Do not error when -E provided (PR pch/78970).

2017-01-09  Martin Liska  <mliska@suse.cz>

	PR pch/78970
	* gcc.c (driver_handle_option): Handle OPT_E and set
	have_E.
	(lookup_compiler): Do not show error message with have_E.

From-SVN: r244227

gcc/ChangeLog

+2017-01-09  Martin Liska  <mliska@suse.cz>
+
+	PR pch/78970
+	* gcc.c (driver_handle_option): Handle OPT_E and set
+	have_E.
+	(lookup_compiler): Do not show error message with have_E.
+
 2017-01-09  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/78938

gcc/gcc.c

@@ -1931,6 +1931,9 @@ static int have_c = 0;
 /* Was the option -o passed.  */
 static int have_o = 0;
 
+/* Was the option -E passed.  */
+static int have_E = 0;
+
 /* Pointer to output file name passed in with -o. */
 static const char *output_file = 0;
 
@@ -4067,6 +4070,10 @@ driver_handle_option (struct gcc_options *opts,
       validated = true;
       break;
 
+    case OPT_E:
+      have_E = true;
+      break;
+
     case OPT_x:
       spec_lang = arg;
       if (!strcmp (spec_lang, "none"))
@@ -8328,7 +8335,8 @@ lookup_compiler (const char *name, size_t length, const char *language)
 	  {
 	    if (name != NULL && strcmp (name, "-") == 0
 		&& (strcmp (cp->suffix, "@c-header") == 0
-		    || strcmp (cp->suffix, "@c++-header") == 0))
+		    || strcmp (cp->suffix, "@c++-header") == 0)
+		&& !have_E)
 	      fatal_error (input_location,
 			   "cannot use %<-%> as input filename for a "
 			   "precompiled header");