[mtouch] Put 'mono_profiler_startup_log' in the symbol list. Fixes #5…

…8778. (#2501)

We need the 'mono_profiler_startup_log' symbol when profiling is enabled, so
make sure to add the symbol to the correct list of symbols we need.

Previously we were passing `-u _mono_profiler_startup_log` to clang directly,
which is fine, but not complete, since it does not write the symbol to the
symbollist file (--symbollist=file), which means it wouldn't be preserved when
the MSBuild tasks strip the executable.

https://bugzilla.xamarin.com/show_bug.cgi?id=58778

tests/mtouch/MTouch.cs

@@ -33,6 +33,59 @@ public enum Profile { iOS, tvOS, watchOS }
 	[TestFixture]
 	public class MTouch
 	{
+		[Test]
+		//[TestCase (Profile.iOS)] // tested as part of the watchOS case below, since that builds both for iOS and watchOS.
+		[TestCase (Profile.tvOS)]
+		[TestCase (Profile.watchOS)]
+		public void Profiling (Profile profile)
+		{
+			using (var mtouch = new MTouchTool ()) {
+				var tmpdir = mtouch.CreateTemporaryDirectory ();
+				MTouchTool ext = null;
+				if (profile == Profile.watchOS) {
+					mtouch.Profile = Profile.iOS;
+
+					ext = new MTouchTool ();
+					ext.Profile = profile;
+					ext.Profiling = true;
+					ext.SymbolList = Path.Combine (tmpdir, "extsymbollist.txt");
+					ext.CreateTemporaryWatchKitExtension ();
+					ext.CreateTemporaryDirectory ();
+					mtouch.AppExtensions.Add (ext);
+					ext.AssertExecute (MTouchAction.BuildDev, "ext build");
+				} else {
+					mtouch.Profile = profile;
+				}
+				mtouch.CreateTemporaryApp ();
+				mtouch.CreateTemporaryCacheDirectory ();
+
+				mtouch.DSym = false; // faster test
+				mtouch.MSym = false; // faster test
+				mtouch.NoStrip = true; // faster test
+
+				mtouch.Profiling = true;
+				mtouch.SymbolList = Path.Combine (tmpdir, "symbollist.txt");
+				mtouch.AssertExecute (MTouchAction.BuildDev, "build");
+
+				var profiler_symbol = "_mono_profiler_startup_log";
+
+				var symbols = File.ReadAllLines (mtouch.SymbolList);
+				Assert.That (symbols, Contains.Item (profiler_symbol), profiler_symbol);
+
+				symbols = ExecutionHelper.Execute ("nm", StringUtils.Quote (mtouch.NativeExecutablePath), hide_output: true).Split ('\n');
+				Assert.That (symbols, Has.Some.EndsWith (" T " + profiler_symbol), $"{profiler_symbol} nm");
+
+				if (ext != null) {
+					symbols = File.ReadAllLines (ext.SymbolList);
+					Assert.That (symbols, Contains.Item (profiler_symbol), $"{profiler_symbol} - extension");
+
+					symbols = ExecutionHelper.Execute ("nm", StringUtils.Quote (ext.NativeExecutablePath), hide_output: true).Split ('\n');
+					Assert.That (symbols, Has.Some.EndsWith (" T " + profiler_symbol), $"{profiler_symbol} extension nm");
+
+				}
+			}
+		}
+
 		[Test]
 		public void ExceptionMarshaling ()
 		{

tests/mtouch/MTouchTool.cs

@@ -120,6 +120,8 @@ class MTouchTool : Tool, IDisposable
 		public string AotOtherArguments;
 		public string [] LinkSkip;
 		public string [] XmlDefinitions;
+		public bool? Profiling;
+		public string SymbolList;
 
 #pragma warning restore 649
 
@@ -307,6 +309,12 @@ string BuildArguments (MTouchAction action)
 				}
 			}
 
+			if (Profiling.HasValue)
+				sb.Append (" --profiling:").Append (Profiling.Value ? "true" : "false");
+
+			if (!string.IsNullOrEmpty (SymbolList))
+				sb.Append (" --symbollist=").Append (StringUtils.Quote (SymbolList));
+
 			if (MSym.HasValue)
 				sb.Append (" --msym:").Append (MSym.Value ? "true" : "false");
 

tools/common/CompilerFlags.cs

@@ -45,14 +45,6 @@ public HashSet<string> AllLibraries {
 			}
 		}
 
-		public void ReferenceSymbol (string symbol)
-		{
-			if (UnresolvedSymbols == null)
-				UnresolvedSymbols = new HashSet<string> ();
-
-			UnresolvedSymbols.Add (symbol);
-		}
-
 		public void ReferenceSymbols (IEnumerable<Symbol> symbols)
 		{
 			if (UnresolvedSymbols == null)

tools/common/Target.cs

@@ -238,6 +238,11 @@ public void CollectAllSymbols ()
 					dynamic_symbols.AddFunction ("xamarin_dyn_objc_msgSendSuper_stret");
 				}
 
+#if MONOTOUCH
+				if (App.EnableProfiling && App.LibProfilerLinkMode == AssemblyBuildTarget.StaticObject)
+					dynamic_symbols.AddFunction ("mono_profiler_startup_log");
+#endif
+
 				dynamic_symbols.Save (cache_location);
 			}
 

tools/mtouch/Target.cs

@@ -1396,8 +1396,6 @@ public void NativeLink (BuildTasks build_tasks)
 				case AssemblyBuildTarget.StaticObject:
 					libprofiler = Path.Combine (libdir, "libmono-profiler-log.a");
 					linker_flags.AddLinkWith (libprofiler);
-					if (!App.EnableBitCode)
-						linker_flags.ReferenceSymbol ("mono_profiler_startup_log");
 					break;
 				case AssemblyBuildTarget.Framework: // We don't ship the profiler as a framework, so this should be impossible.
 				default: