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authorDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
committerDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
commit0b57cec536236d46e3dba9bd041533462f33dbb7 (patch)
tree56229dbdbbf76d18580f72f789003db17246c8d9 /contrib/llvm/tools/llvm-objcopy/ELF/Object.cpp
parent718ef55ec7785aae63f98f8ca05dc07ed399c16d (diff)
Notes
Diffstat (limited to 'contrib/llvm/tools/llvm-objcopy/ELF/Object.cpp')
-rw-r--r--contrib/llvm/tools/llvm-objcopy/ELF/Object.cpp2301
1 files changed, 0 insertions, 2301 deletions
diff --git a/contrib/llvm/tools/llvm-objcopy/ELF/Object.cpp b/contrib/llvm/tools/llvm-objcopy/ELF/Object.cpp
deleted file mode 100644
index fa696380e17c..000000000000
--- a/contrib/llvm/tools/llvm-objcopy/ELF/Object.cpp
+++ /dev/null
@@ -1,2301 +0,0 @@
-//===- Object.cpp ---------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "Object.h"
-#include "llvm-objcopy.h"
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/StringRef.h"
-#include "llvm/ADT/Twine.h"
-#include "llvm/ADT/iterator_range.h"
-#include "llvm/BinaryFormat/ELF.h"
-#include "llvm/MC/MCTargetOptions.h"
-#include "llvm/Object/ELFObjectFile.h"
-#include "llvm/Support/Compression.h"
-#include "llvm/Support/Endian.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/FileOutputBuffer.h"
-#include "llvm/Support/Path.h"
-#include <algorithm>
-#include <cstddef>
-#include <cstdint>
-#include <iterator>
-#include <unordered_set>
-#include <utility>
-#include <vector>
-
-namespace llvm {
-namespace objcopy {
-namespace elf {
-
-using namespace object;
-using namespace ELF;
-
-template <class ELFT> void ELFWriter<ELFT>::writePhdr(const Segment &Seg) {
- uint8_t *B = Buf.getBufferStart() + Obj.ProgramHdrSegment.Offset +
- Seg.Index * sizeof(Elf_Phdr);
- Elf_Phdr &Phdr = *reinterpret_cast<Elf_Phdr *>(B);
- Phdr.p_type = Seg.Type;
- Phdr.p_flags = Seg.Flags;
- Phdr.p_offset = Seg.Offset;
- Phdr.p_vaddr = Seg.VAddr;
- Phdr.p_paddr = Seg.PAddr;
- Phdr.p_filesz = Seg.FileSize;
- Phdr.p_memsz = Seg.MemSize;
- Phdr.p_align = Seg.Align;
-}
-
-Error SectionBase::removeSectionReferences(
- bool AllowBrokenLinks,
- function_ref<bool(const SectionBase *)> ToRemove) {
- return Error::success();
-}
-
-Error SectionBase::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
- return Error::success();
-}
-
-void SectionBase::initialize(SectionTableRef SecTable) {}
-void SectionBase::finalize() {}
-void SectionBase::markSymbols() {}
-void SectionBase::replaceSectionReferences(
- const DenseMap<SectionBase *, SectionBase *> &) {}
-
-template <class ELFT> void ELFWriter<ELFT>::writeShdr(const SectionBase &Sec) {
- uint8_t *B = Buf.getBufferStart() + Sec.HeaderOffset;
- Elf_Shdr &Shdr = *reinterpret_cast<Elf_Shdr *>(B);
- Shdr.sh_name = Sec.NameIndex;
- Shdr.sh_type = Sec.Type;
- Shdr.sh_flags = Sec.Flags;
- Shdr.sh_addr = Sec.Addr;
- Shdr.sh_offset = Sec.Offset;
- Shdr.sh_size = Sec.Size;
- Shdr.sh_link = Sec.Link;
- Shdr.sh_info = Sec.Info;
- Shdr.sh_addralign = Sec.Align;
- Shdr.sh_entsize = Sec.EntrySize;
-}
-
-template <class ELFT> void ELFSectionSizer<ELFT>::visit(Section &Sec) {}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(OwnedDataSection &Sec) {}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(StringTableSection &Sec) {}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(DynamicRelocationSection &Sec) {}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(SymbolTableSection &Sec) {
- Sec.EntrySize = sizeof(Elf_Sym);
- Sec.Size = Sec.Symbols.size() * Sec.EntrySize;
- // Align to the largest field in Elf_Sym.
- Sec.Align = ELFT::Is64Bits ? sizeof(Elf_Xword) : sizeof(Elf_Word);
-}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(RelocationSection &Sec) {
- Sec.EntrySize = Sec.Type == SHT_REL ? sizeof(Elf_Rel) : sizeof(Elf_Rela);
- Sec.Size = Sec.Relocations.size() * Sec.EntrySize;
- // Align to the largest field in Elf_Rel(a).
