1 //===--- UndefinedArraySubscriptChecker.h ----------------------*- 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 defines UndefinedArraySubscriptChecker, a builtin check in ExprEngine 10 // that performs checks for undefined array subscripts. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" 15 #include "clang/AST/DeclCXX.h" 16 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 17 #include "clang/StaticAnalyzer/Core/Checker.h" 18 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 19 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 20 21 using namespace clang; 22 using namespace ento; 23 24 namespace { 25 class UndefinedArraySubscriptChecker 26 : public Checker< check::PreStmt<ArraySubscriptExpr> > { 27 mutable std::unique_ptr<BugType> BT; 28 29 public: 30 void checkPreStmt(const ArraySubscriptExpr *A, CheckerContext &C) const; 31 }; 32 } // end anonymous namespace 33 34 void 35 UndefinedArraySubscriptChecker::checkPreStmt(const ArraySubscriptExpr *A, 36 CheckerContext &C) const { 37 const Expr *Index = A->getIdx(); 38 if (!C.getSVal(Index).isUndef()) 39 return; 40 41 // Sema generates anonymous array variables for copying array struct fields. 42 // Don't warn if we're in an implicitly-generated constructor. 43 const Decl *D = C.getLocationContext()->getDecl(); 44 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(D)) 45 if (Ctor->isDefaulted()) 46 return; 47 48 ExplodedNode *N = C.generateErrorNode(); 49 if (!N) 50 return; 51 if (!BT) 52 BT.reset(new BuiltinBug(this, "Array subscript is undefined")); 53 54 // Generate a report for this bug. 55 auto R = llvm::make_unique<BugReport>(*BT, BT->getName(), N); 56 R->addRange(A->getIdx()->getSourceRange()); 57 bugreporter::trackExpressionValue(N, A->getIdx(), *R); 58 C.emitReport(std::move(R)); 59 } 60 61 void ento::registerUndefinedArraySubscriptChecker(CheckerManager &mgr) { 62 mgr.registerChecker<UndefinedArraySubscriptChecker>(); 63 } 64 65 bool ento::shouldRegisterUndefinedArraySubscriptChecker(const LangOptions &LO) { 66 return true; 67 } 68