1 //===- COFFObjectFile.cpp - COFF object file implementation -----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the COFFObjectFile class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Object/COFF.h"
15 #include "llvm/ADT/StringSwitch.h"
16 #include "llvm/ADT/Triple.h"
19 using namespace object;
22 using support::ulittle8_t;
23 using support::ulittle16_t;
24 using support::ulittle32_t;
25 using support::little16_t;
29 // Returns false if size is greater than the buffer size. And sets ec.
30 bool checkSize(const MemoryBuffer *m, error_code &ec, uint64_t size) {
31 if (m->getBufferSize() < size) {
32 ec = object_error::unexpected_eof;
38 // Returns false if any bytes in [addr, addr + size) fall outsize of m.
39 bool checkAddr(const MemoryBuffer *m,
43 if (addr + size < addr ||
45 addr + size > uintptr_t(m->getBufferEnd())) {
46 ec = object_error::unexpected_eof;
53 const coff_symbol *COFFObjectFile::toSymb(DataRefImpl Symb) const {
54 const coff_symbol *addr = reinterpret_cast<const coff_symbol*>(Symb.p);
57 // Verify that the symbol points to a valid entry in the symbol table.
58 uintptr_t offset = uintptr_t(addr) - uintptr_t(base());
59 if (offset < Header->PointerToSymbolTable
60 || offset >= Header->PointerToSymbolTable
61 + (Header->NumberOfSymbols * sizeof(coff_symbol)))
62 report_fatal_error("Symbol was outside of symbol table.");
64 assert((offset - Header->PointerToSymbolTable) % sizeof(coff_symbol)
65 == 0 && "Symbol did not point to the beginning of a symbol");
71 const coff_section *COFFObjectFile::toSec(DataRefImpl Sec) const {
72 const coff_section *addr = reinterpret_cast<const coff_section*>(Sec.p);
75 // Verify that the section points to a valid entry in the section table.
76 if (addr < SectionTable
77 || addr >= (SectionTable + Header->NumberOfSections))
78 report_fatal_error("Section was outside of section table.");
80 uintptr_t offset = uintptr_t(addr) - uintptr_t(SectionTable);
81 assert(offset % sizeof(coff_section) == 0 &&
82 "Section did not point to the beginning of a section");
88 error_code COFFObjectFile::getSymbolNext(DataRefImpl Symb,
89 SymbolRef &Result) const {
90 const coff_symbol *symb = toSymb(Symb);
91 symb += 1 + symb->NumberOfAuxSymbols;
92 Symb.p = reinterpret_cast<uintptr_t>(symb);
93 Result = SymbolRef(Symb, this);
94 return object_error::success;
97 error_code COFFObjectFile::getSymbolName(DataRefImpl Symb,
98 StringRef &Result) const {
99 const coff_symbol *symb = toSymb(Symb);
100 // Check for string table entry. First 4 bytes are 0.
101 if (symb->Name.Offset.Zeroes == 0) {
102 uint32_t Offset = symb->Name.Offset.Offset;
103 if (error_code ec = getString(Offset, Result))
105 return object_error::success;
108 if (symb->Name.ShortName[7] == 0)
109 // Null terminated, let ::strlen figure out the length.
110 Result = StringRef(symb->Name.ShortName);
112 // Not null terminated, use all 8 bytes.
113 Result = StringRef(symb->Name.ShortName, 8);
114 return object_error::success;
117 error_code COFFObjectFile::getSymbolAddress(DataRefImpl Symb,
118 uint64_t &Result) const {
119 const coff_symbol *symb = toSymb(Symb);
120 const coff_section *Section = NULL;
121 if (error_code ec = getSection(symb->SectionNumber, Section))
124 if (error_code ec = getSymbolNMTypeChar(Symb, Type))
126 if (Type == 'U' || Type == 'w')
127 Result = UnknownAddressOrSize;
129 Result = Section->VirtualAddress + symb->Value;
131 Result = symb->Value;
132 return object_error::success;
135 error_code COFFObjectFile::getSymbolSize(DataRefImpl Symb,
136 uint64_t &Result) const {
137 // FIXME: Return the correct size. This requires looking at all the symbols
138 // in the same section as this symbol, and looking for either the next
139 // symbol, or the end of the section.
140 const coff_symbol *symb = toSymb(Symb);
141 const coff_section *Section = NULL;
142 if (error_code ec = getSection(symb->SectionNumber, Section))
145 if (error_code ec = getSymbolNMTypeChar(Symb, Type))
147 if (Type == 'U' || Type == 'w')
148 Result = UnknownAddressOrSize;
150 Result = Section->SizeOfRawData - symb->Value;
153 return object_error::success;
156 error_code COFFObjectFile::getSymbolNMTypeChar(DataRefImpl Symb,
157 char &Result) const {
158 const coff_symbol *symb = toSymb(Symb);
160 if (error_code ec = getSymbolName(Symb, name))
162 char ret = StringSwitch<char>(name)
163 .StartsWith(".debug", 'N')
164 .StartsWith(".sxdata", 'N')
169 return object_error::success;
172 uint32_t Characteristics = 0;
173 if (symb->SectionNumber > 0) {
174 const coff_section *Section = NULL;
175 if (error_code ec = getSection(symb->SectionNumber, Section))
177 Characteristics = Section->Characteristics;
180 switch (symb->SectionNumber) {
181 case COFF::IMAGE_SYM_UNDEFINED:
182 // Check storage classes.
