ObjCNoReturn.cpp

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//= ObjCNoReturn.cpp - Handling of Cocoa APIs known not to return --*- C++ -*---
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements special handling of recognizing ObjC API hooks that
// do not return but aren't marked as such in API headers.
//
//===----------------------------------------------------------------------===//
 
#include "clang/AST/ASTContext.h"
#include "clang/AST/ExprObjC.h"
#include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
 
using namespace clang;
 
static bool isSubclass(const ObjCInterfaceDecl *Class, IdentifierInfo *II) {
  if (!Class)
    return false;
  if (Class->getIdentifier() == II)
    return true;
  return isSubclass(Class->getSuperClass(), II);
}
 
ObjCNoReturn::ObjCNoReturn(ASTContext &C)
  : RaiseSel(GetNullarySelector("raise", C)),
    NSExceptionII(&C.Idents.get("NSException"))
{
  // Generate selectors.
  SmallVector<IdentifierInfo*, 3> II;
 
  // raise:format:
  II.push_back(&C.Idents.get("raise"));
  II.push_back(&C.Idents.get("format"));
  NSExceptionInstanceRaiseSelectors[0] =
    C.Selectors.getSelector(II.size(), &II[0]);
 
  // raise:format:arguments:
  II.push_back(&C.Idents.get("arguments"));
  NSExceptionInstanceRaiseSelectors[1] =
    C.Selectors.getSelector(II.size(), &II[0]);
}
 
 
bool ObjCNoReturn::isImplicitNoReturn(const ObjCMessageExpr *ME) {
  Selector S = ME->getSelector();
 
  if (ME->isInstanceMessage()) {
    // Check for the "raise" message.
    return S == RaiseSel;
  }
 
  if (const ObjCInterfaceDecl *ID = ME->getReceiverInterface()) {
    if (isSubclass(ID, NSExceptionII) &&
        llvm::is_contained(NSExceptionInstanceRaiseSelectors, S))
      return true;
  }
 
  return false;
}