clang  15.0.0git
TrustReturnsNonnullChecker.cpp
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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"
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(*L, /*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>(Mgr.getASTContext());
56 }
57 
58 bool ento::shouldRegisterTrustReturnsNonnullChecker(const CheckerManager &mgr) {
59  return true;
60 }
clang::Decl::hasAttr
bool hasAttr() const
Definition: DeclBase.h:549
clang::ento::ProgramStateRef
IntrusiveRefCntPtr< const ProgramState > ProgramStateRef
Definition: ProgramState_Fwd.h:37
clang::QualType
A (possibly-)qualified type.
Definition: Type.h:731
Attr.h
AttributeLangSupport::C
@ C
Definition: SemaDeclAttr.cpp:55
clang::index::SymbolRole::Call
@ Call
Decl.h
CallEvent.h
BuiltinCheckerRegistration.h
clang::ASTContext
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:208
clang::Decl
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:83
State
LineState State
Definition: UnwrappedLineFormatter.cpp:1126
CheckerContext.h
clang
Definition: CalledOnceCheck.h:17
clang::Type::isAnyPointerType
bool isAnyPointerType() const
Definition: Type.h:6811