Improved seed() generation

Drop support for CLOCK_SGI_CYCLE.

Improved seed() generation.  Improved some comments in seed.c.
Added have_environ.c to build have_environ.h in order to
determine if:

    extern char **environ;	/* user environment */

is an valid external symbol.

.gitignore

@@ -35,6 +35,7 @@ endian_calc.h
 fposval.h
 have_ban_pragma.h
 have_const.h
+have_environ.h
 have_fpos.h
 have_fpos_pos.h
 have_getpgid.h

CHANGES

@@ -3,6 +3,7 @@ The following are the changes from calc version 2.14.0.11 to date:
     Fixed a number of typos.
 
     Drop support for SunOS, IRIX and MINGW32_NT-5.0 targets.
+    Drop support for CLOCK_SGI_CYCLE.
 
     Minor improvement of various help files.  Made format of help
     files more consistent.
@@ -10,6 +11,14 @@ The following are the changes from calc version 2.14.0.11 to date:
     Corrected a few comments in zrandom.c, including a case where
     the comment referred to 1007 when it should have used 2^32.
 
+    Improved seed() generation.  Improved some comments in seed.c.
+    Added have_environ.c to build have_environ.h in order to
+    determine if:
+
+	extern char **environ;	/* user environment */
+
+    is an valid external symbol.
+
 
 The following are the changes from calc version 2.14.0.9 to 2.14.0.10:
 

Makefile.ship

@@ -379,6 +379,19 @@ HAVE_CONST=
 HAVE_UID_T=
 #HAVE_UID_T= -DHAVE_NO_UID_T
 
+# Determine if we have user environment external:
+#
+#	extern char **environ;
+#
+# If HAVE_ENVIRON is empty, this Makefile will run the have_environ program
+# to determine if environ exsuts.  If HAVE_ENVIRON is set to -DHAVE_NO_ENVIRON,
+# then calc will assume there is no external environ symbol.
+#
+# If in doubt, leave HAVE_ENVIRON empty and this Makefile will figure it out.
+#
+HAVE_ENVIRON=
+#HAVE_ENVIRON= -DHAVE_NO_ENVIRON
+
 # Determine if we have memcpy(), memset() and strchr()
 #
 # If HAVE_NEWSTR is empty, this Makefile will run the have_newstr program
@@ -1914,7 +1927,7 @@ BUILD_H_SRC= align32.h args.h calcerr.h conf.h endian_calc.h \
 	have_posscl.h have_rusage.h have_stdlib.h have_strdup.h \
 	have_string.h have_strlcat.h have_strlcpy.h have_times.h \
 	have_uid_t.h have_unistd.h have_unused.h have_urandom.h \
-	have_ustat.h longbits.h terminal.h
+	have_ustat.h longbits.h terminal.h have_environ.h
 
 # we build these .c files during the make
 #
@@ -1927,7 +1940,7 @@ BUILD_C_SRC= calcerr.c
 UTIL_C_SRC= align32.c endian.c longbits.c have_newstr.c have_uid_t.c \
 	have_const.c have_stdvs.c have_varvs.c fposval.c have_fpos.c \
 	have_fpos_pos.c have_offscl.c have_posscl.c have_memmv.c \
-	have_ustat.c have_getsid.c have_getpgid.c \
+	have_ustat.c have_getsid.c have_getpgid.c have_environ.c \
 	have_gettime.c have_getprid.c have_rusage.c have_strdup.c \
 	have_unused.c have_ban_pragma.c have_strlcpy.c have_strlcat.c
 
@@ -1944,7 +1957,7 @@ UTIL_MISC_SRC= calcerr_h.sed calcerr_h.awk calcerr_c.sed calcerr_c.awk \
 UTIL_OBJS= endian.o longbits.o have_newstr.o have_uid_t.o \
 	have_const.o fposval.o have_fpos.o have_fpos_pos.o \
 	try_strarg.o have_stdvs.o have_varvs.o have_posscl.o have_memmv.o \
-	have_ustat.o have_getsid.o have_getpgid.o \
+	have_ustat.o have_getsid.o have_getpgid.o have_environ.o \
 	have_gettime.o have_getprid.o ver_calc.o have_rusage.o have_strdup.o \
 	have_unused.o have_ban_pragma.o have_strlcpy.o have_strlcat.o
 
