[memprof] Update YAML traits for writer purposes (#118720)
[llvm-project.git] / clang / lib / StaticAnalyzer / Checkers / ArrayBoundChecker.cpp
blobc990ad138f89050182fbc847a575c4f5654e363a
1 //== ArrayBoundChecker.cpp ------------------------------*- 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 file defines ArrayBoundChecker, which is a path-sensitive check
10 // which looks for an out-of-bound array element access.
12 //===----------------------------------------------------------------------===//
14 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
15 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
16 #include "clang/StaticAnalyzer/Core/Checker.h"
17 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
18 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
19 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicExtent.h"
20 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
22 using namespace clang;
23 using namespace ento;
25 namespace {
26 class ArrayBoundChecker :
27 public Checker<check::Location> {
28 const BugType BT{this, "Out-of-bound array access"};
30 public:
31 void checkLocation(SVal l, bool isLoad, const Stmt* S,
32 CheckerContext &C) const;
36 void ArrayBoundChecker::checkLocation(SVal l, bool isLoad, const Stmt* LoadS,
37 CheckerContext &C) const {
38 // Check for out of bound array element access.
39 const MemRegion *R = l.getAsRegion();
40 if (!R)
41 return;
43 const ElementRegion *ER = dyn_cast<ElementRegion>(R);
44 if (!ER)
45 return;
47 // Get the index of the accessed element.
48 DefinedOrUnknownSVal Idx = ER->getIndex().castAs<DefinedOrUnknownSVal>();
50 // Zero index is always in bound, this also passes ElementRegions created for
51 // pointer casts.
52 if (Idx.isZeroConstant())
53 return;
55 ProgramStateRef state = C.getState();
57 // Get the size of the array.
58 DefinedOrUnknownSVal ElementCount = getDynamicElementCount(
59 state, ER->getSuperRegion(), C.getSValBuilder(), ER->getValueType());
61 ProgramStateRef StInBound, StOutBound;
62 std::tie(StInBound, StOutBound) = state->assumeInBoundDual(Idx, ElementCount);
63 if (StOutBound && !StInBound) {
64 ExplodedNode *N = C.generateErrorNode(StOutBound);
65 if (!N)
66 return;
68 // FIXME: It would be nice to eventually make this diagnostic more clear,
69 // e.g., by referencing the original declaration or by saying *why* this
70 // reference is outside the range.
72 // Generate a report for this bug.
73 auto report = std::make_unique<PathSensitiveBugReport>(
74 BT, "Access out-of-bound array element (buffer overflow)", N);
76 report->addRange(LoadS->getSourceRange());
77 C.emitReport(std::move(report));
78 return;
81 // Array bound check succeeded. From this point forward the array bound
82 // should always succeed.
83 C.addTransition(StInBound);
86 void ento::registerArrayBoundChecker(CheckerManager &mgr) {
87 mgr.registerChecker<ArrayBoundChecker>();
90 bool ento::shouldRegisterArrayBoundChecker(const CheckerManager &mgr) {
91 return true;