- Sec.Align = ELFT::Is64Bits ? sizeof(Elf_Xword) : sizeof(Elf_Word);
-}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(GnuDebugLinkSection &Sec) {}
-
-template <class ELFT> void ELFSectionSizer<ELFT>::visit(GroupSection &Sec) {}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(SectionIndexSection &Sec) {}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(CompressedSection &Sec) {}
-
-template <class ELFT>
-void ELFSectionSizer<ELFT>::visit(DecompressedSection &Sec) {}
-
-void BinarySectionWriter::visit(const SectionIndexSection &Sec) {
- error("cannot write symbol section index table '" + Sec.Name + "' ");
-}
-
-void BinarySectionWriter::visit(const SymbolTableSection &Sec) {
- error("cannot write symbol table '" + Sec.Name + "' out to binary");
-}
-
-void BinarySectionWriter::visit(const RelocationSection &Sec) {
- error("cannot write relocation section '" + Sec.Name + "' out to binary");
-}
-
-void BinarySectionWriter::visit(const GnuDebugLinkSection &Sec) {
- error("cannot write '" + Sec.Name + "' out to binary");
-}
-
-void BinarySectionWriter::visit(const GroupSection &Sec) {
- error("cannot write '" + Sec.Name + "' out to binary");
-}
-
-void SectionWriter::visit(const Section &Sec) {
- if (Sec.Type != SHT_NOBITS)
- llvm::copy(Sec.Contents, Out.getBufferStart() + Sec.Offset);
-}
-
-static bool addressOverflows32bit(uint64_t Addr) {
- // Sign extended 32 bit addresses (e.g 0xFFFFFFFF80000000) are ok
- return Addr > UINT32_MAX && Addr + 0x80000000 > UINT32_MAX;
-}
-
-template <class T> static T checkedGetHex(StringRef S) {
- T Value;
- bool Fail = S.getAsInteger(16, Value);
- assert(!Fail);
- (void)Fail;
- return Value;
-}
-
-// Fills exactly Len bytes of buffer with hexadecimal characters
-// representing value 'X'
-template <class T, class Iterator>
-static Iterator utohexstr(T X, Iterator It, size_t Len) {
- // Fill range with '0'
- std::fill(It, It + Len, '0');
-
- for (long I = Len - 1; I >= 0; --I) {
- unsigned char Mod = static_cast<unsigned char>(X) & 15;
- *(It + I) = hexdigit(Mod, false);
- X >>= 4;
- }
- assert(X == 0);
- return It + Len;
-}
-
-uint8_t IHexRecord::getChecksum(StringRef S) {
- assert((S.size() & 1) == 0);
- uint8_t Checksum = 0;
- while (!S.empty()) {
- Checksum += checkedGetHex<uint8_t>(S.take_front(2));
- S = S.drop_front(2);
- }
- return -Checksum;
-}
-
-IHexLineData IHexRecord::getLine(uint8_t Type, uint16_t Addr,
- ArrayRef<uint8_t> Data) {
- IHexLineData Line(getLineLength(Data.size()));
- assert(Line.size());
- auto Iter = Line.begin();
- *Iter++ = ':';
- Iter = utohexstr(Data.size(), Iter, 2);
- Iter = utohexstr(Addr, Iter, 4);
- Iter = utohexstr(Type, Iter, 2);
- for (uint8_t X : Data)
- Iter = utohexstr(X, Iter, 2);
- StringRef S(Line.data() + 1, std::distance(Line.begin() + 1, Iter));
- Iter = utohexstr(getChecksum(S), Iter, 2);
- *Iter++ = '\r';
- *Iter++ = '\n';
- assert(Iter == Line.end());
- return Line;
-}
-
-static Error checkRecord(const IHexRecord &R) {
- switch (R.Type) {
- case IHexRecord::Data:
- if (R.HexData.size() == 0)
- return createStringError(
- errc::invalid_argument,
- "zero data length is not allowed for data records");
- break;
- case IHexRecord::EndOfFile:
- break;
- case IHexRecord::SegmentAddr:
- // 20-bit segment address. Data length must be 2 bytes
- // (4 bytes in hex)
- if (R.HexData.size() != 4)
- return createStringError(
- errc::invalid_argument,
- "segment address data should be 2 bytes in size");
- break;
- case IHexRecord::StartAddr80x86:
- case IHexRecord::StartAddr:
- if (R.HexData.size() != 8)
- return createStringError(errc::invalid_argument,
- "start address data should be 4 bytes in size");
- // According to Intel HEX specification '03' record
- // only specifies the code address within the 20-bit
- // segmented address space of the 8086/80186. This
- // means 12 high order bits should be zeroes.
- if (R.Type == IHexRecord::StartAddr80x86 &&
- R.HexData.take_front(3) != "000")
- return createStringError(errc::invalid_argument,
- "start address exceeds 20 bit for 80x86");
- break;
- case IHexRecord::ExtendedAddr:
- // 16-31 bits of linear base address
- if (R.HexData.size() != 4)
- return createStringError(
- errc::invalid_argument,
- "extended address data should be 2 bytes in size");
- break;
- default:
- // Unknown record type
- return createStringError(errc::invalid_argument, "unknown record type: %u",
- static_cast<unsigned>(R.Type));
- }
- return Error::success();
-}
-
-// Checks that IHEX line contains valid characters.
-// This allows converting hexadecimal data to integers
-// without extra verification.
-static Error checkChars(StringRef Line) {
- assert(!Line.empty());
- if (Line[0] != ':')
- return createStringError(errc::invalid_argument,
- "missing ':' in the beginning of line.");
-
- for (size_t Pos = 1; Pos < Line.size(); ++Pos)
- if (hexDigitValue(Line[Pos]) == -1U)
- return createStringError(errc::invalid_argument,
- "invalid character at position %zu.", Pos + 1);
- return Error::success();
-}
-
-Expected<IHexRecord> IHexRecord::parse(StringRef Line) {
- assert(!Line.empty());
-
- // ':' + Length + Address + Type + Checksum with empty data ':LLAAAATTCC'
- if (Line.size() < 11)
- return createStringError(errc::invalid_argument,
- "line is too short: %zu chars.", Line.size());
-
- if (Error E = checkChars(Line))
- return std::move(E);
-
- IHexRecord Rec;
- size_t DataLen = checkedGetHex<uint8_t>(Line.substr(1, 2));
- if (Line.size() != getLength(DataLen))
- return createStringError(errc::invalid_argument,
- "invalid line length %zu (should be %zu)",
- Line.size(), getLength(DataLen));
-
- Rec.Addr = checkedGetHex<uint16_t>(Line.substr(3, 4));
- Rec.Type = checkedGetHex<uint8_t>(Line.substr(7, 2));
- Rec.HexData = Line.substr(9, DataLen * 2);
-
- if (getChecksum(Line.drop_front(1)) != 0)
- return createStringError(errc::invalid_argument, "incorrect checksum.");
- if (Error E = checkRecord(Rec))
- return std::move(E);
- return Rec;
-}
-
-static uint64_t sectionPhysicalAddr(const SectionBase *Sec) {
- Segment *Seg = Sec->ParentSegment;
- if (Seg && Seg->Type != ELF::PT_LOAD)
- Seg = nullptr;
- return Seg ? Seg->PAddr + Sec->OriginalOffset - Seg->OriginalOffset
- : Sec->Addr;
-}
-
-void IHexSectionWriterBase::writeSection(const SectionBase *Sec,
- ArrayRef<uint8_t> Data) {
- assert(Data.size() == Sec->Size);
- const uint32_t ChunkSize = 16;
- uint32_t Addr = sectionPhysicalAddr(Sec) & 0xFFFFFFFFU;
- while (!Data.empty()) {
- uint64_t DataSize = std::min<uint64_t>(Data.size(), ChunkSize);
- if (Addr > SegmentAddr + BaseAddr + 0xFFFFU) {
- if (Addr > 0xFFFFFU) {
- // Write extended address record, zeroing segment address
- // if needed.
