1 //===--- XCOFFObjectFile.cpp - XCOFF object file implementation -----------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file defines the XCOFFObjectFile class.
11 //===----------------------------------------------------------------------===//
13 #include "llvm/Object/XCOFFObjectFile.h"
14 #include "llvm/ADT/ArrayRef.h"
15 #include "llvm/Support/BinaryStreamReader.h"
16 #include "llvm/Support/Endian.h"
17 #include "llvm/Support/ErrorHandling.h"
18 #include "llvm/Support/MathExtras.h"
25 // Checks that [Ptr, Ptr + Size) bytes fall inside the memory buffer
26 // 'M'. Returns a pointer to the underlying object on success.
28 static Expected<const T *> getObject(MemoryBufferRef M, const void *Ptr,
29 const uint64_t Size = sizeof(T)) {
30 uintptr_t Addr = uintptr_t(Ptr);
31 if (std::error_code EC = Binary::checkOffset(M, Addr, Size))
32 return errorCodeToError(EC);
33 return reinterpret_cast<const T *>(Addr);
36 static uintptr_t getWithOffset(uintptr_t Base, ptrdiff_t Offset) {
37 return reinterpret_cast<uintptr_t>(reinterpret_cast<const char *>(Base) +
41 template <typename T> static const T *viewAs(uintptr_t in) {
42 return reinterpret_cast<const T *>(in);
45 static StringRef generateStringRef(const char *Name, uint64_t Size) {
46 auto NulCharPtr = static_cast<const char *>(memchr(Name, '\0', Size));
47 return NulCharPtr ? StringRef(Name, NulCharPtr - Name)
48 : StringRef(Name, Size);
51 void XCOFFObjectFile::checkSectionAddress(uintptr_t Addr,
52 uintptr_t TableAddress) const {
53 if (Addr < TableAddress)
54 report_fatal_error("Section header outside of section header table.");
56 uintptr_t Offset = Addr - TableAddress;
57 if (Offset >= getSectionHeaderSize() * getNumberOfSections())
58 report_fatal_error("Section header outside of section header table.");
60 if (Offset % getSectionHeaderSize() != 0)
62 "Section header pointer does not point to a valid section header.");
65 const XCOFFSectionHeader32 *
66 XCOFFObjectFile::toSection32(DataRefImpl Ref) const {
67 assert(!is64Bit() && "32-bit interface called on 64-bit object file.");
69 checkSectionAddress(Ref.p, getSectionHeaderTableAddress());
71 return viewAs<XCOFFSectionHeader32>(Ref.p);
74 const XCOFFSectionHeader64 *
75 XCOFFObjectFile::toSection64(DataRefImpl Ref) const {
76 assert(is64Bit() && "64-bit interface called on a 32-bit object file.");
78 checkSectionAddress(Ref.p, getSectionHeaderTableAddress());
80 return viewAs<XCOFFSectionHeader64>(Ref.p);
83 const XCOFFSymbolEntry *XCOFFObjectFile::toSymbolEntry(DataRefImpl Ref) const {
84 assert(!is64Bit() && "Symbol table support not implemented for 64-bit.");
85 assert(Ref.p != 0 && "Symbol table pointer can not be nullptr!");
86 auto SymEntPtr = viewAs<XCOFFSymbolEntry>(Ref.p);
90 const XCOFFFileHeader32 *XCOFFObjectFile::fileHeader32() const {
91 assert(!is64Bit() && "32-bit interface called on 64-bit object file.");
92 return static_cast<const XCOFFFileHeader32 *>(FileHeader);
95 const XCOFFFileHeader64 *XCOFFObjectFile::fileHeader64() const {
96 assert(is64Bit() && "64-bit interface called on a 32-bit object file.");
97 return static_cast<const XCOFFFileHeader64 *>(FileHeader);
100 const XCOFFSectionHeader32 *
101 XCOFFObjectFile::sectionHeaderTable32() const {
102 assert(!is64Bit() && "32-bit interface called on 64-bit object file.");
103 return static_cast<const XCOFFSectionHeader32 *>(SectionHeaderTable);
106 const XCOFFSectionHeader64 *
107 XCOFFObjectFile::sectionHeaderTable64() const {
108 assert(is64Bit() && "64-bit interface called on a 32-bit object file.");
109 return static_cast<const XCOFFSectionHeader64 *>(SectionHeaderTable);
112 void XCOFFObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
113 const XCOFFSymbolEntry *SymEntPtr = toSymbolEntry(Symb);
114 SymEntPtr += SymEntPtr->NumberOfAuxEntries + 1;
115 Symb.p = reinterpret_cast<uintptr_t>(SymEntPtr);
118 Expected<StringRef> XCOFFObjectFile::getSymbolName(DataRefImpl Symb) const {
119 const XCOFFSymbolEntry *SymEntPtr = toSymbolEntry(Symb);
121 if (SymEntPtr->NameInStrTbl.Magic != XCOFFSymbolEntry::NAME_IN_STR_TBL_MAGIC)
122 return generateStringRef(SymEntPtr->SymbolName, XCOFF::SymbolNameSize);
124 // A storage class value with the high-order bit on indicates that the name is
125 // a symbolic debugger stabstring.
