[Macros] Cope with local types and opaque result types in macros and expansions.

include/swift/Parse/Parser.h

@@ -156,6 +156,7 @@ class Parser {
   /// ASTScopes are not created in inactive clauses and lookups to decls will fail.
   bool InInactiveClauseEnvironment = false;
   bool InSwiftKeyPath = false;
+  bool InFreestandingMacroArgument = false;
 
   /// Whether we should delay parsing nominal type, extension, and function
   /// bodies.

lib/AST/TypeSubstitution.cpp

@@ -1043,8 +1043,8 @@ static bool canSubstituteTypeInto(Type ty, const DeclContext *dc,
 
     // In the same file any visibility is okay.
     if (!dc->isModuleContext() &&
-        typeDecl->getDeclContext()->getParentSourceFile() ==
-        dc->getParentSourceFile())
+        typeDecl->getDeclContext()->getOutermostParentSourceFile() ==
+        dc->getOutermostParentSourceFile())
       return true;
 
     return typeDecl->getEffectiveAccess() > AccessLevel::FilePrivate;

lib/Parse/ParseDecl.cpp

@@ -5209,7 +5209,7 @@ void Parser::recordLocalType(TypeDecl *TD) {
   if (!TD->getDeclContext()->isLocalContext())
     return;
 
-  if (!InInactiveClauseEnvironment)
+  if (!InInactiveClauseEnvironment && !InFreestandingMacroArgument)
     SF.getOutermostParentSourceFile()->LocalTypeDecls.insert(TD);
 }
 
@@ -7980,7 +7980,7 @@ Parser::parseDeclVar(ParseDeclOptions Flags,
     if (auto typedPattern = dyn_cast<TypedPattern>(pattern)) {
       hasOpaqueReturnTy = typedPattern->getTypeRepr()->hasOpaque();
     }
-    auto sf = CurDeclContext->getParentSourceFile();
+    auto sf = CurDeclContext->getOutermostParentSourceFile();
 
     // Configure all vars with attributes, 'static' and parent pattern.
     pattern->forEachVariable([&](VarDecl *VD) {
@@ -7992,7 +7992,8 @@ Parser::parseDeclVar(ParseDeclOptions Flags,
       setOriginalDeclarationForDifferentiableAttributes(Attributes, VD);
 
       Decls.push_back(VD);
-      if (hasOpaqueReturnTy && sf && !InInactiveClauseEnvironment) {
+      if (hasOpaqueReturnTy && sf && !InInactiveClauseEnvironment
+          && !InFreestandingMacroArgument) {
         sf->addUnvalidatedDeclWithOpaqueResultType(VD);
       }
     });
@@ -8282,8 +8283,8 @@ ParserResult<FuncDecl> Parser::parseDeclFunc(SourceLoc StaticLoc,
 
   // Let the source file track the opaque return type mapping, if any.
   if (FuncRetTy && FuncRetTy->hasOpaque() &&
-      !InInactiveClauseEnvironment) {
-    if (auto sf = CurDeclContext->getParentSourceFile()) {
+      !InInactiveClauseEnvironment && !InFreestandingMacroArgument) {
+    if (auto sf = CurDeclContext->getOutermostParentSourceFile()) {
       sf->addUnvalidatedDeclWithOpaqueResultType(FD);
     }
   }
@@ -9230,8 +9231,8 @@ Parser::parseDeclSubscript(SourceLoc StaticLoc,
 
   // Let the source file track the opaque return type mapping, if any.
   if (ElementTy.get() && ElementTy.get()->hasOpaque() &&
-      !InInactiveClauseEnvironment) {
-    if (auto sf = CurDeclContext->getParentSourceFile()) {
+      !InInactiveClauseEnvironment && !InFreestandingMacroArgument) {
+    if (auto sf = CurDeclContext->getOutermostParentSourceFile()) {
       sf->addUnvalidatedDeclWithOpaqueResultType(Subscript);
     }
   }

lib/Parse/ParseExpr.cpp

@@ -2338,6 +2338,8 @@ ParserStatus Parser::parseFreestandingMacroExpansion(
       diagnose(leftAngleLoc, diag::while_parsing_as_left_angle_bracket);
   }
 
+  llvm::SaveAndRestore<bool> inMacroArgument(InFreestandingMacroArgument, true);
+
   if (Tok.isFollowingLParen()) {
     auto result = parseArgumentList(tok::l_paren, tok::r_paren, isExprBasic,
                                     /*allowTrailingClosure*/ true);

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -1850,6 +1850,10 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
   ASTContext &getASTContext() const { return Ctx; }
   void addDelayedFunction(AbstractFunctionDecl *AFD) {
     if (!SF) return;
+
+    while (auto enclosingSF = SF->getEnclosingSourceFile())
+      SF = enclosingSF;
+
     SF->DelayedFunctions.push_back(AFD);
   }
 

test/Macros/macro_expand.swift

@@ -198,6 +198,22 @@ public struct Outer {
 // CHECK: (2, "a + b")
 testStringify(a: 1, b: 1)
 
+protocol P { }
+extension Int: P { }
+
+// Stringify with closures that have local types.
+@available(SwiftStdlib 5.1, *)
+func testStringifyWithLocalTypes() {
+  _ = #stringify({
+    struct LocalType: P {
+      static var name: String = "Taylor"
+      var something: some P { self }
+    }
+
+    func f() -> some P { return LocalType().something }
+  })
+}
+
 func maybeThrowing() throws -> Int { 5 }
 
 #if TEST_DIAGNOSTICS