Merge pull request #24209 from DougGregor/opaque-result-types-mangling-fixes

[Opaque result types] Fix mangling issues with opaque result types.

Author: DougGregor

include/swift/Serialization/ModuleFormat.h

@@ -52,7 +52,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 486; // Last change: Opaque result types
+const uint16_t SWIFTMODULE_VERSION_MINOR = 487; // Last change: Opaque result types generic params
 
 using DeclIDField = BCFixed<31>;
 
@@ -1101,6 +1101,7 @@ namespace decls_block {
     TypeIDField, // interface type for opaque type
     GenericEnvironmentIDField, // generic environment
     SubstitutionMapIDField // optional substitution map for underlying type
+    // trailed by generic parameters
   >;
 
   // TODO: remove the unnecessary FuncDecl components here

lib/AST/ASTMangler.cpp

@@ -985,7 +985,7 @@ void ASTMangler::appendType(Type type, const ValueDecl *forDecl) {
       // Use the fully elaborated explicit mangling.
       appendOpaqueDeclName(opaqueDecl);
       bool isFirstArgList = true;
-      appendBoundGenericArgs(opaqueDecl->getInnermostDeclContext(),
+      appendBoundGenericArgs(opaqueDecl,
                              opaqueType->getSubstitutions(),
                              isFirstArgList);
       appendRetroactiveConformances(opaqueType->getSubstitutions(),
@@ -1168,7 +1168,9 @@ unsigned ASTMangler::appendBoundGenericArgs(DeclContext *dc,
   auto decl = dc->getInnermostDeclarationDeclContext();
   if (!decl) return 0;
 
-  // For an extension declaration, use the nominal type declaration instead.
+  // For a non-protocol extension declaration, use the nominal type declaration
+  // instead.
+  //
   // This is important when extending a nested type, because the generic
   // parameters will line up with the (semantic) nesting of the nominal type.
   if (auto ext = dyn_cast<ExtensionDecl>(decl))

lib/Demangling/Demangler.cpp

@@ -690,7 +690,8 @@ NodePointer Demangler::demangleSymbolicReference(unsigned char rawKind,
     return nullptr;
 
   // Types register as substitutions even when symbolically referenced.
-  if (kind == SymbolicReferenceKind::Context)
+  if (kind == SymbolicReferenceKind::Context &&
+      resolved->getKind() != Node::Kind::OpaqueTypeDescriptorSymbolicReference)
     addSubstitution(resolved);
   return resolved;
 }

lib/Serialization/Deserialization.cpp

@@ -3099,6 +3099,9 @@ class swift::DeclDeserializer {
                                sig, interfaceType);
     declOrOffset = opaqueDecl;
 
+    if (auto genericParams = MF.maybeReadGenericParams(opaqueDecl))
+      opaqueDecl->setGenericParams(genericParams);
+
     auto genericEnv = MF.getGenericEnvironment(genericEnvID);
     opaqueDecl->setGenericEnvironment(genericEnv);
     if (underlyingTypeID)

lib/Serialization/Serialization.cpp

@@ -3437,6 +3437,7 @@ void Serializer::writeDecl(const Decl *D) {
                                  contextID, namingDeclID, interfaceSigID,
                                  interfaceTypeID, genericEnvID,
                                  underlyingTypeID);
+    writeGenericParams(opaqueDecl->getGenericParams());
     break;
   }
 

test/Interpreter/opaque_return_type_protocol_ext.swift

@@ -6,9 +6,16 @@ protocol P {
   func foo() -> AT
 }
 
+struct Adapter<T: P>: P {
+  var inner: T
+  func foo() -> some P {
+    return inner
+  }
+}
+
 extension P {
   func foo() -> some P {
-    return self
+    return Adapter(inner: self)
   }
 }
 
@@ -18,5 +25,5 @@ func getPAT<T: P>(_: T.Type) -> Any.Type {
 
 extension Int: P { }
 
-// CHECK: Int
+// CHECK: Adapter<Int>
 print(getPAT(Int.self))

test/Serialization/Inputs/OpaqueCrossFileB.swift

@@ -19,3 +19,9 @@ public struct Subscript {
     return FooImpl()
   }
 }
+
+extension Foo {
+  public func identity<T>(_: T) -> some Foo {
+    return self
+  }
+}

test/Serialization/opaque_cross_file.swift

@@ -1,10 +1,18 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-swift-frontend -emit-module-path %t/OpaqueCrossFileB.swiftmodule -module-name OpaqueCrossFileB %S/Inputs/OpaqueCrossFileB.swift
-// RUN: %target-swift-frontend -I %t -emit-ir -verify %s
+// RUN: %target-swift-frontend -I %t -emit-ir -verify %s | %FileCheck %s
 
 import OpaqueCrossFileB
 
 dump(anyFoo())
 dump(anyFooProp)
 dump(Subscript()[])
 
+public struct UsesAdapterMethod: Foo {
+  // Ensure that the mangling of the result type of adaptFoo correctly captures
+  // both the Self type and the parameter type.
+  // CHECK: @"symbolic _____y______SdQo_ 16OpaqueCrossFileB3FooPAAE8identityyQrqd__lFQO 17opaque_cross_file17UsesAdapterMethodV" =
+  public func adaptFoo(_ d: Double) -> some Foo {
+    return identity(d)
+  }
+}