IgnoreExpr.h

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//===--- IgnoreExpr.h - Ignore intermediate Expressions -----------------===//
//
// 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 common functions to ignore intermediate expression nodes
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_AST_IGNOREEXPR_H
#define LLVM_CLANG_AST_IGNOREEXPR_H
 
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
 
namespace clang {
namespace detail {
/// Given an expression E and functions Fn_1,...,Fn_n : Expr * -> Expr *,
/// Return Fn_n(...(Fn_1(E)))
inline Expr *IgnoreExprNodesImpl(Expr *E) { return E; }
template <typename FnTy, typename... FnTys>
Expr *IgnoreExprNodesImpl(Expr *E, FnTy &&Fn, FnTys &&... Fns) {
  return IgnoreExprNodesImpl(std::forward<FnTy>(Fn)(E),
                             std::forward<FnTys>(Fns)...);
}
} // namespace detail
 
/// Given an expression E and functions Fn_1,...,Fn_n : Expr * -> Expr *,
/// Recursively apply each of the functions to E until reaching a fixed point.
/// Note that a null E is valid; in this case nothing is done.
template <typename... FnTys> Expr *IgnoreExprNodes(Expr *E, FnTys &&... Fns) {
  Expr *LastE = nullptr;
  while (E != LastE) {
    LastE = E;
    E = detail::IgnoreExprNodesImpl(E, std::forward<FnTys>(Fns)...);
  }
  return E;
}
 
template <typename... FnTys>
const Expr *IgnoreExprNodes(const Expr *E, FnTys &&...Fns) {
  return IgnoreExprNodes(const_cast<Expr *>(E), std::forward<FnTys>(Fns)...);
}
 
inline Expr *IgnoreImplicitCastsSingleStep(Expr *E) {
  if (auto *ICE = dyn_cast<ImplicitCastExpr>(