- if (SegmentAddr != 0)
- SegmentAddr = writeSegmentAddr(0U);
- BaseAddr = writeBaseAddr(Addr);
- } else {
- // We can still remain 16-bit
- SegmentAddr = writeSegmentAddr(Addr);
- }
- }
- uint64_t SegOffset = Addr - BaseAddr - SegmentAddr;
- assert(SegOffset <= 0xFFFFU);
- DataSize = std::min(DataSize, 0x10000U - SegOffset);
- writeData(0, SegOffset, Data.take_front(DataSize));
- Addr += DataSize;
- Data = Data.drop_front(DataSize);
- }
-}
-
-uint64_t IHexSectionWriterBase::writeSegmentAddr(uint64_t Addr) {
- assert(Addr <= 0xFFFFFU);
- uint8_t Data[] = {static_cast<uint8_t>((Addr & 0xF0000U) >> 12), 0};
- writeData(2, 0, Data);
- return Addr & 0xF0000U;
-}
-
-uint64_t IHexSectionWriterBase::writeBaseAddr(uint64_t Addr) {
- assert(Addr <= 0xFFFFFFFFU);
- uint64_t Base = Addr & 0xFFFF0000U;
- uint8_t Data[] = {static_cast<uint8_t>(Base >> 24),
- static_cast<uint8_t>((Base >> 16) & 0xFF)};
- writeData(4, 0, Data);
- return Base;
-}
-
-void IHexSectionWriterBase::writeData(uint8_t Type, uint16_t Addr,
- ArrayRef<uint8_t> Data) {
- Offset += IHexRecord::getLineLength(Data.size());
-}
-
-void IHexSectionWriterBase::visit(const Section &Sec) {
- writeSection(&Sec, Sec.Contents);
-}
-
-void IHexSectionWriterBase::visit(const OwnedDataSection &Sec) {
- writeSection(&Sec, Sec.Data);
-}
-
-void IHexSectionWriterBase::visit(const StringTableSection &Sec) {
- // Check that sizer has already done its work
- assert(Sec.Size == Sec.StrTabBuilder.getSize());
- // We are free to pass an invalid pointer to writeSection as long
- // as we don't actually write any data. The real writer class has
- // to override this method .
- writeSection(&Sec, {nullptr, static_cast<size_t>(Sec.Size)});
-}
-
-void IHexSectionWriterBase::visit(const DynamicRelocationSection &Sec) {
- writeSection(&Sec, Sec.Contents);
-}
-
-void IHexSectionWriter::writeData(uint8_t Type, uint16_t Addr,
- ArrayRef<uint8_t> Data) {
- IHexLineData HexData = IHexRecord::getLine(Type, Addr, Data);
- memcpy(Out.getBufferStart() + Offset, HexData.data(), HexData.size());
- Offset += HexData.size();
-}
-
-void IHexSectionWriter::visit(const StringTableSection &Sec) {
- assert(Sec.Size == Sec.StrTabBuilder.getSize());
- std::vector<uint8_t> Data(Sec.Size);
- Sec.StrTabBuilder.write(Data.data());
- writeSection(&Sec, Data);
-}
-
-void Section::accept(SectionVisitor &Visitor) const { Visitor.visit(*this); }
-
-void Section::accept(MutableSectionVisitor &Visitor) { Visitor.visit(*this); }
-
-void SectionWriter::visit(const OwnedDataSection &Sec) {
- llvm::copy(Sec.Data, Out.getBufferStart() + Sec.Offset);
-}
-
-static const std::vector<uint8_t> ZlibGnuMagic = {'Z', 'L', 'I', 'B'};
-
-static bool isDataGnuCompressed(ArrayRef<uint8_t> Data) {
- return Data.size() > ZlibGnuMagic.size() &&
- std::equal(ZlibGnuMagic.begin(), ZlibGnuMagic.end(), Data.data());
-}
-
-template <class ELFT>
-static std::tuple<uint64_t, uint64_t>
-getDecompressedSizeAndAlignment(ArrayRef<uint8_t> Data) {
- const bool IsGnuDebug = isDataGnuCompressed(Data);
- const uint64_t DecompressedSize =
- IsGnuDebug
- ? support::endian::read64be(Data.data() + ZlibGnuMagic.size())
- : reinterpret_cast<const Elf_Chdr_Impl<ELFT> *>(Data.data())->ch_size;
- const uint64_t DecompressedAlign =
- IsGnuDebug ? 1
- : reinterpret_cast<const Elf_Chdr_Impl<ELFT> *>(Data.data())
- ->ch_addralign;
-
- return std::make_tuple(DecompressedSize, DecompressedAlign);
-}
-
-template <class ELFT>
-void ELFSectionWriter<ELFT>::visit(const DecompressedSection &Sec) {
- const size_t DataOffset = isDataGnuCompressed(Sec.OriginalData)
- ? (ZlibGnuMagic.size() + sizeof(Sec.Size))
- : sizeof(Elf_Chdr_Impl<ELFT>);
-
- StringRef CompressedContent(
- reinterpret_cast<const char *>(Sec.OriginalData.data()) + DataOffset,
- Sec.OriginalData.size() - DataOffset);
-
- SmallVector<char, 128> DecompressedContent;
- if (Error E = zlib::uncompress(CompressedContent, DecompressedContent,
- static_cast<size_t>(Sec.Size)))
- reportError(Sec.Name, std::move(E));
-
- uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
- std::copy(DecompressedContent.begin(), DecompressedContent.end(), Buf);
-}
-
-void BinarySectionWriter::visit(const DecompressedSection &Sec) {
- error("cannot write compressed section '" + Sec.Name + "' ");
-}
-
-void DecompressedSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void DecompressedSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-void OwnedDataSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void OwnedDataSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-void OwnedDataSection::appendHexData(StringRef HexData) {
- assert((HexData.size() & 1) == 0);
- while (!HexData.empty()) {
- Data.push_back(checkedGetHex<uint8_t>(HexData.take_front(2)));
- HexData = HexData.drop_front(2);
- }
- Size = Data.size();
-}
-
-void BinarySectionWriter::visit(const CompressedSection &Sec) {
- error("cannot write compressed section '" + Sec.Name + "' ");
-}
-
-template <class ELFT>
-void ELFSectionWriter<ELFT>::visit(const CompressedSection &Sec) {
- uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
- if (Sec.CompressionType == DebugCompressionType::None) {
- std::copy(Sec.OriginalData.begin(), Sec.OriginalData.end(), Buf);
- return;
- }
-
- if (Sec.CompressionType == DebugCompressionType::GNU) {
- const char *Magic = "ZLIB";
- memcpy(Buf, Magic, strlen(Magic));
- Buf += strlen(Magic);
- const uint64_t DecompressedSize =
- support::endian::read64be(&Sec.DecompressedSize);
