libstdc++: Support getentropy and arc4random in std::random_device

This adds additional "getentropy" and "arc4random" tokens to
std::random_device. The former is supported on Glibc and OpenBSD (and
apparently wasm), and the latter is supported on various BSDs.

libstdc++-v3/ChangeLog:

	* acinclude.m4 (GLIBCXX_CHECK_GETENTROPY, GLIBCXX_CHECK_ARC4RANDOM):
	Define.
	* configure.ac (GLIBCXX_CHECK_GETENTROPY, GLIBCXX_CHECK_ARC4RANDOM):
	Use them.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* src/c++11/random.cc (random_device): Add getentropy and
	arc4random as sources.
	* testsuite/26_numerics/random/random_device/cons/token.cc:
	Check new tokens.
	* testsuite/26_numerics/random/random_device/entropy.cc:
	Likewise.

1 files changed, 103 insertions, 0 deletions

diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index c1aea82..2137103 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -75429,6 +75429,109 @@ $as_echo "#define _GLIBCXX_X86_RDSEED 1" >>confdefs.h
 $as_echo "$ac_cv_x86_rdseed" >&6; }
 
 
+# Check for other random number APIs
+
+
+
+  ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for getentropy" >&5
+$as_echo_n "checking for getentropy... " >&6; }
+  if ${glibcxx_cv_getentropy+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <unistd.h>
+int
+main ()
+{
+unsigned i;
+	 ::getentropy(&i, sizeof(i));
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  glibcxx_cv_getentropy=yes
+else
+  glibcxx_cv_getentropy=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+
+
+  if test $glibcxx_cv_getentropy = yes; then
+
+$as_echo "#define HAVE_GETENTROPY 1" >>confdefs.h
+
+  fi
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_getentropy" >&5
+$as_echo "$glibcxx_cv_getentropy" >&6; }
+  ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
+
+
+  ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for arc4random" >&5
+$as_echo_n "checking for arc4random... " >&6; }
+  if ${glibcxx_cv_arc4random+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdlib.h>
+int
+main ()
+{
+unsigned i = ::arc4random();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  glibcxx_cv_arc4random=yes
+else
+  glibcxx_cv_arc4random=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+
+
+  if test $glibcxx_cv_arc4random = yes; then
+
+$as_echo "#define HAVE_ARC4RANDOM 1" >>confdefs.h
+
+  fi
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_arc4random" >&5
+$as_echo "$glibcxx_cv_arc4random" >&6; }
+  ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
 # This depends on GLIBCXX_ENABLE_SYMVERS and GLIBCXX_IS_NATIVE.
 
   # Do checks for resource limit functions.