
+
+int
+main (void)
+{
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.dwarf2/gdb-index-types-dwarf5.exp b/gdb/testsuite/gdb.dwarf2/gdb-index-types-dwarf5.exp
new file mode 100644
index 00000000000..27cadc523cd
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/gdb-index-types-dwarf5.exp
@@ -0,0 +1,41 @@
+# 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/>.
+
+standard_testfile
+
+set flags {}
+lappend flags {additional_flags=-fdebug-types-section}
+lappend flags {additional_flags=-gdwarf-5}
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+	  $srcfile $flags] } {
+    return -1
+}
+
+require {ensure_gdb_index $binfile} == 1
+
+clean_restart ${binfile}
+
+# Verify that .gdb_index section is not ignored.
+set index [have_index $binfile]
+gdb_assert { [string equal $index "gdb_index"] } ".gdb_index used"
+
+# Verify that we can find the type in the type unit.
+set re \
+    [multi_line \
+	 "type = struct struct_with_int_member {" \
+	 "    int member;" \
+	 "}"]
+gdb_test "ptype struct struct_with_int_member" $re