[llvm] r200767 - Implemented support for Process::GetRandomNumber on Windows.

[Aaron Ballman]

That doesn't appear to be the case for the MinGW bot Galina had -- it
was also lacking errno_t, so my guess is that it's an age problem. The
new implementation skirts the issue by using the underlying Win32 APIs
to generate the random numbers.

~Aaron

On Tue, Feb 11, 2014 at 1:48 AM, Yaron Keren <yaron.keren at gmail.com> wrote:
> Hi,
>
> Sorry for not catching this thread earlier, MinGW does have rand_s if
> _CRT_RAND_S is defined.
> From stdio.h:
>
> #ifdef _CRT_RAND_S
>   _CRTIMP errno_t __cdecl rand_s(unsigned int *randomValue);
> #endif
>
> libcxx already uses rand_s in random_device and compiles with MinGW, here is
> the discussion:
>
>
> http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20131007/090656.html
>
> Yaron
>
>
>
>
>
> 2014-02-11 5:46 GMT+02:00 Aaron Ballman <aaron at aaronballman.com>:
>>
>> This is hopefully resolved in r201124; I reimplemented the original
>> patch using CryptGenRandom, which is effectively what rand_s() uses
>> internally anyway.
>>
>> ~Aaron
>>
>> On Mon, Feb 10, 2014 at 8:52 PM, Aaron Ballman <aaron at aaronballman.com>
>> wrote:
>> > It appears there is no rand_s() implementation for MinGW 32, so the
>> > question becomes whether we back this change out, or fall back on
>> > rand(). Unfortunately, r185126 is relying on this, and I'm loathe to
>> > start backing out other people's work because of this. So instead, I
>> > will gin up a replacement for MinGW 32 and hopefully Stephan can
>> > either come up with a better fix, or mine will be sufficient for the
>> > task.
>> >
>> > ~Aaron
>> >
>> > On Mon, Feb 10, 2014 at 2:15 PM, Aaron Ballman <aaron at aaronballman.com>
>> > wrote:
>> >> Thank you for pointing this out, Galina and sorry for the difficulties!
>> >>
>> >> Stephan, would you be able to look into this?
>> >>
>> >> ~Aaron
>> >>
>> >> On Mon, Feb 10, 2014 at 2:05 PM, Galina Kistanova
>> >> <gkistanova at gmail.com> wrote:
>> >>> Hi Aaron,
>> >>>
>> >>> Seems this revision broke clang-native-mingw32-win7 builder:
>> >>>
>> >>> http://lab.llvm.org:8011/builders/clang-native-mingw32-win7/builds/5557
>> >>>
>> >>> The last successful build was for revision 200765:
>> >>>
>> >>> http://lab.llvm.org:8011/builders/clang-native-mingw32-win7/builds/5578
>> >>> Please have a look at it.
>> >>>
>> >>> Thanks
>> >>>
>> >>> Galina
>> >>>
>> >>>
>> >>>
>> >>> On Tue, Feb 4, 2014 at 6:49 AM, Aaron Ballman <aaron at aaronballman.com>
>> >>> wrote:
>> >>>>
>> >>>> Author: aaronballman
>> >>>> Date: Tue Feb  4 08:49:21 2014
>> >>>> New Revision: 200767
>> >>>>
>> >>>> URL: http://llvm.org/viewvc/llvm-project?rev=200767&view=rev
>> >>>> Log:
>> >>>> Implemented support for Process::GetRandomNumber on Windows.
>> >>>>
>> >>>> Patch thanks to Stephan Tolksdorf!
>> >>>>
>> >>>> Modified:
>> >>>>     llvm/trunk/lib/Support/Process.cpp
>> >>>>     llvm/trunk/lib/Support/Windows/Process.inc
>> >>>>     llvm/trunk/unittests/Support/ProcessTest.cpp
>> >>>>
>> >>>> Modified: llvm/trunk/lib/Support/Process.cpp
>> >>>> URL:
>> >>>>
>> >>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Process.cpp?rev=200767&r1=200766&r2=200767&view=diff
>> >>>>
>> >>>>
>> >>>> ==============================================================================
>> >>>> --- llvm/trunk/lib/Support/Process.cpp (original)
>> >>>> +++ llvm/trunk/lib/Support/Process.cpp Tue Feb  4 08:49:21 2014
>> >>>> @@ -12,6 +12,11 @@
>> >>>>
>> >>>>
>> >>>> //===----------------------------------------------------------------------===//
>> >>>>
>> >>>>  #include "llvm/Config/config.h"
>> >>>> +#if LLVM_ON_WIN32
>> >>>> +  // This define makes stdlib.h declare the rand_s function.
>> >>>> +#define _CRT_RAND_S
>> >>>> +#include <stdlib.h>
>> >>>> +#endif
>> >>>>  #include "llvm/Support/ErrorHandling.h"
>> >>>>  #include "llvm/Support/Process.h"
>> >>>>
>> >>>>
>> >>>> Modified: llvm/trunk/lib/Support/Windows/Process.inc
>> >>>> URL:
>> >>>>
>> >>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Windows/Process.inc?rev=200767&r1=200766&r2=200767&view=diff
>> >>>>
>> >>>>
>> >>>> ==============================================================================
>> >>>> --- llvm/trunk/lib/Support/Windows/Process.inc (original)
>> >>>> +++ llvm/trunk/lib/Support/Windows/Process.inc Tue Feb  4 08:49:21
>> >>>> 2014
>> >>>> @@ -360,3 +360,10 @@ const char *Process::ResetColor() {
>> >>>>    SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),
>> >>>> defaultColors());
>> >>>>    return 0;
>> >>>>  }
>> >>>> +
>> >>>> +unsigned Process::GetRandomNumber() {
>> >>>> +  unsigned int result;
>> >>>> +  const errno_t ec = rand_s(&result);
>> >>>> +  assert(ec == 0 && "rand_s failed");
>> >>>> +  return result;
>> >>>> +}
>> >>>>
>> >>>> Modified: llvm/trunk/unittests/Support/ProcessTest.cpp
>> >>>> URL:
>> >>>>
>> >>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/ProcessTest.cpp?rev=200767&r1=200766&r2=200767&view=diff
>> >>>>
>> >>>>
>> >>>> ==============================================================================
>> >>>> --- llvm/trunk/unittests/Support/ProcessTest.cpp (original)
>> >>>> +++ llvm/trunk/unittests/Support/ProcessTest.cpp Tue Feb  4 08:49:21
>> >>>> 2014
>> >>>> @@ -39,6 +39,13 @@ TEST(ProcessTest, SelfProcess) {
>> >>>>    EXPECT_GT(TimeValue::MaxTime,
>> >>>> process::get_self()->get_wall_time());
>> >>>>  }
>> >>>>
>> >>>> +TEST(ProcessTest, GetRandomNumberTest) {
>> >>>> +  const unsigned r1 = Process::GetRandomNumber();
>> >>>> +  const unsigned r2 = Process::GetRandomNumber();
>> >>>> +  // It should be extremely unlikely that both r1 and r2 are 0.
>> >>>> +  EXPECT_NE((r1 | r2), 0);
>> >>>> +}
>> >>>> +
>> >>>>  #ifdef _MSC_VER
>> >>>>  #define setenv(name, var, ignore) _putenv_s(name, var)
>> >>>>  #endif
>> >>>>
>> >>>>
>> >>>> _______________________________________________
>> >>>> llvm-commits mailing list
>> >>>> llvm-commits at cs.uiuc.edu
>> >>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>> >>>
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>> Thanks
>> >>>
>> >>> Galina
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
>