Update property prefix regex to allow numbers.

[Wizard]

Summary

Allow property names with prefix containing numbers like abc2_fooBar

clang-tidy/objc/PropertyDeclarationCheck.cpp

std::string validPropertyNameRegex(bool UsedInMatcher) {
   //
   // aRbITRaRyCapS is allowed to avoid generating false positives for names
   // like isVitaminBSupplement, CProgrammingLanguage, and isBeforeM.
   std::string StartMatcher = UsedInMatcher ? "::" : "^";
   return StartMatcher + "([a-z]|[A-Z][A-Z0-9])[a-z0-9A-Z]*$";
 }
 
 bool hasCategoryPropertyPrefix(llvm::StringRef PropertyName) {
-  auto RegexExp = llvm::Regex("^[a-zA-Z]+_[a-zA-Z0-9][a-zA-Z0-9_]+$");
+  auto RegexExp =
+      llvm::Regex("^[a-zA-Z][a-zA-Z0-9]*_[a-zA-Z0-9][a-zA-Z0-9_]+$");
   return RegexExp.match(PropertyName);
 }
 
 bool prefixedPropertyNameValid(llvm::StringRef PropertyName) {
   size_t Start = PropertyName.find_first_of('_');
   assert(Start != llvm::StringRef::npos && Start + 1 < PropertyName.size());
   auto Prefix = PropertyName.substr(0, Start);
   if (Prefix.lower() != Prefix) {
     return false;
   }
-  auto RegexExp =
-      llvm::Regex(llvm::StringRef(validPropertyNameRegex(false)));
+  auto RegexExp = llvm::Regex(llvm::StringRef(validPropertyNameRegex(false)));
   return RegexExp.match(PropertyName.substr(Start + 1));
 }
 }  // namespace
 
 PropertyDeclarationCheck::PropertyDeclarationCheck(StringRef Name,
                                                    ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       SpecialAcronyms(
           utils::options::parseStringList(Options.get("Acronyms", ""))),
       IncludeDefaultAcronyms(Options.get("IncludeDefaultAcronyms", true)),
       EscapedAcronyms() {}
 
 void PropertyDeclarationCheck::registerMatchers(MatchFinder *Finder) {
   // this check should only be applied to ObjC sources.
   if (!getLangOpts().ObjC) return;
 
-  Finder->addMatcher(
-      objcPropertyDecl(
+  Finder->addMatcher(objcPropertyDecl(
                          // the property name should be in Lower Camel Case like
                          // 'lowerCamelCase'
                          unless(matchesName(validPropertyNameRegex(true))))
                          .bind("property"),
                      this);
 }
 
 void PropertyDeclarationCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *MatchedDecl =
       Result.Nodes.getNodeAs<ObjCPropertyDecl>("property");
   assert(MatchedDecl->getName().size() > 0);
   auto *DeclContext = MatchedDecl->getDeclContext();
   auto *CategoryDecl = llvm::dyn_cast<ObjCCategoryDecl>(DeclContext);

test/clang-tidy/objc-property-declaration.m

 @property(assign, nonatomic) int abCD_NotCamelCase;
 // CHECK-MESSAGES: :[[@LINE-1]]:34: warning: property name 'abCD_NotCamelCase' not using lowerCamelCase style or not prefixed in a category, according to the Apple Coding Guidelines [objc-property-declaration]
 // CHECK-FIXES: @property(assign, nonatomic) int abcd_notCamelCase;
 @property(assign, nonatomic) int wrongFormat_;
 // CHECK-MESSAGES: :[[@LINE-1]]:34: warning: property name 'wrongFormat_' not using lowerCamelCase style or not prefixed in a category, according to the Apple Coding Guidelines [objc-property-declaration]
 @property(strong, nonatomic) NSString *URLStr;
 @property(assign, nonatomic) int abc_camelCase;
 @property(strong, nonatomic) NSString *abc_URL;
+@property(strong, nonatomic) NSString *opac2_sourceComponent;
 @end
 
 @interface Foo ()
 @property(assign, nonatomic) int abc_inClassExtension;
 // CHECK-MESSAGES: :[[@LINE-1]]:34: warning: property name 'abc_inClassExtension' not using lowerCamelCase style or not prefixed in a category, according to the Apple Coding Guidelines [objc-property-declaration]
 @end
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