From: Andy Dougherty <doughera@lafayette.edu>
Date: Wed, 15 Jul 1998 14:23:39 +0000 (-0400)
Subject: Re: Configure s?rand support [PATCH 5.004_75] -- better patch
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=56cb0a1cdc8ec02cd8a47636454b897d7f8bb403;p=p5sagit%2Fp5-mst-13.2.git

Re: Configure s?rand support [PATCH 5.004_75] -- better patch

	Message-Id: <Pine.SUN.3.96.980715135257.1310F-100000@newton.phys>

p4raw-id: //depot/perl@1551
---

diff --git a/INSTALL b/INSTALL
index aadf2c7..fe78b1b 100644
--- a/INSTALL
+++ b/INSTALL
@@ -773,14 +773,18 @@ config.sh.
 
 For example, you can replace the rand() and srand() functions in the
 perl source by any other random number generator by a trick such as the
-following:
+following (this should all be on one line):
 
-	sh Configure -Dccflags='-Drand=random -Dsrand=srandom'
+	sh Configure -Dccflags='-Dmy_rand=random -Dmy_srand=srandom' \
+		-Drandbits=31
 
-or by adding -Drand=random and -Dsrand=srandom to your ccflags
-at the appropriate Configure prompt.  (Note:  Although this worked for
-me, it might not work for you if your system's header files give
-different prototypes for rand() and random() or srand() and srandom().)
+or you can use the drand48 family of functions with
+
+	sh Configure -Dccflags='-Dmy_rand=lrand48 -Dmy_srand=srand48' \
+		-Drandbits=31
+
+or by adding the -D flags to your ccflags at the appropriate Configure
+prompt.  (Read pp.c to see how this works.)
 
 You should also run Configure interactively to verify that a hint file
 doesn't inadvertently override your ccflags setting.  (Hints files
@@ -1573,4 +1577,4 @@ the contact information to match your distribution.
 
 =head1 LAST MODIFIED
 
-$Id: INSTALL,v 1.40 1998/07/06 14:49:02 doughera Released $
+$Id: INSTALL,v 1.42 1998/07/15 18:04:44 doughera Released $
diff --git a/pp.c b/pp.c
index 8625a39..ff37a9f 100644
--- a/pp.c
+++ b/pp.c
@@ -1550,6 +1550,19 @@ PP(pp_cos)
     }
 }
 
+/* Support Configure command-line overrides for rand() functions.
+   After 5.005, perhaps we should replace this by Configure support
+   for drand48(), random(), or rand().  For 5.005, though, maintain
+   compatibility by calling rand() but allow the user to override it.
+   See INSTALL for details.  --Andy Dougherty  15 July 1998
+*/
+#ifndef my_rand
+#  define my_rand	rand
+#endif
+#ifndef my_srand
+#  define my_srand	srand
+#endif
+
 PP(pp_rand)
 {
     djSP; dTARGET;
@@ -1561,19 +1574,19 @@ PP(pp_rand)
     if (value == 0.0)
 	value = 1.0;
     if (!srand_called) {
-	(void)srand((unsigned)seed());
+	(void)my_srand((unsigned)seed());
 	srand_called = TRUE;
     }
 #if RANDBITS == 31
-    value = rand() * value / 2147483648.0;
+    value = my_rand() * value / 2147483648.0;
 #else
 #if RANDBITS == 16
-    value = rand() * value / 65536.0;
+    value = my_rand() * value / 65536.0;
 #else
 #if RANDBITS == 15
-    value = rand() * value / 32768.0;
+    value = my_rand() * value / 32768.0;
 #else
-    value = rand() * value / (double)(((unsigned long)1) << RANDBITS);
+    value = my_rand() * value / (double)(((unsigned long)1) << RANDBITS);
 #endif
 #endif
 #endif
@@ -1589,7 +1602,7 @@ PP(pp_srand)
 	anum = seed();
     else
 	anum = POPu;
-    (void)srand((unsigned)anum);
+    (void)my_srand((unsigned)anum);
     srand_called = TRUE;
     EXTEND(SP, 1);
     RETPUSHYES;