Merge pull request #63587 from apple/revert-63505-issue-63455

Revert "[CSGen] Handle recursive use of variable declarations"

Author: xedin

lib/Sema/CSGen.cpp

@@ -1354,33 +1354,20 @@ namespace {
     Type visitDeclRefExpr(DeclRefExpr *E) {
       auto locator = CS.getConstraintLocator(E);
 
-      auto invalidateReference = [&]() -> Type {
-        auto *hole = CS.createTypeVariable(locator, TVO_CanBindToHole);
-        (void)CS.recordFix(AllowRefToInvalidDecl::create(CS, locator));
-        CS.setType(E, hole);
-        return hole;
-      };
-
       Type knownType;
       if (auto *VD = dyn_cast<VarDecl>(E->getDecl())) {
         knownType = CS.getTypeIfAvailable(VD);
         if (!knownType)
           knownType = CS.getVarType(VD);
 
         if (knownType) {
-          // An out-of-scope type variable could be a type of a declaration
-          // only in diagnostic mode when invalid variable declaration is
-          // recursively referenced inside of a multi-statement closure
-          // located somewhere within its initializer e.g.:
-          // `let x = [<call>] { ... print(x) }`
-          if (auto *typeVar = knownType->getAs<TypeVariableType>()) {
-            if (!CS.isActiveTypeVariable(typeVar))
-              return invalidateReference();
-          }
-
           // If the known type has an error, bail out.
           if (knownType->hasError()) {
-            return invalidateReference();
+            auto *hole = CS.createTypeVariable(locator, TVO_CanBindToHole);
+            (void)CS.recordFix(AllowRefToInvalidDecl::create(CS, locator));
+            if (!CS.hasType(E))
+              CS.setType(E, hole);
+            return hole;
           }
 
           if (!knownType->hasPlaceholder()) {
@@ -1397,7 +1384,10 @@ namespace {
       // (in getTypeOfReference) so we can match non-error param types.
       if (!knownType && E->getDecl()->isInvalid() &&
           !CS.isForCodeCompletion()) {
-        return invalidateReference();
+        auto *hole = CS.createTypeVariable(locator, TVO_CanBindToHole);
+        (void)CS.recordFix(AllowRefToInvalidDecl::create(CS, locator));
+        CS.setType(E, hole);
+        return hole;
       }
 
       // Create an overload choice referencing this declaration and immediately

lib/Sema/CSSyntacticElement.cpp

@@ -74,7 +74,7 @@ class TypeVariableRefFinder : public ASTWalker {
     if (auto *DRE = dyn_cast<DeclRefExpr>(expr)) {
       auto *decl = DRE->getDecl();
 
-      if (auto type = CS.getTypeIfAvailable(decl)) {
+      if (auto type = CS.getTypeIfAvailable(DRE->getDecl())) {
         auto &ctx = CS.getASTContext();
         // If this is not one of the closure parameters which
         // is inferrable from the body, let's replace type

test/expr/closure/multi_statement.swift

@@ -650,16 +650,3 @@ func test_that_closures_are_attempted_in_order() {
     return false
   }
 }
-
-// https://github.com/apple/swift/issues/63455
-func test_recursive_var_reference_in_multistatement_closure() {
-  func takeClosure(_ x: () -> Void) {}
-
-  func test(optionalInt: Int?) {
-    takeClosure {
-      let int = optionalInt { // expected-error {{cannot call value of non-function type 'Int?'}}
-        print(int)
-      }
-    }
-  }
-}