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Re: [patch] generated string libraries & -Wformat
- From: Bruce Korb <bkorb at gnu dot org>
- To: patch Patches <gcc-patches at gcc dot gnu dot org>
- Cc: Bruce Korb <Bruce dot Korb at gmail dot com>, gcc at gcc dot gnu dot org
- Date: Sat, 24 Mar 2007 17:35:55 -0700
- Subject: Re: [patch] generated string libraries & -Wformat
- References: <4605869C.8060102@gmail.com>
- Reply-to: bkorb at gnu dot org
This bootstraps in Linux i686 & I can use -Wno-format-contains-nul to
suppress that warning. OK?
Bruce Korb wrote:
> Hello,
>
> I mess around with a lot of generated code. That means I do automated
> construction of libraries that use literal strings. In order to
> reduce address fixups, I often put all the literal strings into one long
> string with each piece separated from the others with a NUL byte.
> Unfortunately, I am then constrained from using ``-Wformat'' because
> it fears I might accidentally be doing something wrong.
>
> I believe the attached patch is sufficient to implement
> -Wno-format-contains-nul
> (I am bootstrapping GCC and will be testing for a few hours.)
>
> I'd like to hear any complaints about the change before I
> spend too much time polishing it. Thank you!
>
> Regards, Bruce
2007-03-24 Bruce Korb <bkorb@gnu.org>
* c-format.c (set_Wformat): set warn_format_contains_nul to -Wformat
setting
(check_format_info_main): changed embedded NUL byte warning to test
for OPT_Wformat_contains_nul
* c.opt: define Wformat-contains-nul
* c-opts.c (c_common_post_options): complain if -Wformat-contains-nul
is set and -Wformat is not set
> Index: c-format.c
> ===================================================================
> --- c-format.c (revision 123186)
> +++ c-format.c (working copy)
> @@ -43,6 +43,7 @@
> if (setting != 1)
> {
> warn_format_nonliteral = setting;
> + warn_format_contains_nul = setting;
> warn_format_security = setting;
> warn_format_y2k = setting;
> }
> @@ -1482,7 +1483,7 @@
> if (*format_chars == 0)
> {
> if (format_chars - orig_format_chars != format_length)
> - warning (OPT_Wformat, "embedded %<\\0%> in format");
> + warning (OPT_Wformat_contains_nul, "embedded %<\\0%> in format");
> if (info->first_arg_num != 0 && params != 0
> && has_operand_number <= 0)
> {
> Index: c.opt
> ===================================================================
> --- c.opt (revision 123186)
> +++ c.opt (working copy)
> @@ -216,6 +216,10 @@
> C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning
> Warn about format strings that are not literals
>
> +Wformat-contains-nul
> +C ObjC C++ ObjC++ Var(warn_format_contains_nul)
> +Warn about format strings that contain NUL bytes
> +
> Wformat-security
> C ObjC C++ ObjC++ Var(warn_format_security) Warning
> Warn about possible security problems with format functions
> Index: c-opts.c
> ===================================================================
> --- c-opts.c (revision 123186)
> +++ c-opts.c (working copy)
> @@ -1106,6 +1106,8 @@
> "-Wformat-zero-length ignored without -Wformat");
> warning (OPT_Wformat_nonliteral,
> "-Wformat-nonliteral ignored without -Wformat");
> + warning (OPT_Wformat_contains_nul,
> + "-Wformat-contains-nul ignored without -Wformat");
> warning (OPT_Wformat_security,
> "-Wformat-security ignored without -Wformat");
> }
>