[libcxx] random_device, use arc4random() on FreeBSD, NetBSD and DragonFlyBSD
Reviewed By: ldionne, emaste, dim
Differential Revision: https://reviews.llvm.org/D122628
NOKEYCHECK=True
GitOrigin-RevId: d13f5023891c92fc79818e02a838f913bf3e452b
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index ddb785b..0445b7b 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -97,6 +97,11 @@
``_LIBCPP_ABI_USE_CXX03_NULLPTR_EMULATION`` will not be honoured anymore and there
will be no way to opt back into the C++03 emulation of ``std::nullptr_t``.
+- On FreeBSD, NetBSD and DragonFlyBSD, ``std::random_device`` is now implemented on top of
+ ``arc4random()`` instead of reading from ``/dev/urandom``. Any implementation-defined
+ token used when constructing a ``std::random_device`` will now be ignored instead of
+ interpreted as a file to read entropy from.
+
Build System Changes
--------------------
diff --git a/include/__config b/include/__config
index 660e98f..050e8c8 100644
--- a/include/__config
+++ b/include/__config
@@ -350,7 +350,8 @@
// Use rand_s(), for use on Windows.
// When this option is used, the token passed to `std::random_device`'s
// constructor *must* be "/dev/urandom" -- anything else is an error.
-#if defined(__OpenBSD__) || defined(__APPLE__)
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || \
+ defined(__OpenBSD__) || defined(__DragonFly__)
# define _LIBCPP_USING_ARC4_RANDOM
#elif defined(__wasi__)
# define _LIBCPP_USING_GETENTROPY