[6.2 🍒][Dependency Scanning] Consider '-swift-module-file' inputs when looking for dependencies

artemcm · artemcm · commit 89268e9b4d3e · 2025-07-18T10:12:22.000-07:00
Previously this flag was only used to pass explicit dependencies to compilation tasks. This change adds support for the dependency scanner to also consider these inputs when resolving dependencies. Resolves swiftlang/swift-driver#1951
diff --git a/include/swift/AST/ModuleLoader.h b/include/swift/AST/ModuleLoader.h
@@ -375,6 +375,7 @@ class ModuleLoader {
                         StringRef moduleOutputPath, StringRef sdkModuleOutputPath,
                         const llvm::DenseSet<clang::tooling::dependencies::ModuleID> &alreadySeenClangModules,
                         const std::vector<std::string> &swiftModuleClangCC1CommandLineArgs,
+                        const llvm::StringMap<std::string> &explicitSwiftModuleInputs,
                         InterfaceSubContextDelegate &delegate,
                         llvm::PrefixMapper *mapper = nullptr,
                         bool isTestableImport = false) = 0;
diff --git a/include/swift/AST/SearchPathOptions.h b/include/swift/AST/SearchPathOptions.h
@@ -519,7 +519,7 @@ class SearchPathOptions {
 
   /// Module inputs specified with -swift-module-input,
   /// <ModuleName, Path to .swiftmodule file>
-  std::vector<std::pair<std::string, std::string>> ExplicitSwiftModuleInputs;
+  llvm::StringMap<std::string> ExplicitSwiftModuleInputs;
 
   /// A map of placeholder Swift module dependency information.
   std::string PlaceholderDependencyModuleMap;
diff --git a/include/swift/ClangImporter/ClangImporter.h b/include/swift/ClangImporter/ClangImporter.h
@@ -509,6 +509,7 @@ class ClangImporter final : public ClangModuleLoader {
   getModuleDependencies(Identifier moduleName, StringRef moduleOutputPath, StringRef sdkModuleOutputPath,
                         const llvm::DenseSet<clang::tooling::dependencies::ModuleID> &alreadySeenClangModules,
                         const std::vector<std::string> &swiftModuleClangCC1CommandLineArgs,
+                        const llvm::StringMap<std::string> &explicitSwiftModuleInputs,
                         InterfaceSubContextDelegate &delegate,
                         llvm::PrefixMapper *mapper,
                         bool isTestableImport = false) override;
diff --git a/include/swift/DependencyScan/ModuleDependencyScanner.h b/include/swift/DependencyScan/ModuleDependencyScanner.h
@@ -101,6 +101,9 @@ class ModuleDependencyScanningWorker {
   std::vector<std::string> swiftModuleClangCC1CommandLineArgs;
   // Working directory for clang module lookup queries
   std::string clangScanningWorkingDirectoryPath;
+  
+  /// Module inputs specified with -swift-module-input,
+  llvm::StringMap<std::string> explicitSwiftModuleInputs;
 
   // CAS instance.
   std::shared_ptr<llvm::cas::ObjectStore> CAS;
diff --git a/include/swift/Frontend/ModuleInterfaceLoader.h b/include/swift/Frontend/ModuleInterfaceLoader.h
@@ -176,7 +176,7 @@ class ExplicitSwiftModuleLoader: public SerializedModuleLoaderBase {
   create(ASTContext &ctx,
          DependencyTracker *tracker, ModuleLoadingMode loadMode,
          StringRef ExplicitSwiftModuleMap,
-         const std::vector<std::pair<std::string, std::string>> &ExplicitSwiftModuleInputs,
+         const llvm::StringMap<std::string> &ExplicitSwiftModuleInputs,
          bool IgnoreSwiftSourceInfoFile);
 
   /// Append visible module names to \p names. Note that names are possibly
@@ -224,8 +224,7 @@ class ExplicitCASModuleLoader : public SerializedModuleLoaderBase {
   create(ASTContext &ctx, llvm::cas::ObjectStore &CAS,
          llvm::cas::ActionCache &cache, DependencyTracker *tracker,
          ModuleLoadingMode loadMode, StringRef ExplicitSwiftModuleMap,
-         const std::vector<std::pair<std::string, std::string>>
-             &ExplicitSwiftModuleInputs,
+         const llvm::StringMap<std::string> &ExplicitSwiftModuleInputs,
          bool IgnoreSwiftSourceInfoFile);
 
