[6.0][ScanDependency] Pass crossimport overlay file to swift-frontend

include/swift/AST/ModuleDependencies.h

@@ -812,8 +812,9 @@ class ModuleDependencyInfo {
   /// Collect a map from a secondary module name to a list of cross-import
   /// overlays, when this current module serves as the primary module.
   llvm::StringMap<llvm::SmallSetVector<Identifier, 4>>
-  collectCrossImportOverlayNames(ASTContext &ctx, StringRef moduleName,
-                                 std::vector<std::string> &overlayFiles) const;
+  collectCrossImportOverlayNames(
+      ASTContext &ctx, StringRef moduleName,
+      std::vector<std::pair<std::string, std::string>> &overlayFiles) const;
 };
 
 using ModuleDependencyVector = llvm::SmallVector<std::pair<ModuleDependencyID, ModuleDependencyInfo>, 1>;

include/swift/AST/SearchPathOptions.h

@@ -504,6 +504,14 @@ class SearchPathOptions {
   /// version inheritance.
   std::optional<std::string> PlatformAvailabilityInheritanceMapPath;
 
+  /// Cross import module information. Map from module name to the list of cross
+  /// import overlay files that associate with that module.
+  using CrossImportMap = llvm::StringMap<std::vector<std::string>>;
+  CrossImportMap CrossImportInfo;
+
+  /// Whether to search for cross import overlay on file system.
+  bool DisableCrossImportOverlaySearch = false;
+
   /// Debug path mappings to apply to serialized search paths. These are
   /// specified in LLDB from the target.source-map entries.
   PathRemapper SearchPathRemapper;

include/swift/Option/FrontendOptions.td

@@ -220,6 +220,13 @@ def swift_module_file: Joined<["-"], "swift-module-file=">,
   MetaVarName<"<name>=<path>">,
   HelpText<"Specify Swift module input explicitly built from textual interface">;
 
+def swift_module_cross_import: MultiArg<["-"], "swift-module-cross-import", 2>,
+  MetaVarName<"<moduleName> <crossImport.swiftoverlay>">,
+  HelpText<"Specify the cross import module">;
+
+def disable_cross_import_overlay_search: Flag<["-"], "disable-cross-import-overlay-search">,
+  HelpText<"Disable searching for cross import overlay file">;
+
 def explicit_swift_module_map
   : Separate<["-"], "explicit-swift-module-map-file">, MetaVarName<"<path>">,
     HelpText<"Specify a JSON file containing information of explicit Swift modules">;

lib/AST/ModuleLoader.cpp

@@ -171,6 +171,19 @@ void ModuleLoader::findOverlayFiles(SourceLoc diagLoc, ModuleDecl *module,
   using namespace llvm::sys;
   using namespace file_types;
 
+  // If cross import information is passed on command-line, prefer use that.
+  auto &crossImports = module->getASTContext().SearchPathOpts.CrossImportInfo;
+  auto overlays = crossImports.find(module->getNameStr());
+  if (overlays != crossImports.end()) {
+    for (auto entry : overlays->second) {
+      module->addCrossImportOverlayFile(entry);
+      if (dependencyTracker)
+        dependencyTracker->addDependency(entry, module->isSystemModule());
+    }
+  }
+  if (module->getASTContext().SearchPathOpts.DisableCrossImportOverlaySearch)
+    return;
+
   if (file->getModuleDefiningPath().empty())
     return;
   findOverlayFilesInternal(module->getASTContext(),
@@ -188,7 +201,7 @@ void ModuleLoader::findOverlayFiles(SourceLoc diagLoc, ModuleDecl *module,
 llvm::StringMap<llvm::SmallSetVector<Identifier, 4>>
 ModuleDependencyInfo::collectCrossImportOverlayNames(
     ASTContext &ctx, StringRef moduleName,
-    std::vector<std::string> &overlayFiles) const {
+    std::vector<std::pair<std::string, std::string>> &overlayFiles) const {
   using namespace llvm::sys;
   using namespace file_types;
   std::optional<std::string> modulePath;
@@ -240,7 +253,7 @@ ModuleDependencyInfo::collectCrossImportOverlayNames(
       ModuleDecl::collectCrossImportOverlay(ctx, file, moduleName,
                                             bystandingModule);
     result[bystandingModule] = std::move(overlayNames);
-    overlayFiles.push_back(file.str());
+    overlayFiles.push_back({moduleName.str(), file.str()});
   });
   return result;
 }

lib/DependencyScan/ModuleDependencyScanner.cpp

@@ -789,7 +789,7 @@ void ModuleDependencyScanner::discoverCrossImportOverlayDependencies(
     llvm::function_ref<void(ModuleDependencyID)> action) {
   // Modules explicitly imported. Only these can be secondary module.
   llvm::SetVector<Identifier> newOverlays;
-  std::vector<std::string> overlayFiles;
+  std::vector<std::pair<std::string, std::string>> overlayFiles;
   for (auto dep : allDependencies) {
     auto moduleName = dep.ModuleName;
     // Do not look for overlays of main module under scan
@@ -876,9 +876,15 @@ void ModuleDependencyScanner::discoverCrossImportOverlayDependencies(
                     mainDep.addModuleDependency(crossImportOverlayModID);
                 });
 