@@ -1961,7 +1974,7 @@ UTIL_PROGS= align32${EXT} fposval${EXT} have_uid_t${EXT} have_const${EXT} \
 	endian${EXT} longbits${EXT} have_newstr${EXT} have_stdvs${EXT} \
 	have_varvs${EXT} have_ustat${EXT} have_getsid${EXT} \
 	have_getpgid${EXT} have_gettime${EXT} have_getprid${EXT} \
-	ver_calc${EXT} have_strdup${EXT} \
+	ver_calc${EXT} have_strdup${EXT} have_environ{EXT} \
 	have_unused${EXT} have_fpos${EXT} have_fpos_pos${EXT} \
 	have_offscl${EXT} have_rusage${EXT} have_ban_pragma${EXT} \
 	have_strlcpy${EXT} have_strlcat${EXT}
@@ -3248,6 +3261,47 @@ have_uid_t.h: have_uid_t.c have_unistd.h \
 	    ${TRUE}; \
 	fi
 
+have_environ.h: have_environ.c \
+	banned.h have_ban_pragma.h ${MAKE_FILE} ${LOC_MKF}
+	${Q} ${RM} -f have_environ environ_tmp $@
+	${H} echo 'forming $@'
+	${Q} echo '/*' > $@
+	${Q} echo ' * DO NOT EDIT -- generated by the Makefile' >> $@
+	${Q} echo ' */' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '#if !defined(CALC_HAVE_ENVIRON_H)' >> $@
+	${Q} echo '#define CALC_HAVE_ENVIRON_H' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '/* do we have or want environ? */' >> $@
+	${Q} ${RM} -f have_environ.o have_environ${EXT}
+	-${Q} ${LCC} ${ICFLAGS} ${HAVE_ENVIRON} have_environ.c -c ${S} \
+		|| ${TRUE}
+	-${Q} ${LCC} ${ILDFLAGS} have_environ.o -o have_environ${EXT} ${S} \
+		|| ${TRUE}
+	-${Q} ./have_environ${EXT} > environ_tmp ${E} \
+		|| ${TRUE}
+	-${Q} if [ -s environ_tmp ]; then \
+	    ${CAT} environ_tmp >> $@; \
+	else \
+	    echo '#undef HAVE_ENVIRON /* no */' >> $@; \
+	fi
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '#endif /* !CALC_HAVE_ENVIRON_H */' >> $@
+	${Q} ${RM} -f have_environ${EXT} have_environ.o environ_tmp
+	${H} echo '$@ formed'
+	-@if [ -z "${Q}" ]; then \
+	    echo ''; \
+	    echo '=-=-= start of $@ =-=-='; \
+	    ${CAT} $@; \
+	    echo '=-=-= end of $@ =-=-='; \
+	    echo ''; \
+	else \
+	    ${TRUE}; \
+	fi
+
 have_newstr.h: have_newstr.c banned.h have_ban_pragma.h ${MAKE_FILE} ${LOC_MKF}
 	${Q} ${RM} -f newstr_tmp $@
 	${H} echo 'forming $@'
@@ -4425,6 +4479,7 @@ env:
 	@echo 'GREP=${GREP}'; echo ''
 	@echo 'H=${H}'; echo ''
 	@echo 'HAVE_CONST=${HAVE_CONST}'; echo ''
+	@echo 'HAVE_ENVIRON=${HAVE_ENVIRON}'; echo ''
 	@echo 'HAVE_FPOS=${HAVE_FPOS}'; echo ''
 	@echo 'HAVE_FPOS_POS=${HAVE_FPOS_POS}'; echo ''
 	@echo 'HAVE_GETPGID=${HAVE_GETPGID}'; echo ''
@@ -5817,6 +5872,9 @@ have_ban_pragma.o: have_ban_pragma.h
 have_const.o: banned.h
 have_const.o: have_ban_pragma.h
 have_const.o: have_const.c
+have_environ.o: banned.h
+have_environ.o: have_ban_pragma.h
+have_environ.o: have_environ.c
 have_fpos.o: banned.h
 have_fpos.o: have_ban_pragma.h
 have_fpos.o: have_fpos.c
@@ -6456,6 +6514,7 @@ seed.o: decl.h
 seed.o: endian_calc.h
 seed.o: have_ban_pragma.h
 seed.o: have_const.h
+seed.o: have_environ.h
 seed.o: have_getpgid.h
 seed.o: have_getprid.h
 seed.o: have_getsid.h

have_gettime.c

@@ -34,10 +34,9 @@
  * This prog outputs several defines:
  *
  *	HAVE_GETTIME
- *		defined ==> use clock_gettime() for either CLOCK_SGI_CYCLE
+ *		defined ==> use clock_gettime() from CLOCK_REALTIME
- *			    and/or CLOCK_REALTIME
+ *		undefined ==> clock_gettime() is not available from
- *		undefined ==> clock_gettime() is not available for both
+ *			      CLOCK_REALTIME
- *			      CLOCK_SGI_CYCLE and CLOCK_REALTIME
  */
 
