[lldb] [unittests] Use non-empty format string for Timer()

[mgorny]

Summary

Pass dummy '.' as format string for Timer() rather than an empty string,
in order to silence gcc warnings about empty format string
(-Wformat-zero-length). The actual format string is irrelevant
to the test in question.

[labath]

Honestly, I think I'd just change the tests to use a non-zero format string. It's a silly warning, but it probably not worth bloating our cmake code because of it. I mean, it's not like the tests actually *have* to have an empty string. The string is just empty because there wasn't anything useful to put there.

[mgorny]

Changed to use '.' instead. Thanks for the suggestion, I like this option more too ;-). I have wrongly assumed the tests purposely check whether empty string works correctly.

[labath]

Thanks for tackling this. I've been annoyed by this warning too, but I haven't gotten around to doing anything about it yet. :/

[mgorny]

Heh, and I thought we're (NetBSD) the only ones getting it ;-).

lldb/trunk/unittests/Utility/TimerTest.cpp

 #include <thread>
 
 using namespace lldb_private;
 
 TEST(TimerTest, CategoryTimes) {
   Timer::ResetCategoryTimes();
   {
     static Timer::Category tcat("CAT1");
-    Timer t(tcat, "");
+    Timer t(tcat, ".");
     std::this_thread::sleep_for(std::chrono::milliseconds(10));
   }
   StreamString ss;
   Timer::DumpCategoryTimes(&ss);
   double seconds;
   ASSERT_EQ(1, sscanf(ss.GetData(), "%lf sec for CAT1", &seconds));
   EXPECT_LT(0.001, seconds);
   EXPECT_GT(0.1, seconds);
 }
 
 TEST(TimerTest, CategoryTimesNested) {
   Timer::ResetCategoryTimes();
   {
     static Timer::Category tcat1("CAT1");
-    Timer t1(tcat1, "");
+    Timer t1(tcat1, ".");
     std::this_thread::sleep_for(std::chrono::milliseconds(10));
     // Explicitly testing the same category as above.
-    Timer t2(tcat1, "");
+    Timer t2(tcat1, ".");
     std::this_thread::sleep_for(std::chrono::milliseconds(10));
   }
   StreamString ss;
   Timer::DumpCategoryTimes(&ss);
   double seconds;
   // It should only appear once.
   ASSERT_EQ(ss.GetString().count("CAT1"), 1U);
   ASSERT_EQ(1, sscanf(ss.GetData(), "%lf sec for CAT1", &seconds));
   EXPECT_LT(0.002, seconds);
   EXPECT_GT(0.2, seconds);
 }
 
 TEST(TimerTest, CategoryTimes2) {
   Timer::ResetCategoryTimes();
   {
     static Timer::Category tcat1("CAT1");
-    Timer t1(tcat1, "");
+    Timer t1(tcat1, ".");
     std::this_thread::sleep_for(std::chrono::milliseconds(100));
     static Timer::Category tcat2("CAT2");
-    Timer t2(tcat2, "");
+    Timer t2(tcat2, ".");
     std::this_thread::sleep_for(std::chrono::milliseconds(10));
   }
   StreamString ss;
   Timer::DumpCategoryTimes(&ss);
   double seconds1, seconds2;
   ASSERT_EQ(2, sscanf(ss.GetData(), "%lf sec for CAT1%*[\n ]%lf sec for CAT2",
                       &seconds1, &seconds2))
       << "String: " << ss.GetData();
   EXPECT_LT(0.01, seconds1);
   EXPECT_GT(1, seconds1);
   EXPECT_LT(0.001, seconds2);
   EXPECT_GT(0.1, seconds2);
 }