clang-tools-extra/clang-tidy/google/AvoidThrowingObjCExceptionCheck.cpp

   1 //===--- AvoidThrowingObjCExceptionCheck.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 "AvoidThrowingObjCExceptionCheck.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::google::objc {
  16
  17 void AvoidThrowingObjCExceptionCheck::registerMatchers(MatchFinder *Finder) {
  18
  19   Finder->addMatcher(objcThrowStmt().bind("throwStmt"), this);
  20   Finder->addMatcher(
  21       objcMessageExpr(anyOf(hasSelector("raise:format:"),
  22                             hasSelector("raise:format:arguments:")),
  23                       hasReceiverType(asString("NSException")))
  24           .bind("raiseException"),
  25       this);
  26 }
  27
  28 void AvoidThrowingObjCExceptionCheck::check(
  29     const MatchFinder::MatchResult &Result) {
  30   const auto *MatchedStmt =
  31       Result.Nodes.getNodeAs<ObjCAtThrowStmt>("throwStmt");
  32   const auto *MatchedExpr =
  33       Result.Nodes.getNodeAs<ObjCMessageExpr>("raiseException");
  34   auto SourceLoc = MatchedStmt == nullptr ? MatchedExpr->getSelectorStartLoc()
  35                                           : MatchedStmt->getThrowLoc();
  36
  37   // Early return on invalid locations.
  38   if (SourceLoc.isInvalid())
  39     return;
  40
  41   // If the match location was in a macro, check if the macro was in a system
  42   // header.
  43   if (SourceLoc.isMacroID()) {
  44     SourceManager &SM = *Result.SourceManager;
  45     auto MacroLoc = SM.getImmediateMacroCallerLoc(SourceLoc);
  46
  47     // Matches in system header macros should be ignored.
  48     if (SM.isInSystemHeader(MacroLoc))
  49       return;
  50   }
  51
  52   diag(SourceLoc,
  53        "pass in NSError ** instead of throwing exception to indicate "
  54        "Objective-C errors");
  55 }
  56
  57 } // namespace clang::tidy::google::objc