1 //===- SymbolicFile.h - Interface that only provides symbols ----*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file declares the SymbolicFile interface.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #ifndef LLVM_OBJECT_SYMBOLICFILE_H
15 #define LLVM_OBJECT_SYMBOLICFILE_H
16
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/ADT/iterator_range.h"
19 #include "llvm/BinaryFormat/Magic.h"
20 #include "llvm/Object/Binary.h"
21 #include "llvm/Support/Error.h"
22 #include "llvm/Support/FileSystem.h"
23 #include "llvm/Support/Format.h"
24 #include "llvm/Support/MemoryBuffer.h"
25 #include <cinttypes>
26 #include <cstdint>
27 #include <cstring>
28 #include <iterator>
29 #include <memory>
30 #include <system_error>
31
32 namespace llvm {
33 namespace object {
34
35 union DataRefImpl {
36 // This entire union should probably be a
37 // char[max(8, sizeof(uintptr_t))] and require the impl to cast.
38 struct {
39 uint32_t a, b;
40 } d;
41 uintptr_t p;
42
DataRefImpl()43 DataRefImpl() { std::memset(this, 0, sizeof(DataRefImpl)); }
44 };
45
46 template <typename OStream>
47 OStream& operator<<(OStream &OS, const DataRefImpl &D) {
48 OS << "(" << format("0x%08" PRIxPTR, D.p) << " (" << format("0x%08x", D.d.a)
49 << ", " << format("0x%08x", D.d.b) << "))";
50 return OS;
51 }
52
53 inline bool operator==(const DataRefImpl &a, const DataRefImpl &b) {
54 // Check bitwise identical. This is the only legal way to compare a union w/o
55 // knowing which member is in use.
56 return std::memcmp(&a, &b, sizeof(DataRefImpl)) == 0;
57 }
58
59 inline bool operator!=(const DataRefImpl &a, const DataRefImpl &b) {
60 return !operator==(a, b);
61 }
62
63 inline bool operator<(const DataRefImpl &a, const DataRefImpl &b) {
64 // Check bitwise identical. This is the only legal way to compare a union w/o
65 // knowing which member is in use.
66 return std::memcmp(&a, &b, sizeof(DataRefImpl)) < 0;
67 }
68
69 template <class content_type>
70 class content_iterator
71 : public std::iterator<std::forward_iterator_tag, content_type> {
72 content_type Current;
73
74 public:
content_iterator(content_type symb)75 content_iterator(content_type symb) : Current(std::move(symb)) {}
76
77 const content_type *operator->() const { return &Current; }
78
79 const content_type &operator*() const { return Current; }
80
81 bool operator==(const content_iterator &other) const {
82 return Current == other.Current;
83 }
84
85 bool operator!=(const content_iterator &other) const {
86 return !(*this == other);
87 }
88
89 content_iterator &operator++() { // preincrement
90 Current.moveNext();
91 return *this;
92 }
93 };
94
95 class SymbolicFile;
96
97 /// This is a value type class that represents a single symbol in the list of
98 /// symbols in the object file.
99 class BasicSymbolRef {
100 DataRefImpl SymbolPimpl;
101 const SymbolicFile *OwningObject = nullptr;
102
103 public:
104 enum Flags : unsigned {
105 SF_None = 0,
106 SF_Undefined = 1U << 0, // Symbol is defined in another object file
107 SF_Global = 1U << 1, // Global symbol
108 SF_Weak = 1U << 2, // Weak symbol
109 SF_Absolute = 1U << 3, // Absolute symbol
110 SF_Common = 1U << 4, // Symbol has common linkage
111 SF_Indirect = 1U << 5, // Symbol is an alias to another symbol
112 SF_Exported = 1U << 6, // Symbol is visible to other DSOs
113 SF_FormatSpecific = 1U << 7, // Specific to the object file format
114 // (e.g. section symbols)
115 SF_Thumb = 1U << 8, // Thumb symbol in a 32-bit ARM binary
116 SF_Hidden = 1U << 9, // Symbol has hidden visibility
117 SF_Const = 1U << 10, // Symbol value is constant
118 SF_Executable = 1U << 11, // Symbol points to an executable section
119 // (IR only)
120 };
121
122 BasicSymbolRef() = default;
123 BasicSymbolRef(DataRefImpl SymbolP, const SymbolicFile *Owner);
124
125 bool operator==(const BasicSymbolRef &Other) const;
126 bool operator<(const BasicSymbolRef &Other) const;
127
128 void moveNext();
129
130 std::error_code printName(raw_ostream &OS) const;
131
132 /// Get symbol flags (bitwise OR of SymbolRef::Flags)
133 uint32_t getFlags() const;
134
135 DataRefImpl getRawDataRefImpl() const;
136 const SymbolicFile *getObject() const;
137 };
138
139 using basic_symbol_iterator = content_iterator<BasicSymbolRef>;
140
141 class SymbolicFile : public Binary {
142 public:
143 SymbolicFile(unsigned int Type, MemoryBufferRef Source);
144 ~SymbolicFile() override;
145
146 // virtual interface.
