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//=-- GRExprEngineInternalChecks.cpp - Builtin GRExprEngine Checks---*- C++ -*-=
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the BugType classes used by GRExprEngine to report
// bugs derived from builtin checks in the path-sensitive engine.
//
//===----------------------------------------------------------------------===//
#include "GRExprEngineInternalChecks.h"
#include "clang/Analysis/PathSensitive/BugReporter.h"
#include "clang/Analysis/PathSensitive/GRExprEngine.h"
#include "clang/Analysis/PathSensitive/CheckerVisitor.h"
#include "clang/Analysis/PathDiagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
using namespace clang::bugreporter;
//===----------------------------------------------------------------------===//
// Utility functions.
//===----------------------------------------------------------------------===//
template <typename ITERATOR> inline
ExplodedNode* GetNode(ITERATOR I) {
return *I;
}
//===----------------------------------------------------------------------===//
// Bug Descriptions.
//===----------------------------------------------------------------------===//
namespace clang {
class BuiltinBugReport : public RangedBugReport {
public:
BuiltinBugReport(BugType& bt, const char* desc,
ExplodedNode *n)
: RangedBugReport(bt, desc, n) {}
BuiltinBugReport(BugType& bt, const char *shortDesc, const char *desc,
ExplodedNode *n)
: RangedBugReport(bt, shortDesc, desc, n) {}
void registerInitialVisitors(BugReporterContext& BRC,
const ExplodedNode* N);
};
void BuiltinBugReport::registerInitialVisitors(BugReporterContext& BRC,
const ExplodedNode* N) {
static_cast<BuiltinBug&>(getBugType()).registerInitialVisitors(BRC, N, this);
}
template <typename ITER>
void BuiltinBug::Emit(BugReporter& BR, ITER I, ITER E) {
for (; I != E; ++I) BR.EmitReport(new BuiltinBugReport(*this, desc.c_str(),
GetNode(I)));
}
class VISIBILITY_HIDDEN NilReceiverStructRet : public BuiltinBug {
public:
NilReceiverStructRet(GRExprEngine* eng) :
BuiltinBug(eng, "'nil' receiver with struct return type") {}
void FlushReportsImpl(BugReporter& BR, GRExprEngine& Eng) {
for (GRExprEngine::nil_receiver_struct_ret_iterator
I=Eng.nil_receiver_struct_ret_begin(),
E=Eng.nil_receiver_struct_ret_end(); I!=E; ++I) {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
PostStmt P = cast<PostStmt>((*I)->getLocation());
const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(P.getStmt());
os << "The receiver in the message expression is 'nil' and results in the"
" returned value (of type '"
<< ME->getType().getAsString()
<< "') to be garbage or otherwise undefined";
BuiltinBugReport *R = new BuiltinBugReport(*this, os.str().c_str(), *I);
R->addRange(ME->getReceiver()->getSourceRange());
BR.EmitReport(R);
}
}
void registerInitialVisitors(BugReporterContext& BRC,
const ExplodedNode* N,
BuiltinBugReport *R) {
registerTrackNullOrUndefValue(BRC, GetReceiverExpr(N), N);
}
};
class VISIBILITY_HIDDEN NilReceiverLargerThanVoidPtrRet : public BuiltinBug {
public:
NilReceiverLargerThanVoidPtrRet(GRExprEngine* eng) :
BuiltinBug(eng,
"'nil' receiver with return type larger than sizeof(void *)") {}
void FlushReportsImpl(BugReporter& BR, GRExprEngine& Eng) {
for (GRExprEngine::nil_receiver_larger_than_voidptr_ret_iterator
I=Eng.nil_receiver_larger_than_voidptr_ret_begin(),
E=Eng.nil_receiver_larger_than_voidptr_ret_end(); I!=E; ++I) {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
PostStmt P = cast<PostStmt>((*I)->getLocation());
const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(P.getStmt());
os << "The receiver in the message expression is 'nil' and results in the"
" returned value (of type '"
<< ME->getType().getAsString()
<< "' and of size "
<< Eng.getContext().getTypeSize(ME->getType()) / 8
<< " bytes) to be garbage or otherwise undefined";
BuiltinBugReport *R = new BuiltinBugReport(*this, os.str().c_str(), *I);
R->addRange(ME->getReceiver()->getSourceRange());
BR.EmitReport(R);
}
}
void registerInitialVisitors(BugReporterContext& BRC,
const ExplodedNode* N,
BuiltinBugReport *R) {
registerTrackNullOrUndefValue(BRC, GetReceiverExpr(N), N);
}
};
class VISIBILITY_HIDDEN UndefResult : public BuiltinBug {
public:
UndefResult(GRExprEngine* eng)
: BuiltinBug(eng,"Undefined or garbage result",
"Result of operation is garbage or undefined") {}
void FlushReportsImpl(BugReporter& BR, GRExprEngine& Eng) {
for (GRExprEngine::undef_result_iterator I=Eng.undef_results_begin(),
E = Eng.undef_results_end(); I!=E; ++I) {
ExplodedNode *N = *I;
const Stmt *S = N->getLocationAs<PostStmt>()->getStmt();
BuiltinBugReport *report = NULL;
if (const BinaryOperator *B = dyn_cast<BinaryOperator>(S)) {
llvm::SmallString<256> sbuf;
llvm::raw_svector_ostream OS(sbuf);
const GRState *ST = N->getState();
const Expr *Ex = NULL;
bool isLeft = true;
if (ST->getSVal(B->getLHS()).isUndef()) {
Ex = B->getLHS()->IgnoreParenCasts();
isLeft = true;
}
else if (ST->getSVal(B->getRHS()).isUndef()) {
Ex = B->getRHS()->IgnoreParenCasts();
isLeft = false;
}
if (Ex) {
OS << "The " << (isLeft ? "left" : "right")
<< " operand of '"
<< BinaryOperator::getOpcodeStr(B->getOpcode())
<< "' is a garbage value";
}
else {
// Neither operand was undefined, but the result is undefined.
OS << "The result of the '"
<< BinaryOperator::getOpcodeStr(B->getOpcode())
<< "' expression is undefined";
}
// FIXME: Use StringRefs to pass string information.
report = new BuiltinBugReport(*this, OS.str().str().c_str(), N);
if (Ex) report->addRange(Ex->getSourceRange());
}
else {
report = new BuiltinBugReport(*this,
"Expression evaluates to an uninitialized"
" or undefined value", N);
}
BR.EmitReport(report);
}
}
void registerInitialVisitors(BugReporterContext& BRC,
const ExplodedNode* N,
BuiltinBugReport *R) {
const Stmt *S = N->getLocationAs<StmtPoint>()->getStmt();
const Stmt *X = S;
if (const BinaryOperator *B = dyn_cast<BinaryOperator>(S)) {
const GRState *ST = N->getState();
if (ST->getSVal(B->getLHS()).isUndef())
X = B->getLHS();
else if (ST->getSVal(B->getRHS()).isUndef())
X = B->getRHS();
}
registerTrackNullOrUndefValue(BRC, X, N);
}
};
} // end clang namespace
//===----------------------------------------------------------------------===//
// Check registration.
//===----------------------------------------------------------------------===//
void GRExprEngine::RegisterInternalChecks() {
// Register internal "built-in" BugTypes with the BugReporter. These BugTypes
// are different than what probably many checks will do since they don't
// create BugReports on-the-fly but instead wait until GRExprEngine finishes
// analyzing a function. Generation of BugReport objects is done via a call
// to 'FlushReports' from BugReporter.
BR.Register(new UndefResult(this));
BR.Register(new NilReceiverStructRet(this));
BR.Register(new NilReceiverLargerThanVoidPtrRet(this));
// The following checks do not need to have their associated BugTypes
// explicitly registered with the BugReporter. If they issue any BugReports,
// their associated BugType will get registered with the BugReporter
// automatically. Note that the check itself is owned by the GRExprEngine
// object.
RegisterAttrNonNullChecker(*this);
RegisterUndefinedArgChecker(*this);
RegisterDereferenceChecker(*this);
RegisterVLASizeChecker(*this);
RegisterDivZeroChecker(*this);
RegisterReturnStackAddressChecker(*this);
RegisterReturnUndefChecker(*this);
RegisterUndefinedArraySubscriptChecker(*this);
RegisterUndefinedAssignmentChecker(*this);
RegisterUndefBranchChecker(*this);
}
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