[c-family/49654/49655] reject invalid options in pragma diagnostic

Use find_opt instead of linear search through options in
handle_pragma_diagnostic (PR 49654) and reject non-warning options and
options not valid for the current language (PR 49655).

gcc/testsuite/ChangeLog:

2015-09-23  Manuel López-Ibáñez  <manu@gcc.gnu.org>

	PR c/49655
	* gcc.dg/pragma-diag-6.c: New test.

gcc/ChangeLog:

2015-09-23  Manuel López-Ibáñez  <manu@gcc.gnu.org>

	PR c/49655
	* opts.h (write_langs): Declare.
	* opts-global.c (write_langs): Make it extern.

gcc/c-family/ChangeLog:

2015-09-23  Manuel López-Ibáñez  <manu@gcc.gnu.org>

	PR c/49654
	PR c/49655
	* c-pragma.c (handle_pragma_diagnostic): Detect non-warning
	options and options not valid for the current language.

From-SVN: r228049

gcc/ChangeLog

+2015-09-23  Manuel López-Ibáñez  <manu@gcc.gnu.org>
+
+	PR c/49655
+	* opts.h (write_langs): Declare.
+	* opts-global.c (write_langs): Make it extern.
+
 2015-09-23  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	PR target/67391

gcc/c-family/ChangeLog

+2015-09-23  Manuel López-Ibáñez  <manu@gcc.gnu.org>
+
+	PR c/49654
+	PR c/49655
+	* c-pragma.c (handle_pragma_diagnostic): Detect non-warning
+	options and options not valid for the current language.
+
 2015-09-22  Patrick Palka  <ppalka@gcc.gnu.org>
 
 	* c-indentation.c (should_warn_for_misleading_indentation):

gcc/c-family/c-pragma.c

@@ -749,22 +749,40 @@ handle_pragma_diagnostic(cpp_reader *ARG_UNUSED(dummy))
       return;
     }
 
+  const char *option_string = TREE_STRING_POINTER (x);
+  unsigned int lang_mask = c_common_option_lang_mask () | CL_COMMON;
+  /* option_string + 1 to skip the initial '-' */
+  unsigned int option_index = find_opt (option_string + 1, lang_mask);
+  if (option_index == OPT_SPECIAL_unknown)
+    {
+      warning_at (loc, OPT_Wpragmas,
+		  "unknown option after %<#pragma GCC diagnostic%> kind");
+      return;
+    }
+  else if (!(cl_options[option_index].flags & CL_WARNING))
+    {
+      warning_at (loc, OPT_Wpragmas,
+		  "%qs is not an option that controls warnings", option_string);
+      return;
+    }
+  else if (!(cl_options[option_index].flags & lang_mask))
+    {
+      char *ok_langs = write_langs (cl_options[option_index].flags);
+      char *bad_lang = write_langs (c_common_option_lang_mask ());
+      warning_at (loc, OPT_Wpragmas,
+		  "option %qs is valid for %s but not for %s",
+		  option_string, ok_langs, bad_lang);
+      free (ok_langs);
+      free (bad_lang);
+      return;
+    }
+
   struct cl_option_handlers handlers;
   set_default_handlers (&handlers);
-
-  unsigned int option_index;
-  const char *option_string = TREE_STRING_POINTER (x);
-  for (option_index = 0; option_index < cl_options_count; option_index++)
-    if (strcmp (cl_options[option_index].opt_text, option_string) == 0)
-      {
-	control_warning_option (option_index, (int) kind, kind != DK_IGNORED,
-				input_location, c_family_lang_mask, &handlers,
-				&global_options, &global_options_set,
-				global_dc);
-	return;
-      }
-  warning_at (loc, OPT_Wpragmas,
-	      "unknown option after %<#pragma GCC diagnostic%> kind");
+  control_warning_option (option_index, (int) kind, kind != DK_IGNORED,
+			  loc, lang_mask, &handlers,
+			  &global_options, &global_options_set,
+			  global_dc);
 }
 
 /*  Parse #pragma GCC target (xxx) to set target specific options.  */

gcc/opts-global.c

@@ -54,7 +54,7 @@ unsigned num_in_fnames;
 
 /* Return a malloced slash-separated list of languages in MASK.  */
 
-static char *
+char *
 write_langs (unsigned int mask)
 {
   unsigned int n = 0, len = 0;

gcc/opts.h

@@ -368,6 +368,7 @@ extern void control_warning_option (unsigned int opt_index, int kind,
 				    struct gcc_options *opts,
 				    struct gcc_options *opts_set,
 				    diagnostic_context *dc);
+extern char *write_langs (unsigned int mask);
 extern void print_ignored_options (void);
 extern void handle_common_deferred_options (void);
 extern bool common_handle_option (struct gcc_options *opts,

gcc/testsuite/ChangeLog

+2015-09-23  Manuel López-Ibáñez  <manu@gcc.gnu.org>
+
+	PR c/49655
+	* gcc.dg/pragma-diag-6.c: New test.
+
 2015-09-23  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	* gcc.target/aarch64/advsimd-intrinsics/vcvt_high_1.c: New.

gcc/testsuite/gcc.dg/pragma-diag-6.c

+/* { dg-do compile } */
+#pragma GCC diagnostic error "-Wnoexcept" /* { dg-warning "is valid for C../ObjC.. but not for C" } */
+#pragma GCC diagnostic error "-fstrict-aliasing" /* { dg-warning "not an option that controls warnings" } */
+#pragma GCC diagnostic error "-Werror" /* { dg-warning "not an option that controls warnings" } */
+int i;