clang-tools-extra/clang-tidy/objc/SuperSelfCheck.cpp

   1 //===--- SuperSelfCheck.cpp - clang-tidy ----------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "SuperSelfCheck.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/ASTMatchers/ASTMatchFinder.h"
  12
  13 using namespace clang::ast_matchers;
  14
  15 namespace clang::tidy::objc {
  16
  17 namespace {
  18
  19 /// Matches Objective-C methods in the initializer family.
  20 ///
  21 /// Example matches -init and -initWithInt:.
  22 ///   (matcher = objcMethodDecl(isInitializer()))
  23 /// \code
  24 ///   @interface Foo
  25 ///   - (instancetype)init;
  26 ///   - (instancetype)initWithInt:(int)i;
  27 ///   + (instancetype)init;
  28 ///   - (void)bar;
  29 ///   @end
  30 /// \endcode
  31 AST_MATCHER(ObjCMethodDecl, isInitializer) {
  32   return Node.getMethodFamily() == OMF_init;
  33 }
  34
  35 /// Matches Objective-C implementations with interfaces that match
  36 /// \c Base.
  37 ///
  38 /// Example matches implementation declarations for X.
  39 ///   (matcher = objcImplementationDecl(hasInterface(hasName("X"))))
  40 /// \code
  41 ///   @interface X
  42 ///   @end
  43 ///   @implementation X
  44 ///   @end
  45 ///   @interface Y
  46 //    @end
  47 ///   @implementation Y
  48 ///   @end
  49 /// \endcode
  50 AST_MATCHER_P(ObjCImplementationDecl, hasInterface,
  51               ast_matchers::internal::Matcher<ObjCInterfaceDecl>, Base) {
  52   const ObjCInterfaceDecl *InterfaceDecl = Node.getClassInterface();
  53   return Base.matches(*InterfaceDecl, Finder, Builder);
  54 }
  55
  56 /// Matches Objective-C message expressions where the receiver is the
  57 /// super instance.
  58 ///
  59 /// Example matches the invocations of -banana and -orange.
  60 ///   (matcher = objcMessageExpr(isMessagingSuperInstance()))
  61 /// \code
  62 ///   - (void)banana {
  63 ///     [self apple]
  64 ///     [super banana];
  65 ///     [super orange];
  66 ///   }
  67 /// \endcode
  68 AST_MATCHER(ObjCMessageExpr, isMessagingSuperInstance) {
  69   return Node.getReceiverKind() == ObjCMessageExpr::SuperInstance;
  70 }
  71
  72 } // namespace
  73
  74 void SuperSelfCheck::registerMatchers(MatchFinder *Finder) {
  75   Finder->addMatcher(
  76       objcMessageExpr(hasSelector("self"), isMessagingSuperInstance(),
  77                       hasAncestor(objcMethodDecl(
  78                           isInitializer(),
  79                           hasDeclContext(objcImplementationDecl(hasInterface(
  80                               isDerivedFrom(hasName("NSObject"))))))))
  81           .bind("message"),
  82       this);
  83 }
  84
  85 void SuperSelfCheck::check(const MatchFinder::MatchResult &Result) {
  86   const auto *Message = Result.Nodes.getNodeAs<ObjCMessageExpr>("message");
  87
  88   auto Diag = diag(Message->getExprLoc(), "suspicious invocation of %0 in "
  89                                           "initializer; did you mean to "
  90                                           "invoke a superclass initializer?")
  91               << Message->getMethodDecl();
  92
  93   SourceLocation ReceiverLoc = Message->getReceiverRange().getBegin();
  94   if (ReceiverLoc.isMacroID() || ReceiverLoc.isInvalid())
  95     return;
  96
  97   SourceLocation SelectorLoc = Message->getSelectorStartLoc();
  98   if (SelectorLoc.isMacroID() || SelectorLoc.isInvalid())
  99     return;
 100
 101   Diag << FixItHint::CreateReplacement(Message->getSourceRange(),
 102                                        StringRef("[super init]"));
 103 }
 104
 105 } // namespace clang::tidy::objc