AST: Correctly set parent DeclContext of ParamDecls in EnumElementDecls

When an EnumElementDecl is parsed, we create the parameter list before
creating the EnumElementDecl itself, so we have to re-parent those
ParamDecls just like we do for functions and subscripts.

Author: slavapestov

include/swift/AST/Decl.h

@@ -6355,13 +6355,7 @@ class EnumElementDecl : public DeclContext, public ValueDecl {
                   ParameterList *Params,
                   SourceLoc EqualsLoc,
                   LiteralExpr *RawValueExpr,
-                  DeclContext *DC)
-  : DeclContext(DeclContextKind::EnumElementDecl, DC),
-    ValueDecl(DeclKind::EnumElement, DC, Name, IdentifierLoc),
-    Params(Params),
-    EqualsLoc(EqualsLoc),
-    RawValueExpr(RawValueExpr)
-  {}
+                  DeclContext *DC);
 
   Identifier getName() const { return getFullName().getBaseIdentifier(); }
 
@@ -6377,6 +6371,7 @@ class EnumElementDecl : public DeclContext, public ValueDecl {
 
   Type getArgumentInterfaceType() const;
 
+  void setParameterList(ParameterList *params);
   ParameterList *getParameterList() const { return Params; }
 
   /// Retrieves a fully typechecked raw value expression associated

lib/AST/Decl.cpp

@@ -7070,6 +7070,18 @@ SourceRange FuncDecl::getSourceRange() const {
   return StartLoc;
 }
 
+EnumElementDecl::EnumElementDecl(SourceLoc IdentifierLoc, DeclName Name,
+                                 ParameterList *Params,
+                                 SourceLoc EqualsLoc,
+                                 LiteralExpr *RawValueExpr,
+                                 DeclContext *DC)
+  : DeclContext(DeclContextKind::EnumElementDecl, DC),
+    ValueDecl(DeclKind::EnumElement, DC, Name, IdentifierLoc),
+    EqualsLoc(EqualsLoc),
+    RawValueExpr(RawValueExpr) {
+  setParameterList(Params);
+}
+
 SourceRange EnumElementDecl::getSourceRange() const {
   if (RawValueExpr && !RawValueExpr->isImplicit())
     return {getStartLoc(), RawValueExpr->getEndLoc()};
@@ -7127,6 +7139,13 @@ Type EnumElementDecl::getArgumentInterfaceType() const {
   return TupleType::get(elements, ctx);
 }
 
+void EnumElementDecl::setParameterList(ParameterList *params) {
+  Params = params;
+
+  if (params)
+    params->setDeclContextOfParamDecls(this);
+}
+
 EnumCaseDecl *EnumElementDecl::getParentCase() const {
   for (EnumCaseDecl *EC : getParentEnum()->getAllCases()) {
     ArrayRef<EnumElementDecl *> CaseElements = EC->getElements();

lib/AST/UnqualifiedLookup.cpp

@@ -778,7 +778,8 @@ void UnqualifiedLookupFactory::lookupNamesIntroducedByMiscContext(
   assert(isa<TopLevelCodeDecl>(dc) ||
          isa<Initializer>(dc) ||
          isa<TypeAliasDecl>(dc) ||
-         isa<SubscriptDecl>(dc));
+         isa<SubscriptDecl>(dc) ||
+         isa<EnumElementDecl>(dc));
   finishLookingInContext(
     AddGenericParameters::Yes,
     dc,

lib/Serialization/Deserialization.cpp

@@ -1874,6 +1874,8 @@ DeclContext *ModuleFile::getDeclContext(DeclContextID DCID) {
     return AFD;
   if (auto SD = dyn_cast<SubscriptDecl>(D))
     return SD;
+  if (auto EED = dyn_cast<EnumElementDecl>(D))
+    return EED;
 
   llvm_unreachable("Unknown Decl : DeclContext kind");
 }
@@ -3554,24 +3556,24 @@ class swift::DeclDeserializer {
       }
     }
 
-    // Read payload parameter list, if it exists.
-    ParameterList *paramList = nullptr;
-    if (hasPayload) {
-      paramList = MF.readParameterList();
-    }
-
     DeclContext *DC = MF.getDeclContext(contextID);
     if (declOrOffset.isComplete())
       return declOrOffset;
 
     auto elem = MF.createDecl<EnumElementDecl>(SourceLoc(),
                                                name,
-                                               paramList,
+                                               nullptr,
                                                SourceLoc(),
                                                nullptr,
                                                DC);
     declOrOffset = elem;
 
+    // Read payload parameter list, if it exists.
+    if (hasPayload) {
+      auto *paramList = MF.readParameterList();
+      elem->setParameterList(paramList);
+    }
+
     // Deserialize the literal raw value, if any.
     switch ((EnumElementRawValueKind)rawValueKindID) {
     case EnumElementRawValueKind::None:

lib/Serialization/Serialization.cpp

@@ -439,7 +439,7 @@ static ASTContext &getContext(ModuleOrSourceFile DC) {
 
 static bool shouldSerializeAsLocalContext(const DeclContext *DC) {
   return DC->isLocalContext() && !isa<AbstractFunctionDecl>(DC) &&
-        !isa<SubscriptDecl>(DC);
+        !isa<SubscriptDecl>(DC) && !isa<EnumElementDecl>(DC);
 }
 
 namespace {

test/IDE/comment_attach.swift

@@ -293,10 +293,10 @@ func unterminatedBlockDocComment() {}
 // CHECK-NEXT: comment_attach.swift:166:6: Enum/decl_enum_1 RawComment=[/// decl_enum_1 Aaa.\n]
 // CHECK-NEXT: comment_attach.swift:168:8: EnumElement/decl_enum_1.Case1 RawComment=[/// Case1 Aaa.\n]
 // CHECK-NEXT: comment_attach.swift:171:8: EnumElement/decl_enum_1.Case2 RawComment=[/// Case2 Aaa.\n]
-// CHECK-NEXT: Param/decl_enum_1.<anonymous> RawComment=none BriefComment=none DocCommentAsXML=none
+// CHECK-NEXT: Param/<anonymous> RawComment=none BriefComment=none DocCommentAsXML=none
 // CHECK-NEXT: comment_attach.swift:174:8: EnumElement/decl_enum_1.Case3 RawComment=[/// Case3 Aaa.\n]
-// CHECK-NEXT: Param/decl_enum_1.<anonymous> RawComment=none BriefComment=none DocCommentAsXML=none
-// CHECK-NEXT: Param/decl_enum_1.<anonymous> RawComment=none BriefComment=none DocCommentAsXML=none
+// CHECK-NEXT: Param/<anonymous> RawComment=none BriefComment=none DocCommentAsXML=none
+// CHECK-NEXT: Param/<anonymous> RawComment=none BriefComment=none DocCommentAsXML=none
 // CHECK-NEXT: comment_attach.swift:177:8: EnumElement/decl_enum_1.Case4 RawComment=[/// Case4 Case5 Aaa.\n]
 // CHECK-NEXT: comment_attach.swift:177:15: EnumElement/decl_enum_1.Case5 RawComment=[/// Case4 Case5 Aaa.\n]
 // CHECK-NEXT: comment_attach.swift:181:7: Class/decl_class_1 RawComment=[/// decl_class_1 Aaa.\n]