Allow relative paths in output file map

Author: zienag

Sources/SwiftDriver/Driver/Driver.swift

@@ -46,7 +46,7 @@ public struct Driver {
     case subcommandPassedToDriver
     case relativeFrontendPath(String)
   }
-  
+
   /// The set of environment variables that are visible to the driver and
   /// processes it launches. This is a hook for testing; in actual use
   /// it should be identical to the real environment.
@@ -233,10 +233,10 @@ public struct Driver {
     }
 
     // Compute the working directory.
+    let cwd = localFileSystem.currentWorkingDirectory
     workingDirectory = try parsedOptions.getLastArgument(.workingDirectory).map { workingDirectoryArg in
-      let cwd = localFileSystem.currentWorkingDirectory
-      return try cwd.map{ AbsolutePath(workingDirectoryArg.asSingle, relativeTo: $0) } ?? AbsolutePath(validating: workingDirectoryArg.asSingle)
-    }
+      try cwd.map { AbsolutePath(workingDirectoryArg.asSingle, relativeTo: $0) } ?? AbsolutePath(validating: workingDirectoryArg.asSingle)
+    } ?? cwd
 
     // Apply the working directory to the parsed options.
     if let workingDirectory = self.workingDirectory {
@@ -247,15 +247,22 @@ public struct Driver {
     let inputFiles = try Self.collectInputFiles(&self.parsedOptions)
     self.inputFiles = inputFiles
 
+    let outputFileMap: OutputFileMap?
     // Initialize an empty output file map, which will be populated when we start creating jobs.
     if let outputFileMapArg = parsedOptions.getLastArgument(.outputFileMap)?.asSingle {
       let path = try AbsolutePath(validating: outputFileMapArg)
-      self.outputFileMap = try .load(file: path, diagnosticEngine: diagnosticEngine)
+      outputFileMap = try .load(file: path, diagnosticEngine: diagnosticEngine)
+    } else {
+      outputFileMap = nil
     }
-    else {
-      self.outputFileMap = nil
+
+    if let workingDirectory = self.workingDirectory {
+      self.outputFileMap = outputFileMap?.resolveRelativePaths(relativeTo: workingDirectory)
+    } else {
+      self.outputFileMap = outputFileMap
     }
 
+
     // Determine the compilation mode.
     self.compilerMode = Self.computeCompilerMode(&parsedOptions, driverKind: driverKind, diagnosticsEngine: diagnosticEngine)
 
@@ -440,7 +447,7 @@ extension Driver {
     var isEscaping = false
     // Indicates if we are currently parsing quoted text.
     var quoted = false
-    
+
     for char in line {
       // Backslash escapes to the next character.
       if char == #"\"#, !isEscaping {
@@ -479,7 +486,7 @@ extension Driver {
     return content.split { $0 == "\n" || $0 == "\r\n" }
            .flatMap { tokenizeResponseFileLine($0) }
   }
-  
+
   /// Recursively expands the response files.
   /// - Parameter visitedResponseFiles: Set containing visited response files to detect recursive parsing.
   private static func expandResponseFiles(
@@ -1250,7 +1257,7 @@ extension Driver {
       // This value will fail the isSwiftIdentifier test below.
       moduleName = ""
     }
-    
+
     func fallbackOrDiagnose(_ error: Diagnostic.Message) {
       // FIXME: Current driver notes that this is a "fallback module name".
       if compilerOutputType == nil || maybeBuildingExecutable(&parsedOptions, linkerOutputType: linkerOutputType) {
@@ -1329,7 +1336,7 @@ extension Driver {
         sdkPath = try? toolchain.defaultSDKPath()?.pathString
       }
     }
-    
+
     // An empty string explicitly clears the SDK.
     if sdkPath == "" {
       sdkPath = nil
@@ -1442,7 +1449,7 @@ extension Driver {
   #else
   static let defaultToolchainType: Toolchain.Type = GenericUnixToolchain.self
   #endif
-  
+
   static func computeToolchain(
     _ explicitTarget: Triple?,
     diagnosticsEngine: DiagnosticsEngine,

Sources/SwiftDriver/Driver/OutputFileMap.swift

@@ -47,6 +47,25 @@ public struct OutputFileMap: Equatable {
     try! existingOutput(inputFile: VirtualPath(path: ""), outputType: outputType)
   }
 
+  public func resolveRelativePaths(relativeTo absPath: AbsolutePath) -> OutputFileMap {
+    let resolvedKeyValues: [(VirtualPath, [FileType : VirtualPath])] = entries.map {
+      let resolvedKey: VirtualPath
+      if ($0.key == .singleDep) {
+        // Special case for single dependency record, leave it as is
+        resolvedKey = $0.key
+      } else {
+        resolvedKey = $0.key.resolvedRelativePath(base: absPath)
+      }
+      let resolvedValue = $0.value.mapValues {
+        $0.resolvedRelativePath(base: absPath)
+      }
+      return (resolvedKey, resolvedValue)
+    }
+    return OutputFileMap(entries: .init(resolvedKeyValues, uniquingKeysWith: { _,_ in
+      fatalError("Paths collided after resolving")
+    }))
+  }
+
   /// Load the output file map at the given path.
   public static func load(
     file: AbsolutePath,
@@ -156,9 +175,9 @@ fileprivate struct OutputFileMapJSON: Codable {
 
   /// Converts into virtual path entries.
   func toVirtualOutputFileMap() throws -> [VirtualPath : [FileType : VirtualPath]] {
-    Dictionary(uniqueKeysWithValues: try entries.map { input, entry in
+    Dictionary(try entries.map { input, entry in
       (try VirtualPath(path: input), try entry.paths.mapValues(VirtualPath.init(path:)))
-    })
+    }, uniquingKeysWith: { $1 })
   }
 
   /// Converts from virtual path entries
@@ -186,3 +205,12 @@ extension String {
     return self + "." + ext
   }
 }
+
+extension VirtualPath {
+  fileprivate func resolvedRelativePath(base: AbsolutePath) -> VirtualPath {
+    guard case let .relative(relPath) = self else { return self }
+    return .absolute(.init(base, relPath))
+  }
+
+  fileprivate static let singleDep = VirtualPath.relative(.init(""))
+}