Merge pull request #63468 from angela-laar/implicit-some-reconstruction

[Sema] Record opaque type decls for type reconstruction after creation instead of in the parser

Author: angela-laar

include/swift/AST/SourceFile.h

@@ -143,12 +143,19 @@ class SourceFile final : public FileUnit {
   /// The scope map that describes this source file.
   NullablePtr<ASTScope> Scope = nullptr;
 
+   /// The set of parsed decls with opaque return types that have not yet
+   /// been validated.
+   llvm::SetVector<ValueDecl *> UnvalidatedDeclsWithOpaqueReturnTypes;
+  
   /// The set of validated opaque return type decls in the source file.
   llvm::SmallVector<OpaqueTypeDecl *, 4> OpaqueReturnTypes;
   llvm::StringMap<OpaqueTypeDecl *> ValidatedOpaqueReturnTypes;
-  /// The set of parsed decls with opaque return types that have not yet
-  /// been validated.
-  llvm::SetVector<ValueDecl *> UnvalidatedDeclsWithOpaqueReturnTypes;
+  /// The set of opaque type decls that have not yet been validated.
+  ///
+  /// \note This is populated as opaque type decls are created. Validation
+  /// requires mangling the naming decl, which would lead to circularity
+  /// if it were done from OpaqueResultTypeRequest.
+  llvm::SetVector<OpaqueTypeDecl *> UnvalidatedOpaqueReturnTypes;
 
   /// The set of declarations with valid runtime discoverable attributes
   /// located in the source file.
@@ -668,6 +675,10 @@ class SourceFile final : public FileUnit {
     UnvalidatedDeclsWithOpaqueReturnTypes.insert(vd);
   }
 
+  void addOpaqueResultTypeDecl(OpaqueTypeDecl *decl) {
+    UnvalidatedOpaqueReturnTypes.insert(decl);
+  }
+
   ArrayRef<OpaqueTypeDecl *> getOpaqueReturnTypeDecls();
 
   /// Returns true if the source file contains concurrency in the top-level

include/swift/Parse/Parser.h

@@ -172,9 +172,7 @@ class Parser {
 
   bool InPoundLineEnvironment = false;
   bool InPoundIfEnvironment = false;
-  /// Do not call \c addUnvalidatedDeclWithOpaqueResultType when in an inactive
-  /// clause because ASTScopes are not created in those contexts and lookups to
-  /// those decls will fail.
+  /// ASTScopes are not created in inactive clauses and lookups to decls will fail.
   bool InInactiveClauseEnvironment = false;
   bool InSwiftKeyPath = false;
 

lib/Sema/TypeCheckGeneric.cpp

@@ -262,6 +262,13 @@ OpaqueResultTypeRequest::evaluate(Evaluator &evaluator,
 
   auto metatype = MetatypeType::get(interfaceType);
   opaqueDecl->setInterfaceType(metatype);
+
+  // Record the opaque return type decl in the parent source file,
+  // which will be used in IRGen to emit all opaque type decls
+  // in a Swift module for type reconstruction.
+  if (auto *sourceFile = dc->getParentSourceFile())
+    sourceFile->addOpaqueResultTypeDecl(opaqueDecl);
+
   return opaqueDecl;
 }
 

test/IRGen/Inputs/implicit_some_b.swift

@@ -0,0 +1,3 @@
+func bar() {
+  let x = foo()
+}

test/IRGen/implicit_some_a.swift

@@ -0,0 +1,6 @@
+// RUN: %target-swift-frontend -emit-ir -disable-availability-checking -primary-file %s %S/Inputs/implicit_some_b.swift -enable-experimental-feature ImplicitSome
+
+protocol P {}
+struct S: P {}
+
+func foo() -> P { return S() }

test/type/implicit_some/opaque_parameters.swift

@@ -64,7 +64,7 @@ func consumingB(fn: FnType<P>) { } // expected-error{{'some' cannot appear in pa
 
 // TO-DO Handle plain generic opaque parameters
 func takePrimaryCollections(
-  _ strings:some  Collection<String>,
+  _ strings:some Collection<String>,
   _ ints : some Collection<Int>
 ) {
   for s in strings {