[Sema] Always install property wrappers during qualified lookup

Revert the property wrappers part of dd51251.

Every part of the qualified lookup stack needs to synthesize property
wrapper members, otherwise we'll be subject to the relativistic effects
of semantic lookups in different files. Besides, Codable was the main
source of cycles and circularity under the old scheme.

Resolves rdar://59531889

Author: CodaFi

lib/AST/NameLookup.cpp

@@ -1534,6 +1534,34 @@ bool DeclContext::lookupQualified(Type type,
   return lookupQualified(nominalTypesToLookInto, member, options, decls);
 }
 
+static void installPropertyWrapperMembersIfNeeded(NominalTypeDecl *target,
+                                                  DeclNameRef member) {
+  auto &Context = target->getASTContext();
+  auto baseName = member.getBaseName();
+  if (!member.isSimpleName() || baseName.isSpecial())
+    return;
+
+  if ((!baseName.getIdentifier().str().startswith("$") &&
+       !baseName.getIdentifier().str().startswith("_")) ||
+      baseName.getIdentifier().str().size() <= 1) {
+    return;
+  }
+
+  // $- and _-prefixed variables can be generated by properties that have
+  // attached property wrappers.
+  auto originalPropertyName =
+      Context.getIdentifier(baseName.getIdentifier().str().substr(1));
+  for (auto member : target->lookupDirect(originalPropertyName)) {
+    if (auto var = dyn_cast<VarDecl>(member)) {
+      if (var->hasAttachedPropertyWrapper()) {
+        auto sourceFile = var->getDeclContext()->getParentSourceFile();
+        if (sourceFile && sourceFile->Kind != SourceFileKind::Interface)
+          (void)var->getPropertyWrapperBackingProperty();
+      }
+    }
+  }
+}
+
 bool DeclContext::lookupQualified(ArrayRef<NominalTypeDecl *> typeDecls,
                                   DeclNameRef member,
                                   NLOptions options,
@@ -1584,6 +1612,7 @@ QualifiedLookupRequest::evaluate(Evaluator &eval, const DeclContext *DC,
 
   // Visit all of the nominal types we know about, discovering any others
   // we need along the way.
+  auto &ctx = DC->getASTContext();
   bool wantProtocolMembers = (options & NL_ProtocolMembers);
   while (!stack.empty()) {
     auto current = stack.back();
@@ -1592,6 +1621,11 @@ QualifiedLookupRequest::evaluate(Evaluator &eval, const DeclContext *DC,
     if (tracker)
       tracker->addUsedMember({current, member.getBaseName()},isLookupCascading);
 
+    // Make sure we've resolved property wrappers, if we need them.
+    if (ctx.areSemanticQueriesEnabled()) {
+      installPropertyWrapperMembersIfNeeded(current, member);
+    }
+
     // Look for results within the current nominal type and its extensions.
     bool currentIsProtocol = isa<ProtocolDecl>(current);
     auto flags = OptionSet<NominalTypeDecl::LookupDirectFlags>();

lib/Sema/TypeCheckNameLookup.cpp

@@ -22,7 +22,6 @@
 #include "swift/AST/NameLookup.h"
 #include "swift/AST/NameLookupRequests.h"
 #include "swift/AST/ProtocolConformance.h"
-#include "swift/AST/SourceFile.h"
 #include "swift/Basic/TopCollection.h"
 #include <algorithm>
 
@@ -230,47 +229,10 @@ convertToUnqualifiedLookupOptions(NameLookupOptions options) {
   return newOptions;
 }
 
-static void installPropertyWrapperMembersIfNeeded(NominalTypeDecl *target,
-                                                  DeclName member) {
-  if (!target) return;
-
-  auto &Context = target->getASTContext();
-  auto baseName = member.getBaseName();
-  if (!member.isSimpleName() || baseName.isSpecial())
-    return;
-
-  if ((!baseName.getIdentifier().str().startswith("$") &&
-       !baseName.getIdentifier().str().startswith("_")) ||
-      baseName.getIdentifier().str().size() <= 1) {
-    return;
-  }
-
-  // $- and _-prefixed variables can be generated by properties that have
-  // attached property wrappers.
-  auto originalPropertyName =
-      Context.getIdentifier(baseName.getIdentifier().str().substr(1));
-  for (auto member : target->lookupDirect(originalPropertyName)) {
-    if (auto var = dyn_cast<VarDecl>(member)) {
-      if (var->hasAttachedPropertyWrapper()) {
-        auto sourceFile = var->getDeclContext()->getParentSourceFile();
-        if (sourceFile && sourceFile->Kind != SourceFileKind::Interface)
-          (void)var->getPropertyWrapperBackingProperty();
-      }
-    }
-  }
-}
-
 LookupResult TypeChecker::lookupUnqualified(DeclContext *dc, DeclNameRef name,
                                             SourceLoc loc,
                                             NameLookupOptions options) {
   auto ulOptions = convertToUnqualifiedLookupOptions(options);
-
-  // Make sure we've resolved implicit members, if we need them.
-  if (auto *current = dc->getInnermostTypeContext()) {
-    installPropertyWrapperMembersIfNeeded(current->getSelfNominalTypeDecl(),
-                                          name.getFullName());
-  }
-
   auto &ctx = dc->getASTContext();
   auto descriptor = UnqualifiedLookupDescriptor(name, dc, loc, ulOptions);
   auto lookup = evaluateOrDefault(ctx.evaluator,
@@ -365,7 +327,6 @@ LookupResult TypeChecker::lookupMember(DeclContext *dc,
   // Make sure we've resolved implicit members, if we need them.
   if (auto *current = type->getAnyNominal()) {
     current->synthesizeSemanticMembersIfNeeded(name.getFullName());
-    installPropertyWrapperMembersIfNeeded(current, name.getFullName());
   }
 
   LookupResultBuilder builder(result, dc, options);
@@ -445,7 +406,6 @@ LookupTypeResult TypeChecker::lookupMemberType(DeclContext *dc,
   // Make sure we've resolved implicit members, if we need them.
   if (auto *current = type->getAnyNominal()) {
     current->synthesizeSemanticMembersIfNeeded(name.getFullName());
-    installPropertyWrapperMembersIfNeeded(current, name.getFullName());
   }
 
   if (!dc->lookupQualified(type, name, subOptions, decls))

test/decl/var/Inputs/property_wrappers_multi_file_2.swift

@@ -0,0 +1,23 @@
+@propertyWrapper
+public struct WrapGod<T> {
+  private var value: T
+  
+  public init(wrappedValue: T) {
+    value = wrappedValue
+  }
+  
+  public var wrappedValue: T {
+    get { value }
+    set { value = newValue }
+  }
+  
+  public var projectedValue: T {
+    get { value }
+    set { value = newValue }
+  }
+}
+
+class BaseClass {
+  @WrapGod final var value: Int = 42
+  init() {}
+}

test/decl/var/property_wrappers_multi_file.swift

@@ -0,0 +1,10 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend %s -verify -O -primary-file %s %S/Inputs/property_wrappers_multi_file_2.swift -c -o %t/use.o
+// RUN: %target-swift-frontend %s -verify -O -primary-file %S/Inputs/property_wrappers_multi_file_2.swift %s -c -o %t/def.o
+
+final class Subclass: BaseClass {
+  override init() {
+    super.init()
+    $value = 42
+  }
+}