Re: [PATCH] zlib.c: use size_t for size

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Junio,

On Fri, 12 Oct 2018, Junio C Hamano wrote:

> From: Martin Koegler <martin.koegler@chello.at>
> Date: Thu, 10 Aug 2017 20:13:08 +0200
> 
> Signed-off-by: Martin Koegler <martin.koegler@chello.at>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
> 
>  * I made minimal adjustments to make the change apply to today's
>    codebase.  I still find some choices and mixing of off_t and
>    size_t done by the patch a bit iffy, and some arith may need to
>    become st_addX().  Extra set of eyes are very much appreciated.
> 
>  builtin/pack-objects.c | 10 +++++-----
>  cache.h                | 10 +++++-----
>  pack-check.c           |  6 +++---
>  pack.h                 |  2 +-
>  packfile.h             |  2 +-
>  wrapper.c              |  8 ++++----
>  zlib.c                 |  8 ++++----
>  7 files changed, 23 insertions(+), 23 deletions(-)
> 
> diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
> index e6316d294d..b9ca04eb8a 100644
> --- a/builtin/pack-objects.c
> +++ b/builtin/pack-objects.c
> @@ -266,15 +266,15 @@ static void copy_pack_data(struct hashfile *f,
>  		struct packed_git *p,
>  		struct pack_window **w_curs,
>  		off_t offset,
> -		off_t len)
> +		size_t len)
>  {
>  	unsigned char *in;
> -	unsigned long avail;
> +	size_t avail;
>  
>  	while (len) {
>  		in = use_pack(p, w_curs, offset, &avail);
>  		if (avail > len)

Do we have to be careful to handle sizeof(off_t) != sizeof(size_t) here? I
guess we would receive a compiler warning about different sizes in that
case, but it makes me worry.

Not that it matters, as we currently have an *even worse* situation where
we *know* that `unsigned long` is 4 bytes on 64-bit Windows, and `off_t`
(the version we use, at least) is 8 bytes.

> -			avail = (unsigned long)len;
> +		avail = len;

Indentation change?

Apart from the consideration about different sizes of the data types
(which could maybe addressed via a comment in the commit message, after
thinking deeply about it), I think this patch is good to go.

