[PATCH] D40319: [libcxx] Support getentropy as a source of randomness for std::random_device

[Roland McGrath via Phabricator via cfe-commits]

mcgrathr added inline comments.


================
Comment at: libcxx/trunk/src/random.cpp:29
+#if defined(_LIBCPP_USING_GETENTROPY)
+#include <sys/random.h>
+#elif defined(_LIBCPP_USING_DEV_RANDOM)
----------------
jwakely wrote:
> jwakely wrote:
> > musl only declares `getentropy` in `<unistd.h>` not `<sys/random.h>`. Glibc declares it in both. Should `<unistd.h>` also be included when `_LIBCPP_USING_GETENTROPY` is defined, so it can work more portably?
> I suppose it doesn't really matter, since `_LIBCPP_USING_GETENTROPY` is currently only defined for fuchsia and wasi, which both declare `getentropy` in `<sys/random.h>`.
FWIW, if there is an emerging norm to declare getentropy in <unistd.h> then Fuchsia's libc can add it to our <unistd.h> and there's no real problem relying on that in libc++ sources within about a week of when we land that change in Fuchsia's trunk.



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  rL LLVM

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  https://reviews.llvm.org/D40319/new/

https://reviews.llvm.org/D40319