- memcpy(Buf, &DecompressedSize, sizeof(DecompressedSize));
- Buf += sizeof(DecompressedSize);
- } else {
- Elf_Chdr_Impl<ELFT> Chdr;
- Chdr.ch_type = ELF::ELFCOMPRESS_ZLIB;
- Chdr.ch_size = Sec.DecompressedSize;
- Chdr.ch_addralign = Sec.DecompressedAlign;
- memcpy(Buf, &Chdr, sizeof(Chdr));
- Buf += sizeof(Chdr);
- }
-
- std::copy(Sec.CompressedData.begin(), Sec.CompressedData.end(), Buf);
-}
-
-CompressedSection::CompressedSection(const SectionBase &Sec,
- DebugCompressionType CompressionType)
- : SectionBase(Sec), CompressionType(CompressionType),
- DecompressedSize(Sec.OriginalData.size()), DecompressedAlign(Sec.Align) {
- if (Error E = zlib::compress(
- StringRef(reinterpret_cast<const char *>(OriginalData.data()),
- OriginalData.size()),
- CompressedData))
- reportError(Name, std::move(E));
-
- size_t ChdrSize;
- if (CompressionType == DebugCompressionType::GNU) {
- Name = ".z" + Sec.Name.substr(1);
- ChdrSize = sizeof("ZLIB") - 1 + sizeof(uint64_t);
- } else {
- Flags |= ELF::SHF_COMPRESSED;
- ChdrSize =
- std::max(std::max(sizeof(object::Elf_Chdr_Impl<object::ELF64LE>),
- sizeof(object::Elf_Chdr_Impl<object::ELF64BE>)),
- std::max(sizeof(object::Elf_Chdr_Impl<object::ELF32LE>),
- sizeof(object::Elf_Chdr_Impl<object::ELF32BE>)));
- }
- Size = ChdrSize + CompressedData.size();
- Align = 8;
-}
-
-CompressedSection::CompressedSection(ArrayRef<uint8_t> CompressedData,
- uint64_t DecompressedSize,
- uint64_t DecompressedAlign)
- : CompressionType(DebugCompressionType::None),
- DecompressedSize(DecompressedSize), DecompressedAlign(DecompressedAlign) {
- OriginalData = CompressedData;
-}
-
-void CompressedSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void CompressedSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-void StringTableSection::addString(StringRef Name) { StrTabBuilder.add(Name); }
-
-uint32_t StringTableSection::findIndex(StringRef Name) const {
- return StrTabBuilder.getOffset(Name);
-}
-
-void StringTableSection::prepareForLayout() {
- StrTabBuilder.finalize();
- Size = StrTabBuilder.getSize();
-}
-
-void SectionWriter::visit(const StringTableSection &Sec) {
- Sec.StrTabBuilder.write(Out.getBufferStart() + Sec.Offset);
-}
-
-void StringTableSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void StringTableSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-template <class ELFT>
-void ELFSectionWriter<ELFT>::visit(const SectionIndexSection &Sec) {
- uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
- llvm::copy(Sec.Indexes, reinterpret_cast<Elf_Word *>(Buf));
-}
-
-void SectionIndexSection::initialize(SectionTableRef SecTable) {
- Size = 0;
- setSymTab(SecTable.getSectionOfType<SymbolTableSection>(
- Link,
- "Link field value " + Twine(Link) + " in section " + Name + " is invalid",
- "Link field value " + Twine(Link) + " in section " + Name +
- " is not a symbol table"));
- Symbols->setShndxTable(this);
-}
-
-void SectionIndexSection::finalize() { Link = Symbols->Index; }
-
-void SectionIndexSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void SectionIndexSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-static bool isValidReservedSectionIndex(uint16_t Index, uint16_t Machine) {
- switch (Index) {
- case SHN_ABS:
- case SHN_COMMON:
- return true;
- }
-
- if (Machine == EM_AMDGPU) {
- return Index == SHN_AMDGPU_LDS;
- }
-
- if (Machine == EM_HEXAGON) {
- switch (Index) {
- case SHN_HEXAGON_SCOMMON:
- case SHN_HEXAGON_SCOMMON_2:
- case SHN_HEXAGON_SCOMMON_4:
- case SHN_HEXAGON_SCOMMON_8:
- return true;
- }
- }
- return false;
-}
-
-// Large indexes force us to clarify exactly what this function should do. This
-// function should return the value that will appear in st_shndx when written
-// out.
-uint16_t Symbol::getShndx() const {
- if (DefinedIn != nullptr) {
- if (DefinedIn->Index >= SHN_LORESERVE)
- return SHN_XINDEX;
- return DefinedIn->Index;
- }
-
- if (ShndxType == SYMBOL_SIMPLE_INDEX) {
- // This means that we don't have a defined section but we do need to
- // output a legitimate section index.
- return SHN_UNDEF;
- }
-
- assert(ShndxType == SYMBOL_ABS || ShndxType == SYMBOL_COMMON ||
- (ShndxType >= SYMBOL_LOPROC && ShndxType <= SYMBOL_HIPROC) ||
- (ShndxType >= SYMBOL_LOOS && ShndxType <= SYMBOL_HIOS));
- return static_cast<uint16_t>(ShndxType);
-}
-
-bool Symbol::isCommon() const { return getShndx() == SHN_COMMON; }
-
-void SymbolTableSection::assignIndices() {
- uint32_t Index = 0;
- for (auto &Sym : Symbols)
- Sym->Index = Index++;
-}
-
-void SymbolTableSection::addSymbol(Twine Name, uint8_t Bind, uint8_t Type,
- SectionBase *DefinedIn, uint64_t Value,
- uint8_t Visibility, uint16_t Shndx,
- uint64_t SymbolSize) {
- Symbol Sym;
- Sym.Name = Name.str();
- Sym.Binding = Bind;
- Sym.Type = Type;
- Sym.DefinedIn = DefinedIn;
- if (DefinedIn != nullptr)
- DefinedIn->HasSymbol = true;
- if (DefinedIn == nullptr) {
- if (Shndx >= SHN_LORESERVE)
- Sym.ShndxType = static_cast<SymbolShndxType>(Shndx);
- else
- Sym.ShndxType = SYMBOL_SIMPLE_INDEX;
- }
- Sym.Value = Value;
- Sym.Visibility = Visibility;
- Sym.Size = SymbolSize;
- Sym.Index = Symbols.size();
- Symbols.emplace_back(llvm::make_unique<Symbol>(Sym));
- Size += this->EntrySize;
-}
-
-Error SymbolTableSection::removeSectionReferences(
- bool AllowBrokenLinks,
- function_ref<bool(const SectionBase *)> ToRemove) {
- if (ToRemove(SectionIndexTable))
- SectionIndexTable = nullptr;
- if (ToRemove(SymbolNames)) {
