Remove rest of time-trace message as it is inconsistent style

Other options which create output files don't produce output messages.
Improve documentation to help find trace file.

Differential Revision: https://reviews.llvm.org/D68710

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374294 91177308-0d34-0410-b5e6-96231b3b80d8

Author: rgal

include/clang/Driver/Options.td

@@ -1791,7 +1791,12 @@ def : Flag<["-"], "fterminated-vtables">, Alias<fapple_kext>;
 def fthreadsafe_statics : Flag<["-"], "fthreadsafe-statics">, Group<f_Group>;
 def ftime_report : Flag<["-"], "ftime-report">, Group<f_Group>, Flags<[CC1Option]>;
 def ftime_trace : Flag<["-"], "ftime-trace">, Group<f_Group>,
-  HelpText<"Turn on time profiler">, Flags<[CC1Option, CoreOption]>;
+  HelpText<"Turn on time profiler. Generates JSON file based on output filename.">,
+  DocBrief<[{
+Turn on time profiler. Generates JSON file based on output filename. Results
+can be analyzed with chrome://tracing or `Speedscope App
+<https://www.speedscope.app>`_ for flamegraph visualization.}]>,
+  Flags<[CC1Option, CoreOption]>;
 def ftime_trace_granularity_EQ : Joined<["-"], "ftime-trace-granularity=">, Group<f_Group>,
   HelpText<"Minimum time granularity (in microseconds) traced by time profiler">,
   Flags<[CC1Option, CoreOption]>;

tools/driver/cc1_main.cpp

@@ -269,8 +269,6 @@ int cc1_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
       // FIXME(ibiryukov): make profilerOutput flush in destructor instead.
       profilerOutput->flush();
       llvm::timeTraceProfilerCleanup();
-
-      llvm::errs() << "Time trace json-file dumped to " << Path.str() << "\n";
     }
   }