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:
PreferIsaOrDynCastInConditionalsCheck(StringRef Name,ClangTidyContext * Context)51   PreferIsaOrDynCastInConditionalsCheck(StringRef Name,
52                                         ClangTidyContext *Context)
53       : ClangTidyCheck(Name, Context) {}
isLanguageVersionSupported(const LangOptions & LangOpts)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
64