xref: /llvm-project/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp (revision e43e2b3667f9bc29c23be5235b53a7d7afcdb181)
1 //===---- CheckerHelpers.cpp - Helper functions for checkers ----*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file defines several static functions for use in checkers.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h"
15 #include "clang/AST/Decl.h"
16 #include "clang/AST/Expr.h"
17 
18 namespace clang {
19 
20 namespace ento {
21 
22 // Recursively find any substatements containing macros
23 bool containsMacro(const Stmt *S) {
24   if (S->getBeginLoc().isMacroID())
25     return true;
26 
27   if (S->getEndLoc().isMacroID())
28     return true;
29 
30   for (const Stmt *Child : S->children())
31     if (Child && containsMacro(Child))
32       return true;
33 
34   return false;
35 }
36 
37 // Recursively find any substatements containing enum constants
38 bool containsEnum(const Stmt *S) {
39   const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);
40 
41   if (DR && isa<EnumConstantDecl>(DR->getDecl()))
42     return true;
43 
44   for (const Stmt *Child : S->children())
45     if (Child && containsEnum(Child))
46       return true;
47 
48   return false;
49 }
50 
51 // Recursively find any substatements containing static vars
52 bool containsStaticLocal(const Stmt *S) {
53   const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);
54 
55   if (DR)
56     if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()))
57       if (VD->isStaticLocal())
58         return true;
59 
60   for (const Stmt *Child : S->children())
61     if (Child && containsStaticLocal(Child))
62       return true;
63 
64   return false;
65 }
66 
67 // Recursively find any substatements containing __builtin_offsetof
68 bool containsBuiltinOffsetOf(const Stmt *S) {
69   if (isa<OffsetOfExpr>(S))
70     return true;
71 
72   for (const Stmt *Child : S->children())
73     if (Child && containsBuiltinOffsetOf(Child))
74       return true;
75 
76   return false;
77 }
78 
79 // Extract lhs and rhs from assignment statement
80 std::pair<const clang::VarDecl *, const clang::Expr *>
81 parseAssignment(const Stmt *S) {
82   const VarDecl *VD = nullptr;
83   const Expr *RHS = nullptr;
84 
85   if (auto Assign = dyn_cast_or_null<BinaryOperator>(S)) {
86     if (Assign->isAssignmentOp()) {
87       // Ordinary assignment
88       RHS = Assign->getRHS();
89       if (auto DE = dyn_cast_or_null<DeclRefExpr>(Assign->getLHS()))
90         VD = dyn_cast_or_null<VarDecl>(DE->getDecl());
91     }
92   } else if (auto PD = dyn_cast_or_null<DeclStmt>(S)) {
93     // Initialization
94     assert(PD->isSingleDecl() && "We process decls one by one");
95     VD = dyn_cast_or_null<VarDecl>(PD->getSingleDecl());
96     RHS = VD->getAnyInitializer();
97   }
98 
99   return std::make_pair(VD, RHS);
100 }
101 
102 Nullability getNullabilityAnnotation(QualType Type) {
103   const auto *AttrType = Type->getAs<AttributedType>();
104   if (!AttrType)
105     return Nullability::Unspecified;
106   if (AttrType->getAttrKind() == attr::TypeNullable)
107     return Nullability::Nullable;
108   else if (AttrType->getAttrKind() == attr::TypeNonNull)
109     return Nullability::Nonnull;
110   return Nullability::Unspecified;
111 }
112 
113 
114 } // end namespace ento
115 } // end namespace clang
116