Bash-5.3-alpha release

lib/sh/random.c

@@ -1,6 +1,6 @@
 /* random.c -- Functions for managing 16-bit and 32-bit random numbers. */
 
-/* Copyright (C) 2020 Free Software Foundation, Inc.
+/* Copyright (C) 2020,2022,2023 Free Software Foundation, Inc.
 
    This file is part of GNU Bash, the Bourne Again SHell.
 
@@ -40,31 +40,32 @@ extern time_t shell_start_time;
 
 extern int last_random_value;
 
-static u_bits32_t intrand32 PARAMS((u_bits32_t));
-static u_bits32_t genseed PARAMS((void));
+static u_bits32_t intrand32 (u_bits32_t);
+static u_bits32_t genseed (void);
 
-static u_bits32_t brand32 PARAMS((void));
-static void sbrand32 PARAMS((u_bits32_t));
-static void perturb_rand32 PARAMS((void));
+static u_bits32_t brand32 (void);
+static void sbrand32 (u_bits32_t);
+static void perturb_rand32 (void);
 
 /* The random number seed.  You can change this by setting RANDOM. */
 static u_bits32_t rseed = 1;
 
 /* Returns a 32-bit pseudo-random number. */
 static u_bits32_t
-intrand32 (last)
-     u_bits32_t last;
+intrand32 (u_bits32_t last)
 {
   /* Minimal Standard generator from
      "Random number generators: good ones are hard to find",
      Park and Miller, Communications of the ACM, vol. 31, no. 10,
      October 1988, p. 1195. Filtered through FreeBSD.
 
-     x(n+1) = 16807 * x(n) mod (m).
+     x(n+1) = 16807 * x(n) mod (m)
+
+     where 16807 == 7^5.
 
      We split up the calculations to avoid overflow.
 
-     h = last / q; l = x - h * q; t = a * l - h * r
+     h = last / q; l = last % q; t = a * l - h * r
      m = 2147483647, a = 16807, q = 127773, r = 2836
 
      There are lots of other combinations of constants to use; look at
@@ -76,7 +77,7 @@ intrand32 (last)
   /* Can't seed with 0. */
   ret = (last == 0) ? 123459876 : last;
   h = ret / 127773;
-  l = ret - (127773 * h);
+  l = ret % 127773;
   t = 16807 * l - 2836 * h;
   ret = (t < 0) ? t + 0x7fffffff : t;
 
@@ -84,13 +85,13 @@ intrand32 (last)
 }
 
 static u_bits32_t
-genseed ()
+genseed (void)
 {
   struct timeval tv;
   u_bits32_t iv;
 
   gettimeofday (&tv, NULL);
-  iv = (u_bits32_t)seedrand;		/* let the compiler truncate */
+  iv = (uintptr_t)seedrand;		/* let the compiler truncate */
   iv = tv.tv_sec ^ tv.tv_usec ^ getpid () ^ getppid () ^ current_user.uid ^ iv;
   return (iv);
 }
@@ -99,7 +100,7 @@ genseed ()
 
 /* Returns a pseudo-random number between 0 and 32767. */
 int
-brand ()
+brand (void)
 {
   unsigned int ret;
 
@@ -113,15 +114,14 @@ brand ()
 
 /* Set the random number generator seed to SEED. */
 void
-sbrand (seed)
-     unsigned long seed;
+sbrand (unsigned long seed)
 {
   rseed = seed;
   last_random_value = 0;
 }
 
 void
-seedrand ()
+seedrand (void)
 {
   u_bits32_t iv;
 
@@ -138,7 +138,7 @@ static int urandfd = -1;
 
 /* Returns a 32-bit pseudo-random number between 0 and 4294967295. */
 static u_bits32_t
-brand32 ()
+brand32 (void)
 {
   u_bits32_t ret;
 
@@ -147,14 +147,13 @@ brand32 ()
 }
 
 static void
-sbrand32 (seed)
-     u_bits32_t seed;
+sbrand32 (u_bits32_t seed)
 {
   last_rand32 = rseed32 = seed;
 }
 
 void
-seedrand32 ()
+seedrand32 (void)
 {
   u_bits32_t iv;
 
@@ -163,14 +162,14 @@ seedrand32 ()
 }
 
 static void
-perturb_rand32 ()
+perturb_rand32 (void)
 {
   rseed32 ^= genseed ();
 }
 
 /* Force another attempt to open /dev/urandom on the next call to get_urandom32 */
 void
-urandom_close ()
+urandom_close (void)
 {
   if (urandfd >= 0)
     close (urandfd);
@@ -185,10 +184,7 @@ urandom_close ()
 #endif
 
 static ssize_t
-getrandom (buf, len, flags)
-     void *buf;
-     size_t len;
-     unsigned int flags;
+getrandom (void *buf, size_t len, unsigned int flags)
 {
   int oflags;
   ssize_t r;
@@ -220,7 +216,7 @@ getrandom (buf, len, flags)
 #endif
       
 u_bits32_t
-get_urandom32 ()
+get_urandom32 (void)
 {
   u_bits32_t ret;