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 {
15 namespace tidy {
16 namespace llvm_check {
17 
18 /// Looks at conditionals and finds and replaces cases of ``cast<>``, which will
19 /// assert rather than return a null pointer, and ``dyn_cast<>`` where
20 /// the return value is not captured.  Additionally, finds and replaces cases that match the
21 /// pattern ``var && isa<X>(var)``, where ``var`` is evaluated twice.
22 ///
23 /// Finds cases like these:
24 /// \code
25 ///  if (auto x = cast<X>(y)) {}
26 ///  // is replaced by:
27 ///  if (auto x = dyn_cast<X>(y)) {}
28 ///
29 ///  if (cast<X>(y)) {}
30 ///  // is replaced by:
31 ///  if (isa<X>(y)) {}
32 ///
33 ///  if (dyn_cast<X>(y)) {}
34 ///  // is replaced by:
35 ///  if (isa<X>(y)) {}
36 ///
37 ///  if (var && isa<T>(var)) {}
38 ///  // is replaced by:
39 ///  if (isa_and_nonnull<T>(var.foo())) {}
40 /// \endcode
41 ///
42 ///  // Other cases are ignored, e.g.:
43 /// \code
44 ///  if (auto f = cast<Z>(y)->foo()) {}
45 ///  if (cast<Z>(y)->foo()) {}
46 ///  if (X.cast(y)) {}
47 /// \endcode
48 ///
49 /// For the user-facing documentation see:
50 /// http://clang.llvm.org/extra/clang-tidy/checks/llvm-prefer-isa-or-dyn-cast-in-conditionals.html
51 class PreferIsaOrDynCastInConditionalsCheck : public ClangTidyCheck {
52 public:
PreferIsaOrDynCastInConditionalsCheck(StringRef Name,ClangTidyContext * Context)53   PreferIsaOrDynCastInConditionalsCheck(StringRef Name,
54                                         ClangTidyContext *Context)
55       : ClangTidyCheck(Name, Context) {}
isLanguageVersionSupported(const LangOptions & LangOpts)56   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
57     return LangOpts.CPlusPlus;
58   }
59   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
60   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
61 };
62 
63 } // namespace llvm_check
64 } // namespace tidy
65 } // namespace clang
66 
67 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_LLVM_PREFERISAORDYNCASTINCONDITIONALSCHECK_H
68