Apache HTTP Server

  Platform specific notes:

  ------------------------

================

  Darwin (OS X):

   Apache 2 relies heavily on the use of autoconf and libtool to

   provide a build environment.  Darwin provides these tools as part

   of the Developers Tools package. Under Darwin, however, GNUlibtool

   is installed as 'glibtool' to avoid conflicting with the Darwin

   'libtool' program.  Apache 2 knows about this so that's not a

   problem.

   As of OS X 10.2 (Jaguar), the bundled versions work perfectly. Partly

   this is due to the fact that /bin/sh is now 'bash' and not 'zsh' as

   well as the fact that the bundled versions are up-to-date: 

   autoconf 2.52 and (g)libtool 1.4.2.

   You will note that GNU libtool should actually be installed as

   glibtool, to avoid conflict with a Darwin program of the same

   name.

   There have been some reports that autoconf 2.52 prevents Apache's

   build system from correctly handling passing multi-value envvars

   to the build system (eg: CFLAGS="-g -O3" ./configure),  causing

   errors.  Use of bash does not seem to help in this situation.  If

   this affects you, downgrading to autoconf 2.13 (which is installed

   on Darwin) will help.

   With Leopard (at least up to 10.5.2), when running configure

   you will likely see errors such as:

      rm: conftest.dSYM: is a directory

   This is a known issue and will be fixed in a later version of the

   autoconf suite. These errors can be safely ignored.

   For later versions of OS X, (10.8 and 10.9), be sure to have Xcode

   AND Xcode Command Line Tools installed. httpd will built both with

   gcc and clang.

==========

  FreeBSD:

   autoconf 2.52 creates scripts that are incompatible with the Posix

   shell implementation (/bin/sh) on FreeBSD.  Be sure to use v2.13

   of autoconf.

   Threaded MPMs are not supported on FreeBSD 4.x.  Current releases of

   FreeBSD 5.x (5.2 or later) support threaded MPMs correctly.  You must pass

   '--enable-threads=yes' to APR's configure in order to enable threads.

   Additionally, you must use libthr or libkse via libmap.conf as the default

   libc_r is still broken as of this writing.  Please consult the man page for

   libmap.conf for more details about configuring libthr or libkse.

================

  HP-UX:

   The dlopen() system call in HP-UX has problems when loading/unloading

   C++ modules. The problem can be resolved by using shl_load() instead

   of dlopen(). This is fixed in the Apache 2.0.44 release.

   To enable loading of C++ modules, the httpd binary has to be linked with

   the following libraries :

   HP-UX (11.0 / 11i):

      When using shl_load        : "cpprt0_stub.s -lcl"

      When using dlopen          : "cpprt0_stub.s -lcl -lCsup"

   HP-UX (11i version 1.5 and greater):

      When using dlopen/shl_load : "cpprt0_stub.s -lcl -lunwind"

   The cpprt0_stub.s can be downloaded from the web site :

      http://h21007.www2.hp.com/hpux-devtools/CXX/hpux-devtools.0107/0083.html

   Compile cpprt0_stub.s with the PIC option

     cc -c +z cpprt0_stub.s

       - OR -

     gcc -c -fPIC cpprt0_stub.s

================

  AIX, using the vendor C compiler with optimization:

    There is an issue with compiling server/core.c with optimization enabled

    which has been seen with C for AIX 5.0.2.3 and above.  (5.0.2.0, 5.0.2.1,

    and 5.0.2.2 have an additional problem with Apache 2.0.x, so either upgrade 

    the compiler or don't use optimization in order to avoid it.)

    cc_r works fine with -O2 but xlc_r does not.  In order to use xlc_r with

    -O2, apply the patch at 

    http://www.apache.org/dist/httpd/patches/apply_to_2.0.49/aix_xlc_optimization.patch

    (That patch works with many recent levels of Apache 2+.)

================

  Solaris:

    On Solaris, better performance may be achieved by using the Sun Studio

    compiler instead of gcc.  As of version 11, it is now free (registration

    required).  Download the compiler from:

    http://developers.sun.com/prodtech/cc/downloads/index.jsp

    If you use Sun Studio, the following compiler flags (CFLAGS) are

    recommended:

      -XO4 -xchip=generic

================

  Ubuntu:

    You will need to ensure that you have either libtool 1.5.6

    or 2.2.6b, or later. Expat 2.0.1 and PCRE 8.02 are also

    recommended to be installed. If building PCRE from source,

    you'll also need g++.