1 //===- ELFYAML.h - ELF YAMLIO implementation --------------------*- 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 /// \file
11 /// \brief This file declares classes for handling the YAML representation
12 /// of ELF.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_OBJECT_ELFYAML_H
17 #define LLVM_OBJECT_ELFYAML_H
18 
19 #include "llvm/MC/YAML.h"
20 #include "llvm/Support/ELF.h"
21 
22 namespace llvm {
23 namespace ELFYAML {
24 
25 // These types are invariant across 32/64-bit ELF, so for simplicity just
26 // directly give them their exact sizes. We don't need to worry about
27 // endianness because these are just the types in the YAMLIO structures,
28 // and are appropriately converted to the necessary endianness when
29 // reading/generating binary object files.
30 // The naming of these types is intended to be ELF_PREFIX, where PREFIX is
31 // the common prefix of the respective constants. E.g. ELF_EM corresponds
32 // to the `e_machine` constants, like `EM_X86_64`.
33 // In the future, these would probably be better suited by C++11 enum
34 // class's with appropriate fixed underlying type.
35 LLVM_YAML_STRONG_TYPEDEF(uint16_t, ELF_ET)
36 LLVM_YAML_STRONG_TYPEDEF(uint32_t, ELF_EM)
37 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_ELFCLASS)
38 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_ELFDATA)
39 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_ELFOSABI)
40 // Just use 64, since it can hold 32-bit values too.
41 LLVM_YAML_STRONG_TYPEDEF(uint64_t, ELF_EF)
42 LLVM_YAML_STRONG_TYPEDEF(uint32_t, ELF_SHT)
43 LLVM_YAML_STRONG_TYPEDEF(uint32_t, ELF_REL)
44 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_RSS)
45 // Just use 64, since it can hold 32-bit values too.
46 LLVM_YAML_STRONG_TYPEDEF(uint64_t, ELF_SHF)
47 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_STT)
48 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_STV)
49 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_STO)
50 
51 // For now, hardcode 64 bits everywhere that 32 or 64 would be needed
52 // since 64-bit can hold 32-bit values too.
53 struct FileHeader {
54   ELF_ELFCLASS Class;
55   ELF_ELFDATA Data;
56   ELF_ELFOSABI OSABI;
57   ELF_ET Type;
58   ELF_EM Machine;
59   ELF_EF Flags;
60   llvm::yaml::Hex64 Entry;
61 };
62 struct Symbol {
63   StringRef Name;
64   ELF_STT Type;
65   StringRef Section;
66   llvm::yaml::Hex64 Value;
67   llvm::yaml::Hex64 Size;
68   uint8_t Other;
69 };
70 struct LocalGlobalWeakSymbols {
71   std::vector<Symbol> Local;
72   std::vector<Symbol> Global;
73   std::vector<Symbol> Weak;
74 };
75 
76 struct SectionOrType {
77   StringRef sectionNameOrType;
78 };
79 
80 struct Section {
81   enum class SectionKind { Group, RawContent, Relocation };
82   SectionKind Kind;
83   StringRef Name;
84   ELF_SHT Type;
85   ELF_SHF Flags;
86   llvm::yaml::Hex64 Address;
87   StringRef Link;
88   StringRef Info;
89   llvm::yaml::Hex64 AddressAlign;
SectionSection90   Section(SectionKind Kind) : Kind(Kind) {}
91   virtual ~Section();
92 };
93 struct RawContentSection : Section {
94   yaml::BinaryRef Content;
95   llvm::yaml::Hex64 Size;
RawContentSectionRawContentSection96   RawContentSection() : Section(SectionKind::RawContent) {}
classofRawContentSection97   static bool classof(const Section *S) {
98     return S->Kind == SectionKind::RawContent;
99   }
100 };
101 
102 struct Group : Section {
103   // Members of a group contain a flag and a list of section indices
104   // that are part of the group.
105   std::vector<SectionOrType> Members;
GroupGroup106   Group() : Section(SectionKind::Group) {}
classofGroup107   static bool classof(const Section *S) {
108     return S->Kind == SectionKind::Group;
109   }
110 };
111 
112 struct Relocation {
113   llvm::yaml::Hex64 Offset;
114   int64_t Addend;
115   ELF_REL Type;
116   StringRef Symbol;
117 };
118 struct RelocationSection : Section {
119   std::vector<Relocation> Relocations;
RelocationSectionRelocationSection120   RelocationSection() : Section(SectionKind::Relocation) {}
classofRelocationSection121   static bool classof(const Section *S) {
122     return S->Kind == SectionKind::Relocation;
123   }
124 };
125 struct Object {
126   FileHeader Header;
127   std::vector<std::unique_ptr<Section>> Sections;
128   // Although in reality the symbols reside in a section, it is a lot
129   // cleaner and nicer if we read them from the YAML as a separate
130   // top-level key, which automatically ensures that invariants like there
131   // being a single SHT_SYMTAB section are upheld.
