1 //===--- MatchConsumer.h - MatchConsumer abstraction ------------*- 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 /// \file This file defines the *MatchConsumer* abstraction: a computation over 10 /// match results, specifically the `ast_matchers::MatchFinder::MatchResult` 11 /// class. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_TOOLING_TRANSFORMER_MATCH_CONSUMER_H_ 16 #define LLVM_CLANG_TOOLING_TRANSFORMER_MATCH_CONSUMER_H_ 17 18 #include "clang/AST/ASTTypeTraits.h" 19 #include "clang/ASTMatchers/ASTMatchFinder.h" 20 #include "llvm/ADT/StringRef.h" 21 #include "llvm/Support/Errc.h" 22 #include "llvm/Support/Error.h" 23 24 namespace clang { 25 namespace transformer { 26 /// A failable computation over nodes bound by AST matchers. 27 /// 28 /// The computation should report any errors though its return value (rather 29 /// than terminating the program) to enable usage in interactive scenarios like 30 /// clang-query. 31 /// 32 /// This is a central abstraction of the Transformer framework. 33 template <typename T> 34 using MatchConsumer = 35 std::function<Expected<T>(const ast_matchers::MatchFinder::MatchResult &)>; 36 37 /// Creates an error that signals that a `MatchConsumer` expected a certain node 38 /// to be bound by AST matchers, but it was not actually bound. 39 inline llvm::Error notBoundError(llvm::StringRef Id) { 40 return llvm::make_error<llvm::StringError>(llvm::errc::invalid_argument, 41 "Id not bound: " + Id); 42 } 43 44 /// Chooses between the two consumers, based on whether \p ID is bound in the 45 /// match. 46 template <typename T> 47 MatchConsumer<T> ifBound(std::string ID, MatchConsumer<T> TrueC, 48 MatchConsumer<T> FalseC) { 49 return [=](const ast_matchers::MatchFinder::MatchResult &Result) { 50 auto &Map = Result.Nodes.getMap(); 51 return (Map.find(ID) != Map.end() ? TrueC : FalseC)(Result); 52 }; 53 } 54 } // namespace transformer 55 56 namespace tooling { 57 // DEPRECATED: Temporary alias supporting client migration to the `transformer` 58 // namespace. 59 using transformer::ifBound; 60 } // namespace tooling 61 } // namespace clang 62 #endif // LLVM_CLANG_TOOLING_TRANSFORMER_MATCH_CONSUMER_H_ 63