Index: clang-tidy/objc/AvoidNserrorInitCheck.h =================================================================== --- /dev/null +++ clang-tidy/objc/AvoidNserrorInitCheck.h @@ -0,0 +1,36 @@ +//===--- AvoidNSErrorInitCheck.h - clang-tidy--------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_OBJC_AVOIDNSERRORINITCHECK_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_OBJC_AVOIDNSERRORINITCHECK_H + +#include "../ClangTidy.h" + +namespace clang { +namespace tidy { +namespace objc { + +/// Finds usages of [NSSError init]. It is not the proper way of creating +/// NSError. errorWithDomain:code:userInfo: should be used instead. +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/objc-avoid-nserror-init.html +class AvoidNSErrorInitCheck : public ClangTidyCheck { + public: + AvoidNSErrorInitCheck(StringRef Name, ClangTidyContext *Context) + : ClangTidyCheck(Name, Context) {} + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; +}; + +} // namespace objc +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_OBJC_AVOIDNSERRORINITCHECK_H Index: clang-tidy/objc/AvoidNserrorInitCheck.cpp =================================================================== --- /dev/null +++ clang-tidy/objc/AvoidNserrorInitCheck.cpp @@ -0,0 +1,37 @@ +//===--- AvoidNSErrorInitCheck.cpp - clang-tidy----------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "AvoidNSErrorInitCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { +namespace objc { + +void AvoidNSErrorInitCheck::registerMatchers(MatchFinder *Finder) { + Finder->addMatcher(objcMessageExpr(hasSelector("init"), + hasReceiverType(asString("NSError *"))) + .bind("nserrorInit"), + this); +} + +void AvoidNSErrorInitCheck::check(const MatchFinder::MatchResult &Result) { + const auto *MatchedExpr = + Result.Nodes.getNodeAs("nserrorInit"); + diag(MatchedExpr->getLocStart(), + "use errorWithDomain:code:userInfo: or initWithDomain:code:userInfo: to " + "create a new NSError"); +} + +} // namespace objc +} // namespace tidy +} // namespace clang Index: clang-tidy/objc/CMakeLists.txt =================================================================== --- clang-tidy/objc/CMakeLists.txt +++ clang-tidy/objc/CMakeLists.txt @@ -1,6 +1,7 @@ set(LLVM_LINK_COMPONENTS support) add_clang_library(clangTidyObjCModule + AvoidNSErrorInitCheck.cpp AvoidSpinlockCheck.cpp ForbiddenSubclassingCheck.cpp ObjCTidyModule.cpp Index: clang-tidy/objc/ObjCTidyModule.cpp =================================================================== --- clang-tidy/objc/ObjCTidyModule.cpp +++ clang-tidy/objc/ObjCTidyModule.cpp @@ -10,6 +10,7 @@ #include "../ClangTidy.h" #include "../ClangTidyModule.h" #include "../ClangTidyModuleRegistry.h" +#include "AvoidNSErrorInitCheck.h" #include "AvoidSpinlockCheck.h" #include "ForbiddenSubclassingCheck.h" #include "PropertyDeclarationCheck.h" @@ -23,6 +24,8 @@ class ObjCModule : public ClangTidyModule { public: void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override { + CheckFactories.registerCheck( + "objc-avoid-nserror-init"); CheckFactories.registerCheck( "objc-avoid-spinlock"); CheckFactories.registerCheck( Index: docs/ReleaseNotes.rst =================================================================== --- docs/ReleaseNotes.rst +++ docs/ReleaseNotes.rst @@ -57,6 +57,11 @@ Improvements to clang-tidy -------------------------- +- New `objc-avoid-nserror-init + `_ check + + Add new check to detect the use of [NSError init]. + - New `objc-avoid-spinlock `_ check Index: docs/clang-tidy/checks/list.rst =================================================================== --- docs/clang-tidy/checks/list.rst +++ docs/clang-tidy/checks/list.rst @@ -174,6 +174,7 @@ modernize-use-using mpi-buffer-deref mpi-type-mismatch + objc-avoid-nserror-init objc-avoid-spinlock objc-forbidden-subclassing objc-property-declaration Index: docs/clang-tidy/checks/objc-avoid-nserror-init.rst =================================================================== --- /dev/null +++ docs/clang-tidy/checks/objc-avoid-nserror-init.rst @@ -0,0 +1,13 @@ +.. title:: clang-tidy - objc-avoid-nserror-init + +objc-avoid-nserror-init +======================= + +This check will find out improper initialization of NSError objects. + +According to Apple developer document, we should always use factory method +``errorWithDomain:code:userInfo:`` to create new NSError objects instead +of ``[NSError alloc] init]``. Otherwise it will lead to a warning message +during runtime. + +The corresponding information about NSError creation: https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/ErrorHandlingCocoa/CreateCustomizeNSError/CreateCustomizeNSError.html Index: test/clang-tidy/objc-avoid-nserror-init.m =================================================================== --- /dev/null +++ test/clang-tidy/objc-avoid-nserror-init.m @@ -0,0 +1,12 @@ +// RUN: %check_clang_tidy %s objc-avoid-nserror-init %t +@interface NSError ++ (instancetype)alloc; +- (instancetype)init; +@end + +@implementation foo +- (void)bar { + NSError *error = [[NSError alloc] init]; + // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: use errorWithDomain:code:userInfo: or initWithDomain:code:userInfo: to create a new NSError [objc-avoid-nserror-init] +} +@end