llvm-project/clang-tools-extra/clang-tidy/ClangTidyCheck.h

195 lines
7.9 KiB
C++

//===--- ClangTidyCheck.h - clang-tidy --------------------------*- 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANGTIDYCHECK_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANGTIDYCHECK_H
#include "ClangTidyDiagnosticConsumer.h"
#include "ClangTidyOptions.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/StringExtras.h"
#include <memory>
#include <type_traits>
#include <vector>
namespace clang {
class CompilerInstance;
namespace tidy {
/// Base class for all clang-tidy checks.
///
/// To implement a ``ClangTidyCheck``, write a subclass and override some of the
/// base class's methods. E.g. to implement a check that validates namespace
/// declarations, override ``registerMatchers``:
///
/// ~~~{.cpp}
/// void registerMatchers(ast_matchers::MatchFinder *Finder) override {
/// Finder->addMatcher(namespaceDecl().bind("namespace"), this);
/// }
/// ~~~
///
/// and then override ``check(const MatchResult &Result)`` to do the actual
/// check for each match.
///
/// A new ``ClangTidyCheck`` instance is created per translation unit.
///
/// FIXME: Figure out whether carrying information from one TU to another is
/// useful/necessary.
class ClangTidyCheck : public ast_matchers::MatchFinder::MatchCallback {
public:
/// Initializes the check with \p CheckName and \p Context.
///
/// Derived classes must implement the constructor with this signature or
/// delegate it. If a check needs to read options, it can do this in the
/// constructor using the Options.get() methods below.
ClangTidyCheck(StringRef CheckName, ClangTidyContext *Context);
/// Override this to register ``PPCallbacks`` in the preprocessor.
///
/// This should be used for clang-tidy checks that analyze preprocessor-
/// dependent properties, e.g. include directives and macro definitions.
///
/// There are two Preprocessors to choose from that differ in how they handle
/// modular #includes:
/// - PP is the real Preprocessor. It doesn't walk into modular #includes and
/// thus doesn't generate PPCallbacks for their contents.
/// - ModuleExpanderPP preprocesses the whole translation unit in the
/// non-modular mode, which allows it to generate PPCallbacks not only for
/// the main file and textual headers, but also for all transitively
/// included modular headers when the analysis runs with modules enabled.
/// When modules are not enabled ModuleExpanderPP just points to the real
/// preprocessor.
virtual void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
Preprocessor *ModuleExpanderPP) {}
/// Override this to register AST matchers with \p Finder.
///
/// This should be used by clang-tidy checks that analyze code properties that
/// dependent on AST knowledge.
///
/// You can register as many matchers as necessary with \p Finder. Usually,
/// "this" will be used as callback, but you can also specify other callback
/// classes. Thereby, different matchers can trigger different callbacks.
///
/// If you need to merge information between the different matchers, you can
/// store these as members of the derived class. However, note that all
/// matches occur in the order of the AST traversal.
virtual void registerMatchers(ast_matchers::MatchFinder *Finder) {}
/// ``ClangTidyChecks`` that register ASTMatchers should do the actual
/// work in here.
virtual void check(const ast_matchers::MatchFinder::MatchResult &Result) {}
/// Add a diagnostic with the check's name.
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description,
DiagnosticIDs::Level Level = DiagnosticIDs::Warning);
/// Should store all options supported by this check with their
/// current values or default values for options that haven't been overridden.
///
/// The check should use ``Options.store()`` to store each option it supports
/// whether it has the default value or it has been overridden.
virtual void storeOptions(ClangTidyOptions::OptionMap &Options) {}
/// Provides access to the ``ClangTidyCheck`` options via check-local
/// names.
///
/// Methods of this class prepend ``CheckName + "."`` to translate check-local
/// option names to global option names.
class OptionsView {
public:
/// Initializes the instance using \p CheckName + "." as a prefix.
OptionsView(StringRef CheckName,
const ClangTidyOptions::OptionMap &CheckOptions);
/// Read a named option from the ``Context``.
///
/// Reads the option with the check-local name \p LocalName from the
/// ``CheckOptions``. If the corresponding key is not present, returns
/// \p Default.
std::string get(StringRef LocalName, StringRef Default) const;
/// Read a named option from the ``Context``.
///
/// Reads the option with the check-local name \p LocalName from local or
/// global ``CheckOptions``. Gets local option first. If local is not
/// present, falls back to get global option. If global option is not
/// present either, returns Default.
std::string getLocalOrGlobal(StringRef LocalName, StringRef Default) const;
/// Read a named option from the ``Context`` and parse it as an
/// integral type ``T``.
///
/// Reads the option with the check-local name \p LocalName from the
/// ``CheckOptions``. If the corresponding key is not present, returns
/// \p Default.
template <typename T>
typename std::enable_if<std::is_integral<T>::value, T>::type
get(StringRef LocalName, T Default) const {
std::string Value = get(LocalName, "");
T Result = Default;
if (!Value.empty())
StringRef(Value).getAsInteger(10, Result);
return Result;
}
/// Read a named option from the ``Context`` and parse it as an
/// integral type ``T``.
///
/// Reads the option with the check-local name \p LocalName from local or
/// global ``CheckOptions``. Gets local option first. If local is not
/// present, falls back to get global option. If global option is not
/// present either, returns Default.
template <typename T>
typename std::enable_if<std::is_integral<T>::value, T>::type
getLocalOrGlobal(StringRef LocalName, T Default) const {
std::string Value = getLocalOrGlobal(LocalName, "");
T Result = Default;
if (!Value.empty())
StringRef(Value).getAsInteger(10, Result);
return Result;
}
/// Stores an option with the check-local name \p LocalName with
/// string value \p Value to \p Options.
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName,
StringRef Value) const;
/// Stores an option with the check-local name \p LocalName with
/// ``int64_t`` value \p Value to \p Options.
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName,
int64_t Value) const;
private:
std::string NamePrefix;
const ClangTidyOptions::OptionMap &CheckOptions;
};
private:
void run(const ast_matchers::MatchFinder::MatchResult &Result) override;
StringRef getID() const override { return CheckName; }
std::string CheckName;
ClangTidyContext *Context;
protected:
OptionsView Options;
/// Returns the main file name of the current translation unit.
StringRef getCurrentMainFile() const { return Context->getCurrentFile(); }
/// Returns the language options from the context.
const LangOptions &getLangOpts() const { return Context->getLangOpts(); }
};
} // namespace tidy
} // namespace clang
#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_CLANGTIDYCHECK_H