Simple install procedure
========================

  % gzip -cd glib-@GLIB_VERSION@.tar.gz | tar xvf -  # unpack the sources
  % cd glib-@GLIB_VERSION@                           # change to the toplevel directory
  % ./configure                             # run the `configure' script
  % make                                    # build GLIB

  [ Become root if necessary ]
  % rm -rf /install-prefix/include/glib.h /install-prefix/include/gmodule.h
  % make install                            # install GLIB

Requirements
============

GLib-2.0 requires pkg-config, which is tool for tracking the
compilation flags needed for libraries. (For each library, a small .pc
text file is installed in a standard location that contains the
compilation flags needed for that library along with version number
information.) Information about pkg-config can be found at:

  http://www.freedesktop.org/software/pkgconfig/

GNU make (http://www.gnu.org/software/make) is also recommended.

In order to implement conversions between character sets,
GLib requires an implementation of the standard iconv() routine.
Most modern systems will have a suitable implementation, however
many older systems lack an iconv() implementation. On such systems, 
you must install the libiconv library. This can be found at:

 http://www.gnu.org/software/libiconv/

If your system has an iconv implementation but you want to use
libiconv instead, you can pass the --with-libiconv option to
configure. This forces libiconv to be used. 

Note that if you have libiconv installed in your default include
search path (for instance, in /usr/local/), but don't enable
it, you will get an error while compiling GTK+ because the
iconv.h that libiconv installs hides the system iconv.

If you are using the native iconv implementation on Solaris
instead of libiconv, you'll need to make sure that you have 
the converters between locale encodings and UTF-8 installed.
At a minimum you'll need the SUNWuiu8 package. You probably
should also install the SUNWciu8, SUNWhiu8, SUNWjiu8, and
SUNWkiu8 packages.

The native iconv on Compaq Tru64 doesn't contain support for
UTF-8, so you'll need to use GNU libiconv instead. (When
using GNU libiconv for GTK+, you'll need to use GNU libiconv
for GNU gettext as well.) This probably applies to related
operating systems as well.

Finally, for message catalog handling, GTK+ requires an implementation
of gettext(). If your system doesn't provide this functionality,
you should use the libintl library from the GNU gettext package,
available from:

 http://www.gnu.org/software/gettext/

The Nitty-Gritty
================

The 'configure' script can be given a number of options to enable
and disable various features. For a complete list, type:

  ./configure --help

A few of the more important ones:

*  --prefix=PREFIX         install architecture-independent files in PREFIX
                           [ Defaults to /usr/local ]

*  --exec-prefix=EPREFIX   install architecture-dependent files in EPREFIX
                           [ Defaults to the value given to --prefix ]

*  --enable-debug=[yes/no/minimum] determines the amount of debugging
                           code to include. 'yes' will includes some
			   extra checks and debugging features that
                           may be useful for people developing with
                           GLib. 'no' produces a somewhat smaller and 
                           faster library at the expense of reduced
                           robustness.
                           [ Defaults to 'minimum' for stable releases ]

*  --enable-gc-friendly    When enabled all memory freed by the application,
                           but retained by GLib for performance reasons  
                           is set to zero, thus making deployed garbage
                           collection or memory profiling tools detect 
                           unlinked memory correctly. This will make GLib 
                           slightly slower.
                           [ --disable-gc-friendly is default ]

*  --disable-mem-pools     Do not cache freed objects. When specified,
                           GLib will immediately return freed memory
                           to the C library instead of keeping around
                           pools of free objects such as linked list
                           and hash table nodes. Specifying this
                           will make GLib slower in most cases, but it
                           will use less memory.
                           [ --enable-mem-pools is the default ]

*  --disable-threads       Do not compile GLib to be multi thread safe. GLib
                           will be slightly faster then. This is however not
                           recommended, as many programs rely on GLib being 
                           multi thread safe.
                           [ --enable-threads is the default ]

*  --with-threads=[none/posix/dce/solaris/win32] Specify a thread 
                           implementation to use. 
                           * 'posix' and 'dce' can be used interchangeable 
                             to mean the different versions of posix 
                             threads. configure tries to find out, which 
                             one is installed. 
                           * 'solaris' uses the native Solaris thread
                             implementation. 
                           * 'none' means that GLib will be thread safe, 
                             but does not have a default thread 
                             implementation. This has to be supplied to 
                             g_thread_init() by the programmer. 
                           [ Determined by configure by default ]

*  --enable-included-printf=[yes/no/auto] Specify whether to build using
                           the included copy of the Trio library
                           for string formatting functions like printf().
                           The default is 'auto', which means that
                           Trio will be used if configure detects
                           missing features in your system native
                           printf implementation.

