| //===--- 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>(); |
| } |