126 if (SymEntPtr->StorageClass & 0x80)
127 return StringRef("Unimplemented Debug Name");
129 uint32_t Offset = SymEntPtr->NameInStrTbl.Offset;
130 // The byte offset is relative to the start of the string table
131 // or .debug section. A byte offset value of 0 is a null or zero-length symbol
132 // name. A byte offset in the range 1 to 3 (inclusive) points into the length
133 // field; as a soft-error recovery mechanism, we treat such cases as having an
136 return StringRef(nullptr, 0);
138 if (StringTable.Data != nullptr && StringTable.Size > Offset)
139 return (StringTable.Data + Offset);
141 return make_error<GenericBinaryError>("Symbol Name parse failed",
142 object_error::parse_failed);
145 Expected<uint64_t> XCOFFObjectFile::getSymbolAddress(DataRefImpl Symb) const {
147 llvm_unreachable("Not yet implemented!");
151 uint64_t XCOFFObjectFile::getSymbolValueImpl(DataRefImpl Symb) const {
152 return toSymbolEntry(Symb)->Value;
155 uint64_t XCOFFObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const {
157 llvm_unreachable("Not yet implemented!");
161 Expected<SymbolRef::Type>
162 XCOFFObjectFile::getSymbolType(DataRefImpl Symb) const {
163 llvm_unreachable("Not yet implemented!");
164 return SymbolRef::ST_Other;
167 Expected<section_iterator>
168 XCOFFObjectFile::getSymbolSection(DataRefImpl Symb) const {
169 const XCOFFSymbolEntry *SymEntPtr = toSymbolEntry(Symb);
170 int16_t SectNum = SymEntPtr->SectionNumber;
172 if (isReservedSectionNumber(SectNum))
173 return section_end();
175 Expected<DataRefImpl> ExpSec = getSectionByNum(SectNum);
177 return ExpSec.takeError();
179 return section_iterator(SectionRef(ExpSec.get(), this));
182 void XCOFFObjectFile::moveSectionNext(DataRefImpl &Sec) const {
183 const char *Ptr = reinterpret_cast<const char *>(Sec.p);
184 Sec.p = reinterpret_cast<uintptr_t>(Ptr + getSectionHeaderSize());
187 Expected<StringRef> XCOFFObjectFile::getSectionName(DataRefImpl Sec) const {
188 return generateStringRef(getSectionNameInternal(Sec), XCOFF::SectionNameSize);
191 uint64_t XCOFFObjectFile::getSectionAddress(DataRefImpl Sec) const {
192 // Avoid ternary due to failure to convert the ubig32_t value to a unit64_t
195 return toSection64(Sec)->VirtualAddress;
197 return toSection32(Sec)->VirtualAddress;
200 uint64_t XCOFFObjectFile::getSectionIndex(DataRefImpl Sec) const {
201 // Section numbers in XCOFF are numbered beginning at 1. A section number of
202 // zero is used to indicate that a symbol is being imported or is undefined.
