* decl2.c (lang_decode_option): Add support for -Wunknown-pragmas.

From-SVN: r17167

gcc/cp/ChangeLog

+Sun Dec 21 15:59:00 1997  Nick Clifton  <nickc@cygnus.com>
+
+	* decl2.c (lang_decode_option): Add support for -Wunknown-pragmas.
+
 Thu Dec 18 14:51:50 1997  Mark Mitchell  <mmitchell@usa.net>
 
 	* pt.c (coerce_template_parms): Make sure to digest_init if

gcc/cp/decl2.c

@@ -272,6 +272,10 @@ int warn_sign_promo;
 
 int warn_old_style_cast;
 
+/* Warn about #pragma directives that are not recognised.  */      
+
+int warn_unknown_pragmas = 0; /* Tri state variable.  */  
+
 /* Nonzero means `$' can be in an identifier.  */
 
 #ifndef DOLLARS_IN_IDENTIFIERS
@@ -654,6 +658,10 @@ lang_decode_option (p)
 	warn_sign_promo = setting;
       else if (!strcmp (p, "old-style-cast"))
 	warn_old_style_cast = setting;
+      else if (!strcmp (p, "unknown-pragmas"))
+	/* Set to greater than 1, so that even unknown pragmas in
+	   system headers will be warned about.  */  
+	warn_unknown_pragmas = setting * 2;
       else if (!strcmp (p, "comment"))
 	;			/* cpp handles this one.  */
       else if (!strcmp (p, "comments"))
@@ -683,6 +691,9 @@ lang_decode_option (p)
 	  warn_template_debugging = setting;
 	  warn_reorder = setting;
 	  warn_sign_promo = setting;
+	  /* Only warn about unknown pragmas that are not in system
+	     headers.  */                                        
+	  warn_unknown_pragmas = 1;                  
 	}
 
       else if (!strcmp (p, "overloaded-virtual"))