- if (!AllowBrokenLinks)
- return createStringError(
- llvm::errc::invalid_argument,
- "string table '%s' cannot be removed because it is "
- "referenced by the symbol table '%s'",
- SymbolNames->Name.data(), this->Name.data());
- SymbolNames = nullptr;
- }
- return removeSymbols(
- [ToRemove](const Symbol &Sym) { return ToRemove(Sym.DefinedIn); });
-}
-
-void SymbolTableSection::updateSymbols(function_ref<void(Symbol &)> Callable) {
- std::for_each(std::begin(Symbols) + 1, std::end(Symbols),
- [Callable](SymPtr &Sym) { Callable(*Sym); });
- std::stable_partition(
- std::begin(Symbols), std::end(Symbols),
- [](const SymPtr &Sym) { return Sym->Binding == STB_LOCAL; });
- assignIndices();
-}
-
-Error SymbolTableSection::removeSymbols(
- function_ref<bool(const Symbol &)> ToRemove) {
- Symbols.erase(
- std::remove_if(std::begin(Symbols) + 1, std::end(Symbols),
- [ToRemove](const SymPtr &Sym) { return ToRemove(*Sym); }),
- std::end(Symbols));
- Size = Symbols.size() * EntrySize;
- assignIndices();
- return Error::success();
-}
-
-void SymbolTableSection::replaceSectionReferences(
- const DenseMap<SectionBase *, SectionBase *> &FromTo) {
- for (std::unique_ptr<Symbol> &Sym : Symbols)
- if (SectionBase *To = FromTo.lookup(Sym->DefinedIn))
- Sym->DefinedIn = To;
-}
-
-void SymbolTableSection::initialize(SectionTableRef SecTable) {
- Size = 0;
- setStrTab(SecTable.getSectionOfType<StringTableSection>(
- Link,
- "Symbol table has link index of " + Twine(Link) +
- " which is not a valid index",
- "Symbol table has link index of " + Twine(Link) +
- " which is not a string table"));
-}
-
-void SymbolTableSection::finalize() {
- uint32_t MaxLocalIndex = 0;
- for (std::unique_ptr<Symbol> &Sym : Symbols) {
- Sym->NameIndex =
- SymbolNames == nullptr ? 0 : SymbolNames->findIndex(Sym->Name);
- if (Sym->Binding == STB_LOCAL)
- MaxLocalIndex = std::max(MaxLocalIndex, Sym->Index);
- }
- // Now we need to set the Link and Info fields.
- Link = SymbolNames == nullptr ? 0 : SymbolNames->Index;
- Info = MaxLocalIndex + 1;
-}
-
-void SymbolTableSection::prepareForLayout() {
- // Reserve proper amount of space in section index table, so we can
- // layout sections correctly. We will fill the table with correct
- // indexes later in fillShdnxTable.
- if (SectionIndexTable)
- SectionIndexTable->reserve(Symbols.size());
-
- // Add all of our strings to SymbolNames so that SymbolNames has the right
- // size before layout is decided.
- // If the symbol names section has been removed, don't try to add strings to
- // the table.
- if (SymbolNames != nullptr)
- for (std::unique_ptr<Symbol> &Sym : Symbols)
- SymbolNames->addString(Sym->Name);
-}
-
-void SymbolTableSection::fillShndxTable() {
- if (SectionIndexTable == nullptr)
- return;
- // Fill section index table with real section indexes. This function must
- // be called after assignOffsets.
- for (const std::unique_ptr<Symbol> &Sym : Symbols) {
- if (Sym->DefinedIn != nullptr && Sym->DefinedIn->Index >= SHN_LORESERVE)
- SectionIndexTable->addIndex(Sym->DefinedIn->Index);
- else
- SectionIndexTable->addIndex(SHN_UNDEF);
- }
-}
-
-const Symbol *SymbolTableSection::getSymbolByIndex(uint32_t Index) const {
- if (Symbols.size() <= Index)
- error("invalid symbol index: " + Twine(Index));
- return Symbols[Index].get();
-}
-
-Symbol *SymbolTableSection::getSymbolByIndex(uint32_t Index) {
- return const_cast<Symbol *>(
- static_cast<const SymbolTableSection *>(this)->getSymbolByIndex(Index));
-}
-
-template <class ELFT>
-void ELFSectionWriter<ELFT>::visit(const SymbolTableSection &Sec) {
- Elf_Sym *Sym = reinterpret_cast<Elf_Sym *>(Out.getBufferStart() + Sec.Offset);
- // Loop though symbols setting each entry of the symbol table.
- for (const std::unique_ptr<Symbol> &Symbol : Sec.Symbols) {
- Sym->st_name = Symbol->NameIndex;
- Sym->st_value = Symbol->Value;
- Sym->st_size = Symbol->Size;
- Sym->st_other = Symbol->Visibility;
- Sym->setBinding(Symbol->Binding);
- Sym->setType(Symbol->Type);
- Sym->st_shndx = Symbol->getShndx();
- ++Sym;
- }
-}
-
-void SymbolTableSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void SymbolTableSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-Error RelocationSection::removeSectionReferences(
- bool AllowBrokenLinks,
- function_ref<bool(const SectionBase *)> ToRemove) {
- if (ToRemove(Symbols)) {
- if (!AllowBrokenLinks)
- return createStringError(
- llvm::errc::invalid_argument,
- "symbol table '%s' cannot be removed because it is "
- "referenced by the relocation section '%s'",
- Symbols->Name.data(), this->Name.data());
- Symbols = nullptr;
- }
-
- for (const Relocation &R : Relocations) {
- if (!R.RelocSymbol->DefinedIn || !ToRemove(R.RelocSymbol->DefinedIn))
- continue;
- return createStringError(llvm::errc::invalid_argument,
- "section '%s' cannot be removed: (%s+0x%" PRIx64
- ") has relocation against symbol '%s'",
- R.RelocSymbol->DefinedIn->Name.data(),
- SecToApplyRel->Name.data(), R.Offset,
- R.RelocSymbol->Name.c_str());
- }
-
- return Error::success();
-}
-
-template <class SymTabType>
-void RelocSectionWithSymtabBase<SymTabType>::initialize(
- SectionTableRef SecTable) {
- if (Link != SHN_UNDEF)
- setSymTab(SecTable.getSectionOfType<SymTabType>(
- Link,
- "Link field value " + Twine(Link) + " in section " + Name +
- " is invalid",
- "Link field value " + Twine(Link) + " in section " + Name +
- " is not a symbol table"));
-
- if (Info != SHN_UNDEF)
