XCOFFObjectFile.h revision d111c7844ec26448764ced627e153f406d730c5f
1//===- XCOFFObjectFile.h - XCOFF object file implementation -----*- 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 XCOFFObjectFile class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_OBJECT_XCOFFOBJECTFILE_H
14#define LLVM_OBJECT_XCOFFOBJECTFILE_H
15
16#include "llvm/ADT/StringRef.h"
17#include "llvm/ADT/iterator_range.h"
18#include "llvm/BinaryFormat/Magic.h"
19#include "llvm/BinaryFormat/XCOFF.h"
20#include "llvm/MC/SubtargetFeature.h"
21#include "llvm/Object/Binary.h"
22#include "llvm/Object/Error.h"
23#include "llvm/Object/ObjectFile.h"
24#include "llvm/Object/SymbolicFile.h"
25#include "llvm/Support/Casting.h"
26#include "llvm/Support/Error.h"
27#include "llvm/Support/FileSystem.h"
28#include "llvm/Support/MemoryBuffer.h"
29#include <cassert>
30#include <cstdint>
31#include <memory>
32#include <system_error>
33
34namespace llvm {
35namespace object {
36
37struct XCOFFFileHeader32 {
38  support::ubig16_t Magic;
39  support::ubig16_t NumberOfSections;
40
41  // Unix time value, value of 0 indicates no timestamp.
42  // Negative values are reserved.
43  support::big32_t TimeStamp;
44
45  support::ubig32_t SymbolTableOffset; // File offset to symbol table.
46  support::big32_t NumberOfSymTableEntries;
47  support::ubig16_t AuxHeaderSize;
48  support::ubig16_t Flags;
49};
50
51struct XCOFFFileHeader64 {
52  support::ubig16_t Magic;
53  support::ubig16_t NumberOfSections;
54
55  // Unix time value, value of 0 indicates no timestamp.
56  // Negative values are reserved.
57  support::big32_t TimeStamp;
58
59  support::ubig64_t SymbolTableOffset; // File offset to symbol table.
60  support::ubig16_t AuxHeaderSize;
61  support::ubig16_t Flags;
62  support::ubig32_t NumberOfSymTableEntries;
63};
64
65struct XCOFFSectionHeader32 {
66  char Name[XCOFF::SectionNameSize];
67  support::ubig32_t PhysicalAddress;
68  support::ubig32_t VirtualAddress;
69  support::ubig32_t SectionSize;
70  support::ubig32_t FileOffsetToRawData;
71  support::ubig32_t FileOffsetToRelocationInfo;
72  support::ubig32_t FileOffsetToLineNumberInfo;
73  support::ubig16_t NumberOfRelocations;
74  support::ubig16_t NumberOfLineNumbers;
75  support::big32_t Flags;
76
77  StringRef getName() const;
78};
79
80struct XCOFFSectionHeader64 {
81  char Name[XCOFF::SectionNameSize];
82  support::ubig64_t PhysicalAddress;
83  support::ubig64_t VirtualAddress;
84  support::ubig64_t SectionSize;
85  support::big64_t FileOffsetToRawData;
86  support::big64_t FileOffsetToRelocationInfo;
87  support::big64_t FileOffsetToLineNumberInfo;
88  support::ubig32_t NumberOfRelocations;
89  support::ubig32_t NumberOfLineNumbers;
90  support::big32_t Flags;
91  char Padding[4];
92
93  StringRef getName() const;
94};
95
96struct XCOFFSymbolEntry {
97  enum { NAME_IN_STR_TBL_MAGIC = 0x0 };
98  typedef struct {
99    support::big32_t Magic; // Zero indicates name in string table.
100    support::ubig32_t Offset;
101  } NameInStrTblType;
102
103  typedef struct {
104    uint8_t LanguageId;
105    uint8_t CpuTypeId;
106  } CFileLanguageIdAndTypeIdType;
107
108  union {
109    char SymbolName[XCOFF::SymbolNameSize];
110    NameInStrTblType NameInStrTbl;
111  };
112
113  support::ubig32_t Value; // Symbol value; storage class-dependent.
114  support::big16_t SectionNumber;
115
116  union {
117    support::ubig16_t SymbolType;
118    CFileLanguageIdAndTypeIdType CFileLanguageIdAndTypeId;
119  };
120
121  XCOFF::StorageClass StorageClass;
122  uint8_t NumberOfAuxEntries;
123};
124
125struct XCOFFStringTable {
126  uint32_t Size;
127  const char *Data;
128};
129
130class XCOFFObjectFile : public ObjectFile {
131private:
132  const void *FileHeader = nullptr;
133  const void *SectionHeaderTable = nullptr;
134
135  const XCOFFSymbolEntry *SymbolTblPtr = nullptr;
136  XCOFFStringTable StringTable = {0, nullptr};
137
138  const XCOFFFileHeader32 *fileHeader32() const;
139  const XCOFFFileHeader64 *fileHeader64() const;
140
141  const XCOFFSectionHeader32 *sectionHeaderTable32() const;
142  const XCOFFSectionHeader64 *sectionHeaderTable64() const;
143
144  size_t getFileHeaderSize() const;
145  size_t getSectionHeaderSize() const;
146
147  const XCOFFSectionHeader32 *toSection32(DataRefImpl Ref) const;
148  const XCOFFSectionHeader64 *toSection64(DataRefImpl Ref) const;
149  void checkSectionAddress(uintptr_t Addr, uintptr_t TableAddr) const;
150  uintptr_t getSectionHeaderTableAddress() const;
151
152  // This returns a pointer to the start of the storage for the name field of
153  // the 32-bit or 64-bit SectionHeader struct. This string is *not* necessarily
154  // null-terminated.
