1//===---- CheckerHelpers.cpp - Helper functions for checkers ----*- 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 file defines several static functions for use in checkers.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h"
14#include "clang/AST/Decl.h"
15#include "clang/AST/Expr.h"
16#include "clang/Lex/Preprocessor.h"
17#include <optional>
18
19namespace clang {
20
21namespace ento {
22
23// Recursively find any substatements containing macros
24bool containsMacro(const Stmt *S) {
25 if (S->getBeginLoc().isMacroID())
26 return true;
27
28 if (S->getEndLoc().isMacroID())
29 return true;
30
31 for (const Stmt *Child : S->children())
32 if (Child && containsMacro(S: Child))
33 return true;
34
35 return false;
36}
37
38// Recursively find any substatements containing enum constants
39bool containsEnum(const Stmt *S) {
40 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Val: S);
41
42 if (DR && isa<EnumConstantDecl>(Val: DR->getDecl()))
43 return true;
44
45 for (const Stmt *Child : S->children())
46 if (Child && containsEnum(S: Child))
47 return true;
48
49 return false;
50}
51
52// Recursively find any substatements containing static vars
53bool containsStaticLocal(const Stmt *S) {
54 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Val: S);
55
56 if (DR)
57 if (const VarDecl *VD = dyn_cast<VarDecl>(Val: DR->getDecl()))
58 if (VD->isStaticLocal())
59 return true;
60
61 for (const Stmt *Child : S->children())
62 if (Child && containsStaticLocal(S: Child))
63 return true;
64
65 return false;
66}
67
68// Recursively find any substatements containing __builtin_offsetof
69bool containsBuiltinOffsetOf(const Stmt *S) {
70 if (isa<OffsetOfExpr>(Val: S))
71 return true;
72
73 for (const Stmt *Child : S->children())
74 if (Child && containsBuiltinOffsetOf(S: Child))
75 return true;
76
77 return false;
78}
79
80// Extract lhs and rhs from assignment statement
81std::pair<const clang::VarDecl *, const clang::Expr *>
82parseAssignment(const Stmt *S) {
83 const VarDecl *VD = nullptr;
84 const Expr *RHS = nullptr;
85
86 if (auto Assign = dyn_cast_or_null<BinaryOperator>(Val: S)) {
87 if (Assign->isAssignmentOp()) {
88 // Ordinary assignment
89 RHS = Assign->getRHS();
90 if (auto DE = dyn_cast_or_null<DeclRefExpr>(Val: Assign->getLHS()))
91 VD = dyn_cast_or_null<VarDecl>(Val: DE->getDecl());
92 }
93 } else if (auto PD = dyn_cast_or_null<DeclStmt>(Val: S)) {
94 // Initialization
95 assert(PD->isSingleDecl() && "We process decls one by one");
96 VD = cast<VarDecl>(Val: PD->getSingleDecl());
97 RHS = VD->getAnyInitializer();
98 }
99
100 return std::make_pair(x&: VD, y&: RHS);
101}
102
103Nullability getNullabilityAnnotation(QualType Type) {
104 const auto *AttrType = Type->getAs<AttributedType>();
105 if (!AttrType)
106 return Nullability::Unspecified;
107 if (AttrType->getAttrKind() == attr::TypeNullable)
108 return Nullability::Nullable;
109 else if (AttrType->getAttrKind() == attr::TypeNonNull)
110 return Nullability::Nonnull;
111 return Nullability::Unspecified;
112}
113
114std::optional<int> tryExpandAsInteger(StringRef Macro, const Preprocessor &PP) {
115 const auto *MacroII = PP.getIdentifierInfo(Name: Macro);
116 if (!MacroII)
117 return std::nullopt;
118 const MacroInfo *MI = PP.getMacroInfo(II: MacroII);
119 if (!MI)
120 return std::nullopt;
121
122 // Filter out parens.
123 std::vector<Token> FilteredTokens;
124 FilteredTokens.reserve(n: MI->tokens().size());
125 for (auto &T : MI->tokens())
126 if (!T.isOneOf(K1: tok::l_paren, K2: tok::r_paren))
127 FilteredTokens.push_back(x: T);
128
129 // Parse an integer at the end of the macro definition.
130 const Token &T = FilteredTokens.back();
131 // FIXME: EOF macro token coming from a PCH file on macOS while marked as
132 // literal, doesn't contain any literal data
133 if (!T.isLiteral() || !T.getLiteralData())
134 return std::nullopt;
135 StringRef ValueStr = StringRef(T.getLiteralData(), T.getLength());
136 llvm::APInt IntValue;
137 constexpr unsigned AutoSenseRadix = 0;
138 if (ValueStr.getAsInteger(Radix: AutoSenseRadix, Result&: IntValue))
139 return std::nullopt;
140
141 // Parse an optional minus sign.
142 size_t Size = FilteredTokens.size();
143 if (Size >= 2) {
144 if (FilteredTokens[Size - 2].is(K: tok::minus))
145 IntValue = -IntValue;
146 }
147
148 return IntValue.getSExtValue();
149}
150
151OperatorKind operationKindFromOverloadedOperator(OverloadedOperatorKind OOK,
152 bool IsBinary) {
153 llvm::StringMap<BinaryOperatorKind> BinOps{
154#define BINARY_OPERATION(Name, Spelling) {Spelling, BO_##Name},
155#include "clang/AST/OperationKinds.def"
156 };
157 llvm::StringMap<UnaryOperatorKind> UnOps{
158#define UNARY_OPERATION(Name, Spelling) {Spelling, UO_##Name},
159#include "clang/AST/OperationKinds.def"
160 };
161
162 switch (OOK) {
163#define OVERLOADED_OPERATOR(Name, Spelling, Token, Unary, Binary, MemberOnly) \
164 case OO_##Name: \
165 if (IsBinary) { \
166 auto BinOpIt = BinOps.find(Spelling); \
167 if (BinOpIt != BinOps.end()) \
168 return OperatorKind(BinOpIt->second); \
169 else \
170 llvm_unreachable("operator was expected to be binary but is not"); \
171 } else { \
172 auto UnOpIt = UnOps.find(Spelling); \
173 if (UnOpIt != UnOps.end()) \
174 return OperatorKind(UnOpIt->second); \
175 else \
176 llvm_unreachable("operator was expected to be unary but is not"); \
177 } \
178 break;
179#include "clang/Basic/OperatorKinds.def"
180 default:
181 llvm_unreachable("unexpected operator kind");
182 }
183}
184
185} // namespace ento
186} // namespace clang
187

source code of clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp