llvm/clang/include/clang/Tooling/Transformer/MatchConsumer.h

//===--- MatchConsumer.h - MatchConsumer abstraction ------------*- 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
//
//===----------------------------------------------------------------------===//
///
/// \file This file defines the *MatchConsumer* abstraction: a computation over
/// match results, specifically the `ast_matchers::MatchFinder::MatchResult`
/// class.
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_TOOLING_TRANSFORMER_MATCHCONSUMER_H
#define LLVM_CLANG_TOOLING_TRANSFORMER_MATCHCONSUMER_H

#include "clang/AST/ASTTypeTraits.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"

namespace clang {
namespace transformer {
/// A failable computation over nodes bound by AST matchers.
///
/// The computation should report any errors though its return value (rather
/// than terminating the program) to enable usage in interactive scenarios like
/// clang-query.
///
/// This is a central abstraction of the Transformer framework.
MatchConsumer;

/// Creates an error that signals that a `MatchConsumer` expected a certain node
/// to be bound by AST matchers, but it was not actually bound.
inline llvm::Error notBoundError(llvm::StringRef Id) { … }

/// Chooses between the two consumers, based on whether \p ID is bound in the
/// match.
template <typename T>
MatchConsumer<T> ifBound(std::string ID, MatchConsumer<T> TrueC,
                         MatchConsumer<T> FalseC) { … }

/// A failable computation over nodes bound by AST matchers, with (limited)
/// reflection via the `toString` method.
///
/// The computation should report any errors though its return value (rather
/// than terminating the program) to enable usage in interactive scenarios like
/// clang-query.
///
/// This is a central abstraction of the Transformer framework. It is a
/// generalization of `MatchConsumer` and intended to replace it.
template <typename T> class MatchComputation { … };

template <typename T>
llvm::Expected<T> MatchComputation<T>::eval(
    const ast_matchers::MatchFinder::MatchResult &R) const { … }
} // namespace transformer
} // namespace clang
#endif // LLVM_CLANG_TOOLING_TRANSFORMER_MATCHCONSUMER_H