On 4/28/21 12:04 PM, Julien Grall wrote:
>
>
> On 27/04/2021 13:05, Costin Lupu wrote:
>> If PATH_MAX is already defined in the system (e.g. in
>> /usr/include/limits.h
>> header) then gcc will trigger a redefinition error because of -Werror.
>>
>> Signed-off-by: Costin Lupu <costin.l...@cs.pub.ro>
>> ---
>> tools/libfsimage/ext2fs/fsys_ext2fs.c | 2 ++
>> tools/libfsimage/reiserfs/fsys_reiserfs.c | 2 ++
>> 2 files changed, 4 insertions(+)
>>
>> diff --git a/tools/libfsimage/ext2fs/fsys_ext2fs.c
>> b/tools/libfsimage/ext2fs/fsys_ext2fs.c
>> index a4ed10419c..5ed8fce90e 100644
>> --- a/tools/libfsimage/ext2fs/fsys_ext2fs.c
>> +++ b/tools/libfsimage/ext2fs/fsys_ext2fs.c
>> @@ -278,7 +278,9 @@ struct ext4_extent_header {
>> #define EXT2_SUPER_MAGIC 0xEF53 /* include/linux/ext2_fs.h */
>> #define EXT2_ROOT_INO 2 /* include/linux/ext2_fs.h */
>> +#ifndef PATH_MAX
>> #define PATH_MAX 1024 /* include/linux/limits.h */
>> +#endif
>
> Can we drop it completely and just rely on limits.h?
>
One problem here is that the system limits.h header doesn't necessarily
include linux/limits.h, which would mean we would have to include
linux/limits.h. But this is problematic for other systems such as BSD.
I had a look on a FreeBSD source tree to see how this is done there. It
seems that there are lots of submodules, apps and libs that redefine
PATH_MAX in case it wasn't defined before so the changes introduced by
the current patch seem to be very popular. Another clean approach I saw
was for jemalloc [1] which includes unistd.h. They redefine PATH_MAX
only for MS C compiler, but AFAIK we don't need that.
So IMHO the current changes seem to be the most portable, but I'm open
to any suggestions.
[1]
https://github.com/jemalloc/jemalloc/blob/dev/include/jemalloc/internal/jemalloc_internal_decls.h#L76
>> #define MAX_LINK_COUNT 5 /* number of symbolic links
>> to follow */
>> /* made up, these are pointers into FSYS_BUF */
>> diff --git a/tools/libfsimage/reiserfs/fsys_reiserfs.c
>> b/tools/libfsimage/reiserfs/fsys_reiserfs.c
>> index 916eb15292..10ca657476 100644
>> --- a/tools/libfsimage/reiserfs/fsys_reiserfs.c
>> +++ b/tools/libfsimage/reiserfs/fsys_reiserfs.c
>> @@ -284,7 +284,9 @@ struct reiserfs_de_head
>> #define S_ISDIR(mode) (((mode) & 0170000) == 0040000)
>> #define S_ISLNK(mode) (((mode) & 0170000) == 0120000)
>> +#ifndef PATH_MAX
>> #define PATH_MAX 1024 /* include/linux/limits.h */
>> +#endif
>> #define MAX_LINK_COUNT 5 /* number of symbolic links to follow */
>> /* The size of the node cache */
>>
>