Options can be given to the compiler and linker by setting
environment variables before running configure. A few of the more
important ones:

 CC       : The C compiler to use
 CPPFLAGS : Flags for the C preprocesser such as -I and -D
 CFLAGS   : C compiler flags

The most important use of this is to set the
optimization/debugging flags. For instance, to compile with no
debugging information at all, run configure as:

 CFLAGS=-O2 ./configure           # Bourne compatible shells (sh/bash/zsh)

or,

 setenv CFLAGS -O2 ; ./configure  # csh and variants


Installation directories
========================

The location of the installed files is determined by the --prefix
and --exec-prefix options given to configure. There are also more
detailed flags to control individual directories. However, the
use of these flags is not tested.

One particular detail to note, is that the architecture-dependent
include file glibconfig.h is installed in:

  $exec_prefix/lib/glib/include/

if you have a version in $prefix/include, this is out of date
and should be deleted.

.pc files for the various libraries are installed in 
$exec_prefix/lib/pkgconfig to provide information when compiling
other packages that depend on GTK+. If you set PKG_CONFIG_PATH
so that it points to this directory, then you can get the 
correct include flags and library flags for compiling a GLib
application with:

 pkg-config --cflags glib-2.0
 pkg-config --libs glib-2.0


Cross-compiling GLib
====================

Cross-compilation is the proceess of compiling a program or
library on a different architecture or operating system then
it will be run upon. GLib is slightly more difficult to 
cross-compile than many packages because much of GLib is
about hiding differences between different systems. 

These notes cover things specific to cross-compiling GLib;
for general information about cross-compilation, see the
autoconf info pages.

GLib tries to detect as much information as possible about
the target system by compiling and linking programs without
actually running anything; however, some information GLib
needs is not available this way. This information needs
to be provided to the configure script via a "cache file"
or by setting the cache variables in your environment.

As an example of using a cache file, to cross compile for
the "MingW32" Win32 runtine environment on a Linux system,
create a file 'win32.cache' with the following contents:

===
glib_cv_long_long_format=ll
glib_cv_stack_grows=no
===

Then execute the following commands:

===
PATH=/path/to/mingw32-compiler/bin:$PATH
chmod a-w win32.cache   # prevent configure from changing it
./configure --cache-file=win32.cache --host=mingw32
===

The complete list of cache file variables follows. Most
of these won't need to be set in most cases.

Cache file variables
====================

glib_cv_long_long_format=[ll/q/I64]

 Format used by printf and scanf for 64 bit integers. "ll" is 
 the C99 standard, and what is used by the 'trio' library
 that GLib builds if your printf() is insufficiently capable.
 Doesn't need to be set if you are compiling using trio.

glib_cv_stack_grows=[yes/no]

 Whether the stack grows up or down. Most places will want "no",
 A few architectures, such as PA-RISC need "yes".

glib_cv_working_bcopy=[yes/no]

 Whether your bcopy can handle overlapping copies. Only needs to be set 
 if you don't have memmove. (Very unlikely)

glib_cv_sane_realloc=[yes/np]
 
 Whether your realloc() conforms to ANSI C and can handle NULL as
 the first argument. Defaults to "yes" and probably doesn't need to be set.

glib_cv_have_strlcpy=[yes/no]

 Whether you have strlcpy that matches OpenBSD. Defaults to "no",
 which is safe, since GLib uses a built-in version in that case.

glib_cv_va_val_copy=[yes/no]
 
  Whether va_list can be copied as a pointer. If set to "no", 
  then memcopy will be used. Only matters if you don't have
  va_copy or __va_copy. (So, doesn't matter for GCC.) Defaults
  to "yes" which is slightly more common than "no".

glib_cv_rtldglobal_broken=[yes/no]
 
  Whether you have a bug found in OSF/1 v5.0. Defaults to "no".

glib_cv_uscore=[yes/no]

  Whether an underscore needs to be prepended to symbols when
  looking them up via dlsym. Only needs to be set if your system
  uses dlopen/dlsym.

ac_cv_func_posix_getpwuid_r=[yes/no]

  Whether you have a getpwuid_r function (in your C library,
  not your thread library) that conforms to the POSIX spec.
  (Takes a 'struct passwd **' as the final argument)

ac_cv_func_nonposix_getpwuid_r=[yes/no]

  Whether you have some variant of getpwuid_r that doesn't
  conform to to the POSIX spec, but GLib might be able to
  use (or might segfault.) Only needs to be set if 
  ac_cv_func_posix_getpwuid_r is not set. It's safest to set
  this to "no".

glib_cv_use_pid_surrogate=[yes/no]

 Whether to use a setpriority() on the PID of the thread as
 a method for setting the priority of threads. This only
 needs to be set when using POSIX threads.

ac_cv_func_printf_unix98=[yes/no]

 Whether your printf() family supports Unix98 style %N$
 positional parameters. Defaults to "no".

ac_cv_func_vsnprintf_c99=[yes/no]

 Whether you have a vsnprintf() with C99 semantics. (C99 semantics
 means returns the number of bytes that would have been written
 had the output buffer had enough space.). Defaults to "no".
