cpplex.c (trigraph_ok): Ensure we don't warn twice.

	* cpplex.c (trigraph_ok): Ensure we don't warn twice.
	* cpplib.h (struct cpp_buffer): New member last_Wtrigraphs.

From-SVN: r37669

gcc/ChangeLog

+2000-11-22  Neil Booth  <neilb@earthling.net>
+
+	* cpplex.c (trigraph_ok): Ensure we don't warn twice.
+	* cpplib.h (struct cpp_buffer): New member last_Wtrigraphs.
+	
 2000-11-22  Richard Henderson  <rth@redhat.com>
 
 	* haifa-sched.c (sched_analyze_1): Don't special-case calls

gcc/cpplex.c

@@ -159,9 +159,13 @@ trigraph_ok (pfile, from_char)
 			       "trigraph ??%c converted to %c",
 			       (int) from_char,
 			       (int) _cpp_trigraph_map[from_char]);
-      else
-	cpp_warning_with_line (pfile, buffer->lineno, CPP_BUF_COL (buffer) - 2,
-			       "trigraph ??%c ignored", (int) from_char);
+      else if (buffer->cur != buffer->last_Wtrigraphs)
+	{
+	  buffer->last_Wtrigraphs = buffer->cur;
+	  cpp_warning_with_line (pfile, buffer->lineno,
+				 CPP_BUF_COL (buffer) - 2,
+				 "trigraph ??%c ignored", (int) from_char);
+	}
     }
 
   return accept;

gcc/cpplib.h

@@ -282,6 +282,10 @@ struct cpp_buffer
   /* Line number at line_base (above). */
   unsigned int lineno;
 
+  /* Because of the way the lexer works, -Wtrigraphs can sometimes
+     warn twice for the same trigraph.  This helps prevent that.  */
+  const unsigned char *last_Wtrigraphs;
+
   /* True if we have already warned about C++ comments in this file.
      The warning happens only for C89 extended mode with -pedantic on,
      or for -Wtraditional, and only once per file (otherwise it would