re PR c++/86900 (-gdwarf-5 -O2 -ffunction-sections = assembler error)

	PR c++/86900
	* dwarf2out.c (secname_for_decl): For functions with
	DECL_SECTION_NAME if in_cold_section_p, try to return
	current_function_section's name if it is a named section.

	* g++.dg/debug/dwarf2/pr86900.C: New test.

From-SVN: r266485

gcc/ChangeLog

+2018-11-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/86900
+	* dwarf2out.c (secname_for_decl): For functions with
+	DECL_SECTION_NAME if in_cold_section_p, try to return
+	current_function_section's name if it is a named section.
+
 2018-11-26  Maya Rashish  <coypu@sdf.org>
 
 	PR target/58397

gcc/dwarf2out.c

@@ -16742,7 +16742,15 @@ secname_for_decl (const_tree decl)
       && DECL_SECTION_NAME (decl))
     secname = DECL_SECTION_NAME (decl);
   else if (current_function_decl && DECL_SECTION_NAME (current_function_decl))
+    {
+      if (in_cold_section_p)
+	{
+	  section *sec = current_function_section ();
+	  if (sec->common.flags & SECTION_NAMED)
+	    return sec->named.name;
+	}
       secname = DECL_SECTION_NAME (current_function_decl);
+    }
   else if (cfun && in_cold_section_p)
     secname = crtl->subsections.cold_section_label;
   else

gcc/testsuite/ChangeLog

+2018-11-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/86900
+	* g++.dg/debug/dwarf2/pr86900.C: New test.
+
 2018-11-26  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
 
 	* gcc.c-torture/compile/20151204.c: Add dg-require-effective-target

gcc/testsuite/g++.dg/debug/dwarf2/pr86900.C

+// PR c++/86900
+// { dg-do assemble { target function_sections } }
+// { dg-options "-O2 -gdwarf-5 -ffunction-sections" }
+
+struct A;
+struct B { B (A); };
+struct A { A (int); ~A (); };
+
+void
+foo (int x)
+{
+  A d(0);
+  B e(d);
+}