Add erand48() to the set of functions supported by our src/port/ library,

and extend configure to test for it properly instead of hard-wiring
an assumption that everybody but Windows has the rand48 functions.
(We do cheat to the extent of assuming that probing for erand48 will do
for the entire rand48 family.)

erand48() is unused as of this commit, but a followon patch will cause
GEQO to depend on it.

Andres Freund, additional hacking by Tom

6 files changed, 45 insertions, 27 deletions

diff --git a/configure b/configure
index 3e8d074f8d..5790a3219c 100755
--- a/configure
+++ b/configure
@@ -18594,7 +18594,8 @@ LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
 
 
 
-for ac_func in crypt getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul
+
+for ac_func in crypt erand48 getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul
 do
 as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 { $as_echo "$as_me:$LINENO: checking for $ac_func" >&5
@@ -19208,12 +19209,6 @@ case " $LIBOBJS " in
 esac
 
 case " $LIBOBJS " in
-  *" rand.$ac_objext "* ) ;;
-  *) LIBOBJS="$LIBOBJS rand.$ac_objext"
- ;;
-esac
-
-case " $LIBOBJS " in
   *" win32env.$ac_objext "* ) ;;
   *) LIBOBJS="$LIBOBJS win32env.$ac_objext"
  ;;
diff --git a/configure.in b/configure.in
index 4e523899f1..3d51c70913 100644
--- a/configure.in
+++ b/configure.in
@@ -1249,7 +1249,7 @@ fi
 pgac_save_LIBS="$LIBS"
 LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
 
-AC_REPLACE_FUNCS([crypt getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul])
+AC_REPLACE_FUNCS([crypt erand48 getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul])
 
 case $host_os in
 
@@ -1294,7 +1294,6 @@ if test "$PORTNAME" = "win32"; then
 AC_REPLACE_FUNCS(gettimeofday)
 AC_LIBOBJ(kill)
 AC_LIBOBJ(open)
-AC_LIBOBJ(rand)
 AC_LIBOBJ(win32env)
 AC_LIBOBJ(win32error)
 AC_DEFINE([HAVE_SYMLINK], 1,
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 39ca31225f..ba807f4275 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -137,6 +137,9 @@
 /* Define to 1 if you have the <editline/readline.h> header file. */
 #undef HAVE_EDITLINE_READLINE_H
 
+/* Define to 1 if you have the `erand48' function. */
+#undef HAVE_ERAND48
+
 /* Define to 1 if you have the `ERR_set_mark' function. */
 #undef HAVE_ERR_SET_MARK
 
diff --git a/src/include/port.h b/src/include/port.h
index cbf9dcf99e..1b9e0e0123 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -316,10 +316,6 @@ extern FILE *pgwin32_fopen(const char *, const char *);
 #define popen(a,b) _popen(a,b)
 #define pclose(a) _pclose(a)
 
-/* Missing rand functions */
-extern long lrand48(void);
-extern void srand48(long seed);
-
 /* New versions of MingW have gettimeofday, old mingw and msvc don't */
 #ifndef HAVE_GETTIMEOFDAY
 /* Last parameter not used */
@@ -351,6 +347,13 @@ extern off_t ftello(FILE *stream);
 #endif
 #endif
 
+#ifndef HAVE_ERAND48
+/* we assume all of these are present or missing together */
+extern double erand48(unsigned short xseed[3]);
+extern long lrand48(void);
+extern void srand48(long seed);
+#endif
+
 #ifndef HAVE_FSEEKO
 #define fseeko(a, b, c) fseek(a, b, c)
 #define ftello(a)		ftell(a)
diff --git a/src/port/rand.c b/src/port/erand48.c
index 6c14a6438a..3f40d54d21 100644
--- a/src/port/rand.c
+++ b/src/port/erand48.c
@@ -1,16 +1,13 @@
-/*
- * $PostgreSQL$
+/*-------------------------------------------------------------------------
  *
- *-------------------------------------------------------------------------
+ * erand48.c
+ *
+ * This file supplies versions of erand48(), lrand48(), and srand48()
+ * for machines that lack them.  (These are all the members of the drand48
+ * family that Postgres currently requires.  We name the file after erand48
+ * because that is the one that configure tests for.)
  *
- * rand.c
- *	  Missing rand implementations for Win32
  *
- *-------------------------------------------------------------------------
- */
-#include "c.h"
-
-/*
  * Copyright (c) 1993 Martin Birgmeier
  * All rights reserved.
  *
@@ -21,7 +18,17 @@
  * This software is provided ``as is'', and comes with no warranties
  * of any kind. I shall in no event be liable for anything that happens
  * to anyone/anything when using this software.
+ *
+ * IDENTIFICATION
+ *	  $PostgreSQL$
+ *
+ *-------------------------------------------------------------------------
  */
+
+#include "c.h"
+
+#include <math.h>
+
 #define RAND48_SEED_0	(0x330e)
 #define RAND48_SEED_1	(0xabcd)
 #define RAND48_SEED_2	(0x1234)
@@ -30,17 +37,18 @@
 #define RAND48_MULT_2	(0x0005)
 #define RAND48_ADD		(0x000b)
 
-unsigned short _rand48_seed[3] = {
+static unsigned short _rand48_seed[3] = {
 	RAND48_SEED_0,
 	RAND48_SEED_1,
 	RAND48_SEED_2
 };
-unsigned short _rand48_mult[3] = {
+static unsigned short _rand48_mult[3] = {
 	RAND48_MULT_0,
 	RAND48_MULT_1,
 	RAND48_MULT_2
 };
-unsigned short _rand48_add = RAND48_ADD;
+static unsigned short _rand48_add = RAND48_ADD;
+
 
 static void
 _dorand48(unsigned short xseed[3])
@@ -62,6 +70,16 @@ _dorand48(unsigned short xseed[3])
 	xseed[2] = (unsigned short) accu;
 }
 
+
+double
+erand48(unsigned short xseed[3])
+{
+	_dorand48(xseed);
+	return ldexp((double) xseed[0], -48) +
+		ldexp((double) xseed[1], -32) +
+		ldexp((double) xseed[2], -16);
+}
+
 long
 lrand48(void)
 {
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 66b7f6a928..c4b9ed5462 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -44,7 +44,7 @@ sub mkvcbuild
 
     our @pgportfiles = qw(
       chklocale.c crypt.c fseeko.c getrusage.c inet_aton.c random.c srandom.c
-      getaddrinfo.c gettimeofday.c kill.c open.c rand.c
+      getaddrinfo.c gettimeofday.c kill.c open.c erand48.c
       snprintf.c strlcat.c strlcpy.c copydir.c dirmod.c exec.c noblock.c path.c pipe.c
       pgsleep.c pgstrcasecmp.c qsort.c qsort_arg.c sprompt.c thread.c
       getopt.c getopt_long.c dirent.c rint.c win32env.c win32error.c);