fixits: suggest running --update if there are fixits

* src/fixits.h, src/fixits.c (fixits_empty): New.
* src/complain.c (deprecated_directive): Register the Wdeprecated
fixits only if -Wdeprecated was enabled, so that we don't apply
updates if the user didn't ask for them.
* src/main.c (main): If there were fixits, issue a warning suggesting
running with --update.
Free uniqstrs after the fixits, since the latter use the former.
* tests/headers.at, tests/input.at: Update expectations.

src/complain.c

@@ -394,7 +394,9 @@ deprecated_directive (location const *loc, char const *old, char const *upd)
     complain (loc, Wdeprecated,
               _("deprecated directive: %s, use %s"),
               quote (old), quote_n (1, upd));
-  fixits_register (loc, upd);
+  /* Register updates only if -Wdeprecated is enabled.  */
+  if (warnings_flag[warning_deprecated] != severity_disabled)
+    fixits_register (loc, upd);
 }
 
 void

src/fixits.c

@@ -91,6 +91,13 @@ fixits_register (location const *loc, char const* fix)
 }
 
 
+bool
+fixits_empty (void)
+{
+  return !fixits;
+}
+
+
 void
 fixits_run (void)
 {

src/fixits.h

@@ -26,6 +26,9 @@ void fixits_register (location const *loc, char const* update);
 /* Apply the fixits: update the source file.  */
 void fixits_run (void);
 
+/* Whether there are no fixits. */
+bool fixits_empty (void);
+
 /* Free the registered fixits.  */
 void fixits_free (void);
 

src/main.c

@@ -103,12 +103,6 @@ main (int argc, char *argv[])
   reader ();
   timevar_pop (tv_reader);
 
-  /* Fix input file now, even if there are errors: that's less
-     warnings in the following runs.  */
-  if (update_flag)
-    fixits_run ();
-  fixits_free ();
-
   if (complaint_status == status_complaint)
     goto finish;
 
@@ -217,7 +211,6 @@ main (int argc, char *argv[])
      contains things such as user actions, prologue, epilogue etc.  */
   gram_scanner_free ();
   muscle_free ();
-  uniqstrs_free ();
   code_scanner_free ();
   skel_scanner_free ();
   quotearg_free ();
@@ -234,5 +227,18 @@ main (int argc, char *argv[])
 
   cleanup_caret ();
 
+  /* Fix input file now, even if there are errors: that's less
+     warnings in the following runs.  */
+  if (!fixits_empty ())
+    {
+      if (update_flag)
+        fixits_run ();
+      else
+        complain (NULL, Wother,
+                  _("fix-its can be applied.  Rerun with option '--update'."));
+      fixits_free ();
+    }
+  uniqstrs_free ();
+
   return complaint_status ? EXIT_FAILURE : EXIT_SUCCESS;
 }