Add jl_ftruncate wrapper

Fix handle ABI compatibility issue on 32bits linux with `_FILE_OFFSET_BITS=64`.

base/mmap.jl

@@ -58,7 +58,7 @@ function grow!(io::IO, offset::Integer, len::Integer)
  pos = position(io)
  filelen = filesize(io)
  if filelen < offset + len
- failure = ccall(:ftruncate, Cint, (Cint, Coff_t), fd(io), offset+len)
+ failure = ccall(:jl_ftruncate, Cint, (Cint, Coff_t), fd(io), offset+len)
  Base.systemerror(:ftruncate, failure != 0)
  end
  seek(io, pos)

base/sharedarray.jl

@@ -531,7 +531,7 @@ function _shm_mmap_array(T, dims, shm_seg_name, mode)
  # On OSX, ftruncate must to used to set size of segment, just lseek does not work.
  # and only at creation time
  if (mode & JL_O_CREAT) == JL_O_CREAT
- rc = ccall(:ftruncate, Cint, (Cint, Coff_t), fd_mem, prod(dims)*sizeof(T))
+ rc = ccall(:jl_ftruncate, Cint, (Cint, Coff_t), fd_mem, prod(dims)*sizeof(T))
  systemerror("ftruncate() failed for shm segment " * shm_seg_name, rc != 0)
  end
 

doc/stdlib/c.rst

@@ -235,7 +235,7 @@
 
 .. data:: Coff_t
 
- Equivalent to the native ``off_t`` c-type
+ Equivalent to the native ``off_t`` c-type. Note that julia defines ``_FILE_OFFSET_BITS=64`` so this may not be the same as the default value on 32bits Linux.
 
 .. data:: Cwchar_t
 

src/sys.c

@@ -75,7 +75,14 @@ JL_DLLEXPORT int jl_sizeof_uv_mutex(void) { return sizeof(uv_mutex_t); }
 JL_DLLEXPORT int jl_sizeof_off_t(void) { return sizeof(off_t); }
 #ifndef _OS_WINDOWS_
 JL_DLLEXPORT int jl_sizeof_mode_t(void) { return sizeof(mode_t); }
-JL_DLLEXPORT off_t jl_lseek(int fd, off_t offset, int whence) { return lseek(fd, offset, whence); }
+JL_DLLEXPORT int jl_ftruncate(int fd, off_t length)
+{
+ return ftruncate(fd, length);
+}
+JL_DLLEXPORT off_t jl_lseek(int fd, off_t offset, int whence)
+{
+ return lseek(fd, offset, whence);
+}
 JL_DLLEXPORT ssize_t jl_pwrite(int fd, const void *buf, size_t count, off_t offset)
 {
  return pwrite(fd, buf, count, offset);