 #include <stdio.h>
@@ -56,13 +55,7 @@ main(void)
 
 #else /* HAVE_NO_GETTIME */
 
-# if defined(CLOCK_SGI_CYCLE)
+# if defined(CLOCK_REALTIME)
-
-	struct timespec sgi_cycle;	/* SGI hardware clock */
-	(void) clock_gettime(CLOCK_SGI_CYCLE, &sgi_cycle);
-	printf("#define HAVE_GETTIME /* yes - w/CLOCK_SGI_CYCLE */\n");
-
-# elif defined(CLOCK_REALTIME)
 
 	struct timespec realtime;	/* POSIX realtime clock */
 	(void) clock_gettime(CLOCK_REALTIME, &realtime);
@@ -70,7 +63,7 @@ main(void)
 
 # else
 
-	printf("#undef HAVE_GETTIME /* no - no SGI_CYCLE and no REALTIME */\n");
+	printf("#undef HAVE_GETTIME /* no - no CLOCK_REALTIME */\n");
 
 # endif /* CLOCK_REALTIME */
 

help/seed

@@ -25,8 +25,8 @@ DESCRIPTION
     sequence each time they are run.
 
     The return value of this builtin function should NOT be considered
-    a random or pseudo-random value.  The return value should be used
+    a random or pseudo-random value.  The return value could be used
-    as an argument to a seed function such as srand() or srandom().
+    as an argument to seed functions such as srand() or srandom().
 
 EXAMPLE
     ; print srand(seed())
@@ -44,7 +44,7 @@ LINK LIBRARY
 SEE ALSO
     seed, srand, randbit, isrand, rand, random, srandom, israndom
 
-## Copyright (C) 1999,2018  Landon Curt Noll
+## Copyright (C) 1999,2018,2021  Landon Curt Noll
 ##
 ## Calc is open software; you can redistribute it and/or modify it under
 ## the terms of the version 2.1 of the GNU Lesser General Public License

seed.c

@@ -1,5 +1,5 @@
 /*
- * seed - produce a pseudo-random seeds
+ * seed - produce pseudo-random seeds
  *
  * Copyright (C) 1999-2007,2021  Landon Curt Noll
  *
@@ -90,6 +90,7 @@
 #include "have_urandom.h"
 #include "have_rusage.h"
 #include "have_uid_t.h"
+#include "have_environ.h"
 #if defined(HAVE_USTAT)
 # include <ustat.h>
 #endif
@@ -108,13 +109,25 @@
  */
 #if defined(HAVE_B64)
 typedef USB64 hash64;
+static hash64 prev_hash64 = 0;	/* previous pseudo_seed() return or 0 */
 #else
 struct s_hash64 {
 	USB32 w32[2];
 };
 typedef struct s_hash64 hash64;
+static hash64 prev_hash64 = { 0, 0 };	/* previous pseudo_seed() return or 0 */
 #endif
 
+#if defined(HAVE_ENVIRON)
+extern char **environ;	/* user environment */
+#endif /* HAVE_ENVIRON */
+
+
+/*
+ * call counter - number of times pseudo_seed() as been called
+ */
+static FULL call_count = 0;
+
 
 /*
  * 64-bit initial basis - Based on the 64-bit FNV basis value
@@ -134,16 +147,16 @@ typedef struct s_hash64 hash64;
  * hashed.
  *
  * Yes, even with this non-zero virgin value there is a set of data
- * that will result in a zero hash value.  Worse, appending any
+ * that will result in a zero hash value.  Worse, appending some
- * about of zero bytes will continue to produce a zero hash value.
+ * mount of zero value bytes will continue to produce a zero hash value.
- * But that would happen with any initial value so long as the
+ * But that would happen with any initial value so long as the hash
- * hash of the initial was the `inverse' of the virgin prefix string.
+ * was the hash `inverse' of the virgin prefix string.
  *
  * But then again for any hash function, there exists sets of data
  * which that the hash of every member is the same value.  That is
- * life with many to few mapping functions.  All we do here is to
+ * life with mapping functions.  All we do here is to prevent sets
- * prevent sets whose members consist of 0 or more bytes of 0's from
+ * whose members consist of 0 or more bytes of 0's from being such
- * being such an awkward set.
+ * an awkward set.
  *
  * And yes, someone can figure out what the magic 'inverse' of the
  * 32 ASCII character are ... but this hash function is NOT intended
@@ -161,27 +174,37 @@ typedef struct s_hash64 hash64;
 
