MacOSXAPIChecker.cpp revision 57964bda54c9b1e10090cae94d776a6b9b7eca33
1// MacOSXAPIChecker.h - Checks proper use of various MacOS X APIs --*- 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 defines MacOSXAPIChecker, which is an assortment of checks on calls 11// to various, widely used Mac OS X functions. 12// 13// FIXME: What's currently in BasicObjCFoundationChecks.cpp should be migrated 14// to here, using the new Checker interface. 15// 16//===----------------------------------------------------------------------===// 17 18#include "ClangSACheckers.h" 19#include "clang/StaticAnalyzer/Core/Checker.h" 20#include "clang/StaticAnalyzer/Core/CheckerManager.h" 21#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 22#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 23#include "clang/StaticAnalyzer/Core/PathSensitive/GRStateTrait.h" 24#include "clang/Basic/TargetInfo.h" 25#include "llvm/ADT/SmallString.h" 26#include "llvm/ADT/StringSwitch.h" 27#include "llvm/Support/raw_ostream.h" 28 29using namespace clang; 30using namespace ento; 31 32namespace { 33class MacOSXAPIChecker : public Checker< check::PreStmt<CallExpr> > { 34 mutable llvm::OwningPtr<BugType> BT_dispatchOnce; 35 36public: 37 void checkPreStmt(const CallExpr *CE, CheckerContext &C) const; 38 39 void CheckDispatchOnce(CheckerContext &C, const CallExpr *CE, 40 const IdentifierInfo *FI) const; 41 42 typedef void (MacOSXAPIChecker::*SubChecker)(CheckerContext &, 43 const CallExpr *, 44 const IdentifierInfo *) const; 45}; 46} //end anonymous namespace 47 48//===----------------------------------------------------------------------===// 49// dispatch_once and dispatch_once_f 50//===----------------------------------------------------------------------===// 51 52void MacOSXAPIChecker::CheckDispatchOnce(CheckerContext &C, const CallExpr *CE, 53 const IdentifierInfo *FI) const { 54 if (CE->getNumArgs() < 1) 55 return; 56 57 // Check if the first argument is stack allocated. If so, issue a warning 58 // because that's likely to be bad news. 59 const GRState *state = C.getState(); 60 const MemRegion *R = state->getSVal(CE->getArg(0)).getAsRegion(); 61 if (!R || !isa<StackSpaceRegion>(R->getMemorySpace())) 62 return; 63 64 ExplodedNode *N = C.generateSink(state); 65 if (!N) 66 return; 67 68 if (!BT_dispatchOnce) 69 BT_dispatchOnce.reset(new BugType("Improper use of 'dispatch_once'", 70 "Mac OS X API")); 71 72 llvm::SmallString<256> S; 73 llvm::raw_svector_ostream os(S); 74 os << "Call to '" << FI->getName() << "' uses"; 75 if (const VarRegion *VR = dyn_cast<VarRegion>(R)) 76 os << " the local variable '" << VR->getDecl()->getName() << '\''; 77 else 78 os << " stack allocated memory"; 79 os << " for the predicate value. Using such transient memory for " 80 "the predicate is potentially dangerous."; 81 if (isa<VarRegion>(R) && isa<StackLocalsSpaceRegion>(R->getMemorySpace())) 82 os << " Perhaps you intended to declare the variable as 'static'?"; 83 84 RangedBugReport *report = new RangedBugReport(*BT_dispatchOnce, os.str(), N); 85 report->addRange(CE->getArg(0)->getSourceRange()); 86 C.EmitReport(report); 87} 88 89//===----------------------------------------------------------------------===// 90// Central dispatch function. 91//===----------------------------------------------------------------------===// 92 93void MacOSXAPIChecker::checkPreStmt(const CallExpr *CE, 94 CheckerContext &C) const { 95 // FIXME: This sort of logic is common to several checkers, including 96 // UnixAPIChecker, PthreadLockChecker, and CStringChecker. Should refactor. 97 const GRState *state = C.getState(); 98 const Expr *Callee = CE->getCallee(); 99 const FunctionDecl *Fn = state->getSVal(Callee).getAsFunctionDecl(); 100 101 if (!Fn) 102 return; 103 104 const IdentifierInfo *FI = Fn->getIdentifier(); 105 if (!FI) 106 return; 107 108 SubChecker SC = 109 llvm::StringSwitch<SubChecker>(FI->getName()) 110 .Cases("dispatch_once", "dispatch_once_f", 111 &MacOSXAPIChecker::CheckDispatchOnce) 112 .Default(NULL); 113 114 if (SC) 115 (this->*SC)(C, CE, FI); 116} 117 118//===----------------------------------------------------------------------===// 119// Registration. 120//===----------------------------------------------------------------------===// 121 122void ento::registerMacOSXAPIChecker(CheckerManager &mgr) { 123 mgr.registerChecker<MacOSXAPIChecker>(); 124} 125