1 | //===- SymbolicFile.h - Interface that only provides symbols ----*- 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 | // This file declares the SymbolicFile interface. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #ifndef LLVM_OBJECT_SYMBOLICFILE_H |
14 | #define LLVM_OBJECT_SYMBOLICFILE_H |
15 | |
16 | #include "llvm/ADT/iterator_range.h" |
17 | #include "llvm/BinaryFormat/Magic.h" |
18 | #include "llvm/Object/Binary.h" |
19 | #include "llvm/Support/Error.h" |
20 | #include "llvm/Support/Format.h" |
21 | #include "llvm/Support/MemoryBufferRef.h" |
22 | #include <cinttypes> |
23 | #include <cstdint> |
24 | #include <cstring> |
25 | #include <iterator> |
26 | #include <memory> |
27 | |
28 | namespace llvm { |
29 | |
30 | class LLVMContext; |
31 | class raw_ostream; |
32 | |
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 | |
43 | DataRefImpl() { std::memset(s: this, c: 0, n: sizeof(DataRefImpl)); } |
44 | }; |
45 | |
46 | template <typename OStream> |
47 | OStream& operator<<(OStream &OS, const DataRefImpl &D) { |
48 | OS << "(" << format(Fmt: "0x%08" PRIxPTR, Vals: D.p) << " (" << format(Fmt: "0x%08x" , Vals: D.d.a) |
49 | << ", " << format(Fmt: "0x%08x" , Vals: 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(s1: &a, s2: &b, n: 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(s1: &a, s2: &b, n: sizeof(DataRefImpl)) < 0; |
67 | } |
68 | |
69 | template <class content_type> class content_iterator { |
70 | content_type Current; |
71 | |
72 | public: |
73 | using iterator_category = std::forward_iterator_tag; |
74 | using value_type = content_type; |
75 | using difference_type = std::ptrdiff_t; |
76 | using pointer = value_type *; |
77 | using reference = value_type &; |
78 | |
79 | content_iterator(content_type symb) : Current(std::move(symb)) {} |
80 | |
81 | const content_type *operator->() const { return &Current; } |
82 | |
83 | const content_type &operator*() const { return Current; } |
84 | |
85 | bool operator==(const content_iterator &other) const { |
86 | return Current == other.Current; |
87 | } |
88 | |
89 | bool operator!=(const content_iterator &other) const { |
90 | return !(*this == other); |
91 | } |
92 | |
93 | content_iterator &operator++() { // preincrement |
94 | Current.moveNext(); |
95 | return *this; |
96 | } |
97 | }; |
98 | |
99 | class SymbolicFile; |
100 | |
101 | /// This is a value type class that represents a single symbol in the list of |
102 | /// symbols in the object file. |
103 | class BasicSymbolRef { |
104 | DataRefImpl SymbolPimpl; |
105 | const SymbolicFile *OwningObject = nullptr; |
106 | |
107 | public: |
108 | enum Flags : unsigned { |
109 | SF_None = 0, |
110 | SF_Undefined = 1U << 0, // Symbol is defined in another object file |
111 | SF_Global = 1U << 1, // Global symbol |
112 | SF_Weak = 1U << 2, // Weak symbol |
113 | SF_Absolute = 1U << 3, // Absolute symbol |
114 | SF_Common = 1U << 4, // Symbol has common linkage |
115 | SF_Indirect = 1U << 5, // Symbol is an alias to another symbol |
116 | SF_Exported = 1U << 6, // Symbol is visible to other DSOs |
117 | SF_FormatSpecific = 1U << 7, // Specific to the object file format |
118 | // (e.g. section symbols) |
119 | SF_Thumb = 1U << 8, // Thumb symbol in a 32-bit ARM binary |
120 | SF_Hidden = 1U << 9, // Symbol has hidden visibility |
121 | SF_Const = 1U << 10, // Symbol value is constant |
122 | SF_Executable = 1U << 11, // Symbol points to an executable section |
123 | // (IR only) |
