Hello,
The analysis and patch look good to me. Gavin, I think that you can
apply it (I know that it is a kind of patch practical for git to get
both the patch and commiter right, but I don't know how to apply that
kind of patch).
On Mon, May 19, 2025 at 06:43:10PM -0700, Collin Funk wrote:
> Hi,
>
> When compiling Texinfo I see the following warning from GCC:
>
> main/get_perl_info.c: In function 'html_get_button_specification_list':
> main/get_perl_info.c:792:28: warning: 'text_type_p' may be used
> uninitialized [-Wmaybe-uninitialized]
> 792 | if (!strcmp (html_command_text_type_name[j],
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 793 | text_type_p))
> | ~~~~~~~~~~~~
> main/get_perl_info.c:780:25: note: 'text_type_p' was declared here
> 780 | char *text_type_p;
> | ^~~~~~~~~~~
>
> Here is the corresponding section of code:
>
> int j;
> char *text_type_string
> = SvPVutf8_nolen (*button_spec_info_type);
> char *text_type_p;
> if (strlen (text_type_string) > 2
> && !(memcmp (text_type_string, "->", 2)))
> {
> button_spec->type
> = BIT_selected_direction_information_type;
> text_type_p = text_type_string +2;
> text_type_p += strspn (text_type_p, whitespace_chars);
> }
> button_spec->bi.direction_information_type = -1;
> for (j = 0; j < HTT_section +1; j++)
> {
> if (!strcmp (html_command_text_type_name[j],
> text_type_p))
> {
> button_spec->bi.direction_information_type = j;
> break;
> }
> }
>
> This warning seems accurate to me, since if the first condition is not
> satisfied the uninitialized pointer is passed to strcmp.
>
> I have attached a proposed patch.
>
> Collin
>
> From a757289836db44501eb667ee222fa48fd5da31a9 Mon Sep 17 00:00:00 2001
> Message-ID:
> <a757289836db44501eb667ee222fa48fd5da31a9.1747705234.git.collin.fu...@gmail.com>
> From: Collin Funk <collin.fu...@gmail.com>
> Date: Mon, 19 May 2025 18:32:19 -0700
> Subject: [PATCH] Fix an uninitialized variable.
>
> * tta/C/main/get_perl_info.c (html_get_button_specification_list):
> Initialize to text_type_p and then check it before accessing.
> ---
> tta/C/main/get_perl_info.c | 19 ++++++++++---------
> 1 file changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/tta/C/main/get_perl_info.c b/tta/C/main/get_perl_info.c
> index bf1035dea3..dae1b8600b 100644
> --- a/tta/C/main/get_perl_info.c
> +++ b/tta/C/main/get_perl_info.c
> @@ -777,7 +777,7 @@ html_get_button_specification_list (const CONVERTER
> *converter,
> int j;
> char *text_type_string
> = SvPVutf8_nolen (*button_spec_info_type);
> - char *text_type_p;
> + char *text_type_p = NULL;
> if (strlen (text_type_string) > 2
> && !(memcmp (text_type_string, "->", 2)))
> {
> @@ -787,15 +787,16 @@ html_get_button_specification_list (const CONVERTER
> *converter,
> text_type_p += strspn (text_type_p, whitespace_chars);
> }
> button_spec->bi.direction_information_type = -1;
> - for (j = 0; j < HTT_section +1; j++)
> - {
> - if (!strcmp (html_command_text_type_name[j],
> + if (text_type_p)
> + for (j = 0; j < HTT_section +1; j++)
> + {
> + if (!strcmp (html_command_text_type_name[j],
> text_type_p))
> - {
> - button_spec->bi.direction_information_type = j;
> - break;
> - }
> - }
> + {
> + button_spec->bi.direction_information_type = j;
> + break;
> + }
> + }
> }
> }
> }
> --
> 2.49.0
>
