1 //===- TaggedUnionModeling.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 #ifndef LLVM_CLANG_LIB_STATICANALYZER_CHECKERS_TAGGEDUNIONMODELING_H
10 #define LLVM_CLANG_LIB_STATICANALYZER_CHECKERS_TAGGEDUNIONMODELING_H
11
12 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
13 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
14 #include "clang/StaticAnalyzer/Core/Checker.h"
15 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
16 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
17 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
18 #include "llvm/ADT/FoldingSet.h"
19 #include <numeric>
20
21 namespace clang::ento::tagged_union_modeling {
22
23 // The implementation of all these functions can be found in the file
24 // StdVariantChecker.cpp under the same directory as this file.
25
26 bool isCopyConstructorCall(const CallEvent &Call);
27 bool isCopyAssignmentCall(const CallEvent &Call);
28 bool isMoveAssignmentCall(const CallEvent &Call);
29 bool isMoveConstructorCall(const CallEvent &Call);
30 bool isStdType(const Type *Type, const std::string &TypeName);
31 bool isStdVariant(const Type *Type);
32
33 // When invalidating regions, we also have to follow that by invalidating the
34 // corresponding custom data in the program state.
35 template <class TypeMap>
36 ProgramStateRef
removeInformationStoredForDeadInstances(const CallEvent & Call,ProgramStateRef State,ArrayRef<const MemRegion * > Regions)37 removeInformationStoredForDeadInstances(const CallEvent &Call,
38 ProgramStateRef State,
39 ArrayRef<const MemRegion *> Regions) {
40 // If we do not know anything about the call we shall not continue.
41 // If the call is happens within a system header it is implementation detail.
42 // We should not take it into consideration.
43 if (Call.isInSystemHeader())
44 return State;
45
46 for (const MemRegion *Region : Regions)
47 State = State->remove<TypeMap>(Region);
48
49 return State;
50 }
51
52 template <class TypeMap>
handleConstructorAndAssignment(const CallEvent & Call,CheckerContext & C,SVal ThisSVal)53 void handleConstructorAndAssignment(const CallEvent &Call, CheckerContext &C,
54 SVal ThisSVal) {
55 ProgramStateRef State = Call.getState();
56
57 if (!State)
58 return;
59
60 auto ArgSVal = Call.getArgSVal(0);
61 const auto *ThisRegion = ThisSVal.getAsRegion();
62 const auto *ArgMemRegion = ArgSVal.getAsRegion();
63
64 // Make changes to the state according to type of constructor/assignment
65 bool IsCopy = isCopyConstructorCall(Call) || isCopyAssignmentCall(Call);
66 bool IsMove = isMoveConstructorCall(Call) || isMoveAssignmentCall(Call);
67 // First we handle copy and move operations
68 if (IsCopy || IsMove) {
69 const QualType *OtherQType = State->get<TypeMap>(ArgMemRegion);
70
71 // If the argument of a copy constructor or assignment is unknown then
72 // we will not know the argument of the copied to object.
73 if (!OtherQType) {
74 State = State->remove<TypeMap>(ThisRegion);
75 } else {
76 // When move semantics is used we can only know that the moved from
77 // object must be in a destructible state. Other usage of the object
78 // than destruction is undefined.
79 if (IsMove)
80 State = State->remove<TypeMap>(ArgMemRegion);
81
82 State = State->set<TypeMap>(ThisRegion, *OtherQType);
83 }
84 } else {
85 // Value constructor
86 auto ArgQType = ArgSVal.getType(C.getASTContext());
87 const Type *ArgTypePtr = ArgQType.getTypePtr();
88
89 QualType WoPointer = ArgTypePtr->getPointeeType();
90 State = State->set<TypeMap>(ThisRegion, WoPointer);
91 }
92
93 C.addTransition(State);
94 }
95
96 } // namespace clang::ento::tagged_union_modeling
97
98 #endif // LLVM_CLANG_LIB_STATICANALYZER_CHECKERS_TAGGEDUNIONMODELING_H
99