-  llvm::for_each(overlayFiles, [&mainDep](const std::string &file) {
-    mainDep.addAuxiliaryFile(file);
-  });
+  auto cmdCopy = mainDep.getCommandline();
+  cmdCopy.push_back("-disable-cross-import-overlay-search");
+  for (auto &entry : overlayFiles) {
+    mainDep.addAuxiliaryFile(entry.second);
+    cmdCopy.push_back("-swift-module-cross-import");
+    cmdCopy.push_back(entry.first);
+    cmdCopy.push_back(entry.second);
+  }
+  mainDep.updateCommandLine(cmdCopy);
 
   cache.updateDependency(
       {mainModuleName.str(), ModuleDependencyKind::SwiftSource}, mainDep);

lib/Frontend/CompilerInvocation.cpp

@@ -2096,6 +2096,12 @@ static bool ParseSearchPathArgs(SearchPathOptions &Opts, ArgList &Args,
                      *forceModuleLoadingMode);
   }
 
+  for (auto *A : Args.filtered(OPT_swift_module_cross_import))
+    Opts.CrossImportInfo[A->getValue(0)].push_back(A->getValue(1));
+
+  Opts.DisableCrossImportOverlaySearch |=
+      Args.hasArg(OPT_disable_cross_import_overlay_search);
+
   // Opts.RuntimeIncludePath is set by calls to
   // setRuntimeIncludePath() or setMainExecutablePath().
   // Opts.RuntimeImportPath is set by calls to

test/CAS/cross_import.swift

@@ -5,29 +5,38 @@
 // RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib \
 // RUN:   -emit-module-interface-path %t/A.swiftinterface -enable-library-evolution -I %t %t/A.swift
 
-// RUN: %target-swift-frontend -emit-module -module-name B -o %t/A.swiftmodule -swift-version 5 \
+// RUN: %target-swift-frontend -emit-module -module-name B -o %t/B.swiftmodule -swift-version 5 \
 // RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib \
 // RUN:   -emit-module-interface-path %t/B.swiftinterface -enable-library-evolution -I %t %t/B.swift
 
-// RUN: %target-swift-frontend -emit-module -module-name _Cross -o %t/A.swiftmodule -swift-version 5 \
+// RUN: %target-swift-frontend -emit-module -module-name _B_A -o %t/_B_A.swiftmodule -swift-version 5 \
 // RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib \
-// RUN:   -emit-module-interface-path %t/_Cross.swiftinterface -enable-library-evolution -I %t %t/cross.swift
+// RUN:   -emit-module-interface-path %t/_B_A.swiftinterface -enable-library-evolution -I %t %t/b_a.swift
 
-// RUN: %target-swift-frontend -scan-dependencies -module-name Test -module-cache-path %t/clang-module-cache %t/main.swift \
+// RUN: %target-swift-frontend -emit-module -module-name _C_A -o %t/_C_A.swiftmodule -swift-version 5 \
 // RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -parse-stdlib \
-// RUN:   -o %t/deps.json -I %t -cache-compile-job -cas-path %t/cas -swift-version 5 -enable-cross-import-overlays -module-load-mode prefer-interface
+// RUN:   -emit-module-interface-path %t/_C_A.swiftinterface -enable-library-evolution -I %t %t/c_a.swift
 
-// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json A > %t/A.cmd
-// RUN: %swift_frontend_plain @%t/A.cmd
-// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json B > %t/B.cmd
-// RUN: %swift_frontend_plain @%t/B.cmd
-// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json _Cross > %t/Cross.cmd
-// RUN: %swift_frontend_plain @%t/Cross.cmd
+// RUN: %target-swift-frontend -scan-dependencies -module-name Test -module-cache-path %t/clang-module-cache %t/main.swift -F %t \
+// RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import -O \
+// RUN:   -o %t/deps.json -I %t -cache-compile-job -cas-path %t/cas -swift-version 5 -enable-cross-import-overlays -module-load-mode prefer-serialized
 
