//===---- CheckerHelpers.cpp - Helper functions for checkers ----*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

//  This file defines several static functions for use in checkers.

//

//===----------------------------------------------------------------------===//

#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h"

#include "clang/AST/Decl.h"

#include "clang/AST/Expr.h"

#include "clang/Lex/Preprocessor.h"

namespace clang {

namespace ento {

// Recursively find any substatements containing macros

bool containsMacro(const Stmt *S) {

  if (S->getBeginLoc().isMacroID())

    return true;

  if (S->getEndLoc().isMacroID())

    return true;

  for (const Stmt *Child : S->children())

    if (Child && containsMacro(Child))

      return true;

  return false;

}

// Recursively find any substatements containing enum constants

bool containsEnum(const Stmt *S) {

  const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);

  if (DR && 
isa<EnumConstantDecl>(DR->getDecl())10
)

    return true;

  for (const Stmt *Child : S->children())

    if (Child && containsEnum(Child))

      return true;

  return false;

}

// Recursively find any substatements containing static vars

bool containsStaticLocal(const Stmt *S) {

  const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);

  if (DR)

    if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()))

      if (VD->isStaticLocal())

        return true;

  for (const Stmt *Child : S->children())

    if (Child && containsStaticLocal(Child))

      return true;

  return false;

}

// Recursively find any substatements containing __builtin_offsetof

bool containsBuiltinOffsetOf(const Stmt *S) {

  if (isa<OffsetOfExpr>(S))

    return true;

  for (const Stmt *Child : S->children())

    if (Child && containsBuiltinOffsetOf(Child))

      return true;

  return false;

}

// Extract lhs and rhs from assignment statement

std::pair<const clang::VarDecl *, const clang::Expr *>

parseAssignment(const Stmt *S) {

  const VarDecl *VD = nullptr;

  const Expr *RHS = nullptr;

  if (auto Assign = dyn_cast_or_null<BinaryOperator>(S)) {

    if (Assign->isAssignmentOp()) {

      // Ordinary assignment

      RHS = Assign->getRHS();

      if (auto DE = dyn_cast_or_null<DeclRefExpr>(Assign->getLHS()))

        VD = dyn_cast_or_null<VarDecl>(DE->getDecl());

    }

  } else if (auto PD = dyn_cast_or_null<DeclStmt>(S)) {

    // Initialization

    assert(PD->isSingleDecl() && "We process decls one by one");

    VD = cast<VarDecl>(PD->getSingleDecl());

    RHS = VD->getAnyInitializer();

  }

  return std::make_pair(VD, RHS);

}

Nullability getNullabilityAnnotation(QualType Type) {

  const auto *AttrType = Type->getAs<AttributedType>();

  if (!AttrType)

    return Nullability::Unspecified;

  if (AttrType->getAttrKind() == attr::TypeNullable)

    return Nullability::Nullable;

  else if (AttrType->getAttrKind() == attr::TypeNonNull)

    return Nullability::Nonnull;

  return Nullability::Unspecified;

}

llvm::Optional<int> tryExpandAsInteger(StringRef Macro,

                                       const Preprocessor &PP) {

  const auto *MacroII = PP.getIdentifierInfo(Macro);

  if (!MacroII)

    return llvm::None;

  const MacroInfo *MI = PP.getMacroInfo(MacroII);

  if (!MI)

    return llvm::None;

  // Filter out parens.

  std::vector<Token> FilteredTokens;

  FilteredTokens.reserve(MI->tokens().size());

  for (auto &T : MI->tokens())

    if (!T.isOneOf(tok::l_paren, tok::r_paren))

      FilteredTokens.push_back(T);

  // Parse an integer at the end of the macro definition.

  const Token &T = FilteredTokens.back();

  // FIXME: EOF macro token coming from a PCH file on macOS while marked as

  //        literal, doesn't contain any literal data

  if (!T.isLiteral() || !T.getLiteralData())

    return llvm::None;

  StringRef ValueStr = StringRef(T.getLiteralData(), T.getLength());

  llvm::APInt IntValue;

  constexpr unsigned AutoSenseRadix = 0;

  if (ValueStr.getAsInteger(AutoSenseRadix, IntValue))

    return llvm::None;

  // Parse an optional minus sign.

  size_t Size = FilteredTokens.size();

  if (Size >= 2) {

    if (FilteredTokens[Size - 2].is(tok::minus))

      IntValue = -IntValue;

  }

  return IntValue.getSExtValue();

}

} // namespace ento

} // namespace clang