[NFC, Typechecker] Remove UnsupportedProtocolVisitor and checkUnsupportedProtocolType()

Author: theblixguy

lib/Sema/MiscDiagnostics.cpp

@@ -3342,8 +3342,6 @@ static void checkSwitch(ASTContext &ctx, const SwitchStmt *stmt) {
   // We want to warn about "case .Foo, .Bar where 1 != 100:" since the where
   // clause only applies to the second case, and this is surprising.
   for (auto cs : stmt->getCases()) {
-    TypeChecker::checkUnsupportedProtocolType(ctx, cs);
-
     // The case statement can have multiple case items, each can have a where.
     // If we find a "where", and there is a preceding item without a where, and
     // if they are on the same source line, then warn.
@@ -4760,8 +4758,6 @@ void swift::performSyntacticExprDiagnostics(const Expr *E,
 void swift::performStmtDiagnostics(const Stmt *S, DeclContext *DC) {
   auto &ctx = DC->getASTContext();
 
-  TypeChecker::checkUnsupportedProtocolType(ctx, const_cast<Stmt *>(S));
-    
   if (auto switchStmt = dyn_cast<SwitchStmt>(S))
     checkSwitch(ctx, switchStmt);
 

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -1659,8 +1659,6 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
 
     DeclVisitor<DeclChecker>::visit(decl);
 
-    TypeChecker::checkUnsupportedProtocolType(decl);
-
     if (auto VD = dyn_cast<ValueDecl>(decl)) {
       auto &Context = getASTContext();
       TypeChecker::checkForForbiddenPrefix(Context, VD->getBaseName());

lib/Sema/TypeCheckType.cpp

@@ -4015,128 +4015,6 @@ Type TypeChecker::substMemberTypeWithBase(ModuleDecl *module,
   return resultType;
 }
 