155  const char *getSectionNameInternal(DataRefImpl Sec) const;
156
157  int32_t getSectionFlags(DataRefImpl Sec) const;
158
159  static bool isReservedSectionNumber(int16_t SectionNumber);
160  Expected<DataRefImpl> getSectionByNum(int16_t Num) const;
161
162  // Constructor and "create" factory function. The constructor is only a thin
163  // wrapper around the base constructor. The "create" function fills out the
164  // XCOFF-specific information and performs the error checking along the way.
165  XCOFFObjectFile(unsigned Type, MemoryBufferRef Object);
166  static Expected<std::unique_ptr<XCOFFObjectFile>> create(unsigned Type,
167                                                           MemoryBufferRef MBR);
168
169  // Helper for parsing the StringTable. Returns an 'Error' if parsing failed
170  // and an XCOFFStringTable if parsing succeeded.
171  static Expected<XCOFFStringTable> parseStringTable(const XCOFFObjectFile *Obj,
172                                                     uint64_t Offset);
173
174  // Make a friend so it can call the private 'create' function.
175  friend Expected<std::unique_ptr<ObjectFile>>
176  ObjectFile::createXCOFFObjectFile(MemoryBufferRef Object, unsigned FileType);
177
178public:
179  // Interface inherited from base classes.
180  void moveSymbolNext(DataRefImpl &Symb) const override;
181  uint32_t getSymbolFlags(DataRefImpl Symb) const override;
182  basic_symbol_iterator symbol_begin() const override;
183  basic_symbol_iterator symbol_end() const override;
184
185  Expected<StringRef> getSymbolName(DataRefImpl Symb) const override;
186  Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override;
187  uint64_t getSymbolValueImpl(DataRefImpl Symb) const override;
188  uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override;
189  Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override;
190  Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override;
191
192  void moveSectionNext(DataRefImpl &Sec) const override;
193  Expected<StringRef> getSectionName(DataRefImpl Sec) const override;
194  uint64_t getSectionAddress(DataRefImpl Sec) const override;
195  uint64_t getSectionIndex(DataRefImpl Sec) const override;
196  uint64_t getSectionSize(DataRefImpl Sec) const override;
197  Expected<ArrayRef<uint8_t>>
198  getSectionContents(DataRefImpl Sec) const override;
199  uint64_t getSectionAlignment(DataRefImpl Sec) const override;
200  bool isSectionCompressed(DataRefImpl Sec) const override;
201  bool isSectionText(DataRefImpl Sec) const override;
202  bool isSectionData(DataRefImpl Sec) const override;
203  bool isSectionBSS(DataRefImpl Sec) const override;
204
205  bool isSectionVirtual(DataRefImpl Sec) const override;
206  relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
207  relocation_iterator section_rel_end(DataRefImpl Sec) const override;
208
209  void moveRelocationNext(DataRefImpl &Rel) const override;
210  uint64_t getRelocationOffset(DataRefImpl Rel) const override;
211  symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override;
212  uint64_t getRelocationType(DataRefImpl Rel) const override;
213  void getRelocationTypeName(DataRefImpl Rel,
214                             SmallVectorImpl<char> &Result) const override;
215
216  section_iterator section_begin() const override;
217  section_iterator section_end() const override;
218  uint8_t getBytesInAddress() const override;
219  StringRef getFileFormatName() const override;
220  Triple::ArchType getArch() const override;
221  SubtargetFeatures getFeatures() const override;
222  Expected<uint64_t> getStartAddress() const override;
223  bool isRelocatableObject() const override;
224
225  // Below here is the non-inherited interface.
226  bool is64Bit() const;
227
228  const XCOFFSymbolEntry *getPointerToSymbolTable() const {
229    assert(!is64Bit() && "Symbol table handling not supported yet.");
230    return SymbolTblPtr;
231  }
232
233  Expected<StringRef>
234  getSymbolSectionName(const XCOFFSymbolEntry *SymEntPtr) const;
235
236  const XCOFFSymbolEntry *toSymbolEntry(DataRefImpl Ref) const;
237
238  // File header related interfaces.
239  uint16_t getMagic() const;
240  uint16_t getNumberOfSections() const;
241  int32_t getTimeStamp() const;
242
243  // Symbol table offset and entry count are handled differently between
244  // XCOFF32 and XCOFF64.
245  uint32_t getSymbolTableOffset32() const;
246  uint64_t getSymbolTableOffset64() const;
247
248  // Note that this value is signed and might return a negative value. Negative
249  // values are reserved for future use.
250  int32_t getRawNumberOfSymbolTableEntries32() const;
251
252  // The sanitized value appropriate to use as an index into the symbol table.
253  uint32_t getLogicalNumberOfSymbolTableEntries32() const;
254
255  uint32_t getNumberOfSymbolTableEntries64() const;
256
257  uint16_t getOptionalHeaderSize() const;
258  uint16_t getFlags() const;
259
260  // Section header table related interfaces.
261  ArrayRef<XCOFFSectionHeader32> sections32() const;
262  ArrayRef<XCOFFSectionHeader64> sections64() const;
263}; // XCOFFObjectFile
264
265} // namespace object
266} // namespace llvm
267
268#endif // LLVM_OBJECT_XCOFFOBJECTFILE_H
269