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 {
  16 namespace tidy {
  17 namespace objc {
  18
  19 namespace {
  20
  21 /// Matches Objective-C methods in the initializer family.
  22 ///
  23 /// Example matches -init and -initWithInt:.
  24 ///   (matcher = objcMethodDecl(isInitializer()))
  25 /// \code
  26 ///   @interface Foo
  27 ///   - (instancetype)init;
  28 ///   - (instancetype)initWithInt:(int)i;
  29 ///   + (instancetype)init;
  30 ///   - (void)bar;
  31 ///   @end
  32 /// \endcode
  33 AST_MATCHER(ObjCMethodDecl, isInitializer) {
  34   return Node.getMethodFamily() == OMF_init;
  35 }
  36
  37 /// Matches Objective-C implementations with interfaces that match
  38 /// \c Base.
  39 ///
  40 /// Example matches implementation declarations for X.
  41 ///   (matcher = objcImplementationDecl(hasInterface(hasName("X"))))
  42 /// \code
  43 ///   @interface X
  44 ///   @end
  45 ///   @implementation X
  46 ///   @end
  47 ///   @interface Y
  48 //    @end
  49 ///   @implementation Y
  50 ///   @end
  51 /// \endcode
  52 AST_MATCHER_P(ObjCImplementationDecl, hasInterface,
  53               ast_matchers::internal::Matcher<ObjCInterfaceDecl>, Base) {
  54   const ObjCInterfaceDecl *InterfaceDecl = Node.getClassInterface();
  55   return Base.matches(*InterfaceDecl, Finder, Builder);
  56 }
  57
  58 /// Matches Objective-C message expressions where the receiver is the
  59 /// super instance.
  60 ///
  61 /// Example matches the invocations of -banana and -orange.
  62 ///   (matcher = objcMessageExpr(isMessagingSuperInstance()))
  63 /// \code
  64 ///   - (void)banana {
  65 ///     [self apple]
  66 ///     [super banana];
  67 ///     [super orange];
  68 ///   }
  69 /// \endcode
  70 AST_MATCHER(ObjCMessageExpr, isMessagingSuperInstance) {
  71   return Node.getReceiverKind() == ObjCMessageExpr::SuperInstance;
  72 }
  73
  74 } // namespace
  75
  76 void SuperSelfCheck::registerMatchers(MatchFinder *Finder) {
  77   Finder->addMatcher(
  78       objcMessageExpr(hasSelector("self"), isMessagingSuperInstance(),
  79                       hasAncestor(objcMethodDecl(
  80                           isInitializer(),
  81                           hasDeclContext(objcImplementationDecl(hasInterface(
  82                               isDerivedFrom(hasName("NSObject"))))))))
  83           .bind("message"),
  84       this);
  85 }
  86
  87 void SuperSelfCheck::check(const MatchFinder::MatchResult &Result) {
  88   const auto *Message = Result.Nodes.getNodeAs<ObjCMessageExpr>("message");
  89
  90   auto Diag = diag(Message->getExprLoc(), "suspicious invocation of %0 in "
  91                                           "initializer; did you mean to "
  92                                           "invoke a superclass initializer?")
  93               << Message->getMethodDecl();
  94
  95   SourceLocation ReceiverLoc = Message->getReceiverRange().getBegin();
  96   if (ReceiverLoc.isMacroID() || ReceiverLoc.isInvalid())
  97     return;
  98
  99   SourceLocation SelectorLoc = Message->getSelectorStartLoc();
 100   if (SelectorLoc.isMacroID() || SelectorLoc.isInvalid())
 101     return;
 102
 103   Diag << FixItHint::CreateReplacement(Message->getSourceRange(),
 104                                        StringRef("[super init]"));
 105 }
 106
 107 } // namespace objc
 108 } // namespace tidy
 109 } // namespace clang