183 if (symb->StorageClass == COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL) {
185 return object_error::success; // Don't do ::toupper.
189 case COFF::IMAGE_SYM_ABSOLUTE:
192 case COFF::IMAGE_SYM_DEBUG:
196 // Check section type.
197 if (Characteristics & COFF::IMAGE_SCN_CNT_CODE)
199 else if ( Characteristics & COFF::IMAGE_SCN_MEM_READ
200 && ~Characteristics & COFF::IMAGE_SCN_MEM_WRITE) // Read only.
202 else if (Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
204 else if (Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
206 else if (Characteristics & COFF::IMAGE_SCN_LNK_INFO)
209 // Check for section symbol.
210 else if ( symb->StorageClass == COFF::IMAGE_SYM_CLASS_STATIC
215 if (symb->StorageClass == COFF::IMAGE_SYM_CLASS_EXTERNAL)
216 ret = ::toupper(ret);
219 return object_error::success;
222 error_code COFFObjectFile::isSymbolInternal(DataRefImpl Symb,
223 bool &Result) const {
225 return object_error::success;
228 error_code COFFObjectFile::getSectionNext(DataRefImpl Sec,
229 SectionRef &Result) const {
230 const coff_section *sec = toSec(Sec);
232 Sec.p = reinterpret_cast<uintptr_t>(sec);
233 Result = SectionRef(Sec, this);
234 return object_error::success;
237 error_code COFFObjectFile::getSectionName(DataRefImpl Sec,
238 StringRef &Result) const {
239 const coff_section *sec = toSec(Sec);
241 if (sec->Name[7] == 0)
242 // Null terminated, let ::strlen figure out the length.
245 // Not null terminated, use all 8 bytes.
246 name = StringRef(sec->Name, 8);
248 // Check for string table entry. First byte is '/'.
249 if (name[0] == '/') {
251 name.substr(1).getAsInteger(10, Offset);
252 if (error_code ec = getString(Offset, name))
257 return object_error::success;
260 error_code COFFObjectFile::getSectionAddress(DataRefImpl Sec,
261 uint64_t &Result) const {
262 const coff_section *sec = toSec(Sec);
263 Result = sec->VirtualAddress;
264 return object_error::success;
267 error_code COFFObjectFile::getSectionSize(DataRefImpl Sec,
268 uint64_t &Result) const {
269 const coff_section *sec = toSec(Sec);
270 Result = sec->SizeOfRawData;
271 return object_error::success;
274 error_code COFFObjectFile::getSectionContents(DataRefImpl Sec,
275 StringRef &Result) const {
276 const coff_section *sec = toSec(Sec);
277 // The only thing that we need to verify is that the contents is contained
278 // within the file bounds. We don't need to make sure it doesn't cover other
279 // data, as there's nothing that says that is not allowed.
280 uintptr_t con_start = uintptr_t(base()) + sec->PointerToRawData;
281 uintptr_t con_end = con_start + sec->SizeOfRawData;
282 if (con_end >= uintptr_t(Data->getBufferEnd()))
283 return object_error::parse_failed;
284 Result = StringRef(reinterpret_cast<const char*>(con_start),
286 return object_error::success;
289 error_code COFFObjectFile::isSectionText(DataRefImpl Sec,
290 bool &Result) const {
291 const coff_section *sec = toSec(Sec);
292 Result = sec->Characteristics & COFF::IMAGE_SCN_CNT_CODE;
293 return object_error::success;
296 COFFObjectFile::COFFObjectFile(MemoryBuffer *Object, error_code &ec)
297 : ObjectFile(Binary::isCOFF, Object, ec) {
298 // Check that we at least have enough room for a header.
299 if (!checkSize(Data, ec, sizeof(coff_file_header))) return;
301 // The actual starting location of the COFF header in the file. This can be
302 // non-zero in PE/COFF files.
303 uint64_t HeaderStart = 0;
305 // Check if this is a PE/COFF file.
306 if (base()[0] == 0x4d && base()[1] == 0x5a) {
307 // PE/COFF, seek through MS-DOS compatibility stub and 4-byte
308 // PE signature to find 'normal' COFF header.