204 return toSection64(Sec) - sectionHeaderTable64() + 1;
206 return toSection32(Sec) - sectionHeaderTable32() + 1;
209 uint64_t XCOFFObjectFile::getSectionSize(DataRefImpl Sec) const {
210 // Avoid ternary due to failure to convert the ubig32_t value to a unit64_t
213 return toSection64(Sec)->SectionSize;
215 return toSection32(Sec)->SectionSize;
218 Expected<ArrayRef<uint8_t>>
219 XCOFFObjectFile::getSectionContents(DataRefImpl Sec) const {
220 llvm_unreachable("Not yet implemented!");
223 uint64_t XCOFFObjectFile::getSectionAlignment(DataRefImpl Sec) const {
225 llvm_unreachable("Not yet implemented!");
229 bool XCOFFObjectFile::isSectionCompressed(DataRefImpl Sec) const {
231 llvm_unreachable("Not yet implemented!");
235 bool XCOFFObjectFile::isSectionText(DataRefImpl Sec) const {
236 return getSectionFlags(Sec) & XCOFF::STYP_TEXT;
239 bool XCOFFObjectFile::isSectionData(DataRefImpl Sec) const {
240 uint32_t Flags = getSectionFlags(Sec);
241 return Flags & (XCOFF::STYP_DATA | XCOFF::STYP_TDATA);
244 bool XCOFFObjectFile::isSectionBSS(DataRefImpl Sec) const {
245 uint32_t Flags = getSectionFlags(Sec);
246 return Flags & (XCOFF::STYP_BSS | XCOFF::STYP_TBSS);
249 bool XCOFFObjectFile::isSectionVirtual(DataRefImpl Sec) const {
251 llvm_unreachable("Not yet implemented!");
255 relocation_iterator XCOFFObjectFile::section_rel_begin(DataRefImpl Sec) const {
256 llvm_unreachable("Not yet implemented!");
257 return relocation_iterator(RelocationRef());
260 relocation_iterator XCOFFObjectFile::section_rel_end(DataRefImpl Sec) const {
261 llvm_unreachable("Not yet implemented!");
262 return relocation_iterator(RelocationRef());
265 void XCOFFObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
266 llvm_unreachable("Not yet implemented!");
270 uint64_t XCOFFObjectFile::getRelocationOffset(DataRefImpl Rel) const {
271 llvm_unreachable("Not yet implemented!");
276 symbol_iterator XCOFFObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
277 llvm_unreachable("Not yet implemented!");
278 return symbol_iterator(SymbolRef());
281 uint64_t XCOFFObjectFile::getRelocationType(DataRefImpl Rel) const {
282 llvm_unreachable("Not yet implemented!");
287 void XCOFFObjectFile::getRelocationTypeName(
288 DataRefImpl Rel, SmallVectorImpl<char> &Result) const {
289 llvm_unreachable("Not yet implemented!");
293 uint32_t XCOFFObjectFile::getSymbolFlags(DataRefImpl Symb) const {
295 llvm_unreachable("Not yet implemented!");
299 basic_symbol_iterator XCOFFObjectFile::symbol_begin() const {
300 assert(!is64Bit() && "64-bit support not implemented yet.");
302 SymDRI.p = reinterpret_cast<uintptr_t>(SymbolTblPtr);
303 return basic_symbol_iterator(SymbolRef(SymDRI, this));
306 basic_symbol_iterator XCOFFObjectFile::symbol_end() const {
307 assert(!is64Bit() && "64-bit support not implemented yet.");
309 SymDRI.p = reinterpret_cast<uintptr_t>(
310 SymbolTblPtr + getLogicalNumberOfSymbolTableEntries32());
311 return basic_symbol_iterator(SymbolRef(SymDRI, this));
314 section_iterator XCOFFObjectFile::section_begin() const {
316 DRI.p = getSectionHeaderTableAddress();
317 return section_iterator(SectionRef(DRI, this));
320 section_iterator XCOFFObjectFile::section_end() const {
322 DRI.p = getWithOffset(getSectionHeaderTableAddress(),
323 getNumberOfSections() * getSectionHeaderSize());
324 return section_iterator(SectionRef(DRI, this));
327 uint8_t XCOFFObjectFile::getBytesInAddress() const { return is64Bit() ? 8 : 4; }
329 StringRef XCOFFObjectFile::getFileFormatName() const {
330 return is64Bit() ? "aix5coff64-rs6000" : "aixcoff-rs6000";
333 Triple::ArchType XCOFFObjectFile::getArch() const {
334 return is64Bit() ? Triple::ppc64 : Triple::ppc;
337 SubtargetFeatures XCOFFObjectFile::getFeatures() const {
338 llvm_unreachable("Not yet implemented!");
339 return SubtargetFeatures();
342 bool XCOFFObjectFile::isRelocatableObject() const {
344 llvm_unreachable("Not yet implemented!");
348 Expected<uint64_t> XCOFFObjectFile::getStartAddress() const {
349 // TODO FIXME Should get from auxiliary_header->o_entry when support for the
350 // auxiliary_header is added.