124 | }; |
125 | |
126 | BasicSymbolRef() = default; |
127 | BasicSymbolRef(DataRefImpl SymbolP, const SymbolicFile *Owner); |
128 | |
129 | bool operator==(const BasicSymbolRef &Other) const; |
130 | bool operator<(const BasicSymbolRef &Other) const; |
131 | |
132 | void moveNext(); |
133 | |
134 | Error printName(raw_ostream &OS) const; |
135 | |
136 | /// Get symbol flags (bitwise OR of SymbolRef::Flags) |
137 | Expected<uint32_t> getFlags() const; |
138 | |
139 | DataRefImpl getRawDataRefImpl() const; |
140 | const SymbolicFile *getObject() const; |
141 | }; |
142 | |
143 | using basic_symbol_iterator = content_iterator<BasicSymbolRef>; |
144 | |
145 | class SymbolicFile : public Binary { |
146 | public: |
147 | SymbolicFile(unsigned int Type, MemoryBufferRef Source); |
148 | ~SymbolicFile() override; |
149 | |
150 | // virtual interface. |
151 | virtual void moveSymbolNext(DataRefImpl &Symb) const = 0; |
152 | |
153 | virtual Error printSymbolName(raw_ostream &OS, DataRefImpl Symb) const = 0; |
154 | |
155 | virtual Expected<uint32_t> getSymbolFlags(DataRefImpl Symb) const = 0; |
156 | |
157 | virtual basic_symbol_iterator symbol_begin() const = 0; |
158 | |
159 | virtual basic_symbol_iterator symbol_end() const = 0; |
160 | |
161 | virtual bool is64Bit() const = 0; |
162 | |
163 | // convenience wrappers. |
164 | using basic_symbol_iterator_range = iterator_range<basic_symbol_iterator>; |
165 | basic_symbol_iterator_range symbols() const { |
166 | return basic_symbol_iterator_range(symbol_begin(), symbol_end()); |
167 | } |
168 | |
169 | // construction aux. |
170 | static Expected<std::unique_ptr<SymbolicFile>> |
171 | createSymbolicFile(MemoryBufferRef Object, llvm::file_magic Type, |
172 | LLVMContext *Context, bool InitContent = true); |
173 | |
174 | static Expected<std::unique_ptr<SymbolicFile>> |
175 | createSymbolicFile(MemoryBufferRef Object) { |
176 | return createSymbolicFile(Object, Type: llvm::file_magic::unknown, Context: nullptr); |
177 | } |
178 | |
179 | static bool classof(const Binary *v) { |
180 | return v->isSymbolic(); |
181 | } |
182 | |
183 | static bool isSymbolicFile(file_magic Type, const LLVMContext *Context); |
184 | }; |
185 | |
186 | inline BasicSymbolRef::BasicSymbolRef(DataRefImpl SymbolP, |
187 | const SymbolicFile *Owner) |
188 | : SymbolPimpl(SymbolP), OwningObject(Owner) {} |
189 | |
190 | inline bool BasicSymbolRef::operator==(const BasicSymbolRef &Other) const { |
191 | return SymbolPimpl == Other.SymbolPimpl; |
192 | } |
193 | |
194 | inline bool BasicSymbolRef::operator<(const BasicSymbolRef &Other) const { |
195 | return SymbolPimpl < Other.SymbolPimpl; |
196 | } |
197 | |
198 | inline void BasicSymbolRef::moveNext() { |
199 | return OwningObject->moveSymbolNext(Symb&: SymbolPimpl); |
200 | } |
201 | |
202 | inline Error BasicSymbolRef::printName(raw_ostream &OS) const { |
203 | return OwningObject->printSymbolName(OS, Symb: SymbolPimpl); |
204 | } |
205 | |
206 | inline Expected<uint32_t> BasicSymbolRef::getFlags() const { |
207 | return OwningObject->getSymbolFlags(Symb: SymbolPimpl); |
208 | } |
209 | |
210 | inline DataRefImpl BasicSymbolRef::getRawDataRefImpl() const { |
211 | return SymbolPimpl; |
212 | } |
213 | |
214 | inline const SymbolicFile *BasicSymbolRef::getObject() const { |
215 | return OwningObject; |
216 | } |
217 | |
218 | } // end namespace object |
219 | } // end namespace llvm |
220 | |
221 | #endif // LLVM_OBJECT_SYMBOLICFILE_H |
222 | |