- setSection(SecTable.getSection(Info, "Info field value " + Twine(Info) +
- " in section " + Name +
- " is invalid"));
- else
- setSection(nullptr);
-}
-
-template <class SymTabType>
-void RelocSectionWithSymtabBase<SymTabType>::finalize() {
- this->Link = Symbols ? Symbols->Index : 0;
-
- if (SecToApplyRel != nullptr)
- this->Info = SecToApplyRel->Index;
-}
-
-template <class ELFT>
-static void setAddend(Elf_Rel_Impl<ELFT, false> &Rel, uint64_t Addend) {}
-
-template <class ELFT>
-static void setAddend(Elf_Rel_Impl<ELFT, true> &Rela, uint64_t Addend) {
- Rela.r_addend = Addend;
-}
-
-template <class RelRange, class T>
-static void writeRel(const RelRange &Relocations, T *Buf) {
- for (const auto &Reloc : Relocations) {
- Buf->r_offset = Reloc.Offset;
- setAddend(*Buf, Reloc.Addend);
- Buf->setSymbolAndType(Reloc.RelocSymbol->Index, Reloc.Type, false);
- ++Buf;
- }
-}
-
-template <class ELFT>
-void ELFSectionWriter<ELFT>::visit(const RelocationSection &Sec) {
- uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
- if (Sec.Type == SHT_REL)
- writeRel(Sec.Relocations, reinterpret_cast<Elf_Rel *>(Buf));
- else
- writeRel(Sec.Relocations, reinterpret_cast<Elf_Rela *>(Buf));
-}
-
-void RelocationSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void RelocationSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-Error RelocationSection::removeSymbols(
- function_ref<bool(const Symbol &)> ToRemove) {
- for (const Relocation &Reloc : Relocations)
- if (ToRemove(*Reloc.RelocSymbol))
- return createStringError(
- llvm::errc::invalid_argument,
- "not stripping symbol '%s' because it is named in a relocation",
- Reloc.RelocSymbol->Name.data());
- return Error::success();
-}
-
-void RelocationSection::markSymbols() {
- for (const Relocation &Reloc : Relocations)
- Reloc.RelocSymbol->Referenced = true;
-}
-
-void RelocationSection::replaceSectionReferences(
- const DenseMap<SectionBase *, SectionBase *> &FromTo) {
- // Update the target section if it was replaced.
- if (SectionBase *To = FromTo.lookup(SecToApplyRel))
- SecToApplyRel = To;
-}
-
-void SectionWriter::visit(const DynamicRelocationSection &Sec) {
- llvm::copy(Sec.Contents, Out.getBufferStart() + Sec.Offset);
-}
-
-void DynamicRelocationSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void DynamicRelocationSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-Error DynamicRelocationSection::removeSectionReferences(
- bool AllowBrokenLinks, function_ref<bool(const SectionBase *)> ToRemove) {
- if (ToRemove(Symbols)) {
- if (!AllowBrokenLinks)
- return createStringError(
- llvm::errc::invalid_argument,
- "symbol table '%s' cannot be removed because it is "
- "referenced by the relocation section '%s'",
- Symbols->Name.data(), this->Name.data());
- Symbols = nullptr;
- }
-
- // SecToApplyRel contains a section referenced by sh_info field. It keeps
- // a section to which the relocation section applies. When we remove any
- // sections we also remove their relocation sections. Since we do that much
- // earlier, this assert should never be triggered.
- assert(!SecToApplyRel || !ToRemove(SecToApplyRel));
- return Error::success();
-}
-
-Error Section::removeSectionReferences(
- bool AllowBrokenDependency,
- function_ref<bool(const SectionBase *)> ToRemove) {
- if (ToRemove(LinkSection)) {
- if (!AllowBrokenDependency)
- return createStringError(llvm::errc::invalid_argument,
- "section '%s' cannot be removed because it is "
- "referenced by the section '%s'",
- LinkSection->Name.data(), this->Name.data());
- LinkSection = nullptr;
- }
- return Error::success();
-}
-
-void GroupSection::finalize() {
- this->Info = Sym->Index;
- this->Link = SymTab->Index;
-}
-
-Error GroupSection::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
- if (ToRemove(*Sym))
- return createStringError(llvm::errc::invalid_argument,
- "symbol '%s' cannot be removed because it is "
- "referenced by the section '%s[%d]'",
- Sym->Name.data(), this->Name.data(), this->Index);
- return Error::success();
-}
-
-void GroupSection::markSymbols() {
- if (Sym)
- Sym->Referenced = true;
-}
-
-void GroupSection::replaceSectionReferences(
- const DenseMap<SectionBase *, SectionBase *> &FromTo) {
- for (SectionBase *&Sec : GroupMembers)
- if (SectionBase *To = FromTo.lookup(Sec))
- Sec = To;
-}
-
-void Section::initialize(SectionTableRef SecTable) {
- if (Link == ELF::SHN_UNDEF)
- return;
- LinkSection =
- SecTable.getSection(Link, "Link field value " + Twine(Link) +
- " in section " + Name + " is invalid");
- if (LinkSection->Type == ELF::SHT_SYMTAB)
- LinkSection = nullptr;
-}
-
-void Section::finalize() { this->Link = LinkSection ? LinkSection->Index : 0; }
-
-void GnuDebugLinkSection::init(StringRef File) {
- FileName = sys::path::filename(File);
- // The format for the .gnu_debuglink starts with the file name and is
- // followed by a null terminator and then the CRC32 of the file. The CRC32
- // should be 4 byte aligned. So we add the FileName size, a 1 for the null
- // byte, and then finally push the size to alignment and add 4.
- Size = alignTo(FileName.size() + 1, 4) + 4;
- // The CRC32 will only be aligned if we align the whole section.
- Align = 4;
- Type = ELF::SHT_PROGBITS;
- Name = ".gnu_debuglink";
- // For sections not found in segments, OriginalOffset is only used to
- // establish the order that sections should go in. By using the maximum
- // possible offset we cause this section to wind up at the end.
