| 1 | //===- Pragma.h - Pragma registration and handling --------------*- 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 | // This file defines the PragmaHandler and PragmaTable interfaces. |
| 10 | // |
| 11 | //===----------------------------------------------------------------------===// |
| 12 | |
| 13 | #ifndef LLVM_CLANG_LEX_PRAGMA_H |
| 14 | #define LLVM_CLANG_LEX_PRAGMA_H |
| 15 | |
| 16 | #include "clang/Basic/LLVM.h" |
| 17 | #include "llvm/ADT/StringMap.h" |
| 18 | #include "llvm/ADT/StringRef.h" |
| 19 | #include <string> |
| 20 | |
| 21 | namespace clang { |
| 22 | |
| 23 | class PragmaNamespace; |
| 24 | class Preprocessor; |
| 25 | class Token; |
| 26 | |
| 27 | /** |
| 28 | * Describes how the pragma was introduced, e.g., with \#pragma, |
| 29 | * _Pragma, or __pragma. |
| 30 | */ |
| 31 | enum PragmaIntroducerKind { |
| 32 | /** |
| 33 | * The pragma was introduced via \#pragma. |
| 34 | */ |
| 35 | PIK_HashPragma, |
| 36 | |
| 37 | /** |
| 38 | * The pragma was introduced via the C99 _Pragma(string-literal). |
| 39 | */ |
| 40 | PIK__Pragma, |
| 41 | |
| 42 | /** |
| 43 | * The pragma was introduced via the Microsoft |
| 44 | * __pragma(token-string). |
| 45 | */ |
| 46 | PIK___pragma |
| 47 | }; |
| 48 | |
| 49 | /// PragmaHandler - Instances of this interface defined to handle the various |
| 50 | /// pragmas that the language front-end uses. Each handler optionally has a |
| 51 | /// name (e.g. "pack") and the HandlePragma method is invoked when a pragma with |
| 52 | /// that identifier is found. If a handler does not match any of the declared |
| 53 | /// pragmas the handler with a null identifier is invoked, if it exists. |
| 54 | /// |
| 55 | /// Note that the PragmaNamespace class can be used to subdivide pragmas, e.g. |
| 56 | /// we treat "\#pragma STDC" and "\#pragma GCC" as namespaces that contain other |
| 57 | /// pragmas. |
| 58 | class PragmaHandler { |
| 59 | std::string Name; |
| 60 | |
| 61 | public: |
| 62 | PragmaHandler() = default; |
| 63 | explicit PragmaHandler(StringRef name) : Name(name) {} |
| 64 | virtual ~PragmaHandler(); |
| 65 | |
| 66 | StringRef getName() const { return Name; } |
| 67 | virtual void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer, |
| 68 | Token &FirstToken) = 0; |
| 69 | |
| 70 | /// getIfNamespace - If this is a namespace, return it. This is equivalent to |
| 71 | /// using a dynamic_cast, but doesn't require RTTI. |
| 72 | virtual PragmaNamespace *getIfNamespace() { return nullptr; } |
| 73 | }; |
| 74 | |
| 75 | /// EmptyPragmaHandler - A pragma handler which takes no action, which can be |
| 76 | /// used to ignore particular pragmas. |
| 77 | class EmptyPragmaHandler : public PragmaHandler { |
| 78 | public: |
| 79 | explicit EmptyPragmaHandler(StringRef Name = StringRef()); |
| 80 | |
| 81 | void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer, |
| 82 | Token &FirstToken) override; |
| 83 | }; |
| 84 | |
| 85 | /// PragmaNamespace - This PragmaHandler subdivides the namespace of pragmas, |
| 86 | /// allowing hierarchical pragmas to be defined. Common examples of namespaces |
| 87 | /// are "\#pragma GCC", "\#pragma STDC", and "\#pragma omp", but any namespaces |
| 88 | /// may be (potentially recursively) defined. |
| 89 | class PragmaNamespace : public PragmaHandler { |
| 90 | /// Handlers - This is a map of the handlers in this namespace with their name |
| 91 | /// as key. |
| 92 | llvm::StringMap<PragmaHandler *> Handlers; |
| 93 | |
| 94 | public: |
| 95 | explicit PragmaNamespace(StringRef Name) : PragmaHandler(Name) {} |
| 96 | ~PragmaNamespace() override; |
| 97 | |
| 98 | /// FindHandler - Check to see if there is already a handler for the |
| 99 | /// specified name. If not, return the handler for the null name if it |
| 100 | /// exists, otherwise return null. If IgnoreNull is true (the default) then |
| 101 | /// the null handler isn't returned on failure to match. |
| 102 | PragmaHandler *FindHandler(StringRef Name, |
| 103 | bool IgnoreNull = true) const; |
| 104 | |
| 105 | /// AddPragma - Add a pragma to this namespace. |
| 106 | void AddPragma(PragmaHandler *Handler); |
| 107 | |
| 108 | /// RemovePragmaHandler - Remove the given handler from the |
| 109 | /// namespace. |
| 110 | void RemovePragmaHandler(PragmaHandler *Handler); |
| 111 | |
| 112 | bool IsEmpty() const { return Handlers.empty(); } |
| 113 | |
| 114 | void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer, |
| 115 | Token &Tok) override; |
| 116 | |
| 117 | PragmaNamespace *getIfNamespace() override { return this; } |
| 118 | }; |
| 119 | |
| 120 | } // namespace clang |
| 121 | |
| 122 | #endif // LLVM_CLANG_LEX_PRAGMA_H |
| 123 |