   /// Append visible module names to \p names. Note that names are possibly
diff --git a/include/swift/Sema/SourceLoader.h b/include/swift/Sema/SourceLoader.h
@@ -102,6 +102,7 @@ class SourceLoader : public ModuleLoader {
   getModuleDependencies(Identifier moduleName, StringRef moduleOutputPath, StringRef sdkModuleOutputPath,
                         const llvm::DenseSet<clang::tooling::dependencies::ModuleID> &alreadySeenClangModules,
                         const std::vector<std::string> &swiftModuleClangCC1CommandLineArgs,
+                        const llvm::StringMap<std::string> &explicitSwiftModuleInputs,
                         InterfaceSubContextDelegate &delegate,
                         llvm::PrefixMapper *mapper,
                         bool isTestableImport) override;
diff --git a/include/swift/Serialization/ScanningLoaders.h b/include/swift/Serialization/ScanningLoaders.h
@@ -46,6 +46,8 @@ class SwiftModuleScanner : public SerializedModuleLoaderBase {
   /// Clang-specific (-Xcc) command-line flags to include on
   /// Swift module compilation commands
   std::vector<std::string> swiftModuleClangCC1CommandLineArgs;
+  /// Module inputs specified with -swift-module-input
+ llvm::StringMap<std::string> explicitSwiftModuleInputs;
 
 public:
   std::optional<ModuleDependencyInfo> dependencies;
@@ -55,13 +57,15 @@ class SwiftModuleScanner : public SerializedModuleLoaderBase {
                      InterfaceSubContextDelegate &astDelegate,
                      StringRef moduleOutputPath, StringRef sdkModuleOutputPath,
                      std::vector<std::string> swiftModuleClangCC1CommandLineArgs,
+                     llvm::StringMap<std::string> explicitSwiftModuleInputs,
                      ScannerKind kind = MDS_plain)
       : SerializedModuleLoaderBase(ctx, nullptr, LoadMode,
                                    /*IgnoreSwiftSourceInfoFile=*/true),
         kind(kind), moduleName(moduleName), astDelegate(astDelegate),
         moduleOutputPath(moduleOutputPath),
         sdkModuleOutputPath(sdkModuleOutputPath),
-        swiftModuleClangCC1CommandLineArgs(swiftModuleClangCC1CommandLineArgs)  {}
+        swiftModuleClangCC1CommandLineArgs(swiftModuleClangCC1CommandLineArgs),
+        explicitSwiftModuleInputs(explicitSwiftModuleInputs) {}
 
   std::error_code findModuleFilesInDirectory(
       ImportPath::Element ModuleID, const SerializedModuleBaseName &BaseName,
@@ -73,6 +77,10 @@ class SwiftModuleScanner : public SerializedModuleLoaderBase {
       bool SkipBuildingInterface, bool IsFramework,
       bool IsTestableDependencyLookup) override;
 
