Fix DebugCounterTest when running all SupportTests

[aganea]

Summary

This fixes DebugCounterTest.CounterCheck when all SupportTests are being ran for a Debug target.

[george.burgess.iv]

Thanks for this!

unittests/Support/DebugCounterTest.cpp

17

Would it be possible/simpler to move this into the TEST instead?

[aganea]

Of course, thanks! See updated diff.

[george.burgess.iv]

LGTM. Thanks again!

unittests/Support/DebugCounterTest.cpp

 //===- llvm/unittest/Support/DebugCounterTest.cpp -------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/DebugCounter.h"
 #include "gtest/gtest.h"
 
 #include <string>
 using namespace llvm;
 
 #ifndef NDEBUG
 DEBUG_COUNTER(TestCounter, "test-counter",
               "Counter used for unit test");
 
 TEST(DebugCounterTest, CounterCheck) {
+  // Unfortunately, the CommandLineTest.GetCommandLineArguments test would
+  // unregister the global counter above.
+  if (!DebugCounter::instance().getCounterId("test-counter")) {
+    const_cast<unsigned &>(TestCounter) =
+        DebugCounter::instance().registerCounter("test-counter",
+                                                 "Counter used for unit test");
+  }
+
   EXPECT_FALSE(DebugCounter::isCounterSet(TestCounter));
 
   auto DC = &DebugCounter::instance();
   DC->push_back("test-counter-skip=1");
   DC->push_back("test-counter-count=3");
 
   EXPECT_TRUE(DebugCounter::isCounterSet(TestCounter));