Implemented support for Process::GetRandomNumber on Windows.

Patch thanks to Stephan Tolksdorf!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200767 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Support/Process.cpp b/lib/Support/Process.cpp
index d5168f03a6de0686c0b0692b7b84b34c8b01fdb3..1360842753d078e118f3a76ea6ef18054bc9b2eb 100644 (file)
--- a/lib/Support/Process.cpp
+++ b/lib/Support/Process.cpp
@@ -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"
 

diff --git a/lib/Support/Windows/Process.inc b/lib/Support/Windows/Process.inc
index 750097eecf48677e741e255fb8897bf5ea9e2316..16e4092e9faf5b3ab2d5ac9921ba26f780b01dc4 100644 (file)
--- a/lib/Support/Windows/Process.inc
+++ b/lib/Support/Windows/Process.inc
@@ -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;
+}

diff --git a/unittests/Support/ProcessTest.cpp b/unittests/Support/ProcessTest.cpp
index af6a6f921b0dab86a29aa81c2ffc2d0f256da90b..19694e55d067477386083ed08d6ede5a0ce6443a 100644 (file)
--- a/unittests/Support/ProcessTest.cpp
+++ b/unittests/Support/ProcessTest.cpp
@@ -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