1 | //===-- ModuleFileExtension.h - Module File Extensions ----------*- 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_SERIALIZATION_MODULEFILEEXTENSION_H |
10 | #define LLVM_CLANG_SERIALIZATION_MODULEFILEEXTENSION_H |
11 | |
12 | #include "llvm/Support/ExtensibleRTTI.h" |
13 | #include "llvm/Support/HashBuilder.h" |
14 | #include "llvm/Support/MD5.h" |
15 | #include <memory> |
16 | #include <string> |
17 | |
18 | namespace llvm { |
19 | class BitstreamCursor; |
20 | class BitstreamWriter; |
21 | class raw_ostream; |
22 | } |
23 | |
24 | namespace clang { |
25 | |
26 | class ASTReader; |
27 | class ASTWriter; |
28 | class Sema; |
29 | |
30 | namespace serialization { |
31 | class ModuleFile; |
32 | } // end namespace serialization |
33 | |
34 | /// Metadata for a module file extension. |
35 | struct ModuleFileExtensionMetadata { |
36 | /// The name used to identify this particular extension block within |
37 | /// the resulting module file. It should be unique to the particular |
38 | /// extension, because this name will be used to match the name of |
39 | /// an extension block to the appropriate reader. |
40 | std::string BlockName; |
41 | |
42 | /// The major version of the extension data. |
43 | unsigned MajorVersion; |
44 | |
45 | /// The minor version of the extension data. |
46 | unsigned MinorVersion; |
47 | |
48 | /// A string containing additional user information that will be |
49 | /// stored with the metadata. |
50 | std::string UserInfo; |
51 | }; |
52 | |
53 | class ModuleFileExtensionReader; |
54 | class ModuleFileExtensionWriter; |
55 | |
56 | /// An abstract superclass that describes a custom extension to the |
57 | /// module/precompiled header file format. |
58 | /// |
59 | /// A module file extension can introduce additional information into |
60 | /// compiled module files (.pcm) and precompiled headers (.pch) via a |
61 | /// custom writer that can then be accessed via a custom reader when |
62 | /// the module file or precompiled header is loaded. |
63 | /// |
64 | /// Subclasses must use LLVM RTTI for open class hierarchies. |
65 | class ModuleFileExtension |
66 | : public llvm::RTTIExtends<ModuleFileExtension, llvm::RTTIRoot> { |
67 | public: |
68 | /// Discriminator for LLVM RTTI. |
69 | static char ID; |
70 | |
71 | virtual ~ModuleFileExtension(); |
72 | |
73 | /// Retrieves the metadata for this module file extension. |
74 | virtual ModuleFileExtensionMetadata getExtensionMetadata() const = 0; |
75 | |
76 | /// Hash information about the presence of this extension into the |
77 | /// module hash. |
78 | /// |
79 | /// The module hash is used to distinguish different variants of a module that |
80 | /// are incompatible. If the presence, absence, or version of the module file |
81 | /// extension should force the creation of a separate set of module files, |
82 | /// override this method to combine that distinguishing information into the |
83 | /// module hash. |
84 | /// |
85 | /// The default implementation of this function simply does nothing, so the |
86 | /// presence/absence of this extension does not distinguish module files. |
87 | using ExtensionHashBuilder = |
88 | llvm::HashBuilder<llvm::MD5, llvm::endianness::native>; |
89 | virtual void hashExtension(ExtensionHashBuilder &HBuilder) const; |
90 | |
91 | /// Create a new module file extension writer, which will be |
92 | /// responsible for writing the extension contents into a particular |
93 | /// module file. |
94 | virtual std::unique_ptr<ModuleFileExtensionWriter> |
95 | createExtensionWriter(ASTWriter &Writer) = 0; |
96 | |
97 | /// Create a new module file extension reader, given the |
98 | /// metadata read from the block and the cursor into the extension |
99 | /// block. |
100 | /// |
101 | /// May return null to indicate that an extension block with the |
102 | /// given metadata cannot be read. |
103 | virtual std::unique_ptr<ModuleFileExtensionReader> |
104 | createExtensionReader(const ModuleFileExtensionMetadata &Metadata, |
105 | ASTReader &Reader, serialization::ModuleFile &Mod, |
106 | const llvm::BitstreamCursor &Stream) = 0; |
107 | }; |
108 | |
109 | /// Abstract base class that writes a module file extension block into |
110 | /// a module file. |
111 | class ModuleFileExtensionWriter { |
112 | ModuleFileExtension *Extension; |
113 | |
114 | protected: |
115 | ModuleFileExtensionWriter(ModuleFileExtension *Extension) |
116 | : Extension(Extension) { } |
117 | |
118 | public: |
119 | virtual ~ModuleFileExtensionWriter(); |
120 | |
121 | /// Retrieve the module file extension with which this writer is |
122 | /// associated. |
123 | ModuleFileExtension *getExtension() const { return Extension; } |
124 | |
125 | /// Write the contents of the extension block into the given bitstream. |
126 | /// |
127 | /// Responsible for writing the contents of the extension into the |
128 | /// given stream. All of the contents should be written into custom |
129 | /// records with IDs >= FIRST_EXTENSION_RECORD_ID. |
130 | virtual void writeExtensionContents(Sema &SemaRef, |
131 | llvm::BitstreamWriter &Stream) = 0; |
132 | }; |
133 | |
134 | /// Abstract base class that reads a module file extension block from |
135 | /// a module file. |
136 | /// |
137 | /// Subclasses |
138 | class ModuleFileExtensionReader { |
139 | ModuleFileExtension *Extension; |
140 | |
141 | protected: |
142 | ModuleFileExtensionReader(ModuleFileExtension *Extension) |
143 | : Extension(Extension) { } |
144 | |
145 | public: |
146 | /// Retrieve the module file extension with which this reader is |
147 | /// associated. |
148 | ModuleFileExtension *getExtension() const { return Extension; } |
149 | |
150 | virtual ~ModuleFileExtensionReader(); |
151 | }; |
152 | |
153 | } // end namespace clang |
154 | |
155 | #endif // LLVM_CLANG_SERIALIZATION_MODULEFILEEXTENSION_H |
156 | |