Merge pull request #40384 from apple/es-scan

Module aliasing: Resolve deps graph with real module names when scanning dependencies.
Resolves rdar://85991587.

Author: elsh

lib/AST/ModuleDependencies.cpp

@@ -100,7 +100,9 @@ void ModuleDependencies::addModuleDependencies(
     if (!importDecl)
       continue;
 
-    addModuleDependency(importDecl->getModulePath(), &alreadyAddedModules);
+    ImportPath::Builder scratch;
+    auto realPath = importDecl->getRealModulePath(scratch);
+    addModuleDependency(realPath, &alreadyAddedModules);
   }
 
   auto fileName = sf.getFilename();

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -1685,6 +1685,7 @@ InterfaceSubContextDelegateImpl::runInSubCompilerInstance(StringRef moduleName,
   if (subInstance.setup(subInvocation)) {
     return std::make_error_code(std::errc::not_supported);
   }
+
   info.BuildArguments = BuildArgs;
   info.Hash = CacheHash;
   auto target = *(std::find(BuildArgs.rbegin(), BuildArgs.rend(), "-target") - 1);
@@ -1826,7 +1827,12 @@ std::error_code ExplicitSwiftModuleLoader::findModuleFilesInDirectory(
 
 bool ExplicitSwiftModuleLoader::canImportModule(
     ImportPath::Element mID, llvm::VersionTuple version, bool underlyingVersion) {
-  StringRef moduleName = mID.Item.str();
+  // Look up the module with the real name (physical name on disk);
+  // in case `-module-alias` is used, the name appearing in source files
+  // and the real module name are different. For example, '-module-alias Foo=Bar'
+  // maps Foo appearing in source files, e.g. 'import Foo', to the real module
+  // name Bar (on-disk name), which should be searched for loading.
+  StringRef moduleName = Ctx.getRealModuleName(mID.Item).str();
   auto it = Impl.ExplicitModuleMap.find(moduleName);
   // If no provided explicit module matches the name, then it cannot be imported.
   if (it == Impl.ExplicitModuleMap.end()) {

lib/Serialization/ModuleDependencyScanner.cpp

@@ -78,7 +78,7 @@ std::error_code PlaceholderSwiftModuleScanner::findModuleFilesInDirectory(
     std::unique_ptr<llvm::MemoryBuffer> *ModuleDocBuffer,
     std::unique_ptr<llvm::MemoryBuffer> *ModuleSourceInfoBuffer,
     bool skipBuildingInterface, bool IsFramework) {
-  StringRef moduleName = ModuleID.Item.str();
+  StringRef moduleName = Ctx.getRealModuleName(ModuleID.Item).str();
   auto it = PlaceholderDependencyModuleMap.find(moduleName);
   // If no placeholder module stub path is given matches the name, return with an
   // error code.
@@ -106,11 +106,12 @@ ErrorOr<ModuleDependencies> ModuleDependencyScanner::scanInterfaceFile(
   // FIXME: Query the module interface loader to determine an appropriate
   // name for the module, which includes an appropriate hash.
   auto newExt = file_types::getExtension(file_types::TY_SwiftModuleFile);
-  llvm::SmallString<32> modulePath = moduleName.str();
+  auto realModuleName = Ctx.getRealModuleName(moduleName);
+  llvm::SmallString<32> modulePath = realModuleName.str();
   llvm::sys::path::replace_extension(modulePath, newExt);
   Optional<ModuleDependencies> Result;
   std::error_code code =
-    astDelegate.runInSubContext(moduleName.str(),
+    astDelegate.runInSubContext(realModuleName.str(),
                                               moduleInterfacePath.str(),
                                               StringRef(),
                                               SourceLoc(),
@@ -119,7 +120,7 @@ ErrorOr<ModuleDependencies> ModuleDependencyScanner::scanInterfaceFile(
                     ArrayRef<StringRef> PCMArgs, StringRef Hash) {
     assert(mainMod);
     std::string InPath = moduleInterfacePath.str();
-    auto compiledCandidates = getCompiledCandidates(Ctx, moduleName.str(),
+    auto compiledCandidates = getCompiledCandidates(Ctx, realModuleName.str(),
                                                     InPath);
     Result = ModuleDependencies::forSwiftInterfaceModule(InPath,
                                                    compiledCandidates,
@@ -136,7 +137,7 @@ ErrorOr<ModuleDependencies> ModuleDependencyScanner::scanInterfaceFile(
 
