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