Add support for pretty print categories in rule registry generation

Documentation/RuleDocumentation.md

@@ -4,7 +4,7 @@
 
 Use the rules below in the `rules` block of your `.swift-format`
 configuration file, as described in
-[Configuration](Configuration.md). All of these rules can be
+[Configuration](Documentation/Configuration.md). All of these rules can be
 applied in the linter, but only some of them can format your source code
 automatically.
 

Sources/SwiftFormat/Core/RuleRegistry+Generated.swift

@@ -57,5 +57,14 @@
     "UseTripleSlashForDocumentationComments": true,
     "UseWhereClausesInForLoops": false,
     "ValidateDocumentationComments": false,
+    "AddLines": true,
+    "EndOfLineComment": true,
+    "Indentation": true,
+    "LineLength": true,
+    "RemoveLine": true,
+    "Spacing": true,
+    "SpacingCharacter": true,
+    "TrailingComma": true,
+    "TrailingWhitespace": true,
   ]
 }

Sources/generate-swift-format/PrettyPrintCollector.swift

@@ -0,0 +1,98 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2019 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
+//
+//===----------------------------------------------------------------------===//
+
+import Foundation
+@_spi(Rules) import SwiftFormat
+import SwiftParser
+import SwiftSyntax
+
+/// Collects information about rules in the formatter code base.
+final class PrettyPrintCollector {
+
+  /// A list of all the format-only pretty-print categories found in the code base.
+  var allPrettyPrinterCategories = Set<String>()
+
+  /// Populates the internal collections with rules in the given directory.
+  ///
+  /// - Parameter url: The file system URL that should be scanned for rules.
+  func collect(from url: URL) throws {
+    // For each file in the Rules directory, find types that either conform to SyntaxLintRule or
+    // inherit from SyntaxFormatRule.
+    let fm = FileManager.default
+    guard let rulesEnumerator = fm.enumerator(atPath: url.path) else {
+      fatalError("Could not list the directory \(url.path)")
+    }
+
+    for baseName in rulesEnumerator {
+      // Ignore files that aren't Swift source files.
+      guard let baseName = baseName as? String, baseName.hasSuffix(".swift") else { continue }
+
+      let fileURL = url.appendingPathComponent(baseName)
+      let fileInput = try String(contentsOf: fileURL)
+      let sourceFile = Parser.parse(source: fileInput)
+
+      for statement in sourceFile.statements {
+        let pp = self.detectPrettyPrintCategories(at: statement)
+        allPrettyPrinterCategories.formUnion(pp)
+      }
+    }
+  }
+
+  private func detectPrettyPrintCategories(at statement: CodeBlockItemSyntax) -> [String] {
+    guard let enumDecl = statement.item.as(EnumDeclSyntax.self) else {
+      return []
+    }
+
+    // Make sure it has an inheritance clause.
+    guard let inheritanceClause = enumDecl.inheritanceClause else {
+      return []
+    }
+
+    // Scan through the inheritance clause to find one of the protocols/types we're interested in.
+    for inheritance in inheritanceClause.inheritedTypes {
+      guard let identifier = inheritance.type.as(IdentifierTypeSyntax.self) else {
+        continue
+      }
+
+      if identifier.name.text != "FindingCategorizing" {
+        // Keep looking at the other inheritances.
+        continue
+      }
+
+      // Now that we know it's a pretty printing category, collect the `description` method and extract the name.
+      for member in enumDecl.memberBlock.members {
+        guard let varDecl = member.decl.as(VariableDeclSyntax.self) else { continue }
+        guard
+          let descriptionDecl = varDecl.bindings
+            .first(where: {
+              $0.pattern.as(IdentifierPatternSyntax.self)?.identifier.text == "description"
+            })
+        else { continue }
+        let pp = PrettyPrintCategoryVisitor(viewMode: .sourceAccurate)
+        _ = pp.walk(descriptionDecl)
+        return pp.prettyPrintCategories
+      }
+    }
+
+    return []
+  }
+}
+
+final class PrettyPrintCategoryVisitor: SyntaxVisitor {
+
+  var prettyPrintCategories: [String] = []
+
+  override func visit(_ node: StringSegmentSyntax) -> SyntaxVisitorContinueKind {
+    prettyPrintCategories.append(node.content.text)
+    return .skipChildren
+  }
+}

Sources/generate-swift-format/RuleRegistryGenerator.swift

@@ -18,9 +18,13 @@ final class RuleRegistryGenerator: FileGenerator {
   /// The rules collected by scanning the formatter source code.
   let ruleCollector: RuleCollector
 
+  /// The pretty-printing categories collected by scanning the formatter source code.
+  let prettyPrintCollector: PrettyPrintCollector
+
   /// Creates a new rule registry generator.
-  init(ruleCollector: RuleCollector) {
+  init(ruleCollector: RuleCollector, prettyPrintCollector: PrettyPrintCollector) {
     self.ruleCollector = ruleCollector
+    self.prettyPrintCollector = prettyPrintCollector
   }
 
   func write(into handle: FileHandle) throws {
@@ -49,6 +53,10 @@ final class RuleRegistryGenerator: FileGenerator {
     for detectedRule in ruleCollector.allLinters.sorted(by: { $0.typeName < $1.typeName }) {
       handle.write("    \"\(detectedRule.typeName)\": \(!detectedRule.isOptIn),\n")
     }
+
+    for ppCategory in prettyPrintCollector.allPrettyPrinterCategories.sorted(by: { $0 < $1 }) {
+      handle.write("    \"\(ppCategory)\": true,\n")
+    }
     handle.write("  ]\n}\n")
   }
 }

Sources/generate-swift-format/main.swift

@@ -20,6 +20,10 @@ let rulesDirectory =
   sourcesDirectory
   .appendingPathComponent("SwiftFormat")
   .appendingPathComponent("Rules")
+let prettyPrintDirectory =
+  sourcesDirectory
+  .appendingPathComponent("SwiftFormat")
+  .appendingPathComponent("PrettyPrint")
 let pipelineFile =
   sourcesDirectory
   .appendingPathComponent("SwiftFormat")
@@ -46,12 +50,15 @@ let ruleDocumentationFile =
 var ruleCollector = RuleCollector()
 try ruleCollector.collect(from: rulesDirectory)
 
+var prettyPrintCollector = PrettyPrintCollector()
+try prettyPrintCollector.collect(from: prettyPrintDirectory)
+
 // Generate a file with extensions for the lint and format pipelines.
 let pipelineGenerator = PipelineGenerator(ruleCollector: ruleCollector)
 try pipelineGenerator.generateFile(at: pipelineFile)
 
 // Generate the rule registry dictionary for configuration.
-let registryGenerator = RuleRegistryGenerator(ruleCollector: ruleCollector)
+let registryGenerator = RuleRegistryGenerator(ruleCollector: ruleCollector, prettyPrintCollector: prettyPrintCollector)
 try registryGenerator.generateFile(at: ruleRegistryFile)
 
 // Generate the rule name cache.