Fasta infrastructure.

pkg/fasta/lib/src/compiler_command_line.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library fasta.compiler_command_line;
+
+import 'dart:io' show
+    exit;
+
+import 'command_line.dart' show
+    CommandLine,
+    argumentError;
+
+const Map<String, dynamic> optionSpecification = const <String, dynamic>{
+  "-o": Uri,
+  "--output": Uri,
+  "--platform": Uri,
+  "--packages": Uri,
+};
+
+class CompilerCommandLine extends CommandLine {
+  final String programName;
+
+  CompilerCommandLine(String programName, List<String> arguments)
+      : programName = programName,
+        super(arguments, specification: optionSpecification,
+            usage: computeUsage(programName, false));
+
+  bool get verify => options.containsKey("--verify");
+
+  bool get dumpIr => options.containsKey("--dump-ir");
+
+  bool get help {
+    return options.containsKey("--help") ||
+        options.containsKey("-h") ||
+        options.containsKey("/h") ||
+        options.containsKey("/?");
+  }
+
+  void validate() {
+    if (help) {
+      print(computeUsage(programName, verbose));
+      exit(0);
+    }
+
+    if (options.containsKey("-o") && options.containsKey("--output")) {
+      return argumentError(usage, "Can't specify both '-o' and '--output'.");
+    }
+    if (options.containsKey("--packages")) {
+      return argumentError(usage, "Option '--packages' isn't supported yet.");
+    }
+    if (arguments.isEmpty) {
+      return argumentError(usage, "No Dart file specified.");
+    }
+  }
+
+  Uri get output {
+    return options["-o"] ?? options["-o"] ?? defaultOutput;

[Johnni Winther, 2017/01/16 09:47:46]

Second `options["-o"]` should be `options["--output"]`.

[ahe, 2017/01/16 12:07:04]

Done.

+  }
+
+  Uri get defaultOutput => Uri.base.resolve("${arguments.first}.dill");
+
+  Uri get platform {
+    return options["--platform"] ?? Uri.base.resolve("platform.dill");
+  }
+}
+
+String computeUsage(String programName, bool verbose) {
+  String basicUsage = "Usage: $programName [options] dartfile\n";
+  String summary;
+  String options = (verbose ? allOptions : frequentOptions).trim();
+  switch (programName) {
+    case "outline":
+      summary =
+          "Creates an outline of a Dart program in the Dill/Kernel IR format.";
+      break;
+
+    case "compile":
+      summary = "Compiles a Dart program to the Dill/Kernel IR format.";
+      break;
+
+    case "kompile":
+      summary =
+          "Compiles a Dart program to the Dill/Kernel IR format via dartk.";
+      break;
+
+    case "run":
+      summary = "Runs a Dart program.";

[Johnni Winther, 2017/01/16 09:47:46]

'Compiles and runs' or 'Runs from .dill' or ... ?

[ahe, 2017/01/16 12:07:04]

It compiles and run. But is it important for a usage message to mention that?

+      break;
+  }
+  StringBuffer sb = new StringBuffer(basicUsage);
+  if (summary != null) {
+    sb.writeln();
+    sb.writeln(summary);
+    sb.writeln();
+  }
+  sb.write(options);
+  return "$sb";
+}
+
+const String frequentOptions = """
+Frequently used options:
+
+  -o <file> Generate the output into <file>.
+  -h        Display this message (add -v for information about all options).
+""";
+
+const String allOptions = """
+Supported options:
+
+  -o <file>, --out=<file>
+    Generate the output into <file>.
+
+  -h, /h, /?, --help
+    Display this message (add -v for information about all options).
+
+  -v, --verbose
+    Display verbose information.
+
+  --
+    Stop option parsing, the rest of the command line is assumed to be
+    arguments.

[Johnni Winther, 2017/01/16 09:47:46]

Arguments for what?

[ahe, 2017/01/16 12:07:04]

Changed to: ... is assumed to be file names or arguments to the Dart program.

+
+  --packages=<file>
+    Use package resolution configuration <file>, which should contain a mapping
+    of package names to paths.
+
+  --platform=<file>
+    Read the SDK platform from <file>, which should be in Dill/Kernel IR format
+    and contain the Dart SDK.
+
+  --verify
+    Check that the generated output is free of various problems. This is mostly
+    useful for developers of this compiler or Kernel transformations.
+
+  --dump-ir
+    Print compiled libraries in Kernel source notation.
+""";