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//===--- 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 UndefinedAssignmentChecker, a builtin check in ExprEngine that
// checks for assigning undefined values.
//
//===----------------------------------------------------------------------===//
#include "ClangSACheckers.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
using namespace clang;
using namespace ento;
namespace {
class UndefinedAssignmentChecker
: public Checker<check::Bind> {
mutable std::unique_ptr<BugType> BT;
public:
void checkBind(SVal location, SVal val, const Stmt *S,
CheckerContext &C) const;
};
}
void UndefinedAssignmentChecker::checkBind(SVal location, SVal val,
const Stmt *StoreE,
CheckerContext &C) const {
if (!val.isUndef())
return;
// Do not report assignments of uninitialized values inside swap functions.
// This should allow to swap partially uninitialized structs
// (radar://14129997)
if (const FunctionDecl *EnclosingFunctionDecl =
dyn_cast<FunctionDecl>(C.getStackFrame()->getDecl()))
if (C.getCalleeName(EnclosingFunctionDecl) == "swap")
return;
ExplodedNode *N = C.generateErrorNode();
if (!N)
return;
const char *str = "Assigned value is garbage or undefined";
if (!BT)
BT.reset(new BuiltinBug(this, str));
// Generate a report for this bug.
const Expr *ex = nullptr;
while (StoreE) {
if (const BinaryOperator *B = dyn_cast<BinaryOperator>(StoreE)) {
if (B->isCompoundAssignmentOp()) {
ProgramStateRef state = C.getState();
if (state->getSVal(B->getLHS(), C.getLocationContext()).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;
}
auto R = llvm::make_unique<BugReport>(*BT, str, N);
if (ex) {
R->addRange(ex->getSourceRange());
bugreporter::trackNullOrUndefValue(N, ex, *R);
}
C.emitReport(std::move(R));
}
void ento::registerUndefinedAssignmentChecker(CheckerManager &mgr) {
mgr.registerChecker<UndefinedAssignmentChecker>();
}
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