- OriginalOffset = std::numeric_limits<uint64_t>::max();
-}
-
-GnuDebugLinkSection::GnuDebugLinkSection(StringRef File,
- uint32_t PrecomputedCRC)
- : FileName(File), CRC32(PrecomputedCRC) {
- init(File);
-}
-
-template <class ELFT>
-void ELFSectionWriter<ELFT>::visit(const GnuDebugLinkSection &Sec) {
- unsigned char *Buf = Out.getBufferStart() + Sec.Offset;
- Elf_Word *CRC =
- reinterpret_cast<Elf_Word *>(Buf + Sec.Size - sizeof(Elf_Word));
- *CRC = Sec.CRC32;
- llvm::copy(Sec.FileName, Buf);
-}
-
-void GnuDebugLinkSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void GnuDebugLinkSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-template <class ELFT>
-void ELFSectionWriter<ELFT>::visit(const GroupSection &Sec) {
- ELF::Elf32_Word *Buf =
- reinterpret_cast<ELF::Elf32_Word *>(Out.getBufferStart() + Sec.Offset);
- *Buf++ = Sec.FlagWord;
- for (SectionBase *S : Sec.GroupMembers)
- support::endian::write32<ELFT::TargetEndianness>(Buf++, S->Index);
-}
-
-void GroupSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
-void GroupSection::accept(MutableSectionVisitor &Visitor) {
- Visitor.visit(*this);
-}
-
-// Returns true IFF a section is wholly inside the range of a segment
-static bool sectionWithinSegment(const SectionBase &Section,
- const Segment &Segment) {
- // If a section is empty it should be treated like it has a size of 1. This is
- // to clarify the case when an empty section lies on a boundary between two
- // segments and ensures that the section "belongs" to the second segment and
- // not the first.
- uint64_t SecSize = Section.Size ? Section.Size : 1;
-
- if (Section.Type == SHT_NOBITS) {
- if (!(Section.Flags & SHF_ALLOC))
- return false;
-
- bool SectionIsTLS = Section.Flags & SHF_TLS;
- bool SegmentIsTLS = Segment.Type == PT_TLS;
- if (SectionIsTLS != SegmentIsTLS)
- return false;
-
- return Segment.VAddr <= Section.Addr &&
- Segment.VAddr + Segment.MemSize >= Section.Addr + SecSize;
- }
-
- return Segment.Offset <= Section.OriginalOffset &&
- Segment.Offset + Segment.FileSize >= Section.OriginalOffset + SecSize;
-}
-
-// Returns true IFF a segment's original offset is inside of another segment's
-// range.
-static bool segmentOverlapsSegment(const Segment &Child,
- const Segment &Parent) {
-
- return Parent.OriginalOffset <= Child.OriginalOffset &&
- Parent.OriginalOffset + Parent.FileSize > Child.OriginalOffset;
-}
-
-static bool compareSegmentsByOffset(const Segment *A, const Segment *B) {
- // Any segment without a parent segment should come before a segment
- // that has a parent segment.
- if (A->OriginalOffset < B->OriginalOffset)
- return true;
- if (A->OriginalOffset > B->OriginalOffset)
- return false;
- return A->Index < B->Index;
-}
-
-static bool compareSegmentsByPAddr(const Segment *A, const Segment *B) {
- if (A->PAddr < B->PAddr)
- return true;
- if (A->PAddr > B->PAddr)
- return false;
- return A->Index < B->Index;
-}
-
-void BasicELFBuilder::initFileHeader() {
- Obj->Flags = 0x0;
- Obj->Type = ET_REL;
- Obj->OSABI = ELFOSABI_NONE;
- Obj->ABIVersion = 0;
- Obj->Entry = 0x0;
- Obj->Machine = EMachine;
- Obj->Version = 1;
-}
-
-void BasicELFBuilder::initHeaderSegment() { Obj->ElfHdrSegment.Index = 0; }
-
-StringTableSection *BasicELFBuilder::addStrTab() {
- auto &StrTab = Obj->addSection<StringTableSection>();
- StrTab.Name = ".strtab";
-
- Obj->SectionNames = &StrTab;
- return &StrTab;
-}
-
-SymbolTableSection *BasicELFBuilder::addSymTab(StringTableSection *StrTab) {
- auto &SymTab = Obj->addSection<SymbolTableSection>();
-
- SymTab.Name = ".symtab";
- SymTab.Link = StrTab->Index;
-
- // The symbol table always needs a null symbol
- SymTab.addSymbol("", 0, 0, nullptr, 0, 0, 0, 0);
-
- Obj->SymbolTable = &SymTab;
- return &SymTab;
-}
-
-void BasicELFBuilder::initSections() {
- for (auto &Section : Obj->sections())
- Section.initialize(Obj->sections());
-}
-
-void BinaryELFBuilder::addData(SymbolTableSection *SymTab) {
- auto Data = ArrayRef<uint8_t>(
- reinterpret_cast<const uint8_t *>(MemBuf->getBufferStart()),
- MemBuf->getBufferSize());
- auto &DataSection = Obj->addSection<Section>(Data);
- DataSection.Name = ".data";
- DataSection.Type = ELF::SHT_PROGBITS;
- DataSection.Size = Data.size();
- DataSection.Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE;
-
- std::string SanitizedFilename = MemBuf->getBufferIdentifier().str();
- std::replace_if(std::begin(SanitizedFilename), std::end(SanitizedFilename),
- [](char C) { return !isalnum(C); }, '_');
- Twine Prefix = Twine("_binary_") + SanitizedFilename;
-
- SymTab->addSymbol(Prefix + "_start", STB_GLOBAL, STT_NOTYPE, &DataSection,
- /*Value=*/0, STV_DEFAULT, 0, 0);
- SymTab->addSymbol(Prefix + "_end", STB_GLOBAL, STT_NOTYPE, &DataSection,
- /*Value=*/DataSection.Size, STV_DEFAULT, 0, 0);
- SymTab->addSymbol(Prefix + "_size", STB_GLOBAL, STT_NOTYPE, nullptr,
- /*Value=*/DataSection.Size, STV_DEFAULT, SHN_ABS, 0);
-}
-
-std::unique_ptr<Object> BinaryELFBuilder::build() {
- initFileHeader();
- initHeaderSegment();
-
- SymbolTableSection *SymTab = addSymTab(addStrTab());
- initSections();
- addData(SymTab);
-
- return std::move(Obj);
-}
-
-// Adds sections from IHEX data file. Data should have been
-// fully validated by this time.
-void IHexELFBuilder::addDataSections() {
- OwnedDataSection *Section = nullptr;
- uint64_t SegmentAddr = 0, BaseAddr = 0;
- uint32_t SecNo = 1;
-
- for (const IHexRecord &R : Records) {
- uint64_t RecAddr;
- switch (R.Type) {
- case IHexRecord::Data:
- // Ignore empty data records
- if (R.HexData.empty())
- continue;
- RecAddr = R.Addr + SegmentAddr + BaseAddr;
- if (!Section || Section->Addr + Section->Size != RecAddr)
- // OriginalOffset field is only used to sort section properly, so
- // instead of keeping track of real offset in IHEX file, we use
- // section number.
