build_string comments

From-SVN: r180537

gcc/c-family/c-lex.c

@@ -344,6 +344,8 @@ c_lex_with_flags (tree *value, location_t *loc, unsigned char *cpp_flags,
 	  {
 	    tree suffix_id = get_identifier (suffix);
 	    int len = tok->val.str.len - strlen (suffix);
+	    /* If this is going to be used as a C string to pass to a
+	       raw literal operator, we need to add a trailing NUL.  */
 	    tree num_string = build_string (len + 1,
 					    (const char *) tok->val.str.text);
 	    TREE_TYPE (num_string) = char_array_type_node;

gcc/cp/decl.c

@@ -8592,7 +8592,7 @@ grokdeclarator (const cp_declarator *declarator,
       error ("declaration of %qD as non-function", dname);
       return error_mark_node;
     }
- 
+
   if (dname
       && TREE_CODE (dname) == IDENTIFIER_NODE
       && UDLIT_OPER_P (dname)

gcc/cp/parser.c

@@ -3667,6 +3667,7 @@ cp_parser_userdef_numeric_literal (cp_parser *parser)
 /* Parse a user-defined string constant.  Returns a call to a user-defined
    literal operator taking a character pointer and the length of the string
    as arguments.  */
+
 static tree
 cp_parser_userdef_string_literal (cp_token *token)
 {

gcc/tree.c

@@ -1525,6 +1525,7 @@ build_real_from_int_cst (tree type, const_tree i)
 
 /* Return a newly constructed STRING_CST node whose value is
    the LEN characters at STR.
+   Note that for a C string literal, LEN should include the trailing NUL.
    The TREE_TYPE is not initialized.  */
 
 tree