re PR lto/81940 (internal compiler error: in dwarf2out_abstract_function, at dwarf2out.c:21613)

2017-08-23  Richard Biener  <rguenther@suse.de>

	PR lto/81940
	* dwarf2out.c (dwarf2out_abstract_function): Handle LTO with
	-g0 at compile-time.

	* g++.dg/lto/pr81940_0.C: New testcase.

From-SVN: r251306

gcc/ChangeLog

+2017-08-23  Richard Biener  <rguenther@suse.de>
+
+	PR lto/81940
+	* dwarf2out.c (dwarf2out_abstract_function): Handle LTO with
+	-g0 at compile-time.
+
 2017-08-23  Tamar Christina  <tamar.christina@arm.com>
 
 	PR middle-end/19706

gcc/dwarf2out.c

@@ -21609,7 +21609,10 @@ dwarf2out_abstract_function (tree decl)
     return;
 
   old_die = lookup_decl_die (decl);
-  /* With early debug we always have an old DIE.  */
+  /* With early debug we always have an old DIE unless we are in LTO
+     and the user did not compile but only link with debug.  */
+  if (in_lto_p && ! old_die)
+    return;
   gcc_assert (old_die != NULL);
   if (get_AT (old_die, DW_AT_inline)
       || get_AT (old_die, DW_AT_abstract_origin))

gcc/testsuite/ChangeLog

+2017-08-23  Richard Biener  <rguenther@suse.de>
+
+	PR lto/81940
+	* g++.dg/lto/pr81940_0.C: New testcase.
+
 2017-08-23  Tamar Christina  <tamar.christina@arm.com>
 
 	PR middle-end/19706

gcc/testsuite/g++.dg/lto/pr81940_0.C

+// { dg-lto-do link }
+// { dg-lto-options { { -O -flto } } }
+// { dg-extra-ld-options "-r -nostdlib -g" }
+
+int a, b = a;