Merge pull request #39887 from keith/ks/allow-explicit-swift-module-map-file-without-full-explicit-module-build

Allow -explicit-swift-module-map-file without full explicit module build

Author: nkcsgexi

lib/Frontend/Frontend.cpp

@@ -546,15 +546,17 @@ bool CompilerInstance::setUpModuleLoaders() {
   // If implicit modules are disabled, we need to install an explicit module
   // loader.
   bool ExplicitModuleBuild = Invocation.getFrontendOptions().DisableImplicitModules;
-  if (ExplicitModuleBuild) {
+  if (ExplicitModuleBuild || !Invocation.getSearchPathOptions().ExplicitSwiftModuleMap.empty()) {
     auto ESML = ExplicitSwiftModuleLoader::create(
         *Context,
         getDependencyTracker(), MLM,
         Invocation.getSearchPathOptions().ExplicitSwiftModuleMap,
         IgnoreSourceInfoFile);
     this->DefaultSerializedLoader = ESML.get();
     Context->addModuleLoader(std::move(ESML));
-  } else {
+  }
+
+  if (!ExplicitModuleBuild) {
     if (MLM != ModuleLoadingMode::OnlySerialized) {
       // We only need ModuleInterfaceLoader for implicit modules.
       auto PIML = ModuleInterfaceLoader::create(

test/ScanDependencies/can_import_with_map_and_implicit.swift

@@ -0,0 +1,21 @@
+// RUN: %empty-directory(%t)
+// RUN: mkdir -p %t/clang-module-cache
+// RUN: mkdir -p %t/inputs
+// RUN: mkdir -p %t/barinputs
+// RUN: echo "public func foo() {}" >> %t/foo.swift
+// RUN: %target-swift-frontend -emit-module -emit-module-path %t/inputs/Foo.swiftmodule -emit-module-doc-path %t/inputs/Foo.swiftdoc -emit-module-source-info -emit-module-source-info-path %t/inputs/Foo.swiftsourceinfo -module-cache-path %t.module-cache %t/foo.swift -module-name Foo
+// RUN: echo "public func bar() {}" >> %t/bar.swift
+// RUN: %target-swift-frontend -emit-module -emit-module-path %t/barinputs/Bar.swiftmodule -emit-module-doc-path %t/barinputs/Bar.swiftdoc -emit-module-source-info -emit-module-source-info-path %t/barinputs/Bar.swiftsourceinfo -module-cache-path %t.module-cache %t/bar.swift -module-name Bar
+
+// RUN: echo "[{" > %/t/inputs/map.json
+// RUN: echo "\"moduleName\": \"Foo\"," >> %/t/inputs/map.json
+// RUN: echo "\"modulePath\": \"%/t/inputs/Foo.swiftmodule\"," >> %/t/inputs/map.json
+// RUN: echo "\"docPath\": \"%/t/inputs/Foo.swiftdoc\"," >> %/t/inputs/map.json
+// RUN: echo "\"sourceInfoPath\": \"%/t/inputs/Foo.swiftsourceinfo\"," >> %/t/inputs/map.json
+// RUN: echo "\"isFramework\": false" >> %/t/inputs/map.json
+// RUN: echo "}]" >> %/t/inputs/map.json
+
+// RUN: not %target-swift-frontend -typecheck %s -explicit-swift-module-map-file %t/inputs/map.json -disable-implicit-swift-modules
+// RUN: %target-swift-frontend -typecheck %s -explicit-swift-module-map-file %t/inputs/map.json -I %t/barinputs
+import Foo
+import Bar