avoid literal 'undef' in $lddlflags under `Configure -Uoptimize`

[p5sagit/p5-mst-13.2.git] / INSTALL

diff --git a/INSTALL b/INSTALL
index fe47668..fc2890d 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -26,6 +26,13 @@ For information on what's new in this release, see the
 pod/perldelta.pod file.  For more detailed information about specific
 changes, see the Changes file.
 
+IMPORTANT NOTE:  5.005_53 and later releases do not export unadorned
+global symbols anymore.  This means most CPAN modules probably won't
+build under this release without adding '-DPERL_POLLUTE' to ccflags
+in config.sh.  This is not the default because we want the modules
+to get fixed *before* the 5.006 release.  pod/perldelta.pod contains
+additional notes about this.
+
 =head1 DESCRIPTION
 
 This document is written in pod format as an easy way to indicate its
@@ -62,7 +69,8 @@ The standard extensions supplied with Perl will be handled automatically.
 
 In a related issue, old extensions may possibly be affected by the
 changes in the Perl language in the current release.  Please see
-pod/perldelta.pod for a description of what's changed.
+pod/perldelta.pod (and pod/perl500Xdelta.pod) for a description of
+what's changed.
 
 =head1 WARNING:  This version requires a compiler that supports ANSI C.
 
@@ -184,6 +192,9 @@ put (symlinks to) perl and its accompanying utilities, such as perldoc,
 into a directory typically found along a user's PATH, or in another
 obvious and convenient place.
 
+You can use "Configure -Uinstallusrbinperl" which causes installperl
+to skip installing perl also as /usr/bin/perl.
+
 By default, Configure will compile perl to use dynamic loading if
 your system supports it.  If you want to force perl to be compiled
 statically, you can either choose this when Configure prompts you or
@@ -538,8 +549,9 @@ some of the main things you can change.
 
 =head2 Threads
 
-On some platforms, perl5.005 can be compiled to use threads.  To
-enable this, read the file README.threads, and then try
+On some platforms, perl5.005 can be compiled with experimental support
+for threads.  To enable this, read the file README.threads, and then
+try:
 
        sh Configure -Dusethreads
 
@@ -736,6 +748,11 @@ To build without perl's malloc, you can use the Configure command
 
 or you can answer 'n' at the appropriate interactive Configure prompt.
 
+Note that Perl's malloc family of functions are called Perl_malloc(),
+Perl_realloc(), Perl_calloc() and Perl_mfree().  The names do not clash
+with the system versions of these functions.  See -DPERL_POLLUTE_MALLOC
+below if you want to do that for some reason.
+
 =head2 Malloc Performance Flags
 
 If you are using Perl's malloc, you may add one or more of the following
@@ -756,6 +773,18 @@ in Perl 5.004.
 Undefined by default.  Defining it in addition to NO_FANCY_MALLOC returns
 malloc to the version used in Perl version 5.000.
 
+=item -DPERL_POLLUTE_MALLOC
+
+Undefined by default.  This is used to force Perl's malloc family of functions
+to have the same names as the system versions.  This is normally only required
+when you have a need to replace the system versions of these functions.
+This may be sometimes required when you have libraries that like to free()
+data that may have been allocated by Perl_malloc() and vice versa.
+
+Note that enabling this option may sometimes lead to duplicate symbols from
+the linker for malloc et al.  In such cases, the system probably does not
+allow its malloc functions to be fully replaced with custom versions.
+
 =back
 
 =head2 Building a debugging perl
@@ -804,6 +833,13 @@ shouldn't do that, but some might.)
 
 =over 4
 
+=item Environment variable clashes
+
+Configure uses a CONFIG variable that is reported to cause trouble on
+ReliantUnix 5.44.  If your system sets this variable, you can try
+unsetting it before you run Configure.  Configure should eventually
+be fixed to avoid polluting the namespace of the environment.
+
 =item Running Configure Interactively
 
 If Configure runs into trouble, remember that you can always run
@@ -1000,11 +1036,6 @@ The latter is especially useful if you see something like this
 
 at Perl startup.
 
-=item malloc duplicates
-
-If you get duplicates upon linking for malloc et al, add -DEMBEDMYMALLOC
-to your ccflags variable in config.sh.
-
 =item varargs
 
 If you get varargs problems with gcc, be sure that gcc is installed