[cxx-interop] Implicitly import Cxx module

lib/ClangImporter/ClangImporter.cpp

@@ -3274,19 +3274,6 @@ static void getImportDecls(ClangModuleUnit *ClangUnit, const clang::Module *M,
     auto *ID = createImportDecl(Ctx, ClangUnit, ImportedMod, Exported);
     Results.push_back(ID);
   }
-
-  if (Ctx.LangOpts.EnableCXXInterop && requiresCPlusPlus(M)) {
-    // Try to load the Cxx module. We don't use it directly here, but we need to
-    // make sure that ASTContext has loaded this module.
-    auto *cxxModule = Ctx.getModuleByIdentifier(Ctx.Id_Cxx);
-    if (cxxModule) {
-      ImportPath::Builder builder(Ctx.Id_Cxx);
-      auto *importCxx =
-          ImportDecl::create(Ctx, ClangUnit, SourceLoc(), ImportKind::Module,
-                             SourceLoc(), builder.get());
-      Results.push_back(importCxx);
-    }
-  }
 }
 
 void ClangModuleUnit::getDisplayDecls(SmallVectorImpl<Decl*> &results, bool recursive) const {
@@ -3923,6 +3910,17 @@ void ClangModuleUnit::getImportedModulesForLookup(
   } else {
     clangModule->getExportedModules(imported);
     topLevel = clangModule->getTopLevelModule();
+
+    // If this is a C++ module, implicitly import the Cxx module, which contains
+    // definitions of Swift protocols that C++ types might conform to, such as
+    // CxxSequence.
+    if (owner.SwiftContext.LangOpts.EnableCXXInterop &&
+        requiresCPlusPlus(clangModule) && clangModule->Name != "CxxShim") {
+      auto *cxxModule =
+          owner.SwiftContext.getModuleByIdentifier(owner.SwiftContext.Id_Cxx);
+      if (cxxModule)
+        imports.push_back({ImportPath::Access(), cxxModule});
+    }
   }
 
   if (imported.empty()) {

lib/IRGen/GenDecl.cpp

@@ -474,6 +474,10 @@ void IRGenModule::emitSourceFile(SourceFile &SF) {
       this->addLinkLibrary(LinkLibrary("c++", LibraryKind::Library));
     else if (Context.LangOpts.Target.isOSLinux())
       this->addLinkLibrary(LinkLibrary("stdc++", LibraryKind::Library));
+
+    // Do not try to link Cxx with itself.
+    if (!getSwiftModule()->getName().is("Cxx"))
+      this->addLinkLibrary(LinkLibrary("swiftCxx", LibraryKind::Library));
   }
 
   // FIXME: It'd be better to have the driver invocation or build system that

test/Interop/Cxx/class/constructors-copy-irgen-android.swift

@@ -0,0 +1,26 @@
+// Target-specific tests for C++ copy constructor code generation.
+
+// RUN: %swift -module-name MySwift -target armv7-none-linux-androideabi -dump-clang-diagnostics -I %S/Inputs -enable-experimental-cxx-interop -emit-ir %s -parse-stdlib -parse-as-library -disable-legacy-type-info | %FileCheck %s -check-prefix=ITANIUM_ARM
+
+// REQUIRES: OS=linux-android || OS=linux-androideabi
+
+// REQUIRES: CODEGENERATOR=X86
+// REQUIRES: CODEGENERATOR=ARM
+
+import Constructors
+import TypeClassification
+
+// ITANIUM_ARM-LABEL: define protected swiftcc void @"$s7MySwift35copyWithUserProvidedCopyConstructorySo03HascdeF0V_ACtACF"
+// ITANIUM_ARM-SAME: (%TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG0:%.*]], %TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG1:%.*]], %TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG2:%.*]])
+// ITANIUM_ARM: [[ARG0_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG0]] to %struct.HasUserProvidedCopyConstructor*
+// ITANIUM_ARM: [[ARG2_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG2]] to %struct.HasUserProvidedCopyConstructor*
+// ITANIUM_ARM: call %struct.HasUserProvidedCopyConstructor* @_ZN30HasUserProvidedCopyConstructorC2ERKS_(%struct.HasUserProvidedCopyConstructor* [[ARG0_AS_STRUCT]], %struct.HasUserProvidedCopyConstructor* [[ARG2_AS_STRUCT]])
+// ITANIUM_ARM: [[ARG1_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG1]] to %struct.HasUserProvidedCopyConstructor*
+// ITANIUM_ARM: [[ARG2_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG2]] to %struct.HasUserProvidedCopyConstructor*
+// ITANIUM_ARM: call %struct.HasUserProvidedCopyConstructor* @_ZN30HasUserProvidedCopyConstructorC2ERKS_(%struct.HasUserProvidedCopyConstructor* [[ARG1_AS_STRUCT]], %struct.HasUserProvidedCopyConstructor* [[ARG2_AS_STRUCT]])
+// ITANIUM_ARM: ret void
+
+public func copyWithUserProvidedCopyConstructor(_ x: HasUserProvidedCopyConstructor)
+  -> (HasUserProvidedCopyConstructor, HasUserProvidedCopyConstructor) {
+  return (x, x)
+}

