220 lines · cpp
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-exception6//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 "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"18#include <optional>19 20namespace clang {21 22namespace ento {23 24// Recursively find any substatements containing macros25bool containsMacro(const Stmt *S) {26 if (S->getBeginLoc().isMacroID())27 return true;28 29 if (S->getEndLoc().isMacroID())30 return true;31 32 for (const Stmt *Child : S->children())33 if (Child && containsMacro(Child))34 return true;35 36 return false;37}38 39// Recursively find any substatements containing enum constants40bool containsEnum(const Stmt *S) {41 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);42 43 if (DR && isa<EnumConstantDecl>(DR->getDecl()))44 return true;45 46 for (const Stmt *Child : S->children())47 if (Child && containsEnum(Child))48 return true;49 50 return false;51}52 53// Recursively find any substatements containing static vars54bool containsStaticLocal(const Stmt *S) {55 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);56 57 if (DR)58 if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()))59 if (VD->isStaticLocal())60 return true;61 62 for (const Stmt *Child : S->children())63 if (Child && containsStaticLocal(Child))64 return true;65 66 return false;67}68 69// Recursively find any substatements containing __builtin_offsetof70bool containsBuiltinOffsetOf(const Stmt *S) {71 if (isa<OffsetOfExpr>(S))72 return true;73 74 for (const Stmt *Child : S->children())75 if (Child && containsBuiltinOffsetOf(Child))76 return true;77 78 return false;79}80 81// Extract lhs and rhs from assignment statement82std::pair<const clang::VarDecl *, const clang::Expr *>83parseAssignment(const Stmt *S) {84 const VarDecl *VD = nullptr;85 const Expr *RHS = nullptr;86 87 if (auto Assign = dyn_cast_or_null<BinaryOperator>(S)) {88 if (Assign->isAssignmentOp()) {89 // Ordinary assignment90 RHS = Assign->getRHS();91 if (auto DE = dyn_cast_or_null<DeclRefExpr>(Assign->getLHS()))92 VD = dyn_cast_or_null<VarDecl>(DE->getDecl());93 }94 } else if (auto PD = dyn_cast_or_null<DeclStmt>(S)) {95 // Initialization96 assert(PD->isSingleDecl() && "We process decls one by one");97 VD = cast<VarDecl>(PD->getSingleDecl());98 RHS = VD->getAnyInitializer();99 }100 101 return std::make_pair(VD, RHS);102}103 104Nullability getNullabilityAnnotation(QualType Type) {105 const auto *AttrType = Type->getAs<AttributedType>();106 if (!AttrType)107 return Nullability::Unspecified;108 if (AttrType->getAttrKind() == attr::TypeNullable)109 return Nullability::Nullable;110 else if (AttrType->getAttrKind() == attr::TypeNonNull)111 return Nullability::Nonnull;112 return Nullability::Unspecified;113}114 115std::optional<int> tryExpandAsInteger(StringRef Macro, const Preprocessor &PP) {116 const auto *MacroII = PP.getIdentifierInfo(Macro);117 if (!MacroII)118 return std::nullopt;119 const MacroInfo *MI = PP.getMacroInfo(MacroII);120 if (!MI)121 return std::nullopt;122 123 // Filter out parens.124 std::vector<Token> FilteredTokens;125 FilteredTokens.reserve(MI->tokens().size());126 for (auto &T : MI->tokens())127 if (!T.isOneOf(tok::l_paren, tok::r_paren))128 FilteredTokens.push_back(T);129 130 // Parse an integer at the end of the macro definition.131 const Token &T = FilteredTokens.back();132 133 if (!T.isLiteral())134 return std::nullopt;135 136 bool InvalidSpelling = false;137 SmallVector<char> Buffer(T.getLength());138 // `Preprocessor::getSpelling` can get the spelling of the token regardless of139 // whether the macro is defined in a PCH or not:140 StringRef ValueStr = PP.getSpelling(T, Buffer, &InvalidSpelling);141 142 if (InvalidSpelling)143 return std::nullopt;144 145 llvm::APSInt IntValue(/*BitWidth=*/0, /*isUnsigned=*/true);146 constexpr unsigned AutoSenseRadix = 0;147 if (ValueStr.getAsInteger(AutoSenseRadix,148 static_cast<llvm::APInt &>(IntValue)))149 return std::nullopt;150 151 // Parse an optional minus sign.152 size_t Size = FilteredTokens.size();153 if (Size >= 2) {154 if (FilteredTokens[Size - 2].is(tok::minus)) {155 // Make sure there's space for a sign bit156 if (IntValue.isSignBitSet())157 IntValue = IntValue.extend(IntValue.getBitWidth() + 1);158 IntValue.setIsUnsigned(false);159 IntValue = -IntValue;160 }161 }162 163 return IntValue.getExtValue();164}165 166OperatorKind operationKindFromOverloadedOperator(OverloadedOperatorKind OOK,167 bool IsBinary) {168 llvm::StringMap<BinaryOperatorKind> BinOps{169#define BINARY_OPERATION(Name, Spelling) {Spelling, BO_##Name},170#include "clang/AST/OperationKinds.def"171 };172 llvm::StringMap<UnaryOperatorKind> UnOps{173#define UNARY_OPERATION(Name, Spelling) {Spelling, UO_##Name},174#include "clang/AST/OperationKinds.def"175 };176 177 switch (OOK) {178#define OVERLOADED_OPERATOR(Name, Spelling, Token, Unary, Binary, MemberOnly) \179 case OO_##Name: \180 if (IsBinary) { \181 auto BinOpIt = BinOps.find(Spelling); \182 if (BinOpIt != BinOps.end()) \183 return OperatorKind(BinOpIt->second); \184 else \185 llvm_unreachable("operator was expected to be binary but is not"); \186 } else { \187 auto UnOpIt = UnOps.find(Spelling); \188 if (UnOpIt != UnOps.end()) \189 return OperatorKind(UnOpIt->second); \190 else \191 llvm_unreachable("operator was expected to be unary but is not"); \192 } \193 break;194#include "clang/Basic/OperatorKinds.def"195 default:196 llvm_unreachable("unexpected operator kind");197 }198}199 200std::optional<SVal> getPointeeVal(SVal PtrSVal, ProgramStateRef State) {201 if (const auto *Ptr = PtrSVal.getAsRegion()) {202 return State->getSVal(Ptr);203 }204 return std::nullopt;205}206 207bool isWithinStdNamespace(const Decl *D) {208 const DeclContext *DC = D->getDeclContext();209 while (DC) {210 if (const auto *NS = dyn_cast<NamespaceDecl>(DC);211 NS && NS->isStdNamespace())212 return true;213 DC = DC->getParent();214 }215 return false;216}217 218} // namespace ento219} // namespace clang220