From 9b80960bbe236a4cdab7e9385f1e487c715fa0b2 Mon Sep 17 00:00:00 2001
From: Eric Eide <eeide@cs.utah.edu>
Date: Fri, 26 May 2017 11:30:55 -0600
Subject: [PATCH] Use `srand48_deterministic` if it is available.

OpenBSD requires a special call to activate the standard, deterministic
behavior of `lrand48'.  Check for the special function and use it if it
is found.  (As far as I know, it is only available on OpenBSD.)

In addition to the principle change above, remove some old,
commented-out calls to `srand48' --- to avoid somebody uncommenting them
in the future and forgetting to call `srnd48_deterministic' instead!
---
 CMakeLists.txt                     |  2 ++
 cmake_config.h.in                  |  3 +++
 config.h.in                        |  3 +++
 configure                          | 15 +++++++++++++++
 configure.ac                       |  5 +++++
 src/AbsRndNumGenerator.cpp         | 10 ++++++++--
 src/DefaultRndNumGenerator.cpp     | 15 ---------------
 src/SimpleDeltaRndNumGenerator.cpp |  2 --
 8 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 48023344d..f83565205 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -77,6 +77,8 @@ check_include_file("sys/types.h"	HAVE_SYS_TYPES_H)
 check_include_file("unistd.h"		HAVE_UNISTD_H)
 
 check_symbol_exists(lrand48 "stdlib.h"	HAVE_LRAND48)
+check_symbol_exists(srand48_deterministic
+			"stdlib.h"	HAVE_SRAND48_DETERMINISTIC)
 
 set(csmith_PACKAGE			"csmith")
 set(csmith_PACKAGE_BUGREPORT		"csmith-bugs@flux.utah.edu")
diff --git a/cmake_config.h.in b/cmake_config.h.in
index b205ed595..3b218ebd4 100755
--- a/cmake_config.h.in
+++ b/cmake_config.h.in
@@ -10,6 +10,9 @@
 /* Define to 1 if you have the <memory.h> header file. */
 #cmakedefine HAVE_MEMORY_H 1
 
+/* Define to 1 if you have the `srand48_deterministic' function. */
+#cmakedefine HAVE_SRAND48_DETERMINISTIC
+
 /* Define to 1 if you have the <stdint.h> header file. */
 #cmakedefine HAVE_STDINT_H 1
 
diff --git a/config.h.in b/config.h.in
index fab02040c..bfbc5fbb2 100644
--- a/config.h.in
+++ b/config.h.in
@@ -12,6 +12,9 @@
 /* Define to 1 if you have the <memory.h> header file. */
 #undef HAVE_MEMORY_H
 
+/* Define to 1 if you have the `srand48_deterministic' function. */
+#undef HAVE_SRAND48_DETERMINISTIC
+
 /* Define to 1 if you have the <stdint.h> header file. */
 #undef HAVE_STDINT_H
 
diff --git a/configure b/configure
index ec58b0c67..cd04f8f72 100755
--- a/configure
+++ b/configure
@@ -15840,6 +15840,21 @@ else
 fi
 
 
+# OpenBSD requires a special call to activate the standard, deterministic
+# behavior of `lrand48'.
+#
+for ac_func in srand48_deterministic
+do :
+  ac_fn_c_check_func "$LINENO" "srand48_deterministic" "ac_cv_func_srand48_deterministic"
+if test "x$ac_cv_func_srand48_deterministic" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_SRAND48_DETERMINISTIC 1
+_ACEOF
+
+fi
+done
+
+
 # If we're using g++, set the default `CXXFLAGS' to something more pedantic.
 #
 if test "$ac_test_CXXFLAGS" = set; then
diff --git a/configure.ac b/configure.ac
index 6459f0705..e6b93c24f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -63,6 +63,11 @@ have_lrand48="no"
 AC_CHECK_FUNCS([lrand48], [have_lrand48="yes"], [have_lrand48="no"])
 AM_CONDITIONAL([HAVE_LRAND48], [test "$have_lrand48" = "yes"])
 
+# OpenBSD requires a special call to activate the standard, deterministic
+# behavior of `lrand48'.
+#
+AC_CHECK_FUNCS([srand48_deterministic])
+
 # If we're using g++, set the default `CXXFLAGS' to something more pedantic.
 #
 if test "$ac_test_CXXFLAGS" = set; then
diff --git a/src/AbsRndNumGenerator.cpp b/src/AbsRndNumGenerator.cpp
index 643bde7ae..68942c2e8 100644
--- a/src/AbsRndNumGenerator.cpp
+++ b/src/AbsRndNumGenerator.cpp
@@ -43,7 +43,7 @@
 
 using namespace std;
 
-#ifdef WIN32
+#ifndef HAVE_LRAND48
 extern "C" {
 	extern void srand48(long seed);
 	extern long lrand48(void);
@@ -94,7 +94,13 @@ AbsRndNumGenerator::make_rndnum_generator(RNDNUM_GENERATOR impl, const unsigned
 void
 AbsRndNumGenerator::seedrand(const unsigned long seed )
 {
-	srand48 (seed);
+#ifdef HAVE_SRAND48_DETERMINISTIC
+	// OpenBSD requires a special call to activate the standard,
+	// deterministic behavior of `lrand48'.
+	srand48_deterministic(seed);
+#else
+	srand48(seed);
+#endif
 }
 
 /*
diff --git a/src/DefaultRndNumGenerator.cpp b/src/DefaultRndNumGenerator.cpp
index 59950d1b7..44816f69d 100644
--- a/src/DefaultRndNumGenerator.cpp
+++ b/src/DefaultRndNumGenerator.cpp
@@ -45,13 +45,6 @@
 #include "CGOptions.h"
 #include "DeltaMonitor.h"
 
-#ifdef WIN32
-extern "C" {
-	extern void srand48(long seed);
-	extern long lrand48(void);
-}
-#endif
-
 DefaultRndNumGenerator *DefaultRndNumGenerator::impl_ = 0;
 
 /*
@@ -181,14 +174,6 @@ DefaultRndNumGenerator::rnd_flipcoin(const unsigned int p, const Filter *f, cons
 	return rv;
 }
 
-#if 0
-void
-DefaultRndNumGenerator::seedrand( unsigned long seed )
-{
-	srand48 (seed);
-}
-#endif
-
 std::string &
 DefaultRndNumGenerator::trace_depth()
 {
diff --git a/src/SimpleDeltaRndNumGenerator.cpp b/src/SimpleDeltaRndNumGenerator.cpp
index 7aaa536d3..6fe3a6eac 100644
--- a/src/SimpleDeltaRndNumGenerator.cpp
+++ b/src/SimpleDeltaRndNumGenerator.cpp
@@ -81,8 +81,6 @@ SimpleDeltaRndNumGenerator::make_rndnum_generator(const unsigned long /*seed*/)
 
 	impl_ = new SimpleDeltaRndNumGenerator(seq);
 
-	//srand48(seed);
-
 	impl_->random_point_ = SimpleDeltaRndNumGenerator::pure_rnd_upto(seq->sequence_length());
 
 	assert(impl_);