Further eliminate POSIX-emulation under LinuxThreads

[perl5.git] / hints / README.hints

diff --git a/hints/README.hints b/hints/README.hints
index 1d0f35c..af31dd9 100644 (file)
--- a/hints/README.hints
+++ b/hints/README.hints
@@ -1,6 +1,6 @@
 =head1 NAME
 
-README.hints
+README.hints - hint files used by Configure
 
 =head1 DESCRIPTION
 
@@ -297,7 +297,18 @@ be circumvented by the use of "call-back units".  That is, the hints
 file can tuck this information away into a file UU/cc.cbu.  Then,
 after Configure prompts the user for the C compiler, it will load in
 and run the UU/cc.cbu "call-back" unit.  See hints/solaris_2.sh for an
-example.
+example. Some callbacks exist for other variables than cc, such as for
+uselongdouble. At the present time, these callbacks are only called if the
+variable in question is defined; however, this may change, so the scheme in
+hints/solaris_2.sh of checking to see if uselongdouble is defined is a good
+idea.
+
+=item Call status
+
+Call-backs are only called always, even if the value for the call-back is
+uset: UU/usethreads.cbu is called when Configure is about to deal with
+threads. All created call-backs from hints should thus check the status
+of the variable, and act upon it.
 
 =item Future status