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// MacOSXAPIChecker.h - Checks proper use of various MacOS X APIs --*- C++ -*-//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This defines MacOSXAPIChecker, which is an assortment of checks on calls
// to various, widely used Mac OS X functions.
//
// FIXME: What's currently in BasicObjCFoundationChecks.cpp should be migrated
// to here, using the new Checker interface.
//
//===----------------------------------------------------------------------===//
#include "ClangSACheckers.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/GRStateTrait.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
using namespace ento;
namespace {
class MacOSXAPIChecker : public Checker< check::PreStmt<CallExpr> > {
mutable llvm::OwningPtr<BugType> BT_dispatchOnce;
public:
void checkPreStmt(const CallExpr *CE, CheckerContext &C) const;
void CheckDispatchOnce(CheckerContext &C, const CallExpr *CE,
const IdentifierInfo *FI) const;
typedef void (MacOSXAPIChecker::*SubChecker)(CheckerContext &,
const CallExpr *,
const IdentifierInfo *) const;
};
} //end anonymous namespace
//===----------------------------------------------------------------------===//
// dispatch_once and dispatch_once_f
//===----------------------------------------------------------------------===//
void MacOSXAPIChecker::CheckDispatchOnce(CheckerContext &C, const CallExpr *CE,
const IdentifierInfo *FI) const {
if (CE->getNumArgs() < 1)
return;
// Check if the first argument is stack allocated. If so, issue a warning
// because that's likely to be bad news.
const GRState *state = C.getState();
const MemRegion *R = state->getSVal(CE->getArg(0)).getAsRegion();
if (!R || !isa<StackSpaceRegion>(R->getMemorySpace()))
return;
ExplodedNode *N = C.generateSink(state);
if (!N)
return;
if (!BT_dispatchOnce)
BT_dispatchOnce.reset(new BugType("Improper use of 'dispatch_once'",
"Mac OS X API"));
llvm::SmallString<256> S;
llvm::raw_svector_ostream os(S);
os << "Call to '" << FI->getName() << "' uses";
if (const VarRegion *VR = dyn_cast<VarRegion>(R))
os << " the local variable '" << VR->getDecl()->getName() << '\'';
else
os << " stack allocated memory";
os << " for the predicate value. Using such transient memory for "
"the predicate is potentially dangerous.";
if (isa<VarRegion>(R) && isa<StackLocalsSpaceRegion>(R->getMemorySpace()))
os << " Perhaps you intended to declare the variable as 'static'?";
RangedBugReport *report = new RangedBugReport(*BT_dispatchOnce, os.str(), N);
report->addRange(CE->getArg(0)->getSourceRange());
C.EmitReport(report);
}
//===----------------------------------------------------------------------===//
// Central dispatch function.
//===----------------------------------------------------------------------===//
void MacOSXAPIChecker::checkPreStmt(const CallExpr *CE,
CheckerContext &C) const {
// FIXME: This sort of logic is common to several checkers, including
// UnixAPIChecker, PthreadLockChecker, and CStringChecker. Should refactor.
const GRState *state = C.getState();
const Expr *Callee = CE->getCallee();
const FunctionDecl *Fn = state->getSVal(Callee).getAsFunctionDecl();
if (!Fn)
return;
const IdentifierInfo *FI = Fn->getIdentifier();
if (!FI)
return;
SubChecker SC =
llvm::StringSwitch<SubChecker>(FI->getName())
.Cases("dispatch_once", "dispatch_once_f",
&MacOSXAPIChecker::CheckDispatchOnce)
.Default(NULL);
if (SC)
(this->*SC)(C, CE, FI);
}
//===----------------------------------------------------------------------===//
// Registration.
//===----------------------------------------------------------------------===//
void ento::registerMacOSXAPIChecker(CheckerManager &mgr) {
mgr.registerChecker<MacOSXAPIChecker>();
}
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