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carbon-lang/migrate_cpp/cpp_refactoring/matcher.h
T
Jon Meow 6fa42a7f3c For-range in replacement logic (#631)
This replaces GetAstMatcher with AddMatcher because cxxForRangeStmt is a StatementMatcher. addMatcher has multiple definitions (https://clang.llvm.org/doxygen/classclang_1_1ast__matchers_1_1MatchFinder.html) and so this approach allows using the right addMatcher without writing per-call overloads.

To handle the `var`, I'm considering something like moving VarDecl logic into a VarMatcherBase so that I can just use CXXForRangeStmt's getLoopVariable. The problem is a for-range statement has multiple VarDecls, and getLoopVariable may be the easiest way to identify the real one.
2021-07-12 16:20:44 -07:00

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3.2 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#ifndef MIGRATE_CPP_CPP_REFACTORING_MATCHER_H_
#define MIGRATE_CPP_CPP_REFACTORING_MATCHER_H_
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
#include "clang/Tooling/Core/Replacement.h"
namespace Carbon {
// This is an abstract class with helpers to make it easier to write matchers.
// Note a MatcherFactory (below) is also typically required.
class Matcher {
public:
using ReplacementMap = std::map<std::string, clang::tooling::Replacements>;
Matcher(const clang::ast_matchers::MatchFinder::MatchResult* in_match_result,
ReplacementMap* in_replacements)
: match_result(in_match_result), replacements(in_replacements) {}
virtual ~Matcher() = default;
// Performs main execution of the matcher when a result is found.
virtual void Run() = 0;
protected:
// Replaces the given range with the specified text.
void AddReplacement(clang::CharSourceRange range,
llvm::StringRef replacement_text);
// Returns a matched node by ID, exiting if not present.
template <typename NodeType>
auto GetNodeAsOrDie(llvm::StringRef id) -> const NodeType& {
auto* node = match_result->Nodes.getNodeAs<NodeType>(id);
if (!node) {
llvm::report_fatal_error(std::string("getNodeAs failed for ") + id);
}
return *node;
}
// Returns the language options.
auto GetLangOpts() -> const clang::LangOptions& {
return match_result->Context->getLangOpts();
}
// Returns the full source manager.
auto GetSourceManager() -> const clang::SourceManager& {
return *match_result->SourceManager;
}
// Returns the source text for a given range.
auto GetSourceText(clang::CharSourceRange range) -> llvm::StringRef {
return clang::Lexer::getSourceText(range, GetSourceManager(),
GetLangOpts());
}
private:
const clang::ast_matchers::MatchFinder::MatchResult* const match_result;
ReplacementMap* const replacements;
};
// A factory used to instantiate per-MatchResult Matchers, to be registered with
// the MatcherManager.
class MatcherFactory {
public:
virtual ~MatcherFactory() = default;
virtual auto CreateMatcher(
const clang::ast_matchers::MatchFinder::MatchResult* match_result,
Matcher::ReplacementMap* replacements) -> std::unique_ptr<Matcher> = 0;
// Adds the Matcher to the finder with the provided callback.
virtual void AddMatcher(
clang::ast_matchers::MatchFinder* finder,
clang::ast_matchers::MatchFinder::MatchCallback* callback) = 0;
};
// A convenience factory that implements CreateMatcher for Matchers that have a
// standard constructor.
template <typename MatcherType>
class MatcherFactoryBase : public MatcherFactory {
public:
auto CreateMatcher(
const clang::ast_matchers::MatchFinder::MatchResult* match_result,
Matcher::ReplacementMap* replacements)
-> std::unique_ptr<Matcher> override {
return std::make_unique<MatcherType>(match_result, replacements);
}
};
} // namespace Carbon
#endif // MIGRATE_CPP_CPP_REFACTORING_MATCHER_H_