     // Create a source file.
     unsigned bufferID = Ctx.SourceMgr.addNewSourceBuffer(std::move(interfaceBuf.get()));
-    auto moduleDecl = ModuleDecl::create(moduleName, Ctx);
+    auto moduleDecl = ModuleDecl::create(realModuleName, Ctx);
     auto sourceFile = new (Ctx) SourceFile(
         *moduleDecl, SourceFileKind::Interface, bufferID);
 

test/Frontend/module-alias-scan-deps.swift

@@ -0,0 +1,50 @@
+/// Test -scan-dependencies module aliasing.
+///
+/// Module 'Lib' imports module 'XLogging' via module aliasing and with various import attributes.
+/// Module 'User' imports 'Lib'.
+
+// RUN: %empty-directory(%t)
+// RUN: %{python} %utils/split_file.py -o %t %s
+
+/// Create AppleLogging.swiftmodule by aliasing XLogging
+// RUN: %target-swift-frontend -module-name AppleLogging -module-alias XLogging=AppleLogging %t/FileLogging.swift -emit-module -emit-module-path %t/AppleLogging.swiftmodule
+// RUN: test -f %t/AppleLogging.swiftmodule
+
+/// Scaned dependencies should contain real name AppleLogging
+// RUN: %target-swift-frontend -scan-dependencies  %t/FileLib.swift -module-alias XLogging=AppleLogging -I %t > %t/scandump.output
+// RUN: %FileCheck %s -check-prefix=CHECK-REAL-NAME -input-file  %t/scandump.output
+// CHECK-REAL-NAME-NOT: "swiftPrebuiltExternal": "XLogging"
+// CHECK-REAL-NAME-NOT: "compiledModulePath":{{.*}}XLogging.swiftmodule",
+// CHECK-REAL-NAME: "swiftPrebuiltExternal": "AppleLogging"
+// CHECK-REAL-NAME: "compiledModulePath":{{.*}}AppleLogging.swiftmodule",
+
+/// Create AppleLoggingIF.swiftinterface by aliasing XLogging
+///
+// RUN: %target-swift-frontend -module-name AppleLoggingIF %t/FileLogging.swift -module-alias XLogging=AppleLoggingIF -I %t -emit-module -emit-module-interface-path %t/AppleLoggingIF.swiftinterface -swift-version 5 -enable-library-evolution -I %t
+// RUN: test -f %t/AppleLoggingIF.swiftinterface
+
+/// Scaned dependencies should contain real name AppleLoggingIF
+// RUN: %target-swift-frontend -scan-dependencies  %t/FileLib.swift -module-alias XLogging=AppleLoggingIF -I %t > %t/scandumpIF.output
+// RUN: %FileCheck %s -check-prefix=CHECK-REAL-NAME-IF -input-file  %t/scandumpIF.output
+// CHECK-REAL-NAME-IF-NOT: "swift": "XLogging"
+// CHECK-REAL-NAME-IF-NOT: "moduleInterfacePath":{{.*}}XLogging.swiftinterface
+// CHECK-REAL-NAME-IF: "swift": "AppleLoggingIF"
+// CHECK-REAL-NAME-IF: "moduleInterfacePath":{{.*}}AppleLoggingIF.swiftinterface
+
+// BEGIN FileLogging.swift
+public struct Logger {
+  public init() {}
+  public func startLogging() {}
+}
+public func setup() -> XLogging.Logger? {
+  return Logger()
+}
+
+// BEGIN FileLib.swift
+import XLogging
+
+public func start() {
+  let it = Logger()
+  it.startLogging()
+}
+