+  bool canImportModule(ImportPath::Module named, SourceLoc loc,
+                          ModuleVersionInfo *versionInfo,
+                          bool isTestableImport) override;
+
   virtual void collectVisibleTopLevelModuleNames(
       SmallVectorImpl<Identifier> &names) const override {
     llvm_unreachable("Not used");
@@ -105,7 +113,7 @@ class PlaceholderSwiftModuleScanner : public SwiftModuleScanner {
                                 StringRef moduleOutputPath,
                                 StringRef sdkModuleOutputPath)
       : SwiftModuleScanner(ctx, LoadMode, moduleName, astDelegate,
-                           moduleOutputPath, sdkModuleOutputPath, {},
+                           moduleOutputPath, sdkModuleOutputPath, {}, {},
                            MDS_placeholder) {
     // FIXME: Find a better place for this map to live, to avoid
     // doing the parsing on every module.
diff --git a/include/swift/Serialization/SerializedModuleLoader.h b/include/swift/Serialization/SerializedModuleLoader.h
@@ -266,6 +266,7 @@ class SerializedModuleLoaderBase : public ModuleLoader {
   getModuleDependencies(Identifier moduleName, StringRef moduleOutputPath, StringRef sdkModuleOutputPath,
                         const llvm::DenseSet<clang::tooling::dependencies::ModuleID> &alreadySeenClangModules,
                         const std::vector<std::string> &swiftModuleClangCC1CommandLineArgs,
+                        const llvm::StringMap<std::string> &explicitSwiftModuleInputs,
                         InterfaceSubContextDelegate &delegate,
                         llvm::PrefixMapper *mapper,
                         bool isTestableImport) override;
diff --git a/lib/ClangImporter/ClangModuleDependencyScanner.cpp b/lib/ClangImporter/ClangModuleDependencyScanner.cpp
@@ -275,6 +275,7 @@ ClangImporter::getModuleDependencies(Identifier moduleName,
                                      StringRef sdkModuleOutputPath,
                                      const llvm::DenseSet<clang::tooling::dependencies::ModuleID> &alreadySeenClangModules,
                                      const std::vector<std::string> &swiftModuleClangCC1CommandLineArgs,
+                                     const llvm::StringMap<std::string> &explicitSwiftModuleInputs,
                                      InterfaceSubContextDelegate &delegate,
                                      llvm::PrefixMapper *mapper,
                                      bool isTestableImport) {
diff --git a/lib/DependencyScan/ModuleDependencyScanner.cpp b/lib/DependencyScan/ModuleDependencyScanner.cpp
@@ -259,6 +259,9 @@ ModuleDependencyScanningWorker::ModuleDependencyScanningWorker(
     swiftModuleClangCC1CommandLineArgs.push_back("-fno-implicit-module-maps");
   }
 
+  explicitSwiftModuleInputs =
+    workerCompilerInvocation->getSearchPathOptions().ExplicitSwiftModuleInputs;
+
   // Set up the Swift interface loader for Swift scanning.
   swiftScannerModuleLoader = ModuleInterfaceLoader::create(
       *workerASTContext,
@@ -275,8 +278,8 @@ ModuleDependencyScanningWorker::scanFilesystemForSwiftModuleDependency(
     bool isTestableImport) {
   return swiftScannerModuleLoader->getModuleDependencies(
       moduleName, moduleOutputPath, sdkModuleOutputPath,
-      {}, swiftModuleClangCC1CommandLineArgs, *scanningASTDelegate,
-      prefixMapper, isTestableImport);
+      {}, swiftModuleClangCC1CommandLineArgs, explicitSwiftModuleInputs,
+      *scanningASTDelegate, prefixMapper, isTestableImport);
 }
 
 ModuleDependencyVector
@@ -299,8 +302,7 @@ ModuleDependencyScanningWorker::scanFilesystemForClangModuleDependency(
   auto clangModuleDependencies = clangScanningTool.getModuleDependencies(
       moduleName.str(), clangScanningModuleCommandLineArgs,
       clangScanningWorkingDirectoryPath,
-      alreadySeenModules,
-      lookupModuleOutput);
+      alreadySeenModules, lookupModuleOutput);
   if (!clangModuleDependencies) {
     auto errorStr = toString(clangModuleDependencies.takeError());
     // We ignore the "module 'foo' not found" error, the Swift dependency
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
@@ -2269,7 +2269,7 @@ static void ParseSymbolGraphArgs(symbolgraphgen::SymbolGraphOptions &Opts,
 
 static bool validateSwiftModuleFileArgumentAndAdd(const std::string &swiftModuleArgument,
                                                   DiagnosticEngine &Diags,
-                                                  std::vector<std::pair<std::string, std::string>> &ExplicitSwiftModuleInputs) {
+                                                  llvm::StringMap<std::string> &ExplicitSwiftModuleInputs) {
   std::size_t foundDelimeterPos = swiftModuleArgument.find_first_of("=");
   if (foundDelimeterPos == std::string::npos) {
     Diags.diagnose(SourceLoc(), diag::error_swift_module_file_requires_delimeter,
@@ -2282,7 +2282,7 @@ static bool validateSwiftModuleFileArgumentAndAdd(const std::string &swiftModule
     Diags.diagnose(SourceLoc(), diag::error_bad_module_name, moduleName, false);
     return true;
   }
-  ExplicitSwiftModuleInputs.emplace_back(std::make_pair(moduleName, modulePath));
+  ExplicitSwiftModuleInputs.insert(std::make_pair(moduleName, modulePath));
   return false;
 }
 