132   LocalGlobalWeakSymbols Symbols;
133 };
134 
135 } // end namespace ELFYAML
136 } // end namespace llvm
137 
138 LLVM_YAML_IS_SEQUENCE_VECTOR(std::unique_ptr<llvm::ELFYAML::Section>)
LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::ELFYAML::Symbol)139 LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::ELFYAML::Symbol)
140 LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::ELFYAML::Relocation)
141 LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::ELFYAML::SectionOrType)
142 
143 namespace llvm {
144 namespace yaml {
145 
146 template <>
147 struct ScalarEnumerationTraits<ELFYAML::ELF_ET> {
148   static void enumeration(IO &IO, ELFYAML::ELF_ET &Value);
149 };
150 
151 template <>
152 struct ScalarEnumerationTraits<ELFYAML::ELF_EM> {
153   static void enumeration(IO &IO, ELFYAML::ELF_EM &Value);
154 };
155 
156 template <>
157 struct ScalarEnumerationTraits<ELFYAML::ELF_ELFCLASS> {
158   static void enumeration(IO &IO, ELFYAML::ELF_ELFCLASS &Value);
159 };
160 
161 template <>
162 struct ScalarEnumerationTraits<ELFYAML::ELF_ELFDATA> {
163   static void enumeration(IO &IO, ELFYAML::ELF_ELFDATA &Value);
164 };
165 
166 template <>
167 struct ScalarEnumerationTraits<ELFYAML::ELF_ELFOSABI> {
168   static void enumeration(IO &IO, ELFYAML::ELF_ELFOSABI &Value);
169 };
170 
171 template <>
172 struct ScalarBitSetTraits<ELFYAML::ELF_EF> {
173   static void bitset(IO &IO, ELFYAML::ELF_EF &Value);
174 };
175 
176 template <>
177 struct ScalarEnumerationTraits<ELFYAML::ELF_SHT> {
178   static void enumeration(IO &IO, ELFYAML::ELF_SHT &Value);
179 };
180 
181 template <>
182 struct ScalarBitSetTraits<ELFYAML::ELF_SHF> {
183   static void bitset(IO &IO, ELFYAML::ELF_SHF &Value);
184 };
185 
186 template <>
187 struct ScalarEnumerationTraits<ELFYAML::ELF_STT> {
188   static void enumeration(IO &IO, ELFYAML::ELF_STT &Value);
189 };
190 
191 template <>
192 struct ScalarEnumerationTraits<ELFYAML::ELF_STV> {
193   static void enumeration(IO &IO, ELFYAML::ELF_STV &Value);
194 };
195 
196 template <>
197 struct ScalarBitSetTraits<ELFYAML::ELF_STO> {
198   static void bitset(IO &IO, ELFYAML::ELF_STO &Value);
199 };
200 
201 template <>
202 struct ScalarEnumerationTraits<ELFYAML::ELF_REL> {
203   static void enumeration(IO &IO, ELFYAML::ELF_REL &Value);
204 };
205 
206 template <>
207 struct ScalarEnumerationTraits<ELFYAML::ELF_RSS> {
208   static void enumeration(IO &IO, ELFYAML::ELF_RSS &Value);
209 };
210 
211 template <>
212 struct MappingTraits<ELFYAML::FileHeader> {
213   static void mapping(IO &IO, ELFYAML::FileHeader &FileHdr);
214 };
215 
216 template <>
217 struct MappingTraits<ELFYAML::Symbol> {
218   static void mapping(IO &IO, ELFYAML::Symbol &Symbol);
219 };
220 
221 template <>
222 struct MappingTraits<ELFYAML::LocalGlobalWeakSymbols> {
223   static void mapping(IO &IO, ELFYAML::LocalGlobalWeakSymbols &Symbols);
224 };
225 
226 template <> struct MappingTraits<ELFYAML::Relocation> {
227   static void mapping(IO &IO, ELFYAML::Relocation &Rel);
228 };
229 
230 template <>
231 struct MappingTraits<std::unique_ptr<ELFYAML::Section>> {
232   static void mapping(IO &IO, std::unique_ptr<ELFYAML::Section> &Section);
233   static StringRef validate(IO &io, std::unique_ptr<ELFYAML::Section> &Section);
234 };
235 
236 template <>
237 struct MappingTraits<ELFYAML::Object> {
238   static void mapping(IO &IO, ELFYAML::Object &Object);
239 };
240 
241 template <> struct MappingTraits<ELFYAML::SectionOrType> {
242   static void mapping(IO &IO, ELFYAML::SectionOrType &sectionOrType);
243 };
244 
245 } // end namespace yaml
246 } // end namespace llvm
247 
248 #endif
249