commit 52b906160a109b84a26f5aa15a653f4aee612942
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Fri Nov 11 06:32:08 2016 -0800

    	PR target/78213
    	* opts.c (finish_options): Set -fsyntax-only if running self
    	tests.

diff --git a/gcc/opts.c b/gcc/opts.c
index d2d6100..cb20154 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -744,6 +744,14 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
       opts->x_flag_toplevel_reorder = 0;
     }
 
+  /* -fself-test depends on the state of the compiler prior to
+     compiling anything.  Ideally it should be run on an empty source
+     file.  However, in case we get run with actual source, assume
+     -fsyntax-only which will inhibit any compiler initialization
+     which may confuse the self tests.  */
+  if (opts->x_flag_self_test)
+    opts->x_flag_syntax_only = 1;
+
   if (opts->x_flag_tm && opts->x_flag_non_call_exceptions)
     sorry ("transactional memory is not supported with non-call exceptions");
 
diff --git a/gcc/testsuite/gcc.dg/pr78213.c b/gcc/testsuite/gcc.dg/pr78213.c
new file mode 100644
index 0000000..e43c83c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr78213.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-fself-test" } */
+
+/* Verify that -fself-test does not fail on a non empty source.  */
+
+int i;                                                                          void bar();                                                                     void foo()
+{
+  while (i--)
+    bar();
+}
+/* { dg-message "fself\-test: " "-fself-test" { target *-*-* } 0 } */