diff --git a/lib/Frontend/ModuleInterfaceLoader.cpp b/lib/Frontend/ModuleInterfaceLoader.cpp
@@ -2251,11 +2251,10 @@ struct ExplicitSwiftModuleLoader::Implementation {
   }
 
   void addCommandLineExplicitInputs(
-      const std::vector<std::pair<std::string, std::string>>
-          &commandLineExplicitInputs) {
+      const llvm::StringMap<std::string> &commandLineExplicitInputs) {
     for (const auto &moduleInput : commandLineExplicitInputs) {
-      ExplicitSwiftModuleInputInfo entry(moduleInput.second, {}, {}, {});
-      ExplicitModuleMap.try_emplace(moduleInput.first, std::move(entry));
+      ExplicitSwiftModuleInputInfo entry(moduleInput.getValue(), {}, {}, {});
+      ExplicitModuleMap.try_emplace(moduleInput.getKey(), std::move(entry));
     }
   }
 };
@@ -2427,7 +2426,7 @@ std::unique_ptr<ExplicitSwiftModuleLoader>
 ExplicitSwiftModuleLoader::create(ASTContext &ctx,
     DependencyTracker *tracker, ModuleLoadingMode loadMode,
     StringRef ExplicitSwiftModuleMap,
-    const std::vector<std::pair<std::string, std::string>> &ExplicitSwiftModuleInputs,
+    const llvm::StringMap<std::string> &ExplicitSwiftModuleInputs,
     bool IgnoreSwiftSourceInfoFile) {
   auto result = std::unique_ptr<ExplicitSwiftModuleLoader>(
     new ExplicitSwiftModuleLoader(ctx, tracker, loadMode,
@@ -2541,11 +2540,10 @@ struct ExplicitCASModuleLoader::Implementation {
   }
 
   void addCommandLineExplicitInputs(
-      const std::vector<std::pair<std::string, std::string>>
-          &commandLineExplicitInputs) {
+      const llvm::StringMap<std::string> &commandLineExplicitInputs) {
     for (const auto &moduleInput : commandLineExplicitInputs) {
-      ExplicitSwiftModuleInputInfo entry(moduleInput.second, {}, {}, {});
-      ExplicitModuleMap.try_emplace(moduleInput.first, std::move(entry));
+      ExplicitSwiftModuleInputInfo entry(moduleInput.getValue(), {}, {}, {});
+      ExplicitModuleMap.try_emplace(moduleInput.getKey(), std::move(entry));
     }
   }
 
@@ -2782,8 +2780,7 @@ std::unique_ptr<ExplicitCASModuleLoader> ExplicitCASModuleLoader::create(
     ASTContext &ctx, llvm::cas::ObjectStore &CAS, llvm::cas::ActionCache &cache,
     DependencyTracker *tracker, ModuleLoadingMode loadMode,
     StringRef ExplicitSwiftModuleMap,
-    const std::vector<std::pair<std::string, std::string>>
-        &ExplicitSwiftModuleInputs,
+    const llvm::StringMap<std::string> &ExplicitSwiftModuleInputs,
     bool IgnoreSwiftSourceInfoFile) {
   auto result =
       std::unique_ptr<ExplicitCASModuleLoader>(new ExplicitCASModuleLoader(
diff --git a/lib/Sema/SourceLoader.cpp b/lib/Sema/SourceLoader.cpp
@@ -159,6 +159,7 @@ SourceLoader::getModuleDependencies(Identifier moduleName,
                                     StringRef moduleOutputPath, StringRef sdkModuleOutputPath,
                                     const llvm::DenseSet<clang::tooling::dependencies::ModuleID> &alreadySeenClangModules,
                                     const std::vector<std::string> &swiftModuleClangCC1CommandLineArgs,
+                                    const llvm::StringMap<std::string> &explicitSwiftModuleInputs,
                                     InterfaceSubContextDelegate &delegate,
                                     llvm::PrefixMapper* mapper,
                                     bool isTestableImport) {
diff --git a/lib/Serialization/ScanningLoaders.cpp b/lib/Serialization/ScanningLoaders.cpp
@@ -83,6 +83,30 @@ std::error_code SwiftModuleScanner::findModuleFilesInDirectory(
   return dependencies.getError();
 }
 