-// RUN: %{python} %S/Inputs/GenerateExplicitModuleMap.py %t/deps.json > %t/map.json
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json clang:SwiftShims > %t/shim.cmd
+// RUN: %swift_frontend_plain @%t/shim.cmd
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json clang:C > %t/C.cmd
+// RUN: %swift_frontend_plain @%t/C.cmd
+
+// RUN: %{python} %S/Inputs/GenerateExplicitModuleMap.py %t/deps.json %t > %t/map.json
 // RUN: llvm-cas --cas %t/cas --make-blob --data %t/map.json > %t/map.casid
 
 // RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json Test > %t/MyApp.cmd
+// RUN: %FileCheck %s --input-file=%t/MyApp.cmd --check-prefix CMD
+// CMD: -swift-module-cross-import
+// CMD-NEXT: B
+// CMD-NEXT: A.swiftoverlay
+// CMD-NEXT: -swift-module-cross-import
+// CMD-NEXT: C
+// CMD-NEXT: A.swiftoverlay
 
 // RUN: %target-swift-frontend -emit-module -o %t/Test.swiftmodule  \
 // RUN:   -emit-module-interface-path %t/Test.swiftinterface \
@@ -40,28 +49,50 @@
 // RUN: %FileCheck %s --input-file=%t/Test.swiftinterface
 
 /// Check to make sure the implicit cross import turned into explicit import in the interface file.
-// CHECK: import _Cross
+// CHECK: import _B_A
+// CHECK: import _C_A
 
 //--- A.swift
 public func a() {}
 
 //--- B.swift
 public func b() {}
 
-//--- cross.swift
-public func cross() {}
+//--- b_a.swift
+public func b_a() {}
+
+//--- c_a.swift
+public func c_a() {}
+
+//--- C.framework/Modules/module.modulemap
+framework module C {
+  umbrella header "C.h"
+  export *
+}
+
+//--- C.framework/Headers/C.h
+void c(void);
+
+//--- C.framework/Modules/C.swiftcrossimport/A.swiftoverlay
+%YAML 1.2
+---
+version: 1
+modules:
+  - name: _C_A
 
 //--- main.swift
 import A
 import B
+import C
 
 func test () {
-  cross()
+  b_a()
+  c_a()
 }
 
 //--- B.swiftcrossimport/A.swiftoverlay
 %YAML 1.2
 ---
 version: 1
 modules:
-  - name: _Cross
+  - name: _B_A

test/CrossImport/explicit-overlay-file.swift

@@ -0,0 +1,14 @@
+// This file tests that the -Rcross-import option causes an appropriate remark to be emitted
+// RUN: %empty-directory(%t)
+// RUN: cp -r %S/Inputs/lib-templates/* %t/
+// RUN: %target-swift-frontend -typecheck %s -enable-cross-import-overlays -Rcross-import -I %t/include -I %t/lib/swift -F %t/Frameworks 2>&1 | %FileCheck %s -check-prefix IMPORT
+// RUN: %target-swift-frontend -typecheck %s -disable-cross-import-overlay-search -enable-cross-import-overlays -Rcross-import -I %t/include -I %t/lib/swift -F %t/Frameworks 2>&1 \
+// RUN:   | %FileCheck %s -check-prefix NO-IMPORT -allow-empty
+// RUN: %target-swift-frontend -typecheck %s -disable-cross-import-overlay-search -enable-cross-import-overlays -Rcross-import -I %t/include -I %t/lib/swift -F %t/Frameworks 2>&1 \
+// RUN:   -swift-module-cross-import DeclaringLibrary %t/lib/swift/DeclaringLibrary.swiftcrossimport/BystandingLibrary.swiftoverlay | %FileCheck %s -check-prefix IMPORT
+
+import DeclaringLibrary
+import BystandingLibrary
+
+// IMPORT: import of 'DeclaringLibrary' and 'BystandingLibrary' triggered a cross-import of '_OverlayLibrary'
+// NO-IMPORT-NOT: import of 'DeclaringLibrary' and 'BystandingLibrary' triggered a cross-import of '_OverlayLibrary'

test/ScanDependencies/module_deps_cross_import_overlay.swift

@@ -30,5 +30,12 @@ import SubEWrapper
 // CHECK-NOT:   "clang": "X"
 // CHECK: ],
 
+// CHECK: "swift": {
+// CHECK-NEXT: "commandLine": [
+// CHECK-NEXT: "-disable-cross-import-overlay-search",
+// CHECK-NEXT: "-swift-module-cross-import",
+// CHECK-NEXT: "E",
+// CHECK-NEXT: SubE.swiftoverlay
+
 // Ensure a transitive dependency via "_cross_import_E" is recorded in the graph still
 // CHECK:   "clang": "X"