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 18 namespace clang { 19 20 namespace ento { 21 22 // Recursively find any substatements containing macros containsMacro(const Stmt * S)23bool 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 containsEnum(const Stmt * S)38bool 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 containsStaticLocal(const Stmt * S)52bool 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 containsBuiltinOffsetOf(const Stmt * S)68bool 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 *> parseAssignment(const Stmt * S)81parseAssignment(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 = cast<VarDecl>(PD->getSingleDecl()); 96 RHS = VD->getAnyInitializer(); 97 } 98 99 return std::make_pair(VD, RHS); 100 } 101 getNullabilityAnnotation(QualType Type)102Nullability 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 tryExpandAsInteger(StringRef Macro,const Preprocessor & PP)113llvm::Optional<int> tryExpandAsInteger(StringRef Macro, 114 const Preprocessor &PP) { 115 const auto *MacroII = PP.getIdentifierInfo(Macro); 116 if (!MacroII) 117 return llvm::None; 118 const MacroInfo *MI = PP.getMacroInfo(MacroII); 119 if (!MI) 120 return llvm::None; 121 122 // Filter out parens. 123 std::vector<Token> FilteredTokens; 124 FilteredTokens.reserve(MI->tokens().size()); 125 for (auto &T : MI->tokens()) 126 if (!T.isOneOf(tok::l_paren, tok::r_paren)) 127 FilteredTokens.push_back(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 llvm::None; 135 StringRef ValueStr = StringRef(T.getLiteralData(), T.getLength()); 136 llvm::APInt IntValue; 137 constexpr unsigned AutoSenseRadix = 0; 138 if (ValueStr.getAsInteger(AutoSenseRadix, IntValue)) 139 return llvm::None; 140 141 // Parse an optional minus sign. 142 size_t Size = FilteredTokens.size(); 143 if (Size >= 2) { 144 if (FilteredTokens[Size - 2].is(tok::minus)) 145 IntValue = -IntValue; 146 } 147 148 return IntValue.getSExtValue(); 149 } 150 151 } // namespace ento 152 } // namespace clang 153