+bool SwiftModuleScanner::canImportModule(ImportPath::Module path, SourceLoc loc,
+                                         ModuleVersionInfo *versionInfo,
+                                         bool isTestableDependencyLookup) {
+  if (path.hasSubmodule())
+    return false;
+
+  // Check explicitly-provided Swift modules with '-swift-module-file'
+  ImportPath::Element mID = path.front();
+  auto it =
+      explicitSwiftModuleInputs.find(Ctx.getRealModuleName(mID.Item).str());
+  if (it != explicitSwiftModuleInputs.end()) {
+    auto dependencies = scanModuleFile(it->getValue(), /* IsFramework */ false,
+                                       isTestableDependencyLookup,
+                                       /* isCandidateForTextualModule */ false);
+    if (dependencies) {
+      this->dependencies = std::move(dependencies.get());
+      return true;
+    }
+  }
+
+  return SerializedModuleLoaderBase::canImportModule(
+      path, loc, versionInfo, isTestableDependencyLookup);
+}
+
 bool PlaceholderSwiftModuleScanner::findModule(
     ImportPath::Element moduleID, SmallVectorImpl<char> *moduleInterfacePath,
     SmallVectorImpl<char> *moduleInterfaceSourcePath,
@@ -291,6 +315,7 @@ ModuleDependencyVector SerializedModuleLoaderBase::getModuleDependencies(
     const llvm::DenseSet<clang::tooling::dependencies::ModuleID>
         &alreadySeenClangModules,
     const std::vector<std::string> &swiftModuleClangCC1CommandLineArgs,
+    const llvm::StringMap<std::string> &explicitSwiftModuleInputs,
     InterfaceSubContextDelegate &delegate, llvm::PrefixMapper *mapper,
     bool isTestableDependencyLookup) {
   ImportPath::Module::Builder builder(moduleName);
@@ -309,7 +334,7 @@ ModuleDependencyVector SerializedModuleLoaderBase::getModuleDependencies(
       delegate, moduleOutputPath, sdkModuleOutputPath));
   scanners.push_back(std::make_unique<SwiftModuleScanner>(
       Ctx, LoadMode, moduleId, delegate, moduleOutputPath, sdkModuleOutputPath,
-      swiftModuleClangCC1CommandLineArgs,
+      swiftModuleClangCC1CommandLineArgs, explicitSwiftModuleInputs,
       SwiftModuleScanner::MDS_plain));
 
   // Check whether there is a module with this name that we can import.
diff --git a/test/ScanDependencies/explicit-scanner-input.swift b/test/ScanDependencies/explicit-scanner-input.swift
@@ -0,0 +1,20 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/module-cache)
+// RUN: %empty-directory(%t/Inputs/Foo.swiftmodule)
+// RUN: split-file %s %t
+
+// Step 1: build swift interface and swift module side by side
+// RUN: %target-swift-frontend -emit-module %t/Foo.swift -emit-module-path %t/Inputs/Foo.swiftmodule/%target-swiftmodule-name -module-name Foo
+
+// Step 2: scan dependency should give us the binary module we specify with 'swift-module-file'
+// RUN: %target-swift-frontend -scan-dependencies %t/test.swift -o %t/deps.json -scanner-module-validation -swift-module-file=Foo=%t/Inputs/Foo.swiftmodule/%target-swiftmodule-name
+// RUN: %validate-json %t/deps.json | %FileCheck %s -check-prefix=CHECK-INPUT
+// CHECK-INPUT: "swiftPrebuiltExternal": "Foo"
+
+//--- Foo.swift
+public func foo() {}
+
+//--- test.swift
+#if canImport(Foo)
+import Foo
+#endif
