Re: [PATCH v2 02/11] bisect--helper: introduce new `write_in_file()` function
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Apr 3, 2020, 05:13 UTC
- Message-ID
- <xmqqeet51794.fsf@gitster.c.googlers.com>
- In-Reply-To
- <20200321161020.22817-3-mirucam@gmail.com>
Miriam Rubio <mirucam@gmail.com> writes:
Show 24 quoted lines
> Let's refactor code adding a new `write_in_file()` function
> that opens a file for writing a message and closes it.
>
> This helper will be used in later steps and makes the code
> simpler and easier to understand.
>
> Mentored-by: Christian Couder <chriscool@tuxfamily.org>
> Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
> Signed-off-by: Miriam Rubio <mirucam@gmail.com>
> ---
> builtin/bisect--helper.c | 27 +++++++++++++++++++++------
> 1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
> index 1f81cff1d8..e949ea74e2 100644
> --- a/builtin/bisect--helper.c
> +++ b/builtin/bisect--helper.c
> @@ -74,6 +74,26 @@ static int one_of(const char *term, ...)
> return res;
> }
>
> +static int write_in_file(const char *filepath, const char *mode, const char *format,...)
> +{
> + FILE *fp = NULL;It is crystal clear in this concise helper function that fp will never be used without getting assigned the returned value from fopen(), so I do not think there is any need to initialize it to NULL.
I'd use "path", not "filepath" (which I do not think we use anywhere in our codebase), if I were writing this function, by the way.
Show 5 quoted lines
> + va_list args;
> + int res = 0;
> +
> + if (!strcmp(mode, "a") && !strcmp(mode, "w"))
> + return error_errno(_("wrong writing mode '%s'"), mode);I do not see where you saw a failure from a call to system library function, which would make 'errno' variable valid at this point, so I am puzzled. By using error_errno(), whose error status are you trying to show?
Puzzled. Shouldn't it be just error(_("..."), mode)?> + fp = fopen(filepath, mode);
> + if (!fp)
> + return error_errno(_("could not open file '%s'"), filepath);This one would show why fopen() failed, so error_errno() would be good. Does it help us help the users if they can tell us which mode we failed to write to the file? Something like
cannot open file '%s' in mode '%s'
perhaps?
Show 5 quoted lines
> + va_start(args, format);
> + res = vfprintf(fp, format, args);
> + va_end(args);
> + if (!res)
> + return error_errno(_("could not write to file '%s'"), filepath);This would show errors from vfprintf(), which is good. However, you fail to fclose the FILE when this return is hit, which is not good.
Show 27 quoted lines
> + return fclose(fp);
> +}
> +
> static int check_term_format(const char *term, const char *orig_term)
> {
> int res;
> @@ -104,7 +124,6 @@ static int check_term_format(const char *term, const char *orig_term)
>
> static int write_terms(const char *bad, const char *good)
> {
> - FILE *fp = NULL;
> int res;
>
> if (!strcmp(bad, good))
> @@ -113,12 +132,8 @@ static int write_terms(const char *bad, const char *good)
> if (check_term_format(bad, "bad") || check_term_format(good, "good"))
> return -1;
>
> - fp = fopen(git_path_bisect_terms(), "w");
> - if (!fp)
> - return error_errno(_("could not open the file BISECT_TERMS"));
> + res = write_in_file(git_path_bisect_terms(), "w", "%s\n%s\n", bad, good);
>
> - res = fprintf(fp, "%s\n%s\n", bad, good);
> - res |= fclose(fp);
> return (res < 0) ? -1 : 0;
> }