1 files changed, 160 insertions, 0 deletions
diff --git a/unittests/ADT/StatisticTest.cpp b/unittests/ADT/StatisticTest.cpp
new file mode 100644
index 000000000000..17a5c7fc204a
--- /dev/null
+++ b/unittests/ADT/StatisticTest.cpp
@@ -0,0 +1,160 @@
+//===- llvm/unittest/ADT/StatisticTest.cpp - Statistic unit tests ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/raw_ostream.h"
+#include "gtest/gtest.h"
+using namespace llvm;
+
+using OptionalStatistic = Optional<std::pair<StringRef, unsigned>>;
+
+namespace {
+#define DEBUG_TYPE "unittest"
+STATISTIC(Counter, "Counts things");
+STATISTIC(Counter2, "Counts other things");
+
+#if LLVM_ENABLE_STATS
+static void
+extractCounters(const std::vector<std::pair<StringRef, unsigned>> &Range,
+                OptionalStatistic &S1, OptionalStatistic &S2) {
+  for (const auto &S : Range) {
+    if (S.first == "Counter")
+      S1 = S;
+    if (S.first == "Counter2")
+      S2 = S;
+  }
+}
+#endif
+
+TEST(StatisticTest, Count) {
+  EnableStatistics();
+
+  Counter = 0;
+  EXPECT_EQ(Counter, 0u);
+  Counter++;
+  Counter++;
+#if LLVM_ENABLE_STATS
+  EXPECT_EQ(Counter, 2u);
+#else
+  EXPECT_EQ(Counter, 0u);
+#endif
+}
+
+TEST(StatisticTest, Assign) {
+  EnableStatistics();
+
+  Counter = 2;
+#if LLVM_ENABLE_STATS
+  EXPECT_EQ(Counter, 2u);
+#else
+  EXPECT_EQ(Counter, 0u);
+#endif
+}
+
+TEST(StatisticTest, API) {
+  EnableStatistics();
+
+  Counter = 0;
+  EXPECT_EQ(Counter, 0u);
+  Counter++;
+  Counter++;
+#if LLVM_ENABLE_STATS
+  EXPECT_EQ(Counter, 2u);
+#else
+  EXPECT_EQ(Counter, 0u);
+#endif
+
+#if LLVM_ENABLE_STATS
+  {
+    const auto Range1 = GetStatistics();
+    EXPECT_NE(Range1.begin(), Range1.end());
+    EXPECT_EQ(Range1.begin() + 1, Range1.end());
+
+    OptionalStatistic S1;
+    OptionalStatistic S2;
+    extractCounters(Range1, S1, S2);
+
+    EXPECT_EQ(S1.hasValue(), true);
+    EXPECT_EQ(S2.hasValue(), false);
+  }
+
+  // Counter2 will be registered when it's first touched.
+  Counter2++;
+
+  {
+    const auto Range = GetStatistics();
+    EXPECT_NE(Range.begin(), Range.end());
+    EXPECT_EQ(Range.begin() + 2, Range.end());
+
+    OptionalStatistic S1;
+    OptionalStatistic S2;
+    extractCounters(Range, S1, S2);
+
+    EXPECT_EQ(S1.hasValue(), true);
+    EXPECT_EQ(S2.hasValue(), true);
+
+    EXPECT_EQ(S1->first, "Counter");
+    EXPECT_EQ(S1->second, 2u);
+
+    EXPECT_EQ(S2->first, "Counter2");
+    EXPECT_EQ(S2->second, 1u);
+  }
+#else
+  Counter2++;
+  auto &Range = GetStatistics();
+  EXPECT_EQ(Range.begin(), Range.end());
+#endif
+
+#if LLVM_ENABLE_STATS
+  // Check that resetting the statistics works correctly.
+  // It should empty the list and zero the counters.
+  ResetStatistics();
+  {
+    auto &Range = GetStatistics();
+    EXPECT_EQ(Range.begin(), Range.end());
+    EXPECT_EQ(Counter, 0u);
+    EXPECT_EQ(Counter2, 0u);
+    OptionalStatistic S1;
+    OptionalStatistic S2;
+    extractCounters(Range, S1, S2);
+    EXPECT_EQ(S1.hasValue(), false);
+    EXPECT_EQ(S2.hasValue(), false);
+  }
+
+  // Now check that they successfully re-register and count.
+  Counter++;
+  Counter2++;
+
+  {
+    auto &Range = GetStatistics();
+    EXPECT_EQ(Range.begin() + 2, Range.end());
+    EXPECT_EQ(Counter, 1u);
+    EXPECT_EQ(Counter2, 1u);
+
+    OptionalStatistic S1;
+    OptionalStatistic S2;
+    extractCounters(Range, S1, S2);
+
+    EXPECT_EQ(S1.hasValue(), true);
+    EXPECT_EQ(S2.hasValue(), true);
+
+    EXPECT_EQ(S1->first, "Counter");
+    EXPECT_EQ(S1->second, 1u);
+
+    EXPECT_EQ(S2->first, "Counter2");
+    EXPECT_EQ(S2->second, 1u);
+  }
+#else
+  // No need to test the output ResetStatistics(), there's nothing to reset so
+  // we can't tell if it failed anyway.
+  ResetStatistics();
+#endif
+}
+
+} // end anonymous namespace