 
 /*
- * private_hash64_buf - perform a Fowler/Noll/Vo-1 64 bit hash
+ * initial_private_hash64 - initial basis of Fowler/Noll/Vo-1 64 bit hash
- *
- * input:
- *	buf	- start of buffer to hash
- *	len	- length of buffer in octets
- *	hval	- the hash value to modify
- *
- * returns:
- *	64 bit hash as a static hash64 structure
  */
 S_FUNC hash64
-private_hash64_buf(char *buf, unsigned len)
+initial_private_hash64(void)
 {
 	hash64 hval;		/* current hash value */
-#if !defined(HAVE_B64)
+#if defined(HAVE_B64)
+	hval = PRIVATE_64_BASIS;
+#else /* HAVE_B64 */
 	USB32 val[4];		/* hash value in base 2^16 */
-	USB32 tmp[4];		/* tmp 64 bit value */
-#endif /* HAVE_B64 */
-	char *buf_end = buf+len;	/* beyond end of hash area */
 
-	/*
+	/* hash each octet of the buffer */
+	val[0] = PRIVATE_64_BASIS_0;
+	val[1] = PRIVATE_64_BASIS_1;
+	val[2] = PRIVATE_64_BASIS_2;
+	val[3] = PRIVATE_64_BASIS_3;
+
+	/* convert to hash64 */
+	/* hval.w32[1] = 0xffff&(val[3]<<16)+val[2]; */
+	hval.w32[1] = (val[3]<<16) + val[2];
+	hval.w32[0] = (val[1]<<16) + val[0];
+#endif /* HAVE_B64 */
+
+	/* return our initial hash value */
+	return hval;
+}
+
+
+/*
+ * private_hash64_buf - perform a Fowler/Noll/Vo-1 64 bit hash
+ *
  * FNV-1 - Fowler/Noll/Vo-1 64 bit hash
  *
  * The basis of this hash algorithm was taken from an idea sent
@@ -210,10 +233,28 @@ private_hash64_buf(char *buf, unsigned len)
  *	 FNV-1a hash function.  The use of FNV-1 is kept
  *	 for backwards compatibility purposes and because
  *	 the use of FNV-1 in this special purpose, suffices.
+ *
+ * input:
+ *	buf	- start of buffer to hash
+ *	len	- length of buffer in octets
+ *	hval	- the hash value to modify
+ *
+ * returns:
+ *	64 bit hash as a static hash64 structure
  */
+S_FUNC hash64
+private_hash64_buf(hash64 hval, char *buf, unsigned len)
+{
+#if !defined(HAVE_B64)
+	USB32 val[4];		/* hash value in base 2^16 */
+	USB32 tmp[4];		/* tmp 64 bit value */
+#endif /* HAVE_B64 */
+	char *buf_end = buf+len;	/* beyond end of hash area */
+
 #if defined(HAVE_B64)
+
 	/* hash each octet of the buffer */
-	for (hval = PRIVATE_64_BASIS; buf < buf_end; ++buf) {
+	for (; buf < buf_end; ++buf) {
 
 	    /* multiply by 1099511628211ULL mod 2^64 using 64 bit longs */
 	    hval *= (hash64)1099511628211ULL;
@@ -224,11 +265,12 @@ private_hash64_buf(char *buf, unsigned len)
 
 #else /* HAVE_B64 */
 
-	/* hash each octet of the buffer */
+	/* load val array from hval argument */
-	val[0] = PRIVATE_64_BASIS_0;
+	val[0] = hval.w32[0] & 0xffff;
-	val[1] = PRIVATE_64_BASIS_1;
+	val[1] = (hval.w32[0]>>16) & 0xffff;
-	val[2] = PRIVATE_64_BASIS_2;
+	val[2] = hval.w32[1] & 0xffff;
-	val[3] = PRIVATE_64_BASIS_3;
+	val[3] = (hval.w32[1]>>16) & 0xffff;
+
 	for (; buf < buf_end; ++buf) {
 