-namespace {
-
-class UnsupportedProtocolVisitor
-  : public TypeReprVisitor<UnsupportedProtocolVisitor>, public ASTWalker
-{
-  ASTContext &Ctx;
-  bool checkStatements;
-  bool hitTopStmt;
-    
-public:
-  UnsupportedProtocolVisitor(ASTContext &ctx, bool checkStatements)
-    : Ctx(ctx), checkStatements(checkStatements), hitTopStmt(false) { }
-
-  bool walkToTypeReprPre(TypeRepr *T) override {
-    if (T->isInvalid())
-      return false;
-    if (auto compound = dyn_cast<CompoundIdentTypeRepr>(T)) {
-      // Only visit the last component to check, because nested typealiases in
-      // existentials are okay.
-      visit(compound->getComponentRange().back());
-      return false;
-    }
-    // Arbitrary protocol constraints are OK on opaque types.
-    if (isa<OpaqueReturnTypeRepr>(T))
-      return false;
-    
-    visit(T);
-    return true;
-  }
-
-  std::pair<bool, Stmt*> walkToStmtPre(Stmt *S) override {
-    if (checkStatements && !hitTopStmt) {
-      hitTopStmt = true;
-      return { true, S };
-    }
-
-    return { false, S };
-  }
-
-  bool walkToDeclPre(Decl *D) override {
-    return !checkStatements;
-  }
-
-  void visitTypeRepr(TypeRepr *T) {
-    // Do nothing for all TypeReprs except the ones listed below.
-  }
-
-  void visitIdentTypeRepr(IdentTypeRepr *T) {
-    return;
-  }
-
-  void visitRequirements(ArrayRef<RequirementRepr> reqts) {
-    for (auto reqt : reqts) {
-      if (reqt.getKind() == RequirementReprKind::SameType) {
-        if (auto *repr = reqt.getFirstTypeRepr())
-          repr->walk(*this);
-        if (auto *repr = reqt.getSecondTypeRepr())
-          repr->walk(*this);
-      }
-    }
-  }
-};
-
-} // end anonymous namespace
-
-void TypeChecker::checkUnsupportedProtocolType(Decl *decl) {
-  if (!decl || decl->isInvalid())
-    return;
-
-  auto &ctx = decl->getASTContext();
-  if (auto *protocolDecl = dyn_cast<ProtocolDecl>(decl)) {
-    checkUnsupportedProtocolType(ctx, protocolDecl->getTrailingWhereClause());
-  } else if (auto *genericDecl = dyn_cast<GenericTypeDecl>(decl)) {
-    checkUnsupportedProtocolType(ctx, genericDecl->getGenericParams());
-    checkUnsupportedProtocolType(ctx, genericDecl->getTrailingWhereClause());
-  } else if (auto *assocType = dyn_cast<AssociatedTypeDecl>(decl)) {
-    checkUnsupportedProtocolType(ctx, assocType->getTrailingWhereClause());
-  } else if (auto *extDecl = dyn_cast<ExtensionDecl>(decl)) {
-    checkUnsupportedProtocolType(ctx, extDecl->getTrailingWhereClause());
-  } else if (auto *subscriptDecl = dyn_cast<SubscriptDecl>(decl)) {
-    checkUnsupportedProtocolType(ctx, subscriptDecl->getGenericParams());
-    checkUnsupportedProtocolType(ctx, subscriptDecl->getTrailingWhereClause());
-  } else if (auto *funcDecl = dyn_cast<AbstractFunctionDecl>(decl)) {
-    if (!isa<AccessorDecl>(funcDecl)) {
-      checkUnsupportedProtocolType(ctx, funcDecl->getGenericParams());
-      checkUnsupportedProtocolType(ctx, funcDecl->getTrailingWhereClause());
-    }
-  }
-
-  if (isa<TypeDecl>(decl) || isa<ExtensionDecl>(decl))
-    return;
-
-  UnsupportedProtocolVisitor visitor(ctx, /*checkStatements=*/false);
-  decl->walk(visitor);
-}
-
-void TypeChecker::checkUnsupportedProtocolType(ASTContext &ctx, Stmt *stmt) {
-  if (!stmt)
-    return;
-
-  UnsupportedProtocolVisitor visitor(ctx, /*checkStatements=*/true);
-  stmt->walk(visitor);
-}
-
-void TypeChecker::checkUnsupportedProtocolType(
-    ASTContext &ctx, TrailingWhereClause *whereClause) {
-  if (whereClause == nullptr)
-    return;
-
-  UnsupportedProtocolVisitor visitor(ctx, /*checkStatements=*/false);
-  visitor.visitRequirements(whereClause->getRequirements());
-}
-
-void TypeChecker::checkUnsupportedProtocolType(
-    ASTContext &ctx, GenericParamList *genericParams) {
-  if (genericParams  == nullptr)
-    return;
-
-  UnsupportedProtocolVisitor visitor(ctx, /*checkStatements=*/false);
-  visitor.visitRequirements(genericParams->getRequirements());
-}
-
 Type CustomAttrTypeRequest::evaluate(Evaluator &eval, CustomAttr *attr,
                                      DeclContext *dc,
                                      CustomAttrTypeKind typeKind) const {

lib/Sema/TypeChecker.h

@@ -242,22 +242,6 @@ Type getOptionalType(SourceLoc loc, Type elementType);
 Expr *resolveDeclRefExpr(UnresolvedDeclRefExpr *UDRE, DeclContext *Context,
                          bool replaceInvalidRefsWithErrors);
 
-/// Check for unsupported protocol types in the given declaration.
-void checkUnsupportedProtocolType(Decl *decl);
-
-/// Check for unsupported protocol types in the given statement.
-void checkUnsupportedProtocolType(ASTContext &ctx, Stmt *stmt);
-
-/// Check for unsupported protocol types in the given generic requirement
-/// list.
-void checkUnsupportedProtocolType(ASTContext &ctx,
-                                  TrailingWhereClause *whereClause);
-
-/// Check for unsupported protocol types in the given generic requirement
-/// list.
-void checkUnsupportedProtocolType(ASTContext &ctx,
-                                  GenericParamList *genericParams);
-
 /// Substitute the given base type into the type of the given nested type,
 /// producing the effective type that the nested type will have.
 ///