147 virtual void moveSymbolNext(DataRefImpl &Symb) const = 0;
148
149 virtual std::error_code printSymbolName(raw_ostream &OS,
150 DataRefImpl Symb) const = 0;
151
152 virtual uint32_t getSymbolFlags(DataRefImpl Symb) const = 0;
153
154 virtual basic_symbol_iterator symbol_begin() const = 0;
155
156 virtual basic_symbol_iterator symbol_end() const = 0;
157
158 // convenience wrappers.
159 using basic_symbol_iterator_range = iterator_range<basic_symbol_iterator>;
symbols()160 basic_symbol_iterator_range symbols() const {
161 return basic_symbol_iterator_range(symbol_begin(), symbol_end());
162 }
163
164 // construction aux.
165 static Expected<std::unique_ptr<SymbolicFile>>
166 createSymbolicFile(MemoryBufferRef Object, llvm::file_magic Type,
167 LLVMContext *Context);
168
169 static Expected<std::unique_ptr<SymbolicFile>>
createSymbolicFile(MemoryBufferRef Object)170 createSymbolicFile(MemoryBufferRef Object) {
171 return createSymbolicFile(Object, llvm::file_magic::unknown, nullptr);
172 }
173 static Expected<OwningBinary<SymbolicFile>>
174 createSymbolicFile(StringRef ObjectPath);
175
classof(const Binary * v)176 static bool classof(const Binary *v) {
177 return v->isSymbolic();
178 }
179 };
180
BasicSymbolRef(DataRefImpl SymbolP,const SymbolicFile * Owner)181 inline BasicSymbolRef::BasicSymbolRef(DataRefImpl SymbolP,
182 const SymbolicFile *Owner)
183 : SymbolPimpl(SymbolP), OwningObject(Owner) {}
184
185 inline bool BasicSymbolRef::operator==(const BasicSymbolRef &Other) const {
186 return SymbolPimpl == Other.SymbolPimpl;
187 }
188
189 inline bool BasicSymbolRef::operator<(const BasicSymbolRef &Other) const {
190 return SymbolPimpl < Other.SymbolPimpl;
191 }
192
moveNext()193 inline void BasicSymbolRef::moveNext() {
194 return OwningObject->moveSymbolNext(SymbolPimpl);
195 }
196
printName(raw_ostream & OS)197 inline std::error_code BasicSymbolRef::printName(raw_ostream &OS) const {
198 return OwningObject->printSymbolName(OS, SymbolPimpl);
199 }
200
getFlags()201 inline uint32_t BasicSymbolRef::getFlags() const {
202 return OwningObject->getSymbolFlags(SymbolPimpl);
203 }
204
getRawDataRefImpl()205 inline DataRefImpl BasicSymbolRef::getRawDataRefImpl() const {
206 return SymbolPimpl;
207 }
208
getObject()209 inline const SymbolicFile *BasicSymbolRef::getObject() const {
210 return OwningObject;
211 }
212
213 } // end namespace object
214 } // end namespace llvm
215
216 #endif // LLVM_OBJECT_SYMBOLICFILE_H
217