1//===-- PCHContainerOperations.h - PCH Containers ---------------*- 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_PCHCONTAINEROPERATIONS_H
10#define LLVM_CLANG_SERIALIZATION_PCHCONTAINEROPERATIONS_H
11
12#include "clang/Basic/Module.h"
13#include "llvm/ADT/SmallVector.h"
14#include "llvm/ADT/StringMap.h"
15#include "llvm/Support/MemoryBufferRef.h"
16#include <memory>
17
18namespace llvm {
19class raw_pwrite_stream;
20}
21
22namespace clang {
23
24class ASTConsumer;
25class CompilerInstance;
26
27struct PCHBuffer {
28 ASTFileSignature Signature;
29 llvm::SmallVector<char, 0> Data;
30 bool IsComplete;
31};
32
33/// This abstract interface provides operations for creating
34/// containers for serialized ASTs (precompiled headers and clang
35/// modules).
36class PCHContainerWriter {
37public:
38 virtual ~PCHContainerWriter() = 0;
39 virtual llvm::StringRef getFormat() const = 0;
40
41 /// Return an ASTConsumer that can be chained with a
42 /// PCHGenerator that produces a wrapper file format containing a
43 /// serialized AST bitstream.
44 virtual std::unique_ptr<ASTConsumer>
45 CreatePCHContainerGenerator(CompilerInstance &CI,
46 const std::string &MainFileName,
47 const std::string &OutputFileName,
48 std::unique_ptr<llvm::raw_pwrite_stream> OS,
49 std::shared_ptr<PCHBuffer> Buffer) const = 0;
50};
51
52/// This abstract interface provides operations for unwrapping
53/// containers for serialized ASTs (precompiled headers and clang
54/// modules).
55class PCHContainerReader {
56public:
57 virtual ~PCHContainerReader() = 0;
58 /// Equivalent to the format passed to -fmodule-format=
59 virtual llvm::ArrayRef<llvm::StringRef> getFormats() const = 0;
60
61 /// Returns the serialized AST inside the PCH container Buffer.
62 virtual llvm::StringRef ExtractPCH(llvm::MemoryBufferRef Buffer) const = 0;
63};
64
65/// Implements write operations for a raw pass-through PCH container.
66class RawPCHContainerWriter : public PCHContainerWriter {
67 llvm::StringRef getFormat() const override { return "raw"; }
68
69 /// Return an ASTConsumer that can be chained with a
70 /// PCHGenerator that writes the module to a flat file.
71 std::unique_ptr<ASTConsumer>
72 CreatePCHContainerGenerator(CompilerInstance &CI,
73 const std::string &MainFileName,
74 const std::string &OutputFileName,
75 std::unique_ptr<llvm::raw_pwrite_stream> OS,
76 std::shared_ptr<PCHBuffer> Buffer) const override;
77};
78
79/// Implements read operations for a raw pass-through PCH container.
80class RawPCHContainerReader : public PCHContainerReader {
81 llvm::ArrayRef<llvm::StringRef> getFormats() const override;
82 /// Simply returns the buffer contained in Buffer.
83 llvm::StringRef ExtractPCH(llvm::MemoryBufferRef Buffer) const override;
84};
85
86/// A registry of PCHContainerWriter and -Reader objects for different formats.
87class PCHContainerOperations {
88 llvm::StringMap<std::unique_ptr<PCHContainerWriter>> Writers;
89 llvm::StringMap<PCHContainerReader *> Readers;
90 llvm::SmallVector<std::unique_ptr<PCHContainerReader>> OwnedReaders;
91
92public:
93 /// Automatically registers a RawPCHContainerWriter and
94 /// RawPCHContainerReader.
95 PCHContainerOperations();
96 void registerWriter(std::unique_ptr<PCHContainerWriter> Writer) {
97 Writers[Writer->getFormat()] = std::move(Writer);
98 }
99 void registerReader(std::unique_ptr<PCHContainerReader> Reader) {
100 assert(!Reader->getFormats().empty() &&
101 "PCHContainerReader must handle >=1 format");
102 for (llvm::StringRef Fmt : Reader->getFormats())
103 Readers[Fmt] = Reader.get();
104 OwnedReaders.push_back(Elt: std::move(Reader));
105 }
106 const PCHContainerWriter *getWriterOrNull(llvm::StringRef Format) {
107 return Writers[Format].get();
108 }
109 const PCHContainerReader *getReaderOrNull(llvm::StringRef Format) {
110 return Readers[Format];
111 }
112 const PCHContainerReader &getRawReader() {
113 return *getReaderOrNull(Format: "raw");
114 }
115};
116
117}
118
119#endif
120