When compiling SVN 1752 on macOS, an error is thrown by src/Command.cc:
g++ -DHAVE_CONFIG_H -I. -I.. -Wall -I sql -I
/Volumes/MyPassport/paulrockwell/Documents/apl/trunk
-I/opt/local/include -std=c++11 -I
/Volumes/MyPassport/paulrockwell/Documents/apl/trunk -MT apl-Command.o -MD -MP
-MF .deps/apl-Command.Tpo -c -o apl-Command.o `test -f 'Command.cc' || echo
'./'`Command.cc
Command.cc:2033:49: error: no member named 'st_mtim' in 'stat'
if (sort == SORT_TIME) return st.st_mtim.tv_sec;
~~ ^
Evidently on macOS the system-defined definition of struct stat is defined
differently than on Linux (from "man 1 stat" on macOS):
The buf argument is a pointer to a stat structure as defined by ⟨sys/stat.h⟩
and into which information is
placed concerning the file. When the macro _DARWIN_FEATURE_64_BIT_INODE is not
defined (see below for more
information about this macro), the stat structure is defined as:
struct stat { /* when _DARWIN_FEATURE_64_BIT_INODE is NOT defined */
dev_t st_dev; /* device inode resides on */
ino_t st_ino; /* inode's number */
mode_t st_mode; /* inode protection mode */
nlink_t st_nlink; /* number of hard links to the file */
uid_t st_uid; /* user-id of owner */
gid_t st_gid; /* group-id of owner */
dev_t st_rdev; /* device type, for special file inode */
struct timespec st_atimespec; /* time of last access */
struct timespec st_mtimespec; /* time of last data modification */
struct timespec st_ctimespec; /* time of last file status change */
off_t st_size; /* file size, in bytes */
quad_t st_blocks; /* blocks allocated for file */
u_long st_blksize;/* optimal file sys I/O ops blocksize */
u_long st_flags; /* user defined flags for file */
u_long st_gen; /* file generation number */
};
However, when the macro _DARWIN_FEATURE_64_BIT_INODE is defined, the stat
structure will now be defined as:
struct stat { /* when _DARWIN_FEATURE_64_BIT_INODE is defined */
dev_t st_dev; /* ID of device containing file */
mode_t st_mode; /* Mode of file (see below) */
nlink_t st_nlink; /* Number of hard links */
ino_t st_ino; /* File serial number */
uid_t st_uid; /* User ID of the file */
gid_t st_gid; /* Group ID of the file */
dev_t st_rdev; /* Device ID */
struct timespec st_atimespec; /* time of last access */
struct timespec st_mtimespec; /* time of last data modification */
struct timespec st_ctimespec; /* time of last status change */
struct timespec st_birthtimespec; /* time of file creation(birth) */
off_t st_size; /* file size, in bytes */
blkcnt_t st_blocks; /* blocks allocated for file */
blksize_t st_blksize; /* optimal blocksize for I/O */
uint32_t st_flags; /* user defined flags for file */
uint32_t st_gen; /* file generation number */
int32_t st_lspare; /* RESERVED: DO NOT USE! */
int64_t st_qspare[2]; /* RESERVED: DO NOT USE! */
};
On Linux, the struct is defined as:
struct stat {
dev_t st_dev; /* ID of device containing file */
ino_t st_ino; /* Inode number */
mode_t st_mode; /* File type and mode */
nlink_t st_nlink; /* Number of hard links */
uid_t st_uid; /* User ID of owner */
gid_t st_gid; /* Group ID of owner */
dev_t st_rdev; /* Device ID (if special file) */
off_t st_size; /* Total size, in bytes */
blksize_t st_blksize; /* Block size for filesystem I/O */
blkcnt_t st_blocks; /* Number of 512 B blocks allocated */
/* Since POSIX.1-2008, this structure supports nanosecond
precision for the following timestamp fields.
For the details before POSIX.1-2008, see VERSIONS. */
struct timespec st_atim; /* Time of last access */
struct timespec st_mtim; /* Time of last modification */
struct timespec st_ctim; /* Time of last status change */
#define st_atime st_atim.tv_sec /* Backward compatibility */
#define st_mtime st_mtim.tv_sec
#define st_ctime st_ctim.tv_sec
};
struct timespec seems to be defined the same on both platforms.
struct stat seems to contain the same information as available on Linux, but
the fields for st_atime, st_mtime, and st_ctime are named differently on the
Mac. It appears that the Mac definitions may pre-date POSIX.1-2008. Maybe
that's why the differences - perhaps Apple anticipated the updated standard but
never went back to update the definitions once approved?
I've modified the source of Command.cc to change line 2033 from
if (sort == SORT_TIME) return st.st_mtim.tv_sec;
to
if (sort == SORT_TIME) return st.st_mtimespec.tv_sec;
and the module compiles successfully. I can conditionalize this with #ifdef
__APPLE__ like I did with my changes to
Backtrace.cc, but thought I'd defer to you to determine how you want to handle
this.
- Paul Rockwell
.
