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

   1 //===--- PropertyDeclarationCheck.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 "PropertyDeclarationCheck.h"
  10 #include "../utils/OptionsUtils.h"
  11 #include "clang/AST/ASTContext.h"
  12 #include "clang/ASTMatchers/ASTMatchFinder.h"
  13 #include "clang/Basic/CharInfo.h"
  14 #include "llvm/ADT/STLExtras.h"
  15 #include "llvm/ADT/StringExtras.h"
  16 #include "llvm/Support/Regex.h"
  17 #include <algorithm>
  18
  19 using namespace clang::ast_matchers;
  20
  21 namespace clang::tidy::objc {
  22
  23 namespace {
  24
  25 // For StandardProperty the naming style is 'lowerCamelCase'.
  26 // For CategoryProperty especially in categories of system class,
  27 // to avoid naming conflict, the suggested naming style is
  28 // 'abc_lowerCamelCase' (adding lowercase prefix followed by '_').
  29 // Regardless of the style, all acronyms and initialisms should be capitalized.
  30 enum NamingStyle {
  31   StandardProperty = 1,
  32   CategoryProperty = 2,
  33 };
  34
  35 /// For now we will only fix 'CamelCase' or 'abc_CamelCase' property to
  36 /// 'camelCase' or 'abc_camelCase'. For other cases the users need to
  37 /// come up with a proper name by their own.
  38 /// FIXME: provide fix for snake_case to snakeCase
  39 FixItHint generateFixItHint(const ObjCPropertyDecl *Decl, NamingStyle Style) {
  40   auto Name = Decl->getName();
  41   auto NewName = Decl->getName().str();
  42   size_t Index = 0;
  43   if (Style == CategoryProperty) {
  44     Index = Name.find_first_of('_') + 1;
  45     NewName.replace(0, Index - 1, Name.substr(0, Index - 1).lower());
  46   }
  47   if (Index < Name.size()) {
  48     NewName[Index] = tolower(NewName[Index]);
  49     if (NewName != Name) {
  50       return FixItHint::CreateReplacement(
  51           CharSourceRange::getTokenRange(SourceRange(Decl->getLocation())),
  52           llvm::StringRef(NewName));
  53     }
  54   }
  55   return {};
  56 }
  57
  58 std::string validPropertyNameRegex(bool UsedInMatcher) {
  59   // Allow any of these names:
  60   // foo
  61   // fooBar
  62   // url
  63   // urlString
  64   // ID
  65   // IDs
  66   // URL
  67   // URLString
  68   // bundleID
  69   // CIColor
  70   //
  71   // Disallow names of this form:
  72   // LongString
  73   //
  74   // aRbITRaRyCapS is allowed to avoid generating false positives for names
  75   // like isVitaminBSupplement, CProgrammingLanguage, and isBeforeM.
  76   std::string StartMatcher = UsedInMatcher ? "::" : "^";
  77   return StartMatcher + "([a-z]|[A-Z][A-Z0-9])[a-z0-9A-Z]*$";
  78 }
  79
  80 bool hasCategoryPropertyPrefix(llvm::StringRef PropertyName) {
  81   auto RegexExp =
  82       llvm::Regex("^[a-zA-Z][a-zA-Z0-9]*_[a-zA-Z0-9][a-zA-Z0-9_]+$");
  83   return RegexExp.match(PropertyName);
  84 }
  85
  86 bool prefixedPropertyNameValid(llvm::StringRef PropertyName) {
  87   size_t Start = PropertyName.find_first_of('_');
  88   assert(Start != llvm::StringRef::npos && Start + 1 < PropertyName.size());
  89   auto Prefix = PropertyName.substr(0, Start);
  90   if (Prefix.lower() != Prefix) {
  91     return false;
  92   }
  93   auto RegexExp = llvm::Regex(llvm::StringRef(validPropertyNameRegex(false)));
  94   return RegexExp.match(PropertyName.substr(Start + 1));
  95 }
  96 }  // namespace
  97
  98 void PropertyDeclarationCheck::registerMatchers(MatchFinder *Finder) {
  99   Finder->addMatcher(objcPropertyDecl(
 100                          // the property name should be in Lower Camel Case like
 101                          // 'lowerCamelCase'
 102                          unless(matchesName(validPropertyNameRegex(true))))
 103                          .bind("property"),
 104                      this);
 105 }
 106
 107 void PropertyDeclarationCheck::check(const MatchFinder::MatchResult &Result) {
 108   const auto *MatchedDecl =
 109       Result.Nodes.getNodeAs<ObjCPropertyDecl>("property");
 110   assert(MatchedDecl->getName().size() > 0);
 111   auto *DeclContext = MatchedDecl->getDeclContext();
 112   auto *CategoryDecl = llvm::dyn_cast<ObjCCategoryDecl>(DeclContext);
 113
 114   if (CategoryDecl != nullptr &&
 115       hasCategoryPropertyPrefix(MatchedDecl->getName())) {
 116     if (!prefixedPropertyNameValid(MatchedDecl->getName()) ||
 117         CategoryDecl->IsClassExtension()) {
 118       NamingStyle Style = CategoryDecl->IsClassExtension() ? StandardProperty
 119                                                            : CategoryProperty;
 120       diag(MatchedDecl->getLocation(),
 121            "property name '%0' not using lowerCamelCase style or not prefixed "
 122            "in a category, according to the Apple Coding Guidelines")
 123           << MatchedDecl->getName() << generateFixItHint(MatchedDecl, Style);
 124     }
 125     return;
 126   }
 127   diag(MatchedDecl->getLocation(),
 128        "property name '%0' not using lowerCamelCase style or not prefixed in "
 129        "a category, according to the Apple Coding Guidelines")
 130       << MatchedDecl->getName()
 131       << generateFixItHint(MatchedDecl, StandardProperty);
 132 }
 133
 134 } // namespace clang::tidy::objc