AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2000.04.19 20:48 "LibTIFF portability, makefiles, install...", by Antonio E. Scuri
2000.04.19 21:05 "Re: LibTIFF portability, makefiles, install...", by Chris Hanson
2000.04.19 22:15 "Re: LibTIFF portability, makefiles, install...", by Antonio E. Scuri

2000.04.19 21:05 "Re: LibTIFF portability, makefiles, install...", by Chris Hanson

After some years developing software that must be portable to many platforms we decided that it is much more simple to use an ANSI C code than to define lots of OS macros and specific files like "tif_win32.c".

ANSI C is almost, but not quite sufficient for building portable libraries.

ANSI C does not have any data types with exact size, only with minimum size. (I.e. "short" can hold at least 16 bits worth of data but does not actually have to be 16 bits.) It also does not define any standard method of specifying structure layout in memory. (Endianness is not an issue for the language, because it's possible to determine this at run time. Though it'd be nice to have it built in.)

I believe the latest draft for the next revision of Standard C has some guaranteed-size data types, but I'm not sure where to find it or what compilers support these types or even whether my belief is well-placed.

(There's also the small issue that ANSI C has a very Unix-centric view of certain things like the filesystem. For instance, on MacOS pathnames don't necessarily uniquely identify files. And copying a file involves more than duplicating its data; you need to duplicate its resources and its Finder information too -- this is the case for NTFS on Windows NT as well. I think the former is more of an issue for libtiff, though.)

-- Chris