1 files changed, 28 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac
index 5a09befea2..d25bebeb1a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -227,6 +227,7 @@ if test "x$CXXFLAGS_overridden" = "xno"; then
   AX_CHECK_COMPILE_FLAG([-Wformat],[CXXFLAGS="$CXXFLAGS -Wformat"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wvla],[CXXFLAGS="$CXXFLAGS -Wvla"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wformat-security],[CXXFLAGS="$CXXFLAGS -Wformat-security"],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_COMPILE_FLAG([-Wshadow],[CXXFLAGS="$CXXFLAGS -Wshadow"],,[[$CXXFLAG_WERROR]])
 
   ## Some compilers (gcc) ignore unknown -Wno-* options, but warn about all
   ## unknown options if any other warning is produced. Test the -Wfoo case, and
@@ -574,6 +575,33 @@ AC_LINK_IFELSE([AC_LANG_SOURCE([
   ]
 )
 
+# Check for different ways of gathering OS randomness
+AC_MSG_CHECKING(for Linux getrandom syscall)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <unistd.h>
+  #include <sys/syscall.h>
+  #include <linux/random.h>]],
+ [[ syscall(SYS_getrandom, nullptr, 32, 0); ]])],
+ [ AC_MSG_RESULT(yes); AC_DEFINE(HAVE_SYS_GETRANDOM, 1,[Define this symbol if the Linux getrandom system call is available]) ],
+ [ AC_MSG_RESULT(no)]
+)
+
+AC_MSG_CHECKING(for getentropy)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <unistd.h>]],
+ [[ getentropy(nullptr, 32) ]])],
+ [ AC_MSG_RESULT(yes); AC_DEFINE(HAVE_GETENTROPY, 1,[Define this symbol if the BSD getentropy system call is available]) ],
+ [ AC_MSG_RESULT(no)]
+)
+
+AC_MSG_CHECKING(for sysctl KERN_ARND)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/types.h>
+  #include <sys/sysctl.h>]],
+ [[ static const int name[2] = {CTL_KERN, KERN_ARND};
+    sysctl(name, 2, nullptr, nullptr, nullptr, 0); ]])],
+ [ AC_MSG_RESULT(yes); AC_DEFINE(HAVE_SYSCTL_ARND, 1,[Define this symbol if the BSD sysctl(KERN_ARND) is available]) ],
+ [ AC_MSG_RESULT(no)]
+)
+
+# Check for reduced exports
 if test x$use_reduce_exports = xyes; then
   AX_CHECK_COMPILE_FLAG([-fvisibility=hidden],[RE_CXXFLAGS="-fvisibility=hidden"],
   [AC_MSG_ERROR([Cannot set default symbol visibility. Use --disable-reduce-exports.])])