[FFmpeg-devel] [PATCH v7 2/3] avformat/os_support: Support long file names on Windows

[nil-admirari at mailo.com]

> + struct win32_stat
> + {
> + _dev_t st_dev; /* ID of device containing file */
> + _ino_t st_ino; /* inode number */
> + unsigned short st_mode; /* protection */
> + short st_nlink; /* number of hard links */
> + short st_uid; /* user ID of owner */
> + short st_gid; /* group ID of owner */
> + _dev_t st_rdev; /* device ID (if special file) */
> + int64_t st_size; /* total size, in bytes */
> + int64_t st_atime; /* time of last access */
> + int64_t st_mtime; /* time of last modification */
> + int64_t st_ctime; /* time of last status change */
> + };

Wouldn't it make sense to add a
static_assert(sizeof(struct win32_stat) == sizeof(struct _stati64))
somewhere?

> +static inline int win32_access(const char *filename_utf8, int par)
> +static inline void copy_stat(struct _stati64 *winstat, struct win32_stat *par)
> +static inline int win32_stat(const char *filename_utf8, struct win32_stat *par)
> +static inline int win32_fstat(int fd, struct win32_stat *par)

How about renaming par to something more appropriate?

> +static inline void copy_stat(struct _stati64 *winstat, struct win32_stat *par)
> +{
> + par->st_dev = winstat->st_dev;
> + par->st_ino = winstat->st_ino;
> + par->st_mode = winstat->st_mode;
> + par->st_nlink = winstat->st_nlink;
> + par->st_uid = winstat->st_uid;
> + par->st_gid = winstat->st_gid;
> + par->st_rdev = winstat->st_rdev;
> + par->st_size = winstat->st_size;
> + par->st_atime = winstat->st_atime;
> + par->st_mtime = winstat->st_mtime;
> + par->st_ctime = winstat->st_ctime;
> }

Would memcpy make more sense here?

> +static inline int win32_stat(const char *filename_utf8, struct win32_stat *par)
> +{
> + struct _stati64 winstat = { 0 };
> ...
> 
> +static inline int win32_fstat(int fd, struct win32_stat *par)
> +{
> + struct _stati64 winstat = { 0 };
> ...

Functions use _stati64 internally, which is affected by _USE_32BIT_TIME_T.
win32_stat does not take _USE_32BIT_TIME_T into account at all.
It was already pointed out that _USE_32BIT_TIME_T is actually used:
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/296731.html.