Merge pull request #256 from artemcm/PrintOutputMap

Add support for printing out the output file map

Author: artemcm

Sources/SwiftDriver/Driver/Driver.swift

@@ -342,6 +342,16 @@ public struct Driver {
       self.outputFileMap = outputFileMap
     }
 
+    // If requested, print the output file map
+    if parsedOptions.contains(.driverPrintOutputFileMap) {
+      if let outputFileMap = self.outputFileMap {
+        stderrStream <<< outputFileMap.description
+        stderrStream.flush()
+      } else {
+        diagnosticsEngine.emit(.error_no_output_file_map_specified)
+      }
+    }
+
     self.fileListThreshold = try Self.computeFileListThreshold(&self.parsedOptions, diagnosticsEngine: diagnosticsEngine)
     self.shouldUseInputFileList = inputFiles.count > fileListThreshold
     if shouldUseInputFileList {
@@ -818,6 +828,10 @@ extension Diagnostic.Message {
   static var warning_cannot_multithread_batch_mode: Diagnostic.Message {
     .warning("ignoring -num-threads argument; cannot multithread batch mode")
   }
+
+  static var error_no_output_file_map_specified: Diagnostic.Message {
+    .error("no output file map specified")
+  }
 }
 
 extension Driver {

Sources/SwiftDriver/Driver/OutputFileMap.swift

@@ -106,6 +106,23 @@ public struct OutputFileMap: Hashable, Codable {
     let contents = try encoder.encode(OutputFileMapJSON.fromVirtualOutputFileMap(entries).entries)
     try fileSystem.writeFileContents(file, bytes: ByteString(contents))
   }
+
+  /// Human-readable texual representation
+  var description: String {
+    var result = ""
+    func outputPairDescription(inputPath: VirtualPath, outputPair: (FileType, VirtualPath))
+    -> String {
+      "\(inputPath.description) -> \(outputPair.0.description): \"\(outputPair.1.description)\"\n"
+    }
+    let maps = entries.map { ($0, $1) }.sorted { $0.0.description < $1.0.description }
+    for (input, map) in maps {
+      let pairs = map.map { ($0, $1) }.sorted { $0.0.description < $1.0.description }
+      for (outputType, outputPath) in pairs {
+        result += outputPairDescription(inputPath: input, outputPair: (outputType, outputPath))
+      }
+    }
+    return result
+  }
 }
 
 /// Struct for loading the JSON file from disk.

Sources/SwiftDriver/Utilities/FileType.swift

@@ -132,10 +132,12 @@ public enum FileType: String, Hashable, CaseIterable, Codable {
 extension FileType: CustomStringConvertible {
   public var description: String {
     switch self {
-    case .swift, .sil, .sib, .image, .object, .dSYM, .dependencies, .autolink,
+    case .swift, .sil, .sib, .image, .dSYM, .dependencies, .autolink,
          .swiftModule, .swiftDocumentation, .swiftInterface, .swiftSourceInfoFile, .assembly,
          .remap, .tbd, .pcm, .pch, .clangModuleMap:
       return rawValue
+    case .object:
+      return "object"
 
     case .ast:
       return "ast-dump"

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -2349,6 +2349,32 @@ final class SwiftDriverTests: XCTestCase {
     }
   }
 
+  func testPrintOutputFileMap() throws {
+    try withTemporaryDirectory { path in
+      // Replace the error stream with one we capture here.
+      let errorStream = stderrStream
+      let errorOutputFile = path.appending(component: "dummy_error_stream")
+      TSCBasic.stderrStream = try! ThreadSafeOutputByteStream(LocalFileOutputByteStream(errorOutputFile))
+
+      let dummyInput = path.appending(component: "output_file_map_test.swift")
+      let outputFileMap = path.appending(component: "output_file_map.json")
+      let fileMap = "{\"\(dummyInput.description)\": {\"object\": \"/build/basic_output_file_map.o\"}, \"\(path)/Inputs/main.swift\": {\"object\": \"/build/main.o\"}, \"\(path)/Inputs/lib.swift\": {\"object\": \"/build/lib.o\"}}"
+      try localFileSystem.writeFileContents(outputFileMap) { $0 <<< fileMap }
+      _ = try Driver(args: ["swiftc", "-driver-print-output-file-map",
+                                     "-target", "x86_64-apple-macosx10.9",
+                                     "-o", "/build/basic_output_file_map.out",
+                                     "-module-name", "OutputFileMap",
+                                     "-output-file-map", outputFileMap.description])
+      let invocationError = try localFileSystem.readFileContents(errorOutputFile).description
+      XCTAssertTrue(invocationError.contains("/Inputs/lib.swift -> object: \"/build/lib.o\""))
+      XCTAssertTrue(invocationError.contains("/Inputs/main.swift -> object: \"/build/main.o\""))
+      XCTAssertTrue(invocationError.contains("/output_file_map_test.swift -> object: \"/build/basic_output_file_map.o\""))
+
+      // Restore the error stream to what it was
+      TSCBasic.stderrStream = errorStream
+    }
+  }
+
   func testDiagnosticOptions() throws {
     do {
       var driver = try Driver(args: ["swift", "-no-warnings-as-errors", "-warnings-as-errors", "foo.swift"])