utils/UseRangesCheck.h

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//===----------------------------------------------------------------------===//
//
// 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_UTILS_USERANGESCHECK_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_USERANGESCHECK_H
 
#include "../ClangTidyCheck.h"
#include "IncludeInserter.h"
#include "clang/AST/Decl.h"
#include "clang/AST/Expr.h"
#include "clang/Basic/Diagnostic.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include <optional>
 
namespace clang::tidy::utils {
 
/// Base class for handling converting std iterator algorithms to a range
/// equivalent.
class UseRangesCheck : public ClangTidyCheck {
public:
  struct Indexes {
    enum Replace { First, Second };
    unsigned BeginArg;
    unsigned EndArg = BeginArg + 1;
    Replace ReplaceArg = First;
  };
 
  using Signature = SmallVector<Indexes, 2>;
 
  struct ReverseIteratorDescriptor {
    StringRef ReverseAdaptorName;
    std::optional<StringRef> ReverseHeader;
    ArrayRef<std::pair<StringRef, StringRef>> FreeReverseNames;
    bool IsPipeSyntax = false;
  };
 
  class Replacer : public llvm::RefCountedBase<Replacer> {
  public:
    struct ResultUsePolicy {
      enum class Kind {
        Preserve,
        AppendAccessorForUsedResult,
      };
 
      Kind PolicyKind = Kind::Preserve;
      StringRef Accessor;
    };
 
    /// Gets the name to replace a function with, return std::nullopt for a
    /// replacement where we just call a different overload.
    virtual std::optional<std::string>
    getReplaceName(const NamedDecl &OriginalName) const = 0;
 
    /// Gets the header needed to access the replaced function
    /// Return std::nullopt if no new header is needed.
    virtual std::optional<std::string>
    getHeaderInclusion(const NamedDecl &OriginalName) const;
 
    /// Gets an array of all the possible overloads for a function with indexes
    /// where begin and end arguments are.
    virtual ArrayRef<Signature> getReplacementSignatures() const = 0;
 
    /// Gets how to handle fix-its when the original algorithm result is used.
    virtual ResultUsePolicy getResultUsePolicy(const NamedDecl &OriginalName,
                                               bool IsStructuredBinding) const;
    virtual ~Replacer() = default;
  };
 
  using ReplacerMap = llvm::StringMap<llvm::IntrusiveRefCntPtr<Replacer>>;
 
  UseRangesCheck(StringRef Name, ClangTidyContext *Context);
  /// Gets a map of function to replace and methods to create the replacements
  virtual ReplacerMap getReplacerMap() const = 0;
  /// Create a diagnostic for the CallExpr
  /// Override this to support custom diagnostic messages
  virtual DiagnosticBuilder createDiag(const CallExpr &Call);
 
  virtual std::optional<ReverseIteratorDescriptor> getReverseDescriptor() const;
 
  /// Gets the fully qualified names of begin and end functions.
  /// The functions must take the container as their one and only argument
  /// `::std::begin` and `::std::end` are a common example
  virtual ArrayRef<std::pair<StringRef, StringRef>>
  getFreeBeginEndMethods() const;
 
  void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
                           Preprocessor *ModuleExpanderPP) final;
  void registerMatchers(ast_matchers::MatchFinder *Finder) final;
  void check(const ast_matchers::MatchFinder::MatchResult &Result) final;
  bool isLanguageVersionSupported(const LangOptions &LangOpts) const override;
  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
  std::optional<TraversalKind> getCheckTraversalKind() const override;
 
private:
  std::vector<llvm::IntrusiveRefCntPtr<Replacer>> Replacers;
  std::optional<ReverseIteratorDescriptor> ReverseDescriptor;
  IncludeInserter Inserter;
};
 
} // namespace clang::tidy::utils
 
#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_USERANGESCHECK_H