On Tue, Aug 15, 2017 at 02:53:01PM +0200, Martin Ågren wrote:
> convert_attrs populates a struct conv_attrs. The field attr_action is
> not set in all code paths, but still one caller unconditionally reads
> it. Since git_check_attr always returns the same value, we'll always end
> up in the same code path and there is no problem right now. But
> convert_attrs is obviously trying not to rely on such an
> implementation-detail of another component.
>
> Initialize attr_action to CRLF_UNDEFINED in the dead code path.
>
> Actually, in the code path that /is/ taken, the variable is assigned to
> twice and the first assignment has no effect. That's not wrong, but
> let's remove that first assignment while we're here.
>
> Signed-off-by: Martin Ågren <martin.agren@xxxxxxxxx>
> ---
> I hit a warning about attr_action possibly being uninitialized when
> building with SANITIZE=thread. I guess it's some random interaction
> between code added by tsan, the optimizer (-O3) and the warning
> machinery. (This was with gcc 5.4.0.)
>
> convert.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/convert.c b/convert.c
> index 1012462e3..943d957b4 100644
> --- a/convert.c
> +++ b/convert.c
> @@ -1040,7 +1040,6 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
> ca->crlf_action = git_path_check_crlf(ccheck + 4);
> if (ca->crlf_action == CRLF_UNDEFINED)
> ca->crlf_action = git_path_check_crlf(ccheck + 0);
> - ca->attr_action = ca->crlf_action;
I don't think the removal of that line is correct.
> ca->ident = git_path_check_ident(ccheck + 1);
> ca->drv = git_path_check_convert(ccheck + 2);
> if (ca->crlf_action != CRLF_BINARY) {
> @@ -1058,6 +1057,7 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
> } else {
> ca->drv = NULL;
> ca->crlf_action = CRLF_UNDEFINED;
> + ca->attr_action = CRLF_UNDEFINED;
But this one can be avoided, when the line
ca->attr_action = ca->crlf_action;
would move completely out of the "if/else" block.
> ca->ident = 0;
> }
> if (ca->crlf_action == CRLF_TEXT)
> --
> 2.14.1.151.gdfeca7a7e
>
Thanks for spotting my mess.
What do you think about the following:
diff --git a/convert.c b/convert.c
index 1012462e3c..fd91b91ada 100644
--- a/convert.c
+++ b/convert.c
@@ -1040,7 +1040,6 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
ca->crlf_action = git_path_check_crlf(ccheck + 4);
if (ca->crlf_action == CRLF_UNDEFINED)
ca->crlf_action = git_path_check_crlf(ccheck + 0);
- ca->attr_action = ca->crlf_action;
ca->ident = git_path_check_ident(ccheck + 1);
ca->drv = git_path_check_convert(ccheck + 2);
if (ca->crlf_action != CRLF_BINARY) {
@@ -1060,6 +1059,8 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
ca->crlf_action = CRLF_UNDEFINED;
ca->ident = 0;
}
+ /* Save attr and make a decision for action */
+ ca->attr_action = ca->crlf_action;
if (ca->crlf_action == CRLF_TEXT)
ca->crlf_action = text_eol_is_crlf() ? CRLF_TEXT_CRLF : CRLF_TEXT_INPUT;
if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_FALSE)
