Add option suggestion for -Werror=foo and corresponding pragma.

2019-04-30  Martin Liska  <mliska@suse.cz>

	* opts.c (enable_warning_as_error): Provide hints
	for unknown options.
2019-04-30  Martin Liska  <mliska@suse.cz>

	* c-pragma.c (handle_pragma_diagnostic): Provide hints
	for unknown options.
2019-04-30  Martin Liska  <mliska@suse.cz>

	* gcc.dg/Werror-13.c: Add new tests for it.
	* gcc.dg/pragma-diag-6.c: Likewise.

From-SVN: r270693

gcc/ChangeLog

 2019-04-30  Martin Liska  <mliska@suse.cz>
 
+	* opts.c (enable_warning_as_error): Provide hints
+	for unknown options.
+
+2019-04-30  Martin Liska  <mliska@suse.cz>
+
 	PR debug/90288
 	* doc/invoke.texi: Add missing dash for gas-locview-support
 	and gno-as-locview-support.

gcc/c-family/ChangeLog

+2019-04-30  Martin Liska  <mliska@suse.cz>
+
+	* c-pragma.c (handle_pragma_diagnostic): Provide hints
+	for unknown options.
+
 2019-04-26  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* c-warn.c (strict_aliasing_warning): Apply COMPLETE_TYPE_P to

gcc/c-family/c-pragma.c

@@ -33,6 +33,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "c-pragma.h"
 #include "opts.h"
 #include "plugin.h"
+#include "opt-suggestions.h"
 
 #define GCC_BAD(gmsgid) \
   do { warning (OPT_Wpragmas, gmsgid); return; } while (0)
@@ -804,8 +805,16 @@ handle_pragma_diagnostic(cpp_reader *ARG_UNUSED(dummy))
   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");
+      option_proposer op;
+      const char *hint = op.suggest_option (option_string + 1);
+      if (hint)
+	warning_at (loc, OPT_Wpragmas,
+		    "unknown option after %<#pragma GCC diagnostic%> kind;"
+		    " did you mean %<-%s%>", hint);
+      else
+	warning_at (loc, OPT_Wpragmas,
+		    "unknown option after %<#pragma GCC diagnostic%> kind");
+
       return;
     }
   else if (!(cl_options[option_index].flags & CL_WARNING))

gcc/opts.c

@@ -31,6 +31,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "insn-attr-common.h"
 #include "common/common-target.h"
 #include "spellcheck.h"
+#include "opt-suggestions.h"
 
 static void set_Wstrict_aliasing (struct gcc_options *opts, int onoff);
 
@@ -3088,10 +3089,20 @@ enable_warning_as_error (const char *arg, int value, unsigned int lang_mask,
   strcpy (new_option + 1, arg);
   option_index = find_opt (new_option, lang_mask);
   if (option_index == OPT_SPECIAL_unknown)
-    error_at (loc, "%<-Werror=%s%>: no option -%s", arg, new_option);
+    {
+      option_proposer op;
+      const char *hint = op.suggest_option (new_option);
+      if (hint)
+	error_at (loc, "%<-W%serror=%s%>: no option %<-%s%>;"
+		  " did you mean %<-%s%>?", value ? "" : "no-",
+		  arg, new_option, hint);
+      else
+	error_at (loc, "%<-W%serror=%s%>: no option %<-%s%>",
+		  value ? "" : "no-", arg, new_option);
+    }
   else if (!(cl_options[option_index].flags & CL_WARNING))
-    error_at (loc, "%<-Werror=%s%>: -%s is not an option that controls "
-	      "warnings", arg, new_option);
+    error_at (loc, "%<-Werror=%s%>: %<-%s%> is not an option that "
+	      "controls warnings", arg, new_option);
   else
     {
       const diagnostic_t kind = value ? DK_ERROR : DK_WARNING;

gcc/testsuite/ChangeLog

+2019-04-30  Martin Liska  <mliska@suse.cz>
+
+	* gcc.dg/Werror-13.c: Add new tests for it.
+	* gcc.dg/pragma-diag-6.c: Likewise.
+
 2019-04-30  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/89093

gcc/testsuite/gcc.dg/Werror-13.c

 /* { dg-do compile } */
-/* { dg-options "-Werror=error -Werror=p, -Werror=l, -Werror=fatal-errors" } */
-/* { dg-error "-Wp, is not an option that controls warnings" "" { target *-*-* } 0 } */
-/* { dg-error "-Wl, is not an option that controls warnings" "" { target *-*-* } 0 } */
-/* { dg-error "-Werror is not an option that controls warnings" "" { target *-*-* } 0 } */
-/* { dg-error "-Wfatal-errors is not an option that controls warnings" "" { target *-*-* } 0 } */
+/* { dg-options "-Werror=error -Werror=p, -Werror=l, -Werror=fatal-errors -Werror=vla2 -Wno-error=misleading-indentation2" } */
+/* { dg-error "'-Wp,' is not an option that controls warnings" "" { target *-*-* } 0 } */
+/* { dg-error "'-Wl,' is not an option that controls warnings" "" { target *-*-* } 0 } */
+/* { dg-error "'-Werror' is not an option that controls warnings" "" { target *-*-* } 0 } */
+/* { dg-error "'-Wfatal-errors' is not an option that controls warnings" "" { target *-*-* } 0 } */
+/* { dg-error "'-Werror=vla2': no option '-Wvla2'; did you mean '-Wvla." "" { target *-*-* } 0 } */
+/* { dg-error "'-Wno-error=misleading-indentation2': no option '-Wmisleading-indentation2'; did you mean '-Wmisleading-indentation'" "" { target *-*-* } 0 } */
 
 int i;

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

@@ -2,4 +2,7 @@
 #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" } */
+#pragma GCC diagnostic error "-Wvla2" /* { dg-warning "unknown option after '#pragma GCC diagnostic' kind; did you mean '-Wvla'" } */
+#pragma GCC diagnostic error "-Walla" /* { dg-warning "unknown option after '#pragma GCC diagnostic' kind; did you mean '-Wall'" } */
+#pragma GCC diagnostic warning "-Walla" /* { dg-warning "unknown option after '#pragma GCC diagnostic' kind; did you mean '-Wall'" } */
 int i;