[lld/mac] Write -v output to stderr

[thakis]

Summary

This matches ld64, and it's conceivable that projects try to read
this information off stderr for that reason.

--version keeps writing to stdout.

[thakis]

(The OR in D113021 is needed because current LLD doesn't do this yet)

[oontvoo]

LGTM

(a bit of an interesting behaviour on LD64 - but then I'd expect nothing less from it ...)

lld/MachO/Driver.cpp

1365

test failures look related - (ie., tests need to read stderr: 2>&1 ?)

[thakis]

Thanks!

lld/Common/ErrorHandler.cpp

 
 void ErrorHandler::log(const Twine &msg) {
   if (!verbose || disableOutput)
     return;
   std::lock_guard<std::mutex> lock(mu);
   reportDiagnostic(logName, Colors::RESET, "", msg);
 }
 
-void ErrorHandler::message(const Twine &msg) {
+void ErrorHandler::message(const Twine &msg, llvm::raw_ostream &s) {
   if (disableOutput)
     return;
   std::lock_guard<std::mutex> lock(mu);
-  lld::outs() << msg << "\n";
-  lld::outs().flush();
+  s << msg << "\n";
+  s.flush();
 }
 
 void ErrorHandler::warn(const Twine &msg) {
   if (fatalWarnings) {
     error(msg);
     return;
   }
 

lld/MachO/Driver.cpp

#endif
   config->saveTemps = args.hasArg(OPT_save_temps);
 
   config->adhocCodesign = args.hasFlag(
       OPT_adhoc_codesign, OPT_no_adhoc_codesign,
       (config->arch() == AK_arm64 || config->arch() == AK_arm64e) &&
           config->platform() == PlatformKind::macOS);
 
   if (args.hasArg(OPT_v)) {
-    message(getLLDVersion());
+    message(getLLDVersion(), lld::errs());
     message(StringRef("Library search paths:") +
                 (config->librarySearchPaths.empty()
                      ? ""
-                 : "\n\t" + join(config->librarySearchPaths, "\n\t")));
+                     : "\n\t" + join(config->librarySearchPaths, "\n\t")),
+            lld::errs());
     message(StringRef("Framework search paths:") +
                 (config->frameworkSearchPaths.empty()
                      ? ""
-                 : "\n\t" + join(config->frameworkSearchPaths, "\n\t")));
+                     : "\n\t" + join(config->frameworkSearchPaths, "\n\t")),
+            lld::errs());
   }
 
   config->progName = argsArr[0];
 
   config->timeTraceEnabled = args.hasArg(
       OPT_time_trace, OPT_time_trace_granularity_eq, OPT_time_trace_file_eq);
   config->timeTraceGranularity =
       args::getInteger(args, OPT_time_trace_granularity_eq, 500);

lld/include/lld/Common/ErrorHandler.h

public:
   bool vsDiagnostics = false;
   bool disableOutput = false;
   std::function<void()> cleanupCallback;
 
   void error(const Twine &msg);
   void error(const Twine &msg, ErrorTag tag, ArrayRef<StringRef> args);
   [[noreturn]] void fatal(const Twine &msg);
   void log(const Twine &msg);
-  void message(const Twine &msg);
+  void message(const Twine &msg, llvm::raw_ostream &s);
   void warn(const Twine &msg);
 
   void reset() {
     if (cleanupCallback)
       cleanupCallback();
     *this = ErrorHandler();
   }
 

 ErrorHandler &errorHandler();
 
 inline void error(const Twine &msg) { errorHandler().error(msg); }
 inline void error(const Twine &msg, ErrorTag tag, ArrayRef<StringRef> args) {
   errorHandler().error(msg, tag, args);
 }
 [[noreturn]] inline void fatal(const Twine &msg) { errorHandler().fatal(msg); }
 inline void log(const Twine &msg) { errorHandler().log(msg); }
-inline void message(const Twine &msg) { errorHandler().message(msg); }
+inline void message(const Twine &msg, llvm::raw_ostream &s = outs()) {
+  errorHandler().message(msg, s);
+}
 inline void warn(const Twine &msg) { errorHandler().warn(msg); }
 inline uint64_t errorCount() { return errorHandler().errorCount; }
 
 [[noreturn]] void exitLld(int val);
 
 void diagnosticHandler(const llvm::DiagnosticInfo &di);
 void checkError(Error e);