1//===-- BinaryHolder.h - Utility class for accessing binaries -------------===//
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 program is a utility that aims to be a dropin replacement for
10// Darwin's dsymutil.
11//
12//===----------------------------------------------------------------------===//
13#ifndef LLVM_TOOLS_DSYMUTIL_BINARYHOLDER_H
14#define LLVM_TOOLS_DSYMUTIL_BINARYHOLDER_H
15
16#include "llvm/ADT/DenseMap.h"
17#include "llvm/ADT/StringMap.h"
18#include "llvm/Object/Archive.h"
19#include "llvm/Object/Error.h"
20#include "llvm/Object/MachOUniversal.h"
21#include "llvm/Object/ObjectFile.h"
22#include "llvm/Support/Chrono.h"
23#include "llvm/Support/Errc.h"
24#include "llvm/Support/ErrorOr.h"
25#include "llvm/Support/VirtualFileSystem.h"
26#include "llvm/TargetParser/Triple.h"
27
28#include <mutex>
29
30namespace llvm {
31namespace dsymutil {
32
33/// The BinaryHolder class is responsible for creating and owning
34/// ObjectFiles and their underlying MemoryBuffers. It differs from a simple
35/// OwningBinary in that it handles accessing and caching of archives and its
36/// members.
37class BinaryHolder {
38public:
39 using TimestampTy = sys::TimePoint<std::chrono::seconds>;
40
41 BinaryHolder(IntrusiveRefCntPtr<vfs::FileSystem> VFS, bool Verbose = false)
42 : VFS(VFS), Verbose(Verbose) {}
43
44 // Forward declarations for friend declaration.
45 class ObjectEntry;
46 class ArchiveEntry;
47
48 /// Base class shared by cached entries, representing objects and archives.
49 class EntryBase {
50 protected:
51 std::unique_ptr<MemoryBuffer> MemBuffer;
52 std::unique_ptr<object::MachOUniversalBinary> FatBinary;
53 std::string FatBinaryName;
54 };
55
56 /// Cached entry holding one or more (in case of a fat binary) object files.
57 class ObjectEntry : public EntryBase {
58 public:
59 /// Load the given object binary in memory.
60 Error load(IntrusiveRefCntPtr<vfs::FileSystem> VFS, StringRef Filename,
61 TimestampTy Timestamp, bool Verbose = false);
62
63 /// Access all owned ObjectFiles.
64 std::vector<const object::ObjectFile *> getObjects() const;
65
66 /// Access to a derived version of all the currently owned ObjectFiles. The
67 /// conversion might be invalid, in which case an Error is returned.
68 template <typename ObjectFileType>
69 Expected<std::vector<const ObjectFileType *>> getObjectsAs() const {
70 std::vector<const ObjectFileType *> Result;
71 Result.reserve(Objects.size());
72 for (auto &Object : Objects) {
73 const auto *Derived = dyn_cast<ObjectFileType>(Object.get());
74 if (!Derived)
75 return errorCodeToError(EC: object::object_error::invalid_file_type);
76 Result.push_back(Derived);
77 }
78 return Result;
79 }
80
81 /// Access the owned ObjectFile with architecture \p T.
82 Expected<const object::ObjectFile &> getObject(const Triple &T) const;
83
84 /// Access to a derived version of the currently owned ObjectFile with
85 /// architecture \p T. The conversion must be known to be valid.
86 template <typename ObjectFileType>
87 Expected<const ObjectFileType &> getObjectAs(const Triple &T) const {
88 auto Object = getObject(T);
89 if (!Object)
90 return Object.takeError();
91 return cast<ObjectFileType>(*Object);
92 }
93
94 private:
95 std::vector<std::unique_ptr<object::ObjectFile>> Objects;
96 friend ArchiveEntry;
97 };
98
99 /// Cached entry holding one or more (in the of a fat binary) archive files.
100 class ArchiveEntry : public EntryBase {
101 public:
102 struct KeyTy {
103 std::string Filename;
104 TimestampTy Timestamp;
105
106 KeyTy() {}
107 KeyTy(StringRef Filename, TimestampTy Timestamp)
108 : Filename(Filename.str()), Timestamp(Timestamp) {}
109 };
110
111 /// Load the given object binary in memory.
112 Error load(IntrusiveRefCntPtr<vfs::FileSystem> VFS, StringRef Filename,
113 TimestampTy Timestamp, bool Verbose = false);
114
115 Expected<const ObjectEntry &> getObjectEntry(StringRef Filename,
116 TimestampTy Timestamp,
117 bool Verbose = false);
118
119 private:
120 std::vector<std::unique_ptr<object::Archive>> Archives;
121 DenseMap<KeyTy, std::unique_ptr<ObjectEntry>> MemberCache;
122 std::mutex MemberCacheMutex;
123 };
124
125 Expected<const ObjectEntry &>
126 getObjectEntry(StringRef Filename, TimestampTy Timestamp = TimestampTy());
127
128 void clear();
129 void eraseObjectEntry(StringRef Filename);
130
131private:
132 /// Cache of static archives. Objects that are part of a static archive are
133 /// stored under this object, rather than in the map below.
134 StringMap<std::unique_ptr<ArchiveEntry>> ArchiveCache;
135 StringMap<uint32_t> ArchiveRefCounter;
136 std::mutex ArchiveCacheMutex;
137
138 /// Object entries for objects that are not in a static archive.
139 StringMap<std::unique_ptr<ObjectEntry>> ObjectCache;
140 StringMap<uint32_t> ObjectRefCounter;
141 std::mutex ObjectCacheMutex;
142
143 /// Virtual File System instance.
144 IntrusiveRefCntPtr<vfs::FileSystem> VFS;
145
146 bool Verbose;
147};
148
149} // namespace dsymutil
150
151template <> struct DenseMapInfo<dsymutil::BinaryHolder::ArchiveEntry::KeyTy> {
152
153 static inline dsymutil::BinaryHolder::ArchiveEntry::KeyTy getEmptyKey() {
154 return dsymutil::BinaryHolder::ArchiveEntry::KeyTy();
155 }
156
157 static inline dsymutil::BinaryHolder::ArchiveEntry::KeyTy getTombstoneKey() {
158 return dsymutil::BinaryHolder::ArchiveEntry::KeyTy("/", {});
159 }
160
161 static unsigned
162 getHashValue(const dsymutil::BinaryHolder::ArchiveEntry::KeyTy &K) {
163 return hash_combine(args: DenseMapInfo<StringRef>::getHashValue(Val: K.Filename),
164 args: DenseMapInfo<unsigned>::getHashValue(
165 Val: K.Timestamp.time_since_epoch().count()));
166 }
167
168 static bool isEqual(const dsymutil::BinaryHolder::ArchiveEntry::KeyTy &LHS,
169 const dsymutil::BinaryHolder::ArchiveEntry::KeyTy &RHS) {
170 return LHS.Filename == RHS.Filename && LHS.Timestamp == RHS.Timestamp;
171 }
172};
173
174} // namespace llvm
175#endif
176