309 if (!checkSize(Data, ec, 0x3c + 8)) return;
310 HeaderStart += *reinterpret_cast<const ulittle32_t *>(base() + 0x3c);
311 // Check the PE header. ("PE\0\0")
312 StringRef Actual(reinterpret_cast<const char *>(base() + HeaderStart), 4);
313 StringRef Expected("PE\0\0", 4);
314 if (Actual != Expect) {
315 ec = object_error::parse_failed;
318 HeaderStart += 4; // Skip the PE Header.
321 Header = reinterpret_cast<const coff_file_header *>(base() + HeaderStart);
322 if (!checkAddr(Data, ec, uintptr_t(Header), sizeof(coff_file_header)))
326 reinterpret_cast<const coff_section *>( base()
328 + sizeof(coff_file_header)
329 + Header->SizeOfOptionalHeader);
330 if (!checkAddr(Data, ec, uintptr_t(SectionTable),
331 Header->NumberOfSections * sizeof(coff_section)))
335 reinterpret_cast<const coff_symbol *>(base()
336 + Header->PointerToSymbolTable);
337 if (!checkAddr(Data, ec, uintptr_t(SymbolTable),
338 Header->NumberOfSymbols * sizeof(coff_symbol)))
341 // Find string table.
342 StringTable = reinterpret_cast<const char *>(base())
343 + Header->PointerToSymbolTable
344 + Header->NumberOfSymbols * sizeof(coff_symbol);
345 if (!checkAddr(Data, ec, uintptr_t(StringTable), sizeof(ulittle32_t)))
348 StringTableSize = *reinterpret_cast<const ulittle32_t *>(StringTable);
349 if (!checkAddr(Data, ec, uintptr_t(StringTable), StringTableSize))
351 // Check that the string table is null terminated if has any in it.
352 if (StringTableSize < 4
353 || (StringTableSize > 4 && StringTable[StringTableSize - 1] != 0)) {
354 ec = object_error::parse_failed;
358 ec = object_error::success;
361 ObjectFile::symbol_iterator COFFObjectFile::begin_symbols() const {
363 std::memset(&ret, 0, sizeof(DataRefImpl));
364 ret.p = reinterpret_cast<intptr_t>(SymbolTable);
365 return symbol_iterator(SymbolRef(ret, this));
368 ObjectFile::symbol_iterator COFFObjectFile::end_symbols() const {
369 // The symbol table ends where the string table begins.
371 std::memset(&ret, 0, sizeof(DataRefImpl));
372 ret.p = reinterpret_cast<intptr_t>(StringTable);
373 return symbol_iterator(SymbolRef(ret, this));
376 ObjectFile::section_iterator COFFObjectFile::begin_sections() const {
378 std::memset(&ret, 0, sizeof(DataRefImpl));
379 ret.p = reinterpret_cast<intptr_t>(SectionTable);
380 return section_iterator(SectionRef(ret, this));
383 ObjectFile::section_iterator COFFObjectFile::end_sections() const {
385 std::memset(&ret, 0, sizeof(DataRefImpl));
386 ret.p = reinterpret_cast<intptr_t>(SectionTable + Header->NumberOfSections);
387 return section_iterator(SectionRef(ret, this));
390 uint8_t COFFObjectFile::getBytesInAddress() const {
391 return getArch() == Triple::x86_64 ? 8 : 4;
394 StringRef COFFObjectFile::getFileFormatName() const {
395 switch(Header->Machine) {
396 case COFF::IMAGE_FILE_MACHINE_I386:
398 case COFF::IMAGE_FILE_MACHINE_AMD64:
399 return "COFF-x86-64";
401 return "COFF-<unknown arch>";
405 unsigned COFFObjectFile::getArch() const {
406 switch(Header->Machine) {
407 case COFF::IMAGE_FILE_MACHINE_I386:
409 case COFF::IMAGE_FILE_MACHINE_AMD64:
410 return Triple::x86_64;
412 return Triple::UnknownArch;
416 error_code COFFObjectFile::getSection(int32_t index,
417 const coff_section *&Result) const {
418 // Check for special index values.
419 if (index == COFF::IMAGE_SYM_UNDEFINED ||
420 index == COFF::IMAGE_SYM_ABSOLUTE ||
421 index == COFF::IMAGE_SYM_DEBUG)
423 else if (index > 0 && index <= Header->NumberOfSections)
424 // We already verified the section table data, so no need to check again.
425 Result = SectionTable + (index - 1);
427 return object_error::parse_failed;
428 return object_error::success;
431 error_code COFFObjectFile::getString(uint32_t offset,
432 StringRef &Result) const {
433 if (StringTableSize <= 4)
434 // Tried to get a string from an empty string table.
435 return object_error::parse_failed;
436 if (offset >= StringTableSize)
437 return object_error::unexpected_eof;
438 Result = StringRef(StringTable + offset);
439 return object_error::success;
444 ObjectFile *ObjectFile::createCOFFObjectFile(MemoryBuffer *Object) {
446 return new COFFObjectFile(Object, ec);
449 } // end namespace llvm