Adapt to dependency scanner outputting canonical Clang PCM output paths

Sources/SwiftDriver/ExplicitModuleBuilds/ExplicitDependencyBuildPlanner.swift

@@ -232,9 +232,19 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
         let moduleMapPath = moduleDetails.moduleMapPath.path
         let modulePCMPath = moduleInfo.modulePath
         outputs.append(TypedVirtualPath(file: modulePCMPath.path, type: .pcm))
-        commandLine.appendFlags("-emit-pcm", "-module-name", moduleId.moduleName,
-                                "-o", modulePCMPath.path.description)
+
+        // TODO: Remove this once toolchain is updated
+        // If the dependency scanner did not append its own "-o", add it here.
+        // This is temporary and is meant to handle both: the scanner that
+        // appends '-o' and one that doesn't, until we have a toolchain snapshot with the scanner
+        // that appends '-o' always.
+        let outputFlagIndeces = commandLine.enumerated().compactMap { $1 == .flag("-o") ? $0 : nil }
+        // One '-o' is expected as an `-Xcc` flag.
+        if outputFlagIndeces.count <= 1 {
+          commandLine.appendFlags("-o", modulePCMPath.path.description)
+        }
 
+        // TODO: Remove this once toolchain is updated
         // Fixup "-o -Xcc '<replace-me>'"
         if let outputIndex = commandLine.firstIndex(of: .flag("<replace-me>")) {
           commandLine[outputIndex] = .path(VirtualPath.lookup(modulePCMPath.path))

Sources/SwiftDriver/Jobs/Planning.swift

@@ -697,10 +697,14 @@ extension Driver {
         }
         let updatedPath = plainPath.parentDirectory.appending(component: "\(plainPath.basenameWithoutExt)-\(contextHash).\(plainPath.extension!)")
         dependencyGraph.modules[moduleId]!.modulePath = TextualVirtualPath(path: updatedPath.intern())
-      } else if case .clang(let clangDetails) = moduleInfo.details {
-        let contextHash = clangDetails.contextHash
-        let updatedPath = plainPath.parentDirectory.appending(component: "\(plainPath.basenameWithoutExt)-\(contextHash).\(plainPath.extension!)")
-        dependencyGraph.modules[moduleId]!.modulePath = TextualVirtualPath(path: updatedPath.intern())
+      }
+      // TODO: Remove this once toolchain is updated
+      else if case .clang(let clangDetails) = moduleInfo.details {
+        if !moduleInfo.modulePath.path.description.contains(clangDetails.contextHash) {
+          let contextHash = clangDetails.contextHash
+          let updatedPath = plainPath.parentDirectory.appending(component: "\(plainPath.basenameWithoutExt)-\(contextHash).\(plainPath.extension!)")
+          dependencyGraph.modules[moduleId]!.modulePath = TextualVirtualPath(path: updatedPath.intern())
+        }
       }
     }
   }
@@ -711,17 +715,28 @@ extension Driver {
   throws {
     for (moduleId, moduleInfo) in dependencyGraph.modules {
       // Output path on the main module is determined by the invocation arguments.
-      if case .swift(let name) = moduleId,
-         name == dependencyGraph.mainModuleName {
-        continue
+      if case .swift(let name) = moduleId {
+        if name == dependencyGraph.mainModuleName {
+          continue
+        }
+        let modulePath = VirtualPath.lookup(moduleInfo.modulePath.path)
+        // Use VirtualPath to get the OS-specific path separators right.
+        let modulePathInCache =
+        try VirtualPath(path: moduleCachePath)
+          .appending(component: modulePath.basename)
+        dependencyGraph.modules[moduleId]!.modulePath =
+        TextualVirtualPath(path: modulePathInCache.intern())
+      }
+      // TODO: Remove this once toolchain is updated
+      else if case .clang(_) = moduleId {
+        let modulePath = VirtualPath.lookup(moduleInfo.modulePath.path)
+        // Use VirtualPath to get the OS-specific path separators right.
+        let modulePathInCache =
+        try VirtualPath(path: moduleCachePath)
+          .appending(component: modulePath.basename)
+        dependencyGraph.modules[moduleId]!.modulePath =
+        TextualVirtualPath(path: modulePathInCache.intern())
       }
-      let modulePath = VirtualPath.lookup(moduleInfo.modulePath.path)
-      // Use VirtualPath to get the OS-specific path separators right.
-      let modulePathInCache =
-      try VirtualPath(path: moduleCachePath)
-        .appending(component: modulePath.basename)
-      dependencyGraph.modules[moduleId]!.modulePath =
-      TextualVirtualPath(path: modulePathInCache.intern())
     }
   }