Add help message for bench-run

Author: Antoine Brunner

bench-run/inputs/apply.in renamed to bench-run/inputs/tuples/apply.in

@@ -11,14 +11,20 @@ import scala.io.Source
 
 object Bench {
   def main(args: Array[String]): Unit = {
+    if (args.contains("--help")) {
+      printUsage()
+      return
+    }
+
     val (intArgs, args1) = args.span(x => try { x.toInt; true } catch { case _: Throwable => false } )
 
     val warmup = if (intArgs.length > 0) intArgs(0).toInt else 20
     val iterations = if (intArgs.length > 1) intArgs(1).toInt else 20
     val forks = if (intArgs.length > 2) intArgs(2).toInt else 1
 
     if (args1.isEmpty) {
-      println("You should specify which benchmarks to run.")
+      println("Error: no benchmark was specified.")
+      printUsage()
       return
     }
 
@@ -36,16 +42,16 @@ object Bench {
       .resultFormat(ResultFormatType.CSV)
 
     if (args1.length > 1 && args1(1) != "--") {
-      for ((param, values) <- paramsFromFile(args1(1)))
+      for ((param, values) <- paramsFromFile("inputs/" ++ args1(1)))
         builder = builder.param(param, values: _*)
     }
 
     if (args1.length > 2) {
       builder = builder.result(args1(2))
     }
 
-    val runner = new Runner(builder.build) // full access to all JMH features, you can also provide a custom output Format here
-    runner.run // actually run the benchmarks
+    val runner = new Runner(builder.build)
+    runner.run
   }
 
   def paramsFromFile(file: String): Array[(String, Array[String])] = {
@@ -54,4 +60,19 @@ object Bench {
       (param, values split ',')
     }
   }
+
+  def printUsage(): Unit = {
+    println()
+    println("Usage:")
+    println()
+    println("dotty-bench-run/jmh:run [<warmup>] [<iterations>] [<forks>] <regexp> [<input>|--] [<output>]")
+    println()
+    println("warmup: warmup iterations. defaults to 20.")
+    println("iterations: benchmark iterations. defaults to 20.")
+    println("forks: number of forks. defaults to 1.")
+    println("regexp: regular expression that selects which benchmarks to run.")
+    println("input: input vector file. each line should have format \'<paramName>: <comma-separated-values>\'")
+    println("output: output file for the results of benchmarks.")
+    println()
+  }
 }