[mlir] Expose output strategies of TimingManager (llvm#166548)

After the original API change to DefaultTimingManager::setOutput() (see
362aa43), users are forced to provide
their own implementation of OutputStrategy. However, default MLIR
implementations are usually sufficient. Expose Text and Json strategies
via factory-like method to avoid the problem in downstream projects.

Author: andrey-golubev

mlir/include/mlir/Support/Timing.h

@@ -473,6 +473,11 @@ void registerDefaultTimingManagerCLOptions();
 /// 'registerDefaultTimingManagerOptions' to a `DefaultTimingManager`.
 void applyDefaultTimingManagerCLOptions(DefaultTimingManager &tm);
 
+/// Create an output strategy for the specified format, to be passed to
+/// DefaultTimingManager::setOutput().
+std::unique_ptr<OutputStrategy>
+createOutputStrategy(DefaultTimingManager::OutputFormat fmt, raw_ostream &os);
+
 } // namespace mlir
 
 #endif // MLIR_SUPPORT_TIMING_H

mlir/lib/Support/Timing.cpp

@@ -621,11 +621,17 @@ void mlir::applyDefaultTimingManagerCLOptions(DefaultTimingManager &tm) {
     return;
   tm.setEnabled(options->timing);
   tm.setDisplayMode(options->displayMode);
+  tm.setOutput(createOutputStrategy(options->outputFormat, llvm::errs()));
+}
 
-  std::unique_ptr<OutputStrategy> printer;
-  if (options->outputFormat == OutputFormat::Text)
-    printer = std::make_unique<OutputTextStrategy>(llvm::errs());
-  else if (options->outputFormat == OutputFormat::Json)
-    printer = std::make_unique<OutputJsonStrategy>(llvm::errs());
-  tm.setOutput(std::move(printer));
+std::unique_ptr<OutputStrategy>
+mlir::createOutputStrategy(DefaultTimingManager::OutputFormat fmt,
+                           raw_ostream &os) {
+  switch (fmt) {
+  case OutputFormat::Text:
+    return std::make_unique<OutputTextStrategy>(os);
+  case OutputFormat::Json:
+    return std::make_unique<OutputJsonStrategy>(os);
+  }
+  llvm_unreachable("Invalid output format");
 }