intermediate changes

ref:8fcd56b3fe762902848ae3f9eabb01e1aa97432c

1 files changed, 24 insertions, 1 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/src/random.cpp b/contrib/libs/cxxsupp/libcxx/src/random.cpp
index c4bda825fbc..a5ac325bdf0 100644
--- a/contrib/libs/cxxsupp/libcxx/src/random.cpp
+++ b/contrib/libs/cxxsupp/libcxx/src/random.cpp
@@ -36,6 +36,8 @@
 #   endif
 #elif defined(_LIBCPP_USING_NACL_RANDOM)
 #   include <nacl/nacl_random.h>
+#elif defined(_LIBCPP_USING_FUCHSIA_CPRNG)
+#  include <zircon/syscalls.h>
 #endif
 
 
@@ -170,6 +172,27 @@ random_device::operator()()
     return r;
 }
 
+#elif defined(_LIBCPP_USING_FUCHSIA_CPRNG)
+
+random_device::random_device(const string& __token) {
+  if (__token != "/dev/urandom")
+    __throw_system_error(ENOENT, ("random device not supported " + __token).c_str());
+}
+
+random_device::~random_device() {}
+
+unsigned random_device::operator()() {
+  // Implicitly link against the vDSO system call ABI without
+  // requiring the final link to specify -lzircon explicitly when
+  // statically linking libc++.
+#  pragma comment(lib, "zircon")
+
+  // The system call cannot fail.  It returns only when the bits are ready.
+  unsigned r;
+  _zx_cprng_draw(&r, sizeof(r));
+  return r;
+}
+
 #else
 #error "Random device not implemented for this architecture"
 #endif
@@ -189,7 +212,7 @@ random_device::entropy() const noexcept
     return std::numeric_limits<result_type>::digits;
 
   return ent;
-#elif defined(__OpenBSD__)
+#elif defined(__OpenBSD__) || defined(_LIBCPP_USING_FUCHSIA_CPRNG)
   return std::numeric_limits<result_type>::digits;
 #else
     return 0;