354 size_t XCOFFObjectFile::getFileHeaderSize() const {
355 return is64Bit() ? sizeof(XCOFFFileHeader64) : sizeof(XCOFFFileHeader32);
358 size_t XCOFFObjectFile::getSectionHeaderSize() const {
359 return is64Bit() ? sizeof(XCOFFSectionHeader64) :
360 sizeof(XCOFFSectionHeader32);
363 bool XCOFFObjectFile::is64Bit() const {
364 return Binary::ID_XCOFF64 == getType();
367 uint16_t XCOFFObjectFile::getMagic() const {
368 return is64Bit() ? fileHeader64()->Magic : fileHeader32()->Magic;
371 Expected<DataRefImpl> XCOFFObjectFile::getSectionByNum(int16_t Num) const {
372 if (Num <= 0 || Num > getNumberOfSections())
373 return errorCodeToError(object_error::invalid_section_index);
376 DRI.p = getWithOffset(getSectionHeaderTableAddress(),
377 getSectionHeaderSize() * (Num - 1));
382 XCOFFObjectFile::getSymbolSectionName(const XCOFFSymbolEntry *SymEntPtr) const {
383 assert(!is64Bit() && "Symbol table support not implemented for 64-bit.");
384 int16_t SectionNum = SymEntPtr->SectionNumber;
386 switch (SectionNum) {
394 Expected<DataRefImpl> SecRef = getSectionByNum(SectionNum);
396 return generateStringRef(getSectionNameInternal(SecRef.get()),
397 XCOFF::SectionNameSize);
398 return SecRef.takeError();
402 bool XCOFFObjectFile::isReservedSectionNumber(int16_t SectionNumber) {
403 return (SectionNumber <= 0 && SectionNumber >= -2);
406 uint16_t XCOFFObjectFile::getNumberOfSections() const {
407 return is64Bit() ? fileHeader64()->NumberOfSections
408 : fileHeader32()->NumberOfSections;
411 int32_t XCOFFObjectFile::getTimeStamp() const {
412 return is64Bit() ? fileHeader64()->TimeStamp : fileHeader32()->TimeStamp;
415 uint16_t XCOFFObjectFile::getOptionalHeaderSize() const {
416 return is64Bit() ? fileHeader64()->AuxHeaderSize
417 : fileHeader32()->AuxHeaderSize;
420 uint32_t XCOFFObjectFile::getSymbolTableOffset32() const {
421 return fileHeader32()->SymbolTableOffset;
424 int32_t XCOFFObjectFile::getRawNumberOfSymbolTableEntries32() const {
425 // As far as symbol table size is concerned, if this field is negative it is
426 // to be treated as a 0. However since this field is also used for printing we
427 // don't want to truncate any negative values.
428 return fileHeader32()->NumberOfSymTableEntries;
431 uint32_t XCOFFObjectFile::getLogicalNumberOfSymbolTableEntries32() const {
432 return (fileHeader32()->NumberOfSymTableEntries >= 0
433 ? fileHeader32()->NumberOfSymTableEntries
437 uint64_t XCOFFObjectFile::getSymbolTableOffset64() const {
438 return fileHeader64()->SymbolTableOffset;
441 uint32_t XCOFFObjectFile::getNumberOfSymbolTableEntries64() const {
442 return fileHeader64()->NumberOfSymTableEntries;
445 uint16_t XCOFFObjectFile::getFlags() const {
446 return is64Bit() ? fileHeader64()->Flags : fileHeader32()->Flags;
449 const char *XCOFFObjectFile::getSectionNameInternal(DataRefImpl Sec) const {
450 return is64Bit() ? toSection64(Sec)->Name : toSection32(Sec)->Name;
453 uintptr_t XCOFFObjectFile::getSectionHeaderTableAddress() const {
454 return reinterpret_cast<uintptr_t>(SectionHeaderTable);
457 int32_t XCOFFObjectFile::getSectionFlags(DataRefImpl Sec) const {
458 return is64Bit() ? toSection64(Sec)->Flags : toSection32(Sec)->Flags;
461 XCOFFObjectFile::XCOFFObjectFile(unsigned int Type, MemoryBufferRef Object)
462 : ObjectFile(Type, Object) {
463 assert(Type == Binary::ID_XCOFF32 || Type == Binary::ID_XCOFF64);
466 ArrayRef<XCOFFSectionHeader64> XCOFFObjectFile::sections64() const {
467 assert(is64Bit() && "64-bit interface called for non 64-bit file.");
468 const XCOFFSectionHeader64 *TablePtr = sectionHeaderTable64();
469 return ArrayRef<XCOFFSectionHeader64>(TablePtr,
470 TablePtr + getNumberOfSections());
473 ArrayRef<XCOFFSectionHeader32> XCOFFObjectFile::sections32() const {
474 assert(!is64Bit() && "32-bit interface called for non 32-bit file.");
475 const XCOFFSectionHeader32 *TablePtr = sectionHeaderTable32();
476 return ArrayRef<XCOFFSectionHeader32>(TablePtr,
477 TablePtr + getNumberOfSections());
480 Expected<XCOFFStringTable>
481 XCOFFObjectFile::parseStringTable(const XCOFFObjectFile *Obj, uint64_t Offset) {
482 // If there is a string table, then the buffer must contain at least 4 bytes
483 // for the string table's size. Not having a string table is not an error.
