c-opts.c (CL_REJECT_NEGATIVE): New.

* c-opts.c (CL_REJECT_NEGATIVE): New.
	(c_common_decode_option): Update to use it.
	* c.opt: Update documentation; use RejectNegative.
	* opts.sh: Handle RejectNegative.

From-SVN: r67325

gcc/ChangeLog

@@ -1,3 +1,10 @@
+2003-06-02  Neil Booth  <neil@daikokuya.co.uk>
+
+	* c-opts.c (CL_REJECT_NEGATIVE): New.
+	(c_common_decode_option): Update to use it.
+	* c.opt: Update documentation; use RejectNegative.
+	* opts.sh: Handle RejectNegative.
+
 2003-06-01  Zack Weinberg  <zack@codesourcery.com>
 
 	* ggc-page.c (init_ggc): Give better diagnostics on failure to

gcc/c-opts.c

@@ -119,12 +119,13 @@ static void finish_options PARAMS ((void));
 #define STDC_0_IN_SYSTEM_HEADERS 0
 #endif
 
-#define CL_C		(1 << 0) /* Only C.  */
+#define CL_C			(1 << 0) /* Only C.  */
-#define CL_OBJC		(1 << 1) /* Only ObjC.  */
+#define CL_OBJC			(1 << 1) /* Only ObjC.  */
-#define CL_CXX		(1 << 2) /* Only C++.  */
+#define CL_CXX			(1 << 2) /* Only C++.  */
-#define CL_OBJCXX	(1 << 3) /* Only ObjC++.  */
+#define CL_OBJCXX		(1 << 3) /* Only ObjC++.  */
-#define CL_JOINED	(1 << 4) /* If takes joined argument.  */
+#define CL_JOINED		(1 << 4) /* If takes joined argument.  */
-#define CL_SEPARATE	(1 << 5) /* If takes a separate argument.  */
+#define CL_SEPARATE		(1 << 5) /* If takes a separate argument.  */
+#define CL_REJECT_NEGATIVE	(1 << 6) /* Reject no- form.  */
 
 #include "c-options.c"
 
@@ -398,9 +399,15 @@ c_common_decode_option (argc, argv)
   if (opt_index == N_OPTS)
     goto done;
 
-  result = 1;
   option = &cl_options[opt_index];
 
+  /* Reject negative form of switches that don't take negatives.  */
+  if (!on && (option->flags & CL_REJECT_NEGATIVE))
+    goto done;
+
+  /* We've recognised this switch.  */
+  result = 1;
+
   /* Sort out any argument the switch takes.  */
   if (option->flags & (CL_JOINED | CL_SEPARATE))
     {
@@ -629,10 +636,7 @@ c_common_decode_option (argc, argv)
       break;
 
     case OPT_Werror_implicit_function_declaration:
-      if (!on)
+      mesg_implicit_function_declaration = 2;
-	result = 0;
-      else
-	mesg_implicit_function_declaration = 2;
       break;
 
     case OPT_Wfloat_equal:
@@ -908,7 +912,7 @@ c_common_decode_option (argc, argv)
       break;
 
     case OPT_fdump_:
-      if (!on || !dump_switch_p (argv[0] + strlen ("-f")))
+      if (!dump_switch_p (argv[0] + strlen ("-f")))
 	result = 0;
       break;
 
@@ -1072,10 +1076,6 @@ c_common_decode_option (argc, argv)
       break;
 
     case OPT_ftabstop_:
-      /* Don't recognize -fno-tabstop=.  */
-      if (!on)
-	return 0;
-
       /* It is documented that we silently ignore silly values.  */
 	{
 	  char *endptr;

gcc/c.opt

@@ -24,7 +24,9 @@
 ; and each field appearing on its own line.  The first field is the
 ; command-line switch with the leading "-" removed.  All options
 ; beginning with "f" or "W" are implicitly assumed to take a "no-"
-; form; this form should not be listed.
+; form; this form should not be listed.  If you do not want this
+; negative form and you want it to be automatically rejected, add
+; RejectNegative to the second field.
 
 ; The second field is a space-separated list of which parts of the
 ; compiler recognize the switch.  Current valid entries are "C",
@@ -144,7 +146,7 @@ Werror
 C ObjC C++ ObjC++
 
 Werror-implicit-function-declaration
-C ObjC
+C ObjC RejectNegative
 
 Wfloat-equal
 C ObjC C++ ObjC++
@@ -339,7 +341,7 @@ fdollars-in-identifiers
 C ObjC C++ ObjC++
 
 fdump-
-C ObjC C++ ObjC++ Joined
+C ObjC C++ ObjC++ Joined RejectNegative
 
 felide-constructors
 C++ ObjC++
@@ -465,7 +467,7 @@ fstrict-prototype
 C++ ObjC++
 
 ftabstop=
-C ObjC C++ ObjC++ Joined
+C ObjC C++ ObjC++ Joined RejectNegative
 
 ftemplate-depth-
 C++ ObjC++ Joined

gcc/opts.sh

@@ -48,8 +48,9 @@ cat "$@" | ${AWK} '
         if (langs ~ ":ObjC:") flags = flags " | CL_OBJC"
         if (langs ~ ":C\\+\\+:") flags = flags " | CL_CXX"
         if (langs ~ ":ObjC\\+\\+:") flags = flags " | CL_OBJCXX"
-        if (langs ~ ":Joined") flags = flags " | CL_JOINED"
+        if (langs ~ ":Joined:") flags = flags " | CL_JOINED"
-        if (langs ~ ":Separate") flags = flags " | CL_SEPARATE"
+        if (langs ~ ":Separate:") flags = flags " | CL_SEPARATE"
+        if (langs ~ ":RejectNegative:") flags = flags " | CL_REJECT_NEGATIVE"
 	sub( "^0 \\| ", "", flags )
 	return flags
     }