General
=======

For more information about the port of GLib, GTk+ and the GIMP to
native Windows, and pre-built DLLs, surf to http://www.gimp.org/win32/
"Native" means that we use the Win32 API only, and no POSIX (Unix)
emulation layer except that provided by the Microsoft runtime C
library. Actually, a pthreads emulation library is used.

To build GLib on Win32, you can use either gcc or the Microsoft
compiler and tools. Both the compiler from MSVC 5.0 and from MSVC 6.0
have been used successfully.

But note that to just *use* GLib on Windows, there is no need to
build it, prebuilt DLLs are available from the website above.

With gcc I mean gcc-2.95 or gcc-2.95.2 as distributed by Mumit Khan,
either as a mingw version (preferred), or running under cygwin. To
successfully use gcc, follow the instructions below. We want to use
gcc -mno-cygwin, i.e. produce executables (.exe and .dll files) that
do *not* require the cygwin runtime library. This is called "mingw".
I also use the -fnative-struct flag, which means that in order to use
the prebuilt DLLs (especiall of GTK+), you *must* also use that flag.
(This flag means that the struct layout is identical to that used by
MSVC.)

To test the GLib functions, go to the tests subdirectory and enter
`nmake -f makefile.msc check` or `make -f makefile.mingw check`.

If you would want to use the cygwin tools to generate executables that
*do* use the cygwin runtime, the normal Unix configuration method
should work as if on Unix. But it won't produce DLLs. At least I
haven't succeeded in that. Also, I have no idea what changes are
necessary to the code for it to run successfully on cygwin.

With some work, it might be possible to use the ./configure mechanism
also with a "mingw32" configuration.

The following preprocessor macros are used for conditional compilation
related to Win32:

- G_OS_WIN32 is defined when compiling for Win32, *and* without
  any POSIX emulation, other that to the extent provided by the
  bundled Microsoft C library (msvcrt.dll) and the pthreads-win32
  library. For instance, pathnames are in the native Windows syntax.

- _WIN32 is defined by the compiler

The Win32 port uses the combination with both of those on. As
G_OS_WIN32 is defined in glibconfig.h, it is available to all source
files that use GLib (or GTk+, which uses GLib).

Additionally, there are the compiler-specific macros:
- _MSC_VER is defined when using the Microsoft compiler
- __GNUC__ is defined when using GCC

Some of the usage of these macros used to be a bit mixed up, and had
to be straightened out when adding the gcc support. In particular, I
used to check for _MSC_VER in some places where I really wanted to
check for the Microsoft C library, and those checks has now been
changed to G_OS_WIN32.

G_OS_WIN32 implies using the Microsoft C runtime MSVCRT.DLL. GLib or
software using it is not known to work with the older CRTDLL.DLL
runtime.

Building software that use GLib or GTk+
=======================================

Unfortunately, even building software that just *use* GLib or GTk+
also require to have the right compiler set up the right way, so if
you intend to use gcc, follow the relevant instructions below in that
case, too.

Pthreads library
================

Before building you must get the pthreads library for Win32 from
http://sourceware.cygnus.com/pthreads-win32/. The pthreads-win32
snapshot from 1999-05-30 is the one that should be used. Edit the
location of the pthreads library and include files in makefile.msc or
makefile.mingw. The pthreads distribution includes the precompiled dll
and import libraries both for MSVC and gcc. Later versions might also
work.

The pthreads for Win32 package that the thread support uses supposedly
isn't quite ready yet, and thus threads stuff should not be relied
upon for anything serious.

Libiconv
========

Before building GLib you must also have the libiconv library, either
from the same website mentioned above, or from it's homepage at
http://clisp.cons.org/~haible/packages-libiconv.html.

Where are the makefiles?
========================

If you are building from a CVS snapshot, you will not have any
makefile.mingw or makefile.msc file. You should copy the corresponding
makefile.mingw.in or makefile.msc.in file to that name, and edit the
line that sets GLIB_VER to the correct version number.

This is done automatically when an official GLib source distribution
package is built.

Building with gcc
=================

I use the latest gcc, gcc-2.95.2. Version 2.95 will most probably also
work.

You can either use gcc running on cygwin, or the "pure" mingw
gcc. Using the latter is much easier. 

Just fetch the latest version of gcc for mingw and the msvcrt runtime,
currently from
ftp://ftp.nanotech.wisc.edu/pub/khan/gnu-win32/mingw32/snapshots/gcc-2.95.2-1/
.

Download the three zip archives: the gcc-<version>-msvcrt,
mingw-msvcrt-<timestamp> and binutils-<timestamp>-msvcrt, and unpack
them in a suitable directory.

Set up your PATH so that the gcc from the bin directory that got
created above is the one that gets used. You can skip steps 1--5
below. Even if you run the mingw gcc, you still want to have cygwin to
run make in.

If you want to run a cygwin-based gcc, it gets a bit more
complicated. We still want gcc to produce code that does not use
cygwin, but the msvcrt runtime. The way to do this can be quite
complex, and the instructions are not included here. Contact me if you
want some possibly outdated, misleading and incomplete advice.

Building with MSVC
==================

If using the Microsoft toolchain, build with `nmake -f
makefile.msc`. Install with `nmake -f makefile.msc install`. 

--Tor Lillqvist <tml@iki.fi>