Ciao,
Dscho

>  		hashwrite(f, in, avail);
>  		offset += avail;
>  		len -= avail;
> @@ -1478,8 +1478,8 @@ static void check_object(struct object_entry *entry)
>  		struct pack_window *w_curs = NULL;
>  		const unsigned char *base_ref = NULL;
>  		struct object_entry *base_entry;
> -		unsigned long used, used_0;
> -		unsigned long avail;
> +		size_t used, used_0;
> +		size_t avail;
>  		off_t ofs;
>  		unsigned char *buf, c;
>  		enum object_type type;
> diff --git a/cache.h b/cache.h
> index d508f3d4f8..fce53fe620 100644
> --- a/cache.h
> +++ b/cache.h
> @@ -20,10 +20,10 @@
>  #include <zlib.h>
>  typedef struct git_zstream {
>  	z_stream z;
> -	unsigned long avail_in;
> -	unsigned long avail_out;
> -	unsigned long total_in;
> -	unsigned long total_out;
> +	size_t avail_in;
> +	size_t avail_out;
> +	size_t total_in;
> +	size_t total_out;
>  	unsigned char *next_in;
>  	unsigned char *next_out;
>  } git_zstream;
> @@ -40,7 +40,7 @@ void git_deflate_end(git_zstream *);
>  int git_deflate_abort(git_zstream *);
>  int git_deflate_end_gently(git_zstream *);
>  int git_deflate(git_zstream *, int flush);
> -unsigned long git_deflate_bound(git_zstream *, unsigned long);
> +size_t git_deflate_bound(git_zstream *, size_t);
>  
>  /* The length in bytes and in hex digits of an object name (SHA-1 value). */
>  #define GIT_SHA1_RAWSZ 20
> diff --git a/pack-check.c b/pack-check.c
> index fa5f0ff8fa..575e3e7125 100644
> --- a/pack-check.c
> +++ b/pack-check.c
> @@ -27,13 +27,13 @@ static int compare_entries(const void *e1, const void *e2)
>  }
>  
>  int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
> -		   off_t offset, off_t len, unsigned int nr)
> +		   off_t offset, size_t len, unsigned int nr)
>  {
>  	const uint32_t *index_crc;
>  	uint32_t data_crc = crc32(0, NULL, 0);
>  
>  	do {
> -		unsigned long avail;
> +		size_t avail;
>  		void *data = use_pack(p, w_curs, offset, &avail);
>  		if (avail > len)
>  			avail = len;
> @@ -68,7 +68,7 @@ static int verify_packfile(struct packed_git *p,
>  
>  	the_hash_algo->init_fn(&ctx);
>  	do {
> -		unsigned long remaining;
> +		size_t remaining;
>  		unsigned char *in = use_pack(p, w_curs, offset, &remaining);
>  		offset += remaining;
>  		if (!pack_sig_ofs)
> diff --git a/pack.h b/pack.h
> index 34a9d458b4..1c9fecf929 100644
> --- a/pack.h
> +++ b/pack.h
> @@ -78,7 +78,7 @@ struct progress;
>  typedef int (*verify_fn)(const struct object_id *, enum object_type, unsigned long, void*, int*);
>  
>  extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, const unsigned char *sha1);
> -extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
> +extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, size_t len, unsigned int nr);
>  extern int verify_pack_index(struct packed_git *);
>  extern int verify_pack(struct packed_git *, verify_fn fn, struct progress *, uint32_t);
>  extern off_t write_pack_header(struct hashfile *f, uint32_t);
> diff --git a/packfile.h b/packfile.h
> index 442625723d..e2daf63426 100644
> --- a/packfile.h
> +++ b/packfile.h
> @@ -78,7 +78,7 @@ extern void close_pack_index(struct packed_git *);
>  
>  extern uint32_t get_pack_fanout(struct packed_git *p, uint32_t value);
>  
> -extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned long *);
> +extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, size_t *);
>  extern void close_pack_windows(struct packed_git *);
>  extern void close_pack(struct packed_git *);
>  extern void close_all_packs(struct raw_object_store *o);
> diff --git a/wrapper.c b/wrapper.c
> index e4fa9d84cd..1a510bd6fc 100644
> --- a/wrapper.c
> +++ b/wrapper.c
> @@ -67,11 +67,11 @@ static void *do_xmalloc(size_t size, int gentle)
>  			ret = malloc(1);
>  		if (!ret) {
>  			if (!gentle)
> -				die("Out of memory, malloc failed (tried to allocate %lu bytes)",
> -				    (unsigned long)size);
> +				die("Out of memory, malloc failed (tried to allocate %" PRIuMAX " bytes)",
> +				    (uintmax_t)size);
>  			else {
> -				error("Out of memory, malloc failed (tried to allocate %lu bytes)",
> -				      (unsigned long)size);
> +				error("Out of memory, malloc failed (tried to allocate %" PRIuMAX " bytes)",
> +				      (uintmax_t)size);
>  				return NULL;
>  			}
>  		}
> diff --git a/zlib.c b/zlib.c
> index d594cba3fc..197a1acc7b 100644
> --- a/zlib.c
> +++ b/zlib.c
> @@ -29,7 +29,7 @@ static const char *zerr_to_string(int status)
>   */
>  /* #define ZLIB_BUF_MAX ((uInt)-1) */
>  #define ZLIB_BUF_MAX ((uInt) 1024 * 1024 * 1024) /* 1GB */
> -static inline uInt zlib_buf_cap(unsigned long len)
> +static inline uInt zlib_buf_cap(size_t len)
>  {
>  	return (ZLIB_BUF_MAX < len) ? ZLIB_BUF_MAX : len;
>  }
> @@ -46,8 +46,8 @@ static void zlib_pre_call(git_zstream *s)
>  
>  static void zlib_post_call(git_zstream *s)
>  {
> -	unsigned long bytes_consumed;
> -	unsigned long bytes_produced;
> +	size_t bytes_consumed;
> +	size_t bytes_produced;
>  
>  	bytes_consumed = s->z.next_in - s->next_in;
>  	bytes_produced = s->z.next_out - s->next_out;
> @@ -150,7 +150,7 @@ int git_inflate(git_zstream *strm, int flush)
>  #define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
>  #endif
>  
> -unsigned long git_deflate_bound(git_zstream *strm, unsigned long size)
> +size_t git_deflate_bound(git_zstream *strm, size_t size)
>  {
>  	return deflateBound(&strm->z, size);
>  }
> -- 
> 2.19.1-328-g5a0cc8aca7
> 
>