ClangImporter: Fixes for non-copyable generics

Author: slavapestov

lib/AST/SwiftNameTranslation.cpp

@@ -215,7 +215,7 @@ swift::cxx_translation::getDeclRepresentation(const ValueDecl *VD) {
     return {Unsupported, UnrepresentableObjC};
   if (getActorIsolation(const_cast<ValueDecl *>(VD)).isActorIsolated())
     return {Unsupported, UnrepresentableIsolatedInActor};
-  llvm::Optional<CanGenericSignature> genericSignature;
+  GenericSignature genericSignature;
   // Don't expose @_alwaysEmitIntoClient decls as they require their
   // bodies to be emitted into client.
   if (VD->getAttrs().hasAttribute<AlwaysEmitIntoClientAttr>())
@@ -228,7 +228,7 @@ swift::cxx_translation::getDeclRepresentation(const ValueDecl *VD) {
             Feature::GenerateBindingsForThrowingFunctionsInCXX))
       return {Unsupported, UnrepresentableThrows};
     if (AFD->isGeneric())
-      genericSignature = AFD->getGenericSignature().getCanonicalSignature();
+      genericSignature = AFD->getGenericSignature();
   }
   if (const auto *typeDecl = dyn_cast<NominalTypeDecl>(VD)) {
     if (isa<ProtocolDecl>(typeDecl))
@@ -239,8 +239,7 @@ swift::cxx_translation::getDeclRepresentation(const ValueDecl *VD) {
     if (typeDecl->isGeneric()) {
       if (isa<ClassDecl>(VD))
         return {Unsupported, UnrepresentableGeneric};
-      genericSignature =
-          typeDecl->getGenericSignature().getCanonicalSignature();
+      genericSignature = typeDecl->getGenericSignature();
     }
     // Nested types are not yet supported.
     if (!typeDecl->hasClangNode() &&
@@ -280,9 +279,24 @@ swift::cxx_translation::getDeclRepresentation(const ValueDecl *VD) {
       }
     }
   }
+
   // Generic requirements are not yet supported in C++.
-  if (genericSignature && !genericSignature->getRequirements().empty())
-    return {Unsupported, UnrepresentableGenericRequirements};
+  if (genericSignature) {
+
+    // FIXME: We're using getRequirementsWithInverses() here as a shortcut for
+    // checking for "no requirements except the implied Copyable ones".
+    //
+    // Eventually you don't want to call getRequirementsWithInverses() at all;
+    // instead, the code here should walk the desugared requirements of the
+    // signature directly and handle everything.
+    SmallVector<Requirement, 2> reqs;
+    SmallVector<InverseRequirement, 2> inverseReqs;
+    genericSignature->getRequirementsWithInverses(reqs, inverseReqs);
+    assert(inverseReqs.empty() && "Non-copyable generics not supported here!");
+    if (!reqs.empty())
+      return {Unsupported, UnrepresentableGenericRequirements};
+  }
+
   return {Representable, llvm::None};
 }
 

lib/ClangImporter/ClangImporter.cpp

@@ -4742,7 +4742,9 @@ TinyPtrVector<ValueDecl *> CXXNamespaceMemberLookup::evaluate(
 
 // Just create a specialized function decl for "__swift_interopStaticCast"
 // using the types base and derived.
+static
 DeclRefExpr *getInteropStaticCastDeclRefExpr(ASTContext &ctx,
+                                             ModuleDecl *swiftModule,
                                              const clang::Module *owningModule,
                                              Type base, Type derived) {
   if (base->isForeignReferenceType() && derived->isForeignReferenceType()) {
@@ -4767,7 +4769,7 @@ DeclRefExpr *getInteropStaticCastDeclRefExpr(ASTContext &ctx,
   // this yet because it can't infer the "To" type.
   auto subst =
       SubstitutionMap::get(staticCastFn->getGenericSignature(), {derived, base},
-                           ArrayRef<ProtocolConformanceRef>());
+                           LookUpConformanceInModule(swiftModule));
   auto functionTemplate = const_cast<clang::FunctionTemplateDecl *>(
       cast<clang::FunctionTemplateDecl>(staticCastFn->getClangDecl()));
   auto spec = ctx.getClangModuleLoader()->instantiateCXXFunctionTemplate(
@@ -4789,6 +4791,7 @@ DeclRefExpr *getInteropStaticCastDeclRefExpr(ASTContext &ctx,
 // %2 = __swift_interopStaticCast<UnsafeMutablePointer<Base>?>(%1)
 // %3 = %2!
 // return %3.pointee
+static
 MemberRefExpr *getSelfInteropStaticCast(FuncDecl *funcDecl,
                                         NominalTypeDecl *baseStruct,
                                         NominalTypeDecl *derivedStruct) {
@@ -4840,7 +4843,7 @@ MemberRefExpr *getSelfInteropStaticCast(FuncDecl *funcDecl,
   selfPointer->setType(derivedPtrType);
 
