clang-tools-extra/clang-tidy/llvm/PreferIsaOrDynCastInConditionalsCheck.h

   1 //===--- PreferIsaOrDynCastInConditionalsCheck.h - clang-tidy ---*- 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 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_LLVM_PREFERISAORDYNCASTINCONDITIONALSCHECK_H
  10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_LLVM_PREFERISAORDYNCASTINCONDITIONALSCHECK_H
  11
  12 #include "../ClangTidyCheck.h"
  13
  14 namespace clang::tidy::llvm_check {
  15
  16 /// Looks at conditionals and finds and replaces cases of ``cast<>``, which will
  17 /// assert rather than return a null pointer, and ``dyn_cast<>`` where
  18 /// the return value is not captured.  Additionally, finds and replaces cases that match the
  19 /// pattern ``var && isa<X>(var)``, where ``var`` is evaluated twice.
  20 ///
  21 /// Finds cases like these:
  22 /// \code
  23 ///  if (auto x = cast<X>(y)) {}
  24 ///  // is replaced by:
  25 ///  if (auto x = dyn_cast<X>(y)) {}
  26 ///
  27 ///  if (cast<X>(y)) {}
  28 ///  // is replaced by:
  29 ///  if (isa<X>(y)) {}
  30 ///
  31 ///  if (dyn_cast<X>(y)) {}
  32 ///  // is replaced by:
  33 ///  if (isa<X>(y)) {}
  34 ///
  35 ///  if (var && isa<T>(var)) {}
  36 ///  // is replaced by:
  37 ///  if (isa_and_nonnull<T>(var.foo())) {}
  38 /// \endcode
  39 ///
  40 ///  // Other cases are ignored, e.g.:
  41 /// \code
  42 ///  if (auto f = cast<Z>(y)->foo()) {}
  43 ///  if (cast<Z>(y)->foo()) {}
  44 ///  if (X.cast(y)) {}
  45 /// \endcode
  46 ///
  47 /// For the user-facing documentation see:
  48 /// http://clang.llvm.org/extra/clang-tidy/checks/llvm/prefer-isa-or-dyn-cast-in-conditionals.html
  49 class PreferIsaOrDynCastInConditionalsCheck : public ClangTidyCheck {
  50 public:
  51   PreferIsaOrDynCastInConditionalsCheck(StringRef Name,
  52                                         ClangTidyContext *Context)
  53       : ClangTidyCheck(Name, Context) {}
  54   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
  55     return LangOpts.CPlusPlus;
  56   }
  57   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
  58   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
  59 };
  60
  61 } // namespace clang::tidy::llvm_check
  62
  63 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_LLVM_PREFERISAORDYNCASTINCONDITIONALSCHECK_H