[Caching] Support -resolved-plugin-validation

Add support for `-resolved-plugin-validation`:
* Unconditionally add the flag if supported for explicit module scan
* Append `-cache-replay-prefix-map` to interface compilation jobs

Author: cachemeifyoucan

Sources/SwiftDriver/ExplicitModuleBuilds/ExplicitDependencyBuildPlanner.swift

@@ -53,6 +53,7 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
   private let mainModuleName: String?
   private let cas: SwiftScanCAS?
   private let swiftScanOracle: InterModuleDependencyOracle
+  private let prefixMap: [(AbsolutePath, AbsolutePath)]
 
   /// Clang PCM names contain a hash of the command-line arguments that were used to build them.
   /// We avoid re-running the hash computation with the use of this cache
@@ -73,7 +74,8 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
               dependencyOracle: InterModuleDependencyOracle,
               integratedDriver: Bool = true,
               supportsExplicitInterfaceBuild: Bool = false,
-              cas: SwiftScanCAS? = nil) throws {
+              cas: SwiftScanCAS? = nil,
+              prefixMap:  [(AbsolutePath, AbsolutePath)] = []) throws {
     self.dependencyGraph = dependencyGraph
     self.toolchain = toolchain
     self.swiftScanOracle = dependencyOracle
@@ -82,6 +84,7 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
     self.reachabilityMap = try dependencyGraph.computeTransitiveClosure()
     self.supportsExplicitInterfaceBuild = supportsExplicitInterfaceBuild
     self.cas = cas
+    self.prefixMap = prefixMap
   }
 
   /// Supports resolving bridging header pch command from swiftScan.
@@ -185,6 +188,12 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
         }
       }
 
+      // Add prefix mapping. The option is cache invariant so it can be added without affecting cache key.
+      for (key, value) in prefixMap {
+        commandLine.appendFlag("-cache-replay-prefix-map")
+        commandLine.appendFlag(value.pathString + "=" + key.pathString)
+      }
+
       jobs.append(Job(
         moduleName: moduleId.moduleName,
         kind: .compileModuleFromInterface,
@@ -238,6 +247,12 @@ public typealias ExternalTargetModuleDetailsMap = [ModuleDependencyId: ExternalT
         cacheKeys = [:]
       }
 
+      // Add prefix mapping. The option is cache invariant so it can be added without affecting cache key.
+      for (key, value) in prefixMap {
+        commandLine.appendFlag("-cache-replay-prefix-map")
+        commandLine.appendFlag(value.pathString + "=" + key.pathString)
+      }
+
       jobs.append(Job(
         moduleName: moduleId.moduleName,
         kind: .generatePCM,

Sources/SwiftDriver/ExplicitModuleBuilds/ModuleDependencyScanning.swift

@@ -195,6 +195,10 @@ public extension Driver {
       }
     }
 
+    if isFrontendArgSupported(.resolvedPluginVerification) {
+      commandLine.appendFlag(.resolvedPluginVerification)
+    }
+
     // Pass on the input files
     commandLine.append(contentsOf: inputFiles.filter { $0.type == .swift }.map { .path($0.file) })
     return (inputs, commandLine)

Sources/SwiftDriver/Jobs/Planning.swift

@@ -688,7 +688,8 @@ extension Driver {
                                          integratedDriver: integratedDriver,
                                          supportsExplicitInterfaceBuild:
                                          isFrontendArgSupported(.explicitInterfaceModuleBuild),
-                                         cas: cas)
+                                         cas: cas,
+                                         prefixMap: prefixMapping)
 
     return try explicitDependencyBuildPlanner!.generateExplicitModuleDependenciesBuildJobs()
   }