test/Interop/Cxx/class/constructors-copy-irgen-macosx.swift

@@ -0,0 +1,27 @@
+// Target-specific tests for C++ copy constructor code generation.
+
+// RUN: %swift -module-name MySwift -target x86_64-apple-macosx10.9 -dump-clang-diagnostics -I %S/Inputs -enable-experimental-cxx-interop -emit-ir %s -parse-stdlib -parse-as-library -disable-legacy-type-info | %FileCheck %s -check-prefix=ITANIUM_X64
+
+// REQUIRES: OS=macosx
+
+// REQUIRES: CODEGENERATOR=X86
+// REQUIRES: CODEGENERATOR=ARM
+
+
+import Constructors
+import TypeClassification
+
+// ITANIUM_X64-LABEL: define swiftcc void @"$s7MySwift35copyWithUserProvidedCopyConstructorySo03Has{{cdeF0V_ACtACF|efgH0V_ADtADF}}"
+// ITANIUM_X64-SAME: (%TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG0:%.*]], %TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG1:%.*]], %TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG2:%.*]])
+// ITANIUM_X64: [[ARG0_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG0]] to %struct.HasUserProvidedCopyConstructor*
+// ITANIUM_X64: [[ARG2_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG2]] to %struct.HasUserProvidedCopyConstructor*
+// ITANIUM_X64: call void @_ZN30HasUserProvidedCopyConstructorC1ERKS_(%struct.HasUserProvidedCopyConstructor* [[ARG0_AS_STRUCT]], %struct.HasUserProvidedCopyConstructor* [[ARG2_AS_STRUCT]])
+// ITANIUM_X64: [[ARG1_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG1]] to %struct.HasUserProvidedCopyConstructor*
+// ITANIUM_X64: [[ARG2_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG2]] to %struct.HasUserProvidedCopyConstructor*
+// ITANIUM_X64: call void @_ZN30HasUserProvidedCopyConstructorC1ERKS_(%struct.HasUserProvidedCopyConstructor* [[ARG1_AS_STRUCT]], %struct.HasUserProvidedCopyConstructor* [[ARG2_AS_STRUCT]])
+// ITANIUM_X64: ret void
+
+public func copyWithUserProvidedCopyConstructor(_ x: HasUserProvidedCopyConstructor)
+  -> (HasUserProvidedCopyConstructor, HasUserProvidedCopyConstructor) {
+  return (x, x)
+}

