Diagnostic: use DiagnosticEngine instead of DiagnosticConsumer in the parser API

Author: nkcsgexi

Sources/SwiftSyntax/DiagnosticConsumer.swift

@@ -18,7 +18,7 @@ public protocol DiagnosticConsumer {
 
   /// Whether the collected diagnostics should calculate line:column pair; true
   /// by default.
-  var calculateLineColumn: Bool { get }
+  var needsLineColumn: Bool { get }
 
   /// Handle the provided diagnostic which has just been registered with the
   /// DiagnosticEngine.
@@ -29,5 +29,5 @@ public protocol DiagnosticConsumer {
 }
 
 public extension DiagnosticConsumer  {
-  var calculateLineColumn: Bool { return true }
+  var needsLineColumn: Bool { return true }
 }

Sources/SwiftSyntax/DiagnosticEngine.swift

@@ -26,6 +26,11 @@ public class DiagnosticEngine {
 
   public private(set) var diagnostics = [Diagnostic]()
 
+  internal var needsLineColumn: Bool {
+    // Check if any consumer is interested in line and column.
+    return consumers.first { $0.needsLineColumn } != nil
+  }
+
   /// Adds the provided consumer to the consumers list.
   public func addConsumer(_ consumer: DiagnosticConsumer) {
     consumers.append(consumer)
@@ -36,6 +41,13 @@ public class DiagnosticEngine {
     }
   }
 
+  internal func diagnose(_ diagnostic: Diagnostic) {
+    diagnostics.append(diagnostic)
+    for consumer in consumers {
+      consumer.handle(diagnostic)
+    }
+  }
+
   /// Registers a diagnostic with the diagnostic engine.
   /// - parameters:
   ///   - message: The message for the diagnostic. This message includes
@@ -44,12 +56,7 @@ public class DiagnosticEngine {
   public func diagnose(_ message: Diagnostic.Message,
                        location: SourceLocation? = nil,
                        actions: ((inout Diagnostic.Builder) -> Void)? = nil) {
-    let diagnostic = Diagnostic(message: message, location: location,
-                                actions: actions)
-    diagnostics.append(diagnostic)
-    for consumer in consumers {
-      consumer.handle(diagnostic)
-    }
+    diagnose(Diagnostic(message: message, location: location, actions: actions))
   }
 
   /// If any of the diagnostics in this engine have the `error` severity.

Sources/SwiftSyntax/SyntaxParser.swift

@@ -71,7 +71,7 @@ public enum SyntaxParser {
     source: String,
     file: String = "",
     parseTransition: IncrementalParseTransition? = nil,
-    diagConsumer: DiagnosticConsumer? = nil
+    diagnosticEngine: DiagnosticEngine? = nil
   ) throws -> SourceFileSyntax {
     guard nodeHashVerifyResult else {
       throw ParserError.parserCompatibilityCheckFailed
@@ -82,7 +82,7 @@ public enum SyntaxParser {
     var utf8Source = source
     utf8Source.makeNativeUTF8IfNeeded()
 
-    let rawSyntax = parseRaw(file, utf8Source, parseTransition, diagConsumer)
+    let rawSyntax = parseRaw(file, utf8Source, parseTransition, diagnosticEngine)
 
     guard let file = makeSyntax(.forRoot(rawSyntax)) as? SourceFileSyntax else {
       throw ParserError.invalidSyntaxData
@@ -98,22 +98,22 @@ public enum SyntaxParser {
   ///            if the parse was successful.
   /// - Throws: `ParserError`
   public static func parse(_ url: URL,
-      diagConsumer: DiagnosticConsumer? = nil) throws -> SourceFileSyntax {
+      diagnosticEngine: DiagnosticEngine? = nil) throws -> SourceFileSyntax {
     // Avoid using `String(contentsOf:)` because it creates a wrapped NSString.
     var fileData = try Data(contentsOf: url)
     fileData.append(0) // null terminate.
     let source = fileData.withUnsafeBytes { (ptr: UnsafePointer<CChar>) in
       return String(cString: ptr)
     }
     return try parse(source: source, file: url.absoluteString,
-                     diagConsumer: diagConsumer)
+                     diagnosticEngine: diagnosticEngine)
   }
 
   private static func parseRaw(
     _ file: String,
     _ source: String,
     _ parseTransition: IncrementalParseTransition?,
-    _ diagConsumer: DiagnosticConsumer?
+    _ diagnosticEngine: DiagnosticEngine?
   ) -> RawSyntax {
     assert(source.isNativeUTF8)
     let c_parser = swiftparse_parser_create()
@@ -148,17 +148,17 @@ public enum SyntaxParser {
     var pendingNotes: [Note] = []
     defer {
       // Consume the pending diagnostic if  present
-      if let diagConsumer = diagConsumer {
+      if let diagnosticEngine = diagnosticEngine {
         if let pendingDiag = pendingDiag {
-          diagConsumer.handle(Diagnostic(pendingDiag, pendingNotes))
+          diagnosticEngine.diagnose(Diagnostic(pendingDiag, pendingNotes))
         }
       }
     }
     // Set up diagnostics consumer if requested by the caller.
-    if let diagConsumer = diagConsumer {
+    if let diagnosticEngine = diagnosticEngine {
       // If requested, we should set up a source location converter to calculate
       // line and column.
-      let converter = diagConsumer.calculateLineColumn ?
+      let converter = diagnosticEngine.needsLineColumn ?
         SourceLocationConverter(file: file, source: source) : nil
       let diagHandler = { (diag: CDiagnostic!) in
         // If the coming diagnostic is a note, we cache the pending note
@@ -168,7 +168,7 @@ public enum SyntaxParser {
         } else {
           // Cosume the pending diagnostic
           if let pendingDiag = pendingDiag {
-            diagConsumer.handle(Diagnostic(pendingDiag, pendingNotes))
+            diagnosticEngine.diagnose(Diagnostic(pendingDiag, pendingNotes))
             // Clear pending notes
             pendingNotes = []
           }
@@ -239,7 +239,7 @@ extension Note {
 extension Diagnostic {
   init(diag: CDiagnostic, using converter: SourceLocationConverter?) {
     // Collect highlighted ranges
-    let hightlights = (0..<swiftparse_diagnostic_get_range_count(diag)).map {
+    let highlights = (0..<swiftparse_diagnostic_get_range_count(diag)).map {
       return SourceRange(swiftparse_diagnostic_get_range(diag, $0), converter)
     }
     // Collect fixits
@@ -249,7 +249,7 @@ extension Diagnostic {
     self.init(message: Diagnostic.Message(diag),
       location: SourceLocation(offset: Int(swiftparse_diagnostic_get_source_loc(diag)),
                                converter: converter),
-      notes: [], highlights: hightlights, fixIts: fixits)
+      notes: [], highlights: highlights, fixIts: fixits)
   }
 
   init(_ diag: Diagnostic, _ notes: [Note]) {

Sources/lit-test-helper/main.swift

@@ -415,7 +415,9 @@ func printParserDiags(args: CommandLineArguments) throws {
       print("\(counter.error) error(s) \(counter.warning) warnings(s) \(counter.note) note(s)")
     }
   }
-  _ = try SyntaxParser.parse(treeURL, diagConsumer: ParserDiagPrinter())
+  let diagEngine = DiagnosticEngine()
+  diagEngine.addConsumer(ParserDiagPrinter())
+  _ = try SyntaxParser.parse(treeURL, diagnosticEngine: diagEngine)
 }
 
 do {