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
17namespace clang {
18
19namespace ento {
20
21// Recursively find any substatements containing macros
22bool containsMacro(const Stmt *S) {
23  if (S->getBeginLoc().isMacroID())
24    return true;
25
26  if (S->getEndLoc().isMacroID())
27    return true;
28
29  for (const Stmt *Child : S->children())
30    if (Child && containsMacro(Child))
31      return true;
32
33  return false;
34}
35
36// Recursively find any substatements containing enum constants
37bool containsEnum(const Stmt *S) {
38  const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);
39
40  if (DR && isa<EnumConstantDecl>(DR->getDecl()))
41    return true;
42
43  for (const Stmt *Child : S->children())
44    if (Child && containsEnum(Child))
45      return true;
46
47  return false;
48}
49
50// Recursively find any substatements containing static vars
51bool containsStaticLocal(const Stmt *S) {
52  const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);
53
54  if (DR)
55    if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()))
56      if (VD->isStaticLocal())
57        return true;
58
59  for (const Stmt *Child : S->children())
60    if (Child && containsStaticLocal(Child))
61      return true;
62
63  return false;
64}
65
66// Recursively find any substatements containing __builtin_offsetof
67bool containsBuiltinOffsetOf(const Stmt *S) {
68  if (isa<OffsetOfExpr>(S))
69    return true;
70
71  for (const Stmt *Child : S->children())
72    if (Child && containsBuiltinOffsetOf(Child))
73      return true;
74
75  return false;
76}
77
78// Extract lhs and rhs from assignment statement
79std::pair<const clang::VarDecl *, const clang::Expr *>
80parseAssignment(const Stmt *S) {
81  const VarDecl *VD = nullptr;
82  const Expr *RHS = nullptr;
83
84  if (auto Assign = dyn_cast_or_null<BinaryOperator>(S)) {
85    if (Assign->isAssignmentOp()) {
86      // Ordinary assignment
87      RHS = Assign->getRHS();
88      if (auto DE = dyn_cast_or_null<DeclRefExpr>(Assign->getLHS()))
89        VD = dyn_cast_or_null<VarDecl>(DE->getDecl());
90    }
91  } else if (auto PD = dyn_cast_or_null<DeclStmt>(S)) {
92    // Initialization
93    assert(PD->isSingleDecl() && "We process decls one by one");
94    VD = cast<VarDecl>(PD->getSingleDecl());
95    RHS = VD->getAnyInitializer();
96  }
97
98  return std::make_pair(VD, RHS);
99}
100
101Nullability getNullabilityAnnotation(QualType Type) {
102  const auto *AttrType = Type->getAs<AttributedType>();
103  if (!AttrType)
104    return Nullability::Unspecified;
105  if (AttrType->getAttrKind() == attr::TypeNullable)
106    return Nullability::Nullable;
107  else if (AttrType->getAttrKind() == attr::TypeNonNull)
108    return Nullability::Nonnull;
109  return Nullability::Unspecified;
110}
111
112
113} // end namespace ento
114} // end namespace clang
115