[NFC] Hide VarDecl::setIntroducer

Author: CodaFi

include/swift/AST/Decl.h

@@ -5060,6 +5060,13 @@ class VarDecl : public AbstractStorageDecl {
           SourceLoc nameLoc, Identifier name, DeclContext *dc,
           StorageIsMutable_t supportsMutation);
 
+protected:
+  // Only \c ParamDecl::setSpecifier is allowed to flip this - and it's also
+  // on the way out of that business.
+  void setIntroducer(Introducer value) {
+    Bits.VarDecl.Introducer = uint8_t(value);
+  }
+
 public:
   VarDecl(bool isStatic, Introducer introducer,
           SourceLoc nameLoc, Identifier name, DeclContext *dc)
@@ -5263,10 +5270,6 @@ class VarDecl : public AbstractStorageDecl {
     return Introducer(Bits.VarDecl.Introducer);
   }
 
-  void setIntroducer(Introducer value) {
-    Bits.VarDecl.Introducer = uint8_t(value);
-  }
-
   CaptureListExpr *getParentCaptureList() const {
     if (!Parent)
       return nullptr;

lib/Sema/DerivedConformanceActor.cpp

@@ -138,10 +138,10 @@ static ValueDecl *deriveActor_unownedExecutor(DerivedConformance &derived) {
   }
   Type executorType = executorDecl->getDeclaredInterfaceType();
 
-  auto propertyPair =
-    derived.declareDerivedProperty(ctx.Id_unownedExecutor,
-                                   executorType, executorType,
-                                   /*static*/ false, /*final*/ false);
+  auto propertyPair = derived.declareDerivedProperty(
+      DerivedConformance::SynthesizedIntroducer::Var, ctx.Id_unownedExecutor,
+      executorType, executorType,
+      /*static*/ false, /*final*/ false);
   auto property = propertyPair.first;
   property->setSynthesized(true);
   property->getAttrs().add(new (ctx) SemanticsAttr(SEMANTICS_DEFAULT_ACTOR,

lib/Sema/DerivedConformanceAdditiveArithmetic.cpp

@@ -302,7 +302,8 @@ static ValueDecl *deriveAdditiveArithmetic_zero(DerivedConformance &derived) {
   VarDecl *propDecl;
   PatternBindingDecl *pbDecl;
   std::tie(propDecl, pbDecl) = derived.declareDerivedProperty(
-      C.Id_zero, returnInterfaceTy, returnTy, /*isStatic*/ true,
+      DerivedConformance::SynthesizedIntroducer::Var, C.Id_zero,
+      returnInterfaceTy, returnTy, /*isStatic*/ true,
       /*isFinal*/ true);
 
   // Create property getter.

lib/Sema/DerivedConformanceCaseIterable.cpp

@@ -98,9 +98,9 @@ ValueDecl *DerivedConformance::deriveCaseIterable(ValueDecl *requirement) {
 
   VarDecl *propDecl;
   PatternBindingDecl *pbDecl;
-  std::tie(propDecl, pbDecl) =
-      declareDerivedProperty(Context.Id_allCases, returnTy, returnTy,
-                             /*isStatic=*/true, /*isFinal=*/true);
+  std::tie(propDecl, pbDecl) = declareDerivedProperty(
+      SynthesizedIntroducer::Var, Context.Id_allCases, returnTy, returnTy,
+      /*isStatic=*/true, /*isFinal=*/true);
 
   // Define the getter.
   auto *getterDecl = addGetterToReadOnlyDerivedProperty(propDecl, returnTy);

lib/Sema/DerivedConformanceCodingKey.cpp

@@ -160,9 +160,9 @@ static ValueDecl *deriveProperty(DerivedConformance &derived, Type type,
   // Define the property.
   VarDecl *propDecl;
   PatternBindingDecl *pbDecl;
-  std::tie(propDecl, pbDecl) =
-      derived.declareDerivedProperty(name, type, type,
-                                     /*isStatic=*/false, /*isFinal=*/false);
+  std::tie(propDecl, pbDecl) = derived.declareDerivedProperty(
+      DerivedConformance::SynthesizedIntroducer::Var, name, type, type,
+      /*isStatic=*/false, /*isFinal=*/false);
 
   // Define the getter.
   auto *getterDecl = derived.addGetterToReadOnlyDerivedProperty(

lib/Sema/DerivedConformanceDistributedActor.cpp

@@ -112,8 +112,8 @@ static ValueDecl *deriveDistributedActor_id(DerivedConformance &derived) {
   VarDecl *propDecl;
   PatternBindingDecl *pbDecl;
   std::tie(propDecl, pbDecl) = derived.declareDerivedProperty(
-      C.Id_id,
-      propertyType, propertyType,
+      DerivedConformance::SynthesizedIntroducer::Let, C.Id_id, propertyType,
+      propertyType,
       /*isStatic=*/false, /*isFinal=*/true);
 
   // mark as nonisolated, allowing access to it from everywhere
@@ -141,7 +141,7 @@ static ValueDecl *deriveDistributedActor_actorSystem(
   VarDecl *propDecl;
   PatternBindingDecl *pbDecl;
   std::tie(propDecl, pbDecl) = derived.declareDerivedProperty(
-      C.Id_actorSystem,
+      DerivedConformance::SynthesizedIntroducer::Let, C.Id_actorSystem,
       propertyType, propertyType,
       /*isStatic=*/false, /*isFinal=*/true);
 

lib/Sema/DerivedConformanceError.cpp

@@ -97,6 +97,7 @@ deriveBridgedNSError_enum_nsErrorDomain(
   VarDecl *propDecl;
   PatternBindingDecl *pbDecl;
   std::tie(propDecl, pbDecl) = derived.declareDerivedProperty(
+      DerivedConformance::SynthesizedIntroducer::Var,
       derived.Context.Id_nsErrorDomain, stringTy, stringTy, /*isStatic=*/true,
       /*isFinal=*/true);
 

lib/Sema/DerivedConformanceRawRepresentable.cpp

@@ -165,7 +165,8 @@ static VarDecl *deriveRawRepresentable_raw(DerivedConformance &derived) {
   VarDecl *propDecl;
   PatternBindingDecl *pbDecl;
   std::tie(propDecl, pbDecl) = derived.declareDerivedProperty(
-      C.Id_rawValue, rawInterfaceType, rawType, /*isStatic=*/false,
+      DerivedConformance::SynthesizedIntroducer::Var, C.Id_rawValue,
+      rawInterfaceType, rawType, /*isStatic=*/false,
       /*isFinal=*/false);
 
   // Define the getter.

lib/Sema/DerivedConformances.cpp

@@ -498,16 +498,27 @@ DerivedConformance::declareDerivedPropertyGetter(VarDecl *property,
   return getterDecl;
 }
 
+static VarDecl::Introducer
+mapIntroducer(DerivedConformance::SynthesizedIntroducer intro) {
+  switch (intro) {
+  case DerivedConformance::SynthesizedIntroducer::Let:
+    return VarDecl::Introducer::Let;
+  case DerivedConformance::SynthesizedIntroducer::Var:
+    return VarDecl::Introducer::Var;
+  }
+  llvm_unreachable("Invalid synthesized introducer!");
+}
+
 std::pair<VarDecl *, PatternBindingDecl *>
-DerivedConformance::declareDerivedProperty(Identifier name,
+DerivedConformance::declareDerivedProperty(SynthesizedIntroducer intro,
+                                           Identifier name,
                                            Type propertyInterfaceType,
                                            Type propertyContextType,
                                            bool isStatic, bool isFinal) {
   auto parentDC = getConformanceContext();
 
-  VarDecl *propDecl = new (Context)
-      VarDecl(/*IsStatic*/ isStatic, VarDecl::Introducer::Var,
-              SourceLoc(), name, parentDC);
+  VarDecl *propDecl = new (Context) VarDecl(
+      /*IsStatic*/ isStatic, mapIntroducer(intro), SourceLoc(), name, parentDC);
   propDecl->setImplicit();
   propDecl->setSynthesized();
   propDecl->copyFormalAccessFrom(Nominal, /*sourceIsParentContext*/ true);

lib/Sema/DerivedConformances.h

@@ -49,6 +49,9 @@ class ValueDecl;
 class VarDecl;
 
 class DerivedConformance {
+public:
+  enum class SynthesizedIntroducer : bool { Let, Var };
+
 public:
   ASTContext &Context;
   Decl *ConformanceDecl;
@@ -335,8 +338,9 @@ class DerivedConformance {
 
   /// Declare a read-only property.
   std::pair<VarDecl *, PatternBindingDecl *>
-  declareDerivedProperty(Identifier name, Type propertyInterfaceType,
-                         Type propertyContextType, bool isStatic, bool isFinal);
+  declareDerivedProperty(SynthesizedIntroducer intro, Identifier name,
+                         Type propertyInterfaceType, Type propertyContextType,
+                         bool isStatic, bool isFinal);
 
   /// Add a getter to a derived property.  The property becomes read-only.
   static AccessorDecl *