re PR debug/85176 (ICE in force_decl_die, at dwarf2out.c:25910)

2018-04-04  Richard Biener  <rguenther@suse.de>

	PR lto/85176
	* dwarf2out.c (dwarf2out_register_external_die): Peel namespaces
	from contexts for DINFO_LEVEL_TERSE and below.

	* g++.dg/lto/pr85176_0.C: New testcase.

From-SVN: r259080

gcc/ChangeLog

+2018-04-04  Richard Biener  <rguenther@suse.de>
+
+	PR lto/85176
+	* dwarf2out.c (dwarf2out_register_external_die): Peel namespaces
+	from contexts for DINFO_LEVEL_TERSE and below.
+
 2018-04-04  Kito Cheng  <kito.cheng@gmail.com>
 
 	* config/nds32/nds32-doubleword.md (move_<mode>): Require

gcc/dwarf2out.c

@@ -5903,8 +5903,13 @@ dwarf2out_register_external_die (tree decl, const char *sym,
     }
   else
     ctx = DECL_CONTEXT (decl);
+  /* Peel types in the context stack.  */
   while (ctx && TYPE_P (ctx))
     ctx = TYPE_CONTEXT (ctx);
+  /* Likewise namespaces in case we do not want to emit DIEs for them.  */
+  if (debug_info_level <= DINFO_LEVEL_TERSE)
+    while (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
+      ctx = DECL_CONTEXT (ctx);
   if (ctx)
     {
       if (TREE_CODE (ctx) == BLOCK)

gcc/testsuite/ChangeLog

 2018-04-04  Richard Biener  <rguenther@suse.de>
 
+	PR lto/85176
+	* g++.dg/lto/pr85176_0.C: New testcase.
+
+2018-04-04  Richard Biener  <rguenther@suse.de>
+
 	PR testsuite/85191
 	* lib/target-supports.exp (check_effective_target_vect_perm_short):
 	Fix typo.

gcc/testsuite/g++.dg/lto/pr85176_0.C

+// { dg-lto-do link }
+// { dg-lto-options { { -flto -g1 } } }
+// { dg-extra-ld-options "-r -nostdlib" }
+namespace a {
+    template <typename b, typename = b> class c;
+    template <typename b, typename d> void e(c<b, d> &);
+    void operator<<(c<char> &f, const char *) { e(f); }
+    extern c<char> cout;
+}
+int main() { a::cout << ""; }