| 1 | //== TrustReturnsNonnullChecker.cpp -- API nullability modeling -*- 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 checker adds nullability-related assumptions to methods annotated with |
| 10 | // returns_nonnull attribute. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "clang/AST/Attr.h" |
| 15 | #include "clang/AST/Decl.h" |
| 16 | #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" |
| 17 | #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" |
| 18 | #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" |
| 19 | |
| 20 | using namespace clang; |
| 21 | using namespace ento; |
| 22 | |
| 23 | namespace { |
| 24 | |
| 25 | class TrustReturnsNonnullChecker : public Checker<check::PostCall> { |
| 26 | |
| 27 | public: |
| 28 | TrustReturnsNonnullChecker(ASTContext &Ctx) {} |
| 29 | |
| 30 | void checkPostCall(const CallEvent &Call, CheckerContext &C) const { |
| 31 | ProgramStateRef State = C.getState(); |
| 32 | |
| 33 | if (isNonNullPtr(Call)) |
| 34 | if (auto L = Call.getReturnValue().getAs<Loc>()) |
| 35 | State = State->assume(Cond: *L, /*assumption=*/Assumption: true); |
| 36 | |
| 37 | C.addTransition(State); |
| 38 | } |
| 39 | |
| 40 | private: |
| 41 | /// \returns Whether the method declaration has the attribute returns_nonnull. |
| 42 | bool isNonNullPtr(const CallEvent &Call) const { |
| 43 | QualType ExprRetType = Call.getResultType(); |
| 44 | const Decl *CallDeclaration = Call.getDecl(); |
| 45 | if (!ExprRetType->isAnyPointerType() || !CallDeclaration) |
| 46 | return false; |
| 47 | |
| 48 | return CallDeclaration->hasAttr<ReturnsNonNullAttr>(); |
| 49 | } |
| 50 | }; |
| 51 | |
| 52 | } // namespace |
| 53 | |
| 54 | void ento::registerTrustReturnsNonnullChecker(CheckerManager &Mgr) { |
| 55 | Mgr.registerChecker<TrustReturnsNonnullChecker>(Args&: Mgr.getASTContext()); |
| 56 | } |
| 57 | |
| 58 | bool ento::shouldRegisterTrustReturnsNonnullChecker(const CheckerManager &mgr) { |
| 59 | return true; |
| 60 | } |
| 61 |