Move 3 porting sanity tests from t/lib/ to t/porting/, a more natural home.

[perl5.git] / INSTALL

diff --git a/INSTALL b/INSTALL
index d2f072f..95c2145 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -772,6 +772,21 @@ simply do:
 
 =back
 
+=head2 Relocatable @INC
+
+To create a relocatable perl tree, use the following command line:
+
+    sh Configure -Duserelocatableinc
+
+Then the paths in @INC (and everything else in %Config) can be
+optionally located via the path of the perl executable.
+
+That means that, if the string ".../" is found at the start of any
+path, it's substituted with the directory of $^X. So, the relocation
+can be configured on a per-directory basis, although the default with
+"-Duserelocatableinc" is that everything is relocated. The initial
+install is done to the original configured prefix.
+
 =head2 Site-wide Policy settings
 
 After Configure runs, it stores a number of common site-wide "policy"
@@ -890,6 +905,22 @@ Removes -g from optimize, and -DDEBUGGING from ccflags.
 If you are using a shared libperl, see the warnings about multiple
 versions of perl under L<Building a shared Perl library>.
 
+Note that a perl built with -DDEBUGGING will be bigger and will run more
+slowly than a standard perl.
+
+=head2 DTrace support
+
+On platforms where DTrace is available, it may be enabled by 
+using the -Dusedtrace option to Configure. DTrace probes are available for
+subroutine entry (sub-entry) and subroutine exit (sub-exit). Here's a
+simple D script that uses them:
+
+  perl$target:::sub-entry, perl$target:::sub-return {
+    printf("%s %s (%s:%d)\n", probename == "sub-entry" ? "->" : "<-",
+              copyinstr(arg0), copyinstr(arg1), arg2);
+  }
+
+
 =head2 Extensions
 
 Perl ships with a number of standard extensions.  These are contained
@@ -1370,6 +1401,18 @@ The latter is especially useful if you see something like this
 
 at Perl startup.
 
+=item other environment variables
+
+Configure does not check for environment variables that can sometimes
+have a major influence on how perl is built or tested. For example,
+OBJECT_MODE on AIX determines the way the compiler and linker deal with
+their objects, but this is a variable that only influences build-time
+behaviour, and should not affect the perl scripts that are eventually
+executed by the perl binary. Other variables, like PERL_UNICODE,
+PERL5LIB, and PERL5OPT will influence the behaviour of the test suite.
+So if you are getting strange test failures, you may want to try
+retesting with the various PERL variables unset.
+
 =item varargs
 
 If you get varargs problems with gcc, be sure that gcc is installed