dwarf2out: Emit DW_AT_export_symbols on anon unions/structs [PR113918]

DWARF5 added DW_AT_export_symbols both for use on inline namespaces (where
we emit it), but also on anonymous unions/structs (and we didn't emit that
attribute there).
The following patch fixes it.

2024-03-08  Jakub Jelinek  <jakub@redhat.com>

	PR debug/113918
gcc/
	* dwarf2out.cc (gen_field_die): Emit DW_AT_export_symbols
	on anonymous unions or structs for -gdwarf-5 or -gno-strict-dwarf.
gcc/c/
	* c-tree.h (c_type_dwarf_attribute): Declare.
	* c-objc-common.h (LANG_HOOKS_TYPE_DWARF_ATTRIBUTE): Redefine.
	* c-objc-common.cc: Include dwarf2.h.
	(c_type_dwarf_attribute): New function.
gcc/cp/
	* cp-objcp-common.cc (cp_type_dwarf_attribute): Return 1
	for DW_AT_export_symbols on anonymous structs or unions.
gcc/testsuite/
	* c-c++-common/dwarf2/pr113918.c: New test.

1 files changed, 23 insertions, 0 deletions

diff --git a/gcc/c/c-objc-common.cc b/gcc/c/c-objc-common.cc
index 116b73a..b7c72d2 100644
--- a/gcc/c/c-objc-common.cc
+++ b/gcc/c/c-objc-common.cc
@@ -30,6 +30,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "gcc-rich-location.h"
 #include "stringpool.h"
 #include "attribs.h"
+#include "dwarf2.h"
 
 static bool c_tree_printer (pretty_printer *, text_info *, const char *,
 			    int, bool, bool, bool, bool *, const char **);
@@ -446,3 +447,25 @@ instantiation_dependent_expression_p (tree)
 {
   return false;
 }
+
+/* Return -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute
+   value otherwise.  */
+int
+c_type_dwarf_attribute (const_tree type, int attr)
+{
+  if (type == NULL_TREE)
+    return -1;
+
+  switch (attr)
+    {
+    case DW_AT_export_symbols:
+      if (RECORD_OR_UNION_TYPE_P (type) && TYPE_NAME (type) == NULL_TREE)
+	return 1;
+      break;
+
+    default:
+      break;
+    }
+
+  return -1;
+}