1 //= ObjCNoReturn.cpp - Handling of Cocoa APIs known not to return --*- C++ -*---
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements special handling of recognizing ObjC API hooks that
11 // do not return but aren't marked as such in API headers.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/ExprObjC.h"
17 #include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
18 
19 using namespace clang;
20 
isSubclass(const ObjCInterfaceDecl * Class,IdentifierInfo * II)21 static bool isSubclass(const ObjCInterfaceDecl *Class, IdentifierInfo *II) {
22   if (!Class)
23     return false;
24   if (Class->getIdentifier() == II)
25     return true;
26   return isSubclass(Class->getSuperClass(), II);
27 }
28 
ObjCNoReturn(ASTContext & C)29 ObjCNoReturn::ObjCNoReturn(ASTContext &C)
30   : RaiseSel(GetNullarySelector("raise", C)),
31     NSExceptionII(&C.Idents.get("NSException"))
32 {
33   // Generate selectors.
34   SmallVector<IdentifierInfo*, 3> II;
35 
36   // raise:format:
37   II.push_back(&C.Idents.get("raise"));
38   II.push_back(&C.Idents.get("format"));
39   NSExceptionInstanceRaiseSelectors[0] =
40     C.Selectors.getSelector(II.size(), &II[0]);
41 
42   // raise:format:arguments:
43   II.push_back(&C.Idents.get("arguments"));
44   NSExceptionInstanceRaiseSelectors[1] =
45     C.Selectors.getSelector(II.size(), &II[0]);
46 }
47 
48 
isImplicitNoReturn(const ObjCMessageExpr * ME)49 bool ObjCNoReturn::isImplicitNoReturn(const ObjCMessageExpr *ME) {
50   Selector S = ME->getSelector();
51 
52   if (ME->isInstanceMessage()) {
53     // Check for the "raise" message.
54     return S == RaiseSel;
55   }
56 
57   if (const ObjCInterfaceDecl *ID = ME->getReceiverInterface()) {
58     if (isSubclass(ID, NSExceptionII)) {
59       for (unsigned i = 0; i < NUM_RAISE_SELECTORS; ++i) {
60         if (S == NSExceptionInstanceRaiseSelectors[i])
61           return true;
62       }
63     }
64   }
65 
66   return false;
67 }
68