   auto staticCastRefExpr = getInteropStaticCastDeclRefExpr(
-      ctx, baseStruct->getClangDecl()->getOwningModule(),
+      ctx, module, baseStruct->getClangDecl()->getOwningModule(),
       baseStruct->getSelfInterfaceType()->wrapInPointer(
           PTK_UnsafeMutablePointer),
       derivedStruct->getSelfInterfaceType()->wrapInPointer(

lib/PrintAsClang/ClangSyntaxPrinter.cpp

@@ -312,7 +312,7 @@ void ClangSyntaxPrinter::printGenericTypeParamTypeName(
 }
 
 void ClangSyntaxPrinter::printGenericSignature(
-    const CanGenericSignature &signature) {
+    GenericSignature signature) {
   os << "template<";
   llvm::interleaveComma(signature.getInnermostGenericParams(), os,
                         [&](const GenericTypeParamType *genericParamType) {
@@ -334,7 +334,7 @@ void ClangSyntaxPrinter::printGenericSignature(
 }
 
 void ClangSyntaxPrinter::printGenericSignatureInnerStaticAsserts(
-    const CanGenericSignature &signature) {
+    GenericSignature signature) {
   os << "#ifndef __cpp_concepts\n";
   llvm::interleave(
       signature.getInnermostGenericParams(), os,
@@ -348,7 +348,7 @@ void ClangSyntaxPrinter::printGenericSignatureInnerStaticAsserts(
 }
 
 void ClangSyntaxPrinter::printGenericSignatureParams(
-    const CanGenericSignature &signature) {
+    GenericSignature signature) {
   os << '<';
   llvm::interleaveComma(signature.getInnermostGenericParams(), os,
                         [&](const GenericTypeParamType *genericParamType) {

lib/PrintAsClang/ClangSyntaxPrinter.h

@@ -183,16 +183,16 @@ class ClangSyntaxPrinter {
 
   /// Print the Swift generic signature as C++ template declaration alongside
   /// its requirements.
-  void printGenericSignature(const CanGenericSignature &signature);
+  void printGenericSignature(GenericSignature signature);
 
   /// Print the `static_assert` statements used for legacy type-checking for
   /// generics in C++14/C++17 mode.
   void
-  printGenericSignatureInnerStaticAsserts(const CanGenericSignature &signature);
+  printGenericSignatureInnerStaticAsserts(GenericSignature signature);
 
   /// Print the C++ template parameters that should be passed for a given
   /// generic signature.
-  void printGenericSignatureParams(const CanGenericSignature &signature);
+  void printGenericSignatureParams(GenericSignature signature);
 
   /// Print the call to the C++ type traits that computes the underlying type /
   /// witness table pointer value that are passed to Swift for the given generic

lib/PrintAsClang/PrintClangValueType.cpp

@@ -180,21 +180,27 @@ void ClangValueTypePrinter::printValueTypeDecl(
     DeclAndTypePrinter &declAndTypePrinter) {
   // FIXME: Add support for generic structs.
   llvm::Optional<IRABIDetailsProvider::SizeAndAlignment> typeSizeAlign;
-  llvm::Optional<CanGenericSignature> genericSignature;
+  GenericSignature genericSignature;
   auto printGenericSignature = [&](raw_ostream &os) {
     if (!genericSignature)
       return;
-    ClangSyntaxPrinter(os).printGenericSignature(*genericSignature);
+    ClangSyntaxPrinter(os).printGenericSignature(genericSignature);
   };
   auto printGenericParamRefs = [&](raw_ostream &os) {
     if (!genericSignature)
       return;
-    ClangSyntaxPrinter(os).printGenericSignatureParams(*genericSignature);
+    ClangSyntaxPrinter(os).printGenericSignatureParams(genericSignature);
   };
   if (typeDecl->isGeneric()) {
-    genericSignature = typeDecl->getGenericSignature().getCanonicalSignature();
+    genericSignature = typeDecl->getGenericSignature();
+
     // FIXME: Support generic requirements.
-    assert(genericSignature->getRequirements().empty());
+    SmallVector<Requirement, 2> reqs;
+    SmallVector<InverseRequirement, 2> inverseReqs;
+    genericSignature->getRequirementsWithInverses(reqs, inverseReqs);
+    assert(inverseReqs.empty() && "Non-copyable generics not supported here!");
+    assert(reqs.empty());
+
     // FIXME: Can we make some better layout than opaque layout for generic
     // types.
   } else if (!typeDecl->isResilient()) {
@@ -275,7 +281,7 @@ void ClangValueTypePrinter::printValueTypeDecl(
   os << "public:\n";
   if (genericSignature)
     ClangSyntaxPrinter(os).printGenericSignatureInnerStaticAsserts(
-        *genericSignature);
+        genericSignature);
 
   // Print out the destructor.
   os << "  ";
@@ -457,7 +463,7 @@ void ClangValueTypePrinter::printValueTypeDecl(
         os << "public:\n";
         if (genericSignature)
           ClangSyntaxPrinter(os).printGenericSignatureInnerStaticAsserts(
-              *genericSignature);
+              genericSignature);
 
         os << "  static ";
         ClangSyntaxPrinter(os).printInlineForThunk();