 	    /*
@@ -241,7 +283,7 @@ private_hash64_buf(char *buf, unsigned len)
 	    /* multiply by the lowest order digit base 2^16 */
 	    tmp[0] = val[0] * 0x1b3;
 	    tmp[1] = val[1] * 0x1b3;
-	    tmp[2] = val[2] * 0x1b3;
+	    tmp[1] = val[2] * 0x1b3;
 	    tmp[3] = val[3] * 0x1b3;
 	    /* multiply by the other non-zero digit */
 	    tmp[2] += val[0] << 8;		/* tmp[2] += val[0] * 0x100 */
@@ -299,9 +341,6 @@ pseudo_seed(void)
 {
     struct {			/* data used for quasi-random seed */
 #if defined(HAVE_GETTIME)
-# if defined(CLOCK_SGI_CYCLE)
-	struct timespec sgi_cycle;	/* SGI hardware clock */
-# endif
 # if defined(CLOCK_REALTIME)
 	struct timespec realtime;	/* POSIX realtime clock */
 # endif
@@ -359,25 +398,36 @@ pseudo_seed(void)
 #endif
 	time_t time;			/* local time */
 	size_t size;			/* size of this data structure */
+	hash64 prev_hash64_copy;	/* copy if the previous hash value */
+	FULL call_count_copy;		/* count pf this funcation was called */
 	jmp_buf env;			/* setjmp() context */
+#if defined(HAVE_ENVIRON)
+	char **environ_copy;		/* copy of extern char **environ */
+#endif /* HAVE_ENVIRON */
 	char *sdata_p;			/* address of this structure */
     } sdata;
     hash64 hash_val;			/* fnv64 hash of sdata */
     ZVALUE hash;			/* hash_val as a ZVALUE */
     NUMBER *ret;			/* return seed as a NUMBER */
+#if defined(HAVE_ENVIRON)
+    int i;
+    size_t envlen;			/* length of an environment variable */
+#endif
+
+    /*
+     * initialize the Fowler/Noll/Vo-1 64 bit hash
+     */
+    hash_val = initial_private_hash64();
 
     /*
      * pick up process/system information
      *
      * NOTE:
-     *	  We do care (that much) if these calls fail.  We do not
+     *	  We do NOT care (that much) if these calls fail.  We do not
      *	  need to process any data in the 'sdata' structure.
      */
     memset(&sdata, 0, sizeof(sdata));
 #if defined(HAVE_GETTIME)
-# if defined(CLOCK_SGI_CYCLE)
-    (void) clock_gettime(CLOCK_SGI_CYCLE, &sdata.sgi_cycle);
-# endif
 # if defined(CLOCK_REALTIME)
     (void) clock_gettime(CLOCK_REALTIME, &sdata.realtime);
 # endif
@@ -441,13 +491,34 @@ pseudo_seed(void)
 #endif
     sdata.time = time(NULL);
     sdata.size = sizeof(sdata);
+    sdata.prev_hash64_copy = prev_hash64;
+    sdata.call_count_copy = ++call_count;
     (void) setjmp(sdata.env);
+#if defined(HAVE_ENVIRON)
+    sdata.environ_copy = environ;
+#endif /* HAVE_ENVIRON */
     sdata.sdata_p = (char *)&sdata;
 
     /*
      * seed the generator with the above data
      */
-    hash_val = private_hash64_buf((char *)&sdata, sizeof(sdata));
+    hash_val = private_hash64_buf(hash_val, (char *)&sdata, sizeof(sdata));
+
+#if defined(HAVE_ENVIRON)
+    /*
+     * seed each envinment variable
+     */
+    for (i=0; environ[i] != NULL; ++i) {
+
+	/* obtain length of this next environment variable string */
+	envlen = strlen(environ[i]);
+
+	/* hash any non-zero length environment variable string */
+	if (envlen > 0) {
+	    hash_val = private_hash64_buf(hash_val, environ[i], envlen);
+	}
+    }
+#endif /* HAVE_ENVIRON */
 
     /*
      * load the hash data into the ZVALUE
@@ -461,6 +532,11 @@ pseudo_seed(void)
     memcpy((void *)hash.v, (void *)&hash_val, hash.len*sizeof(HALF));
     ztrim(&hash);
 
+    /*
+     * save hash value for next call
+     */
+    prev_hash64 = hash_val;
+
     /*
      * return a number
      */

win32.mkdef

@@ -32,6 +32,7 @@ HAVE_SYS_TIMES_H=NO
 HAVE_TIME_H=YES
 HAVE_SYS_TIME_H=NO
 HAVE_UNISTD_H=NO
+HAVE_ENVIRON=-DHAVE_NO_ENVIRON
 
 BINDIR=/usr/bin/calc
 LIBDIR=/lib/calc