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.

diff --git a/gcc/c/c-objc-common.cc b/gcc/c/c-objc-common.cc
index 116b73af6db321c7b4cc555bce72f02b32a61a21..b7c72d2609c6e6d1972f37ea8393261c9248120b 100644 (file)
--- 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;
+}

diff --git a/gcc/c/c-objc-common.h b/gcc/c/c-objc-common.h
index 35a59988e900b61bec37b4103dd4d17f9dd8b2dc..20af5a5bb94475b796c47ba7e7926dbf05247cd0 100644 (file)
--- a/gcc/c/c-objc-common.h
+++ b/gcc/c/c-objc-common.h
@@ -119,6 +119,9 @@ static const scoped_attribute_specs *const c_objc_attribute_table[] =
 #undef LANG_HOOKS_GIMPLIFY_EXPR
 #define LANG_HOOKS_GIMPLIFY_EXPR c_gimplify_expr
 
+#undef LANG_HOOKS_TYPE_DWARF_ATTRIBUTE
+#define LANG_HOOKS_TYPE_DWARF_ATTRIBUTE c_type_dwarf_attribute
+
 #undef LANG_HOOKS_OMP_PREDETERMINED_SHARING
 #define LANG_HOOKS_OMP_PREDETERMINED_SHARING c_omp_predetermined_sharing
 

diff --git a/gcc/c/c-tree.h b/gcc/c/c-tree.h
index 1fba9c8dae765711ebab64a3b2d963783c9c0d35..22b0009874b5f3d134de097c590dc1bcd07b461c 100644 (file)
--- a/gcc/c/c-tree.h
+++ b/gcc/c/c-tree.h
@@ -731,6 +731,7 @@ extern bool c_warn_unused_global_decl (const_tree);
 extern void c_initialize_diagnostics (diagnostic_context *);
 extern bool c_var_mod_p (tree x, tree fn);
 extern alias_set_type c_get_alias_set (tree);
+extern int c_type_dwarf_attribute (const_tree, int);
 
 /* in c-typeck.cc */
 extern int in_alignof;

diff --git a/gcc/cp/cp-objcp-common.cc b/gcc/cp/cp-objcp-common.cc
index 85dde0459faa518cbe9929403c99da5ead9c9e1c..86e0b49d46b8e48b9b3708802feba2d301cc5404 100644 (file)
--- a/gcc/cp/cp-objcp-common.cc
+++ b/gcc/cp/cp-objcp-common.cc
@@ -410,6 +410,11 @@ cp_type_dwarf_attribute (const_tree type, int attr)
        return 1;
       break;
 
+    case DW_AT_export_symbols:
+      if (ANON_AGGR_TYPE_P (type))
+       return 1;
+      break;
+
     default:
       break;
     }

diff --git a/gcc/dwarf2out.cc b/gcc/dwarf2out.cc
index 03d73f9eecda5aa52e268ff4e368545715b5e0d8..87e4240b871565257111f0cd3b19f6c910f77b21 100644 (file)
--- a/gcc/dwarf2out.cc
+++ b/gcc/dwarf2out.cc
@@ -25162,6 +25162,17 @@ gen_field_die (tree decl, struct vlr_context *ctx, dw_die_ref context_die)
 
   add_accessibility_attribute (decl_die, decl);
 
+  /* Add DW_AT_export_symbols to anonymous unions or structs.  */
+  if ((dwarf_version >= 5 || !dwarf_strict) && DECL_NAME (decl) == NULL_TREE)
+    if (tree type = member_declared_type (decl))
+      if (lang_hooks.types.type_dwarf_attribute (TYPE_MAIN_VARIANT (type),
+                                                DW_AT_export_symbols) != -1)
+       {
+         dw_die_ref type_die = lookup_type_die (TYPE_MAIN_VARIANT (type));
+         if (type_die && get_AT (type_die, DW_AT_export_symbols) == NULL)
+           add_AT_flag (type_die, DW_AT_export_symbols, 1);
+       }
+
   /* Equate decl number to die, so that we can look up this decl later on.  */
   equate_decl_number_to_die (decl, decl_die);
 }

diff --git a/gcc/testsuite/c-c++-common/dwarf2/pr113918.c b/gcc/testsuite/c-c++-common/dwarf2/pr113918.c
new file mode 100644 (file)
index 0000000..f72a6c4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/dwarf2/pr113918.c
@@ -0,0 +1,33 @@
+/* PR debug/113918 */
+/* { dg-do compile } */
+/* { dg-options "-gdwarf-5 -dA -fno-merge-debug-strings" } */
+
+struct S {
+  union {
+    int i;
+    long long j;
+  };
+  struct {
+    int k;
+    long long l;
+  };
+  union {
+    int m;
+    long long n;
+  } u;
+  struct {
+    int o;
+    long long p;
+  } v;
+} s;
+
+int
+main ()
+{
+  s.i = 1;
+  s.k = 2;
+  s.u.m = 3;
+  s.v.o = 4;
+}
+
+/* { dg-final { scan-assembler-times "DW_AT_export_symbols" 4 } } */