Index: tree-pretty-print.c
===================================================================
--- tree-pretty-print.c	(revision 135494)
+++ tree-pretty-print.c	(working copy)
@@ -40,7 +40,7 @@ along with GCC; see the file COPYING3.  
 /* Local functions, macros and variables.  */
 static int op_prio (const_tree);
 static const char *op_symbol (const_tree);
-static void pretty_print_string (pretty_printer *, const char*);
+static void pretty_print_string (pretty_printer *, const char *, int len);
 static void print_call_name (pretty_printer *, const_tree);
 static void newline_and_indent (pretty_printer *, int);
 static void maybe_init_pretty_print (FILE *);
@@ -841,7 +841,8 @@ dump_generic_node (pretty_printer *buffe
 
     case STRING_CST:
       pp_string (buffer, "\"");
-      pretty_print_string (buffer, TREE_STRING_POINTER (node));
+      pretty_print_string (buffer, TREE_STRING_POINTER (node),
+			   TREE_STRING_LENGTH (node));
       pp_string (buffer, "\"");
       break;
 
@@ -2740,15 +2741,19 @@ print_call_name (pretty_printer *buffer,
 /* Parses the string STR and replaces new-lines by '\n', tabs by '\t', ...  */
 
 static void
-pretty_print_string (pretty_printer *buffer, const char *str)
+pretty_print_string (pretty_printer *buffer, const char *str, int len)
 {
   if (str == NULL)
     return;
 
-  while (*str)
+  while ((len--) > 0)
     {
       switch (str[0])
 	{
+	case '\0':
+	  pp_string (buffer, "\\0");
+	  break;
+
 	case '\b':
 	  pp_string (buffer, "\\b");
 	  break;
@@ -2785,8 +2790,6 @@ pretty_print_string (pretty_printer *buf
 	  pp_string (buffer, "\\'");
 	  break;
 
-	  /* No need to handle \0; the loop terminates on \0.  */
-
 	case '\1':
 	  pp_string (buffer, "\\1");
 	  break;
@@ -2816,7 +2819,14 @@ pretty_print_string (pretty_printer *buf
 	  break;
 
 	default:
-	  pp_character (buffer, str[0]);
+	  if (ISPRINT (str[0]))
+	    pp_character (buffer, str[0]);
+	  else
+	    {
+	      char s[5];
+	      sprintf (s, "\\x%02x", (unsigned)(unsigned char)str[0]);
+	      pp_string (buffer, s);
+	    }
 	  break;
 	}
       str++;