Merge pull request swiftlang#212 from google/pretty-print-by-default

Enable the pretty-printer pass by default.

Author: dabelknap

Sources/swift-format/DebugOptions.swift

@@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+/// Advanced options that are useful when debugging and developing the formatter, but are otherwise
+/// not meant for general use.
+struct DebugOptions: OptionSet {
+
+  /// Disables the pretty-printer pass entirely, executing only the syntax-transforming rules in the
+  /// pipeline.
+  static let disablePrettyPrint = DebugOptions(rawValue: 1 << 0)
+
+  /// Dumps a verbose representation of the raw pretty-printer token stream.
+  static let dumpTokenStream = DebugOptions(rawValue: 1 << 1)
+
+  let rawValue: Int
+
+  init(rawValue: Int) { self.rawValue = rawValue }
+
+  /// Inserts or removes the given element from the option set, based on the value of `enabled`.
+  mutating func set(_ element: Element, enabled: Bool) {
+    if enabled { insert(element) } else { remove(element) }
+  }
+}

Sources/swift-format/Run.swift

@@ -23,7 +23,7 @@ import SwiftSyntax
 /// - Parameter configuration: The `Configuration` that contains user-specific settings.
 /// - Parameter path: The absolute path to the source file to be linted.
 /// - Returns: Zero if there were no lint errors, otherwise a non-zero number.
-public func lintMain(configuration: Configuration, path: String) -> Int {
+func lintMain(configuration: Configuration, path: String) -> Int {
   let url = URL(fileURLWithPath: path)
   let engine = makeDiagnosticEngine()
 
@@ -50,11 +50,13 @@ public func lintMain(configuration: Configuration, path: String) -> Int {
 
 /// Runs the formatting pipeline over the provided source file.
 ///
-/// - Parameter configuration: The `Configuration` that contains user-specific settings.
-/// - Parameter path: The absolute path to the source file to be linted.
+/// - Parameters:
+///   - configuration: The `Configuration` that contains user-specific settings.
+///   - path: The absolute path to the source file to be formatted.
+///   - debugOptions: The set containing any debug options that were supplied on the command line.
 /// - Returns: Zero if there were no lint errors, otherwise a non-zero number.
-public func formatMain(
-  configuration: Configuration, path: String, prettyPrint: Bool, printTokenStream: Bool
+func formatMain(
+  configuration: Configuration, path: String, debugOptions: DebugOptions
 ) -> Int {
   let url = URL(fileURLWithPath: path)
   let context = Context(configuration: configuration, diagnosticEngine: nil, fileURL: url)
@@ -68,7 +70,7 @@ public func formatMain(
     // version of visit(_: SourceFileSyntax), which will not run the pipeline properly.
     let formatted = pipeline.visit(file as Syntax)
 
-    if prettyPrint {
+    if !debugOptions.contains(.disablePrettyPrint) {
       // We create a different context here because we only want diagnostics from the pretty printer
       // phase when formatting.
       let prettyPrintContext = Context(
@@ -79,8 +81,7 @@ public func formatMain(
       let printer = PrettyPrinter(
         context: prettyPrintContext,
         node: formatted,
-        printTokenStream: printTokenStream
-      )
+        printTokenStream: debugOptions.contains(.dumpTokenStream))
       print(printer.prettyPrint(), terminator: "")
     } else {
       print(formatted.description, terminator: "")

Sources/swift-format/main.swift

@@ -17,7 +17,7 @@ import SwiftFormatCore
 import SwiftFormatPrettyPrint
 import Utility
 
-enum Mode: String, Codable, ArgumentKind {
+fileprivate enum Mode: String, Codable, ArgumentKind {
   case format
   case lint
   case dumpConfiguration = "dump-configuration"
@@ -31,6 +31,14 @@ enum Mode: String, Codable, ArgumentKind {
     ])
   }
 
+  /// Indicates whether the mode requires at least one input file passed as a positional argument.
+  var requiresFiles: Bool {
+    switch self {
+    case .format, .lint: return true
+    case .dumpConfiguration, .version: return false
+    }
+  }
+
   init(argument: String) throws {
     guard let mode = Mode(rawValue: argument) else {
       throw ArgumentParserError.invalidValue(argument: argument, error: .unknown(value: argument))
@@ -39,16 +47,17 @@ enum Mode: String, Codable, ArgumentKind {
   }
 }
 
-struct CommandLineOptions: Codable {
+fileprivate struct CommandLineOptions {
   var configurationPath: String? = nil
   var paths: [String] = []
   var verboseLevel = 0
   var mode: Mode = .format
-  var prettyPrint: Bool = false
-  var printTokenStream: Bool = false
+  var debugOptions: DebugOptions = []
 }
 
-func processArguments(commandName: String, _ arguments: [String]) -> CommandLineOptions {
+fileprivate func processArguments(
+  commandName: String, _ arguments: [String]
+) -> CommandLineOptions {
   let parser = ArgumentParser(commandName: commandName,
                               usage: "[options] <filename or path> ...",
                               overview: "Format or lint Swift source code.")
@@ -84,34 +93,38 @@ func processArguments(commandName: String, _ arguments: [String]) -> CommandLine
   }
   binder.bind(
     option: parser.add(
-      option: "--pretty-print",
-      shortName: "-p",
-      kind: Bool.self,
-      usage: "Pretty-print the output and automatically apply line-wrapping."
+      option: "--configuration",
+      kind: String.self,
+      usage: "The path to a JSON file containing the configuration of the linter/formatter."
   )) {
-    $0.prettyPrint = $1
+    $0.configurationPath = $1
   }
+
+  // Add advanced debug/developer options. These intentionally have no usage strings, which omits
+  // them from the `--help` screen to avoid noise for the general user.
   binder.bind(
     option: parser.add(
-      option: "--token-stream",
-      kind: Bool.self,
-      usage: "Print out the pretty-printer token stream."
+      option: "--debug-disable-pretty-print",
+      kind: Bool.self
   )) {
-    $0.printTokenStream = $1
+    $0.debugOptions.set(.disablePrettyPrint, enabled: $1)
   }
   binder.bind(
     option: parser.add(
-      option: "--configuration",
-      kind: String.self,
-      usage: "The path to a JSON file containing the configuration of the linter/formatter."
+      option: "--debug-dump-token-stream",
+      kind: Bool.self
   )) {
-    $0.configurationPath = $1
+    $0.debugOptions.set(.dumpTokenStream, enabled: $1)
   }
 
   var opts = CommandLineOptions()
   do {
     let args = try parser.parse(arguments)
     binder.fill(args, into: &opts)
+
+    if opts.mode.requiresFiles && opts.paths.isEmpty {
+      throw ArgumentParserError.expectedArguments(parser, ["filenames or paths"])
+    }
   } catch {
     stderrStream.write("error: \(error)\n\n")
     parser.printUsage(on: stderrStream)
@@ -131,9 +144,7 @@ func main(_ arguments: [String]) -> Int32 {
       ret |= formatMain(
         configuration: configuration,
         path: path,
-        prettyPrint: options.prettyPrint,
-        printTokenStream: options.printTokenStream
-      )
+        debugOptions: options.debugOptions)
     }
     return Int32(ret)
   case .lint: