llvm-project/clang/lib/StaticAnalyzer/Checkers/UndefinedAssignmentChecker.cpp

95 lines
2.6 KiB
C++

//===--- UndefinedAssignmentChecker.h ---------------------------*- C++ -*--==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This defines UndefinedAssginmentChecker, a builtin check in ExprEngine that
// checks for assigning undefined values.
//
//===----------------------------------------------------------------------===//
#include "ExprEngineInternalChecks.h"
#include "clang/StaticAnalyzer/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/PathSensitive/CheckerVisitor.h"
using namespace clang;
using namespace ento;
namespace {
class UndefinedAssignmentChecker
: public CheckerVisitor<UndefinedAssignmentChecker> {
BugType *BT;
public:
UndefinedAssignmentChecker() : BT(0) {}
static void *getTag();
virtual void PreVisitBind(CheckerContext &C, const Stmt *StoreE,
SVal location, SVal val);
};
}
void ento::RegisterUndefinedAssignmentChecker(ExprEngine &Eng){
Eng.registerCheck(new UndefinedAssignmentChecker());
}
void *UndefinedAssignmentChecker::getTag() {
static int x = 0;
return &x;
}
void UndefinedAssignmentChecker::PreVisitBind(CheckerContext &C,
const Stmt *StoreE,
SVal location,
SVal val) {
if (!val.isUndef())
return;
ExplodedNode *N = C.generateSink();
if (!N)
return;
const char *str = "Assigned value is garbage or undefined";
if (!BT)
BT = new BuiltinBug(str);
// Generate a report for this bug.
const Expr *ex = 0;
while (StoreE) {
if (const BinaryOperator *B = dyn_cast<BinaryOperator>(StoreE)) {
if (B->isCompoundAssignmentOp()) {
const GRState *state = C.getState();
if (state->getSVal(B->getLHS()).isUndef()) {
str = "The left expression of the compound assignment is an "
"uninitialized value. The computed value will also be garbage";
ex = B->getLHS();
break;
}
}
ex = B->getRHS();
break;
}
if (const DeclStmt *DS = dyn_cast<DeclStmt>(StoreE)) {
const VarDecl* VD = dyn_cast<VarDecl>(DS->getSingleDecl());
ex = VD->getInit();
}
break;
}
EnhancedBugReport *R = new EnhancedBugReport(*BT, str, N);
if (ex) {
R->addRange(ex->getSourceRange());
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, ex);
}
C.EmitReport(R);
}