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/ADT/IntrusiveRefCntPtr.h" |
13 | #include "llvm/Support/ExtensibleRTTI.h" |
14 | #include "llvm/Support/HashBuilder.h" |
15 | #include "llvm/Support/MD5.h" |
16 | #include <memory> |
17 | #include <string> |
18 | |
19 | namespace llvm { |
20 | class BitstreamCursor; |
21 | class BitstreamWriter; |
22 | class raw_ostream; |
23 | } |
24 | |
25 | namespace clang { |
26 | |
27 | class ASTReader; |
28 | class ASTWriter; |
29 | class Sema; |
30 | |
31 | namespace serialization { |
32 | class ModuleFile; |
33 | } // end namespace serialization |
34 | |
35 | /// Metadata for a module file extension. |
36 | struct ModuleFileExtensionMetadata { |
37 | /// The name used to identify this particular extension block within |
38 | /// the resulting module file. It should be unique to the particular |
39 | /// extension, because this name will be used to match the name of |
40 | /// an extension block to the appropriate reader. |
41 | std::string BlockName; |
42 | |
43 | /// The major version of the extension data. |
44 | unsigned MajorVersion; |
45 | |
46 | /// The minor version of the extension data. |
47 | unsigned MinorVersion; |
48 | |
49 | /// A string containing additional user information that will be |
50 | /// stored with the metadata. |
51 | std::string UserInfo; |
52 | }; |
53 | |
54 | class ModuleFileExtensionReader; |
55 | class ModuleFileExtensionWriter; |
56 | |
57 | /// An abstract superclass that describes a custom extension to the |
58 | /// module/precompiled header file format. |
59 | /// |
60 | /// A module file extension can introduce additional information into |
61 | /// compiled module files (.pcm) and precompiled headers (.pch) via a |
62 | /// custom writer that can then be accessed via a custom reader when |
63 | /// the module file or precompiled header is loaded. |
64 | /// |
65 | /// Subclasses must use LLVM RTTI for open class hierarchies. |
66 | class ModuleFileExtension |
67 | : public llvm::RTTIExtends<ModuleFileExtension, llvm::RTTIRoot> { |
68 | public: |
69 | /// Discriminator for LLVM RTTI. |
70 | static char ID; |
71 | |
72 | virtual ~ModuleFileExtension(); |
73 | |
74 | /// Retrieves the metadata for this module file extension. |
75 | virtual ModuleFileExtensionMetadata getExtensionMetadata() const = 0; |
76 | |
77 | /// Hash information about the presence of this extension into the |
78 | /// module hash. |
79 | /// |
80 | /// The module hash is used to distinguish different variants of a module that |
81 | /// are incompatible. If the presence, absence, or version of the module file |
82 | /// extension should force the creation of a separate set of module files, |
83 | /// override this method to combine that distinguishing information into the |
84 | /// module hash. |
85 | /// |
86 | /// The default implementation of this function simply does nothing, so the |
87 | /// presence/absence of this extension does not distinguish module files. |
88 | using ExtensionHashBuilder = |
89 | llvm::HashBuilder<llvm::MD5, llvm::endianness::native>; |
90 | virtual void hashExtension(ExtensionHashBuilder &HBuilder) const; |
91 | |
92 | /// Create a new module file extension writer, which will be |
93 | /// responsible for writing the extension contents into a particular |
94 | /// module file. |
95 | virtual std::unique_ptr<ModuleFileExtensionWriter> |
96 | createExtensionWriter(ASTWriter &Writer) = 0; |
97 | |
98 | /// Create a new module file extension reader, given the |
99 | /// metadata read from the block and the cursor into the extension |
100 | /// block. |
101 | /// |
102 | /// May return null to indicate that an extension block with the |
103 | /// given metadata cannot be read. |
104 | virtual std::unique_ptr<ModuleFileExtensionReader> |
105 | createExtensionReader(const ModuleFileExtensionMetadata &Metadata, |
106 | ASTReader &Reader, serialization::ModuleFile &Mod, |
107 | const llvm::BitstreamCursor &Stream) = 0; |
108 | }; |
109 | |
110 | /// Abstract base class that writes a module file extension block into |
111 | /// a module file. |
112 | class ModuleFileExtensionWriter { |
113 | ModuleFileExtension *Extension; |
114 | |
115 | protected: |
116 | ModuleFileExtensionWriter(ModuleFileExtension *Extension) |
117 | : Extension(Extension) { } |
118 | |
119 | public: |
120 | virtual ~ModuleFileExtensionWriter(); |
121 | |
122 | /// Retrieve the module file extension with which this writer is |
123 | /// associated. |
124 | ModuleFileExtension *getExtension() const { return Extension; } |
125 | |
126 | /// Write the contents of the extension block into the given bitstream. |
127 | /// |
128 | /// Responsible for writing the contents of the extension into the |
129 | /// given stream. All of the contents should be written into custom |
130 | /// records with IDs >= FIRST_EXTENSION_RECORD_ID. |
131 | virtual void writeExtensionContents(Sema &SemaRef, |
132 | llvm::BitstreamWriter &Stream) = 0; |
133 | }; |
134 | |
135 | /// Abstract base class that reads a module file extension block from |
136 | /// a module file. |
137 | /// |
138 | /// Subclasses |
139 | class ModuleFileExtensionReader { |
140 | ModuleFileExtension *Extension; |
141 | |
142 | protected: |
143 | ModuleFileExtensionReader(ModuleFileExtension *Extension) |
144 | : Extension(Extension) { } |
145 | |
146 | public: |
147 | /// Retrieve the module file extension with which this reader is |
148 | /// associated. |
149 | ModuleFileExtension *getExtension() const { return Extension; } |
150 | |
151 | virtual ~ModuleFileExtensionReader(); |
152 | }; |
153 | |
154 | } // end namespace clang |
155 | |
156 | #endif // LLVM_CLANG_SERIALIZATION_MODULEFILEEXTENSION_H |
157 | |