484 if (auto EC = Binary::checkOffset(
485 Obj->Data, reinterpret_cast<uintptr_t>(Obj->base() + Offset), 4))
486 return XCOFFStringTable{0, nullptr};
488 // Read the size out of the buffer.
489 uint32_t Size = support::endian::read32be(Obj->base() + Offset);
491 // If the size is less then 4, then the string table is just a size and no
494 return XCOFFStringTable{4, nullptr};
496 auto StringTableOrErr =
497 getObject<char>(Obj->Data, Obj->base() + Offset, Size);
498 if (Error E = StringTableOrErr.takeError())
501 const char *StringTablePtr = StringTableOrErr.get();
502 if (StringTablePtr[Size - 1] != '\0')
503 return errorCodeToError(object_error::string_table_non_null_end);
505 return XCOFFStringTable{Size, StringTablePtr};
508 Expected<std::unique_ptr<XCOFFObjectFile>>
509 XCOFFObjectFile::create(unsigned Type, MemoryBufferRef MBR) {
510 // Can't use make_unique because of the private constructor.
511 std::unique_ptr<XCOFFObjectFile> Obj;
512 Obj.reset(new XCOFFObjectFile(Type, MBR));
514 uint64_t CurOffset = 0;
515 const auto *Base = Obj->base();
516 MemoryBufferRef Data = Obj->Data;
518 // Parse file header.
519 auto FileHeaderOrErr =
520 getObject<void>(Data, Base + CurOffset, Obj->getFileHeaderSize());
521 if (Error E = FileHeaderOrErr.takeError())
523 Obj->FileHeader = FileHeaderOrErr.get();
525 CurOffset += Obj->getFileHeaderSize();
526 // TODO FIXME we don't have support for an optional header yet, so just skip
528 CurOffset += Obj->getOptionalHeaderSize();
530 // Parse the section header table if it is present.
531 if (Obj->getNumberOfSections()) {
532 auto SecHeadersOrErr = getObject<void>(Data, Base + CurOffset,
533 Obj->getNumberOfSections() *
534 Obj->getSectionHeaderSize());
535 if (Error E = SecHeadersOrErr.takeError())
537 Obj->SectionHeaderTable = SecHeadersOrErr.get();
540 // 64-bit object supports only file header and section headers for now.
542 return std::move(Obj);
544 // If there is no symbol table we are done parsing the memory buffer.
545 if (Obj->getLogicalNumberOfSymbolTableEntries32() == 0)
546 return std::move(Obj);
548 // Parse symbol table.
549 CurOffset = Obj->fileHeader32()->SymbolTableOffset;
550 uint64_t SymbolTableSize = (uint64_t)(sizeof(XCOFFSymbolEntry)) *
551 Obj->getLogicalNumberOfSymbolTableEntries32();
553 getObject<XCOFFSymbolEntry>(Data, Base + CurOffset, SymbolTableSize);
554 if (Error E = SymTableOrErr.takeError())
556 Obj->SymbolTblPtr = SymTableOrErr.get();
557 CurOffset += SymbolTableSize;
559 // Parse String table.
560 Expected<XCOFFStringTable> StringTableOrErr =
561 parseStringTable(Obj.get(), CurOffset);
562 if (Error E = StringTableOrErr.takeError())
564 Obj->StringTable = StringTableOrErr.get();
566 return std::move(Obj);
569 Expected<std::unique_ptr<ObjectFile>>
570 ObjectFile::createXCOFFObjectFile(MemoryBufferRef MemBufRef,
572 return XCOFFObjectFile::create(FileType, MemBufRef);
575 StringRef XCOFFSectionHeader32::getName() const {
576 return generateStringRef(Name, XCOFF::SectionNameSize);
579 StringRef XCOFFSectionHeader64::getName() const {
580 return generateStringRef(Name, XCOFF::SectionNameSize);
583 } // namespace object