Pass -module-path to EBM-enabled compile jobs

rdar://151822009

Author: adrian-prantl

Sources/SwiftDriver/Jobs/CompileJob.swift

@@ -292,7 +292,8 @@ extension Driver {
     }
 
     try addCommonFrontendOptions(commandLine: &commandLine, inputs: &inputs, kind: .compile,
-                                 explicitModulePlanner: explicitModulePlanner)
+                                 explicitModulePlanner: explicitModulePlanner, forVariantEmitModule: false,
+                                 forObject: outputType == .object)
     try addRuntimeLibraryFlags(commandLine: &commandLine)
 
     if Driver.canDoCrossModuleOptimization(parsedOptions: &parsedOptions) &&
@@ -371,6 +372,9 @@ extension Driver {
       commandLine.appendFlag(map)
     }
 
+    if isFrontendArgSupported(.debugModulePath) {
+      try commandLine.appendLast(.debugModulePath, from: &parsedOptions)
+    }
     try commandLine.appendLast(.trackSystemDependencies, from: &parsedOptions)
     try commandLine.appendLast(.CrossModuleOptimization, from: &parsedOptions)
     try commandLine.appendLast(.EnableCMOEverything, from: &parsedOptions)

Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift

@@ -58,7 +58,8 @@ extension Driver {
     kind: Job.Kind,
     bridgingHeaderHandling: BridgingHeaderHandling = .precompiled,
     explicitModulePlanner: ExplicitDependencyBuildPlanner? = nil,
-    forVariantEmitModule: Bool = false
+    forVariantEmitModule: Bool = false,
+    forObject: Bool = false
   ) throws {
     // Only pass -target to the REPL or immediate modes if it was explicitly
     // specified on the command line.
@@ -108,6 +109,12 @@ extension Driver {
       jobNeedPathRemap = false
     }
 
+    if isPlanJobForExplicitModule && forObject && isFrontendArgSupported(.debugModulePath),
+       let explicitModulePlanner {
+      let mainModule = explicitModulePlanner.dependencyGraph.mainModule
+      try addPathOption(option: .debugModulePath, path: VirtualPath.lookup(mainModule.modulePath.path), to: &commandLine, remap: jobNeedPathRemap)
+    }
+
     // Check if dependency scanner has put the job into direct clang cc1 mode.
     // If dependency scanner put us into direct cc1 mode, avoid adding `-Xcc` options, since
     // dependency scanner already adds needed flags and -Xcc options known by swift-driver are
@@ -290,6 +297,7 @@ extension Driver {
     }
     try commandLine.appendAll(.D, from: &parsedOptions)
     try commandLine.appendAll(.debugPrefixMap, .coveragePrefixMap, .filePrefixMap, from: &parsedOptions)
+    try commandLine.appendLast(.debugModulePath, from: &parsedOptions)
     try commandLine.appendAllArguments(.Xfrontend, from: &parsedOptions)
     try commandLine.appendLast(.warnConcurrency, from: &parsedOptions)
     if isFrontendArgSupported(.noAllocations) {

Sources/SwiftOptions/Options.swift

@@ -129,6 +129,8 @@ extension Option {
   public static let debugInverseRequirements: Option = Option("-debug-inverse-requirements", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Print real requirements in -debug-generic-signatures output")
   public static let debugMapping: Option = Option("-debug-mapping", .flag, attributes: [.noDriver], helpText: "Dumping information for debug purposes")
   public static let debugMapping_: Option = Option("--debug-mapping", .flag, alias: Option.debugMapping, attributes: [.noDriver], helpText: "Dumping information for debug purposes")
+  public static let debugModulePathEQ: Option = Option("-debug-module-path=", .joined, alias: Option.debugModulePath, attributes: [.frontend])
+  public static let debugModulePath: Option = Option("-debug-module-path", .separate, attributes: [.frontend], helpText: "Path to this module's binary swiftmodule artifact (required by debug info)")
   public static let debugPrefixMap: Option = Option("-debug-prefix-map", .separate, attributes: [.frontend], metaVar: "<prefix=replacement>", helpText: "Remap source paths in debug info")
   public static let debugRequirementMachine: Option = Option("-debug-requirement-machine=", .joined, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Fine-grained debug output from the generics implementation")
   public static let debugTimeExpressionTypeChecking: Option = Option("-debug-time-expression-type-checking", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Dumps the time it takes to type-check each expression")
@@ -1554,6 +1556,8 @@ extension Option {
       Option.explicitAutoLinking,
       Option.explicitDependencyGraphFormat,
       Option.explicitInterfaceModuleBuild,
+      Option.debugModulePathEQ,
+      Option.debugModulePath,
       Option.driverExplicitModuleBuild,
       Option.explicitSwiftModuleMap,
       Option.exportAs,

Tests/SwiftDriverTests/ExplicitModuleBuildTests.swift

@@ -718,6 +718,10 @@ final class ExplicitModuleBuildTests: XCTestCase {
       for job in jobs {
         XCTAssertEqual(job.outputs.count, 1)
         let outputFilePath = job.outputs[0].file
+        if job.kind == .compile && driver.isFrontendArgSupported(.debugModulePath) {
+          XCTAssertTrue(job.commandLine.contains(subsequence: ["-debug-module-path", try toPathOption("testExplicitModuleBuildJobs.swiftmodule")]))
+
+        }
 
         // Swift dependencies
         if outputFilePath.extension != nil,