test/Interop/Cxx/class/constructors-copy-irgen-windows.swift

@@ -0,0 +1,27 @@
+// Target-specific tests for C++ copy constructor code generation.
+
+// RUN: %swift -module-name MySwift -target x86_64-unknown-windows-msvc -dump-clang-diagnostics -I %S/Inputs -enable-experimental-cxx-interop -emit-ir %s -parse-stdlib -parse-as-library -disable-legacy-type-info | %FileCheck %s -check-prefix=MICROSOFT_X64
+
+// REQUIRES: OS=windows-msvc
+
+// REQUIRES: CODEGENERATOR=X86
+// REQUIRES: CODEGENERATOR=ARM
+
+
+import Constructors
+import TypeClassification
+
+// MICROSOFT_X64-LABEL: define dllexport swiftcc void @"$s7MySwift35copyWithUserProvidedCopyConstructorySo03Has{{efgH0V_ADtADF|cdeF0V_ACtACF}}"
+// MICROSOFT_X64-SAME: (%TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG0:%.*]], %TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG1:%.*]], %TSo30HasUserProvidedCopyConstructorV* {{.*}}[[ARG2:%.*]])
+// MICROSOFT_X64: [[ARG0_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG0]] to %struct.HasUserProvidedCopyConstructor*
+// MICROSOFT_X64: [[ARG2_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG2]] to %struct.HasUserProvidedCopyConstructor*
+// MICROSOFT_X64: call %struct.HasUserProvidedCopyConstructor* @"??0HasUserProvidedCopyConstructor@@QEAA@AEBU0@@Z"(%struct.HasUserProvidedCopyConstructor* [[ARG0_AS_STRUCT]], %struct.HasUserProvidedCopyConstructor* [[ARG2_AS_STRUCT]])
+// MICROSOFT_X64: [[ARG1_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG1]] to %struct.HasUserProvidedCopyConstructor*
+// MICROSOFT_X64: [[ARG2_AS_STRUCT:%.*]] = bitcast %TSo30HasUserProvidedCopyConstructorV* [[ARG2]] to %struct.HasUserProvidedCopyConstructor*
+// MICROSOFT_X64: call %struct.HasUserProvidedCopyConstructor* @"??0HasUserProvidedCopyConstructor@@QEAA@AEBU0@@Z"(%struct.HasUserProvidedCopyConstructor* [[ARG1_AS_STRUCT]], %struct.HasUserProvidedCopyConstructor* [[ARG2_AS_STRUCT]])
+// MICROSOFT_X64: ret void
+
+public func copyWithUserProvidedCopyConstructor(_ x: HasUserProvidedCopyConstructor)
+  -> (HasUserProvidedCopyConstructor, HasUserProvidedCopyConstructor) {
+  return (x, x)
+}

