clang 18.0.0git
FixedAddressChecker.cpp
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1//=== FixedAddressChecker.cpp - Fixed address usage checker ----*- C++ -*--===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This files defines FixedAddressChecker, a builtin checker that checks for
10// assignment of a fixed address to a pointer.
11// This check corresponds to CWE-587.
12//
13//===----------------------------------------------------------------------===//
14
20
21using namespace clang;
22using namespace ento;
23
24namespace {
25class FixedAddressChecker
26 : public Checker< check::PreStmt<BinaryOperator> > {
27 mutable std::unique_ptr<BugType> BT;
28
29public:
30 void checkPreStmt(const BinaryOperator *B, CheckerContext &C) const;
31};
32}
33
34void FixedAddressChecker::checkPreStmt(const BinaryOperator *B,
35 CheckerContext &C) const {
36 // Using a fixed address is not portable because that address will probably
37 // not be valid in all environments or platforms.
38
39 if (B->getOpcode() != BO_Assign)
40 return;
41
42 QualType T = B->getType();
43 if (!T->isPointerType())
44 return;
45
46 SVal RV = C.getSVal(B->getRHS());
47
48 if (!RV.isConstant() || RV.isZeroConstant())
49 return;
50
51 if (ExplodedNode *N = C.generateNonFatalErrorNode()) {
52 // FIXME: improve grammar in the following strings:
53 if (!BT)
54 BT.reset(new BugType(this, "Use fixed address"));
55 constexpr llvm::StringLiteral Msg =
56 "Using a fixed address is not portable because that address will "
57 "probably not be valid in all environments or platforms.";
58 auto R = std::make_unique<PathSensitiveBugReport>(*BT, Msg, N);
59 R->addRange(B->getRHS()->getSourceRange());
60 C.emitReport(std::move(R));
61 }
62}
63
64void ento::registerFixedAddressChecker(CheckerManager &mgr) {
65 mgr.registerChecker<FixedAddressChecker>();
66}
67
68bool ento::shouldRegisterFixedAddressChecker(const CheckerManager &mgr) {
69 return true;
70}
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3862
Expr * getRHS() const
Definition: Expr.h:3913
Opcode getOpcode() const
Definition: Expr.h:3906
QualType getType() const
Definition: Expr.h:142
A (possibly-)qualified type.
Definition: Type.h:736
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:325
bool isPointerType() const
Definition: Type.h:7031
CHECKER * registerChecker(AT &&... Args)
Used to register checkers.
SVal - This represents a symbolic expression, which can be either an L-value or an R-value.
Definition: SVals.h:55
bool isZeroConstant() const
Definition: SVals.cpp:258
bool isConstant() const
Definition: SVals.cpp:246