Attempt at portability.

[perl5.git] / README.aix

diff --git a/README.aix b/README.aix
index 96d82a6..a4134a0 100644 (file)
--- a/README.aix
+++ b/README.aix
@@ -19,7 +19,7 @@ an ANSI compliant C-compiler with AIX by default, but binary builds of
 gcc for AIX are widely available.
 
 At the moment of writing, AIX supports two different native C compilers,
-for which you have to pay: B<xlc> and B<VAC>. If you decide to use eiter
+for which you have to pay: B<xlc> and B<VAC>. If you decide to use either
 of these two (which is quite a lot easier than using gcc), be sure to
 upgrade to the latest available patch level. Currently:
 
@@ -31,6 +31,12 @@ The former is recommended, as not only can it compile Perl with no
 difficulty, but also can take advantage of features listed later that
 require the use of IBM compiler-specific command-line flags.
 
+The IBM's compiler patch levels 5.0.0.0 and 5.0.1.0 have compiler
+optimization bugs that affect compiling perl.c and regcomp.c,
+respectively.  If Perl's configuration detects those compiler patch
+levels, optimization is turned off for the said source code files.
+Upgrading to at least 5.0.2.0 is recommended.
+
 If you decide to use gcc, make sure your installation is recent and
 complete, and be sure to read the Perl README file for more gcc-specific
 details. Please report any hoops you had to jump through to the development
@@ -51,9 +57,22 @@ show the base, but is not always complete:
 
 =head2 Building Dynamic Extensions on AIX
 
-AIX supports dynamically loadable libraries (shared libraries).
-Shared libraries end with the suffix .a, which is a bit misleading,
-because *all* libraries are shared ;-).
+AIX supports dynamically loadable objects as well as shared libraries.
+Shared libraries by convention end with the suffix .a, which is a bit
+misleading, as an archive can contain static as well as dynamic members.
+For perl dynamically loaded objects we use the .so suffix also used on
+many other platforms.
+
+Note that starting from Perl 5.7.2 (and consequently 5.8.0) and AIX 4.3
+or newer Perl uses the AIX native dynamic loading interface in the so
+called runtime linking mode instead of the emulated interface that was
+used in Perl releases 5.6.1 and earlier or, for AIX releases 4.2 and
+earlier.  This change does break backward compatibility with compiled
+modules from earlier perl releases.  The change was made to make Perl
+more compliant with other applications like Apache/modperl which are
+using the AIX native interface. This change also enables the use of C++
+code with static constructors and destructors in perl extensions, which
+was not possible using the emulated interface.
 
 =head2 The IBM ANSI C Compiler
 
@@ -140,7 +159,7 @@ Follow the messages ... and you're done.
 
 =head2 Using GNU's gcc for building perl
 
-We're woking on this using gcc-3.0 ... (any input highly appreciated)
+We're working on this using gcc-3.0 ... (any input highly appreciated)
 
 =head2 Using Large Files with Perl
 
@@ -154,15 +173,18 @@ threads are used in combination with 64bit configurations.
 =head2 64-bit Perl
 
 If your AIX is installed with 64-bit support, you can expect 64bit
-configurations to work. In combination with threads some tests might still fail.
-
-=head2 GDBM and Threads
-
-... ?
+configurations to work. In combination with threads some tests might
+still fail.
 
-=head2 NFS filesystems and utime(2)
+=head2 AIX 4.2 and extensions using C++ with statics
 
-... ?
+In AIX 4.2 Perl extensions that use C++ functions that use statics
+may have problems in that the statics are not getting initialized.
+In newer AIX releases this has been solved by linking Perl with
+the libC_r library, but unfortunately in AIX 4.2 the said library
+has an obscure bug where the various functions related to time
+(such as time() and gettimeofday()) return broken values, and
+therefore in AIX 4.2 Perl is not linked against the libC_r.
 
 =head1 AUTHOR
 
@@ -172,6 +194,6 @@ Structure copied from README.hpux
 
 =head1 DATE
 
-Version 0.0.2: 12 Jul 2001
+Version 0.0.3: 12 Jul 2001
 
 =cut