test/Interop/Cxx/class/constructors-irgen-android.swift

@@ -0,0 +1,57 @@
+// Target-specific tests for C++ constructor call code generation.
+
+// RUN: %swift -module-name MySwift -target armv7-unknown-linux-androideabi -dump-clang-diagnostics -I %S/Inputs -enable-experimental-cxx-interop -emit-ir %s -parse-stdlib -parse-as-library -disable-legacy-type-info | %FileCheck %s -check-prefix=ITANIUM_ARM
+
+// REQUIRES: OS=linux-android || OS=linux-androideabi
+
+// REQUIRES: CODEGENERATOR=X86
+// REQUIRES: CODEGENERATOR=ARM
+
+import Constructors
+import TypeClassification
+
+public func createHasVirtualBase() -> HasVirtualBase {
+  // ITANIUM_ARM: define protected swiftcc void @"$s7MySwift20createHasVirtualBaseSo0bcD0VyF"(%TSo14HasVirtualBaseV* noalias nocapture sret({{.*}}) %0)
+  // To verify that the thunk is inlined, make sure there's no intervening
+  // `define`, i.e. the call to the C++ constructor happens in
+  // createHasVirtualBase(), not some later function.
+  // ITANIUM_ARM-NOT: define
+  // Note `this` return type.
+  // ITANIUM_ARM: call %struct.HasVirtualBase* @_ZN14HasVirtualBaseC1E7ArgType(%struct.HasVirtualBase* %{{[0-9]+}}, [1 x i32] %{{[0-9]+}})
+  return HasVirtualBase(ArgType())
+}
+
+public func createImplicitDefaultConstructor() -> ImplicitDefaultConstructor {
+  // ITANIUM_ARM: define protected swiftcc i32 @"$s7MySwift32createImplicitDefaultConstructorSo0bcD0VyF"()
+  // ITANIUM_ARM-NOT: define
+  // Note `this` return type.
+  // ITANIUM_ARM: call %struct.ImplicitDefaultConstructor* @_ZN26ImplicitDefaultConstructorC2Ev(%struct.ImplicitDefaultConstructor* %{{[0-9]+}})
+  return ImplicitDefaultConstructor()
+}
+
+public func createStructWithSubobjectCopyConstructorAndValue() {
+  // ITANIUM_ARM-LABEL: define protected swiftcc void @"$s7MySwift48createStructWithSubobjectCopyConstructorAndValueyyF"()
+  // ITANIUM_ARM: [[MEMBER:%.*]] = alloca %TSo33StructWithCopyConstructorAndValueV
+  // ITANIUM_ARM: [[OBJ:%.*]] = alloca %TSo42StructWithSubobjectCopyConstructorAndValueV
+  // ITANIUM_ARM: [[TMP:%.*]] = alloca %TSo33StructWithCopyConstructorAndValueV
+  // ITANIUM_ARM: [[MEMBER_AS_STRUCT:%.*]] = bitcast %TSo33StructWithCopyConstructorAndValueV* [[MEMBER]] to %struct.StructWithCopyConstructorAndValue*
+  // ITANIUM_ARM: call %struct.StructWithCopyConstructorAndValue* @_ZN33StructWithCopyConstructorAndValueC2Ev(%struct.StructWithCopyConstructorAndValue* [[MEMBER_AS_STRUCT]])
+  // ITANIUM_ARM: [[TMP_STRUCT:%.*]] = bitcast %TSo33StructWithCopyConstructorAndValueV* [[TMP]] to %struct.StructWithCopyConstructorAndValue*
+  // ITANIUM_ARM: [[MEMBER_AS_STRUCT_2:%.*]] = bitcast %TSo33StructWithCopyConstructorAndValueV* [[MEMBER]] to %struct.StructWithCopyConstructorAndValue*
+  // ITANIUM_ARM: call %struct.StructWithCopyConstructorAndValue* @_ZN33StructWithCopyConstructorAndValueC2ERKS_(%struct.StructWithCopyConstructorAndValue* [[TMP_STRUCT]], %struct.StructWithCopyConstructorAndValue* [[MEMBER_AS_STRUCT_2]])
+  // ITANIUM_ARM: ret void
+  let member = StructWithCopyConstructorAndValue()
+  let obj = StructWithSubobjectCopyConstructorAndValue(member: member)
+}
+
+public func createTemplatedConstructor() {
+  // ITANIUM_ARM-LABEL: define protected swiftcc void @"$s7MySwift26createTemplatedConstructoryyF"()
+  // ITANIUM_ARM: [[OBJ:%.*]] = alloca %TSo20TemplatedConstructorV
+  // ITANIUM_ARM: [[IVAL:%.*]] = load [1 x i32], [1 x i32]*
+  // ITANIUM_ARM: [[OBJ_AS_STRUCT:%.*]] = bitcast %TSo20TemplatedConstructorV* [[OBJ]] to %struct.TemplatedConstructor*
+  // ITANIUM_ARM:  call %struct.TemplatedConstructor* @_ZN20TemplatedConstructorC2I7ArgTypeEET_(%struct.TemplatedConstructor* [[OBJ_AS_STRUCT]], [1 x i32] [[IVAL]])
+  // ITANIUM_ARM: ret void
+
+  // ITANIUM_ARM-LABEL: define {{.*}}%struct.TemplatedConstructor* @_ZN20TemplatedConstructorC2I7ArgTypeEET_(%struct.TemplatedConstructor* {{.*}}, [1 x i32] {{.*}})
+  let templated = TemplatedConstructor(ArgType())
+}