- Section = &Obj->addSection<OwnedDataSection>(
- ".sec" + std::to_string(SecNo++), RecAddr,
- ELF::SHF_ALLOC | ELF::SHF_WRITE, SecNo);
- Section->appendHexData(R.HexData);
- break;
- case IHexRecord::EndOfFile:
- break;
- case IHexRecord::SegmentAddr:
- // 20-bit segment address.
- SegmentAddr = checkedGetHex<uint16_t>(R.HexData) << 4;
- break;
- case IHexRecord::StartAddr80x86:
- case IHexRecord::StartAddr:
- Obj->Entry = checkedGetHex<uint32_t>(R.HexData);
- assert(Obj->Entry <= 0xFFFFFU);
- break;
- case IHexRecord::ExtendedAddr:
- // 16-31 bits of linear base address
- BaseAddr = checkedGetHex<uint16_t>(R.HexData) << 16;
- break;
- default:
- llvm_unreachable("unknown record type");
- }
- }
-}
-
-std::unique_ptr<Object> IHexELFBuilder::build() {
- initFileHeader();
- initHeaderSegment();
- StringTableSection *StrTab = addStrTab();
- addSymTab(StrTab);
- initSections();
- addDataSections();
-
- return std::move(Obj);
-}
-
-template <class ELFT> void ELFBuilder<ELFT>::setParentSegment(Segment &Child) {
- for (Segment &Parent : Obj.segments()) {
- // Every segment will overlap with itself but we don't want a segment to
- // be it's own parent so we avoid that situation.
- if (&Child != &Parent && segmentOverlapsSegment(Child, Parent)) {
- // We want a canonical "most parental" segment but this requires
- // inspecting the ParentSegment.
- if (compareSegmentsByOffset(&Parent, &Child))
- if (Child.ParentSegment == nullptr ||
- compareSegmentsByOffset(&Parent, Child.ParentSegment)) {
- Child.ParentSegment = &Parent;
- }
- }
- }
-}
-
-template <class ELFT> void ELFBuilder<ELFT>::findEhdrOffset() {
- if (!ExtractPartition)
- return;
-
- for (const SectionBase &Section : Obj.sections()) {
- if (Section.Type == SHT_LLVM_PART_EHDR &&
- Section.Name == *ExtractPartition) {
- EhdrOffset = Section.Offset;
- return;
- }
- }
- error("could not find partition named '" + *ExtractPartition + "'");
-}
-
-template <class ELFT>
-void ELFBuilder<ELFT>::readProgramHeaders(const ELFFile<ELFT> &HeadersFile) {
- uint32_t Index = 0;
- for (const auto &Phdr : unwrapOrError(HeadersFile.program_headers())) {
- if (Phdr.p_offset + Phdr.p_filesz > HeadersFile.getBufSize())
- error("program header with offset 0x" + Twine::utohexstr(Phdr.p_offset) +
- " and file size 0x" + Twine::utohexstr(Phdr.p_filesz) +
- " goes past the end of the file");
-
- ArrayRef<uint8_t> Data{HeadersFile.base() + Phdr.p_offset,
- (size_t)Phdr.p_filesz};
- Segment &Seg = Obj.addSegment(Data);
- Seg.Type = Phdr.p_type;
- Seg.Flags = Phdr.p_flags;
- Seg.OriginalOffset = Phdr.p_offset + EhdrOffset;
- Seg.Offset = Phdr.p_offset + EhdrOffset;
- Seg.VAddr = Phdr.p_vaddr;
- Seg.PAddr = Phdr.p_paddr;
- Seg.FileSize = Phdr.p_filesz;
- Seg.MemSize = Phdr.p_memsz;
- Seg.Align = Phdr.p_align;
- Seg.Index = Index++;
- for (SectionBase &Section : Obj.sections()) {
- if (sectionWithinSegment(Section, Seg)) {
- Seg.addSection(&Section);
- if (!Section.ParentSegment ||
- Section.ParentSegment->Offset > Seg.Offset) {
- Section.ParentSegment = &Seg;
- }
- }
- }
- }
-
- auto &ElfHdr = Obj.ElfHdrSegment;
- ElfHdr.Index = Index++;
- ElfHdr.OriginalOffset = ElfHdr.Offset = EhdrOffset;
-
- const auto &Ehdr = *HeadersFile.getHeader();
- auto &PrHdr = Obj.ProgramHdrSegment;
- PrHdr.Type = PT_PHDR;
- PrHdr.Flags = 0;
- // The spec requires us to have p_vaddr % p_align == p_offset % p_align.
- // Whereas this works automatically for ElfHdr, here OriginalOffset is
- // always non-zero and to ensure the equation we assign the same value to
- // VAddr as well.
- PrHdr.OriginalOffset = PrHdr.Offset = PrHdr.VAddr = EhdrOffset + Ehdr.e_phoff;
- PrHdr.PAddr = 0;
- PrHdr.FileSize = PrHdr.MemSize = Ehdr.e_phentsize * Ehdr.e_phnum;
- // The spec requires us to naturally align all the fields.
- PrHdr.Align = sizeof(Elf_Addr);
- PrHdr.Index = Index++;
-
- // Now we do an O(n^2) loop through the segments in order to match up
- // segments.
- for (Segment &Child : Obj.segments())
- setParentSegment(Child);
- setParentSegment(ElfHdr);
- setParentSegment(PrHdr);
-}
-
-template <class ELFT>
-void ELFBuilder<ELFT>::initGroupSection(GroupSection *GroupSec) {
- if (GroupSec->Align % sizeof(ELF::Elf32_Word) != 0)
- error("invalid alignment " + Twine(GroupSec->Align) + " of group section '" +
- GroupSec->Name + "'");
- SectionTableRef SecTable = Obj.sections();
- auto SymTab = SecTable.template getSectionOfType<SymbolTableSection>(
- GroupSec->Link,
- "link field value '" + Twine(GroupSec->Link) + "' in section '" +
- GroupSec->Name + "' is invalid",
- "link field value '" + Twine(GroupSec->Link) + "' in section '" +
- GroupSec->Name + "' is not a symbol table");
- Symbol *Sym = SymTab->getSymbolByIndex(GroupSec->Info);
- if (!Sym)
- error("info field value '" + Twine(GroupSec->Info) + "' in section '" +
- GroupSec->Name + "' is not a valid symbol index");
- GroupSec->setSymTab(SymTab);
- GroupSec->setSymbol(Sym);
- if (GroupSec->Contents.size() % sizeof(ELF::Elf32_Word) ||
- GroupSec->Contents.empty())
- error("the content of the section " + GroupSec->Name + " is malformed");
- const ELF::Elf32_Word *Word =
- reinterpret_cast<const ELF::Elf32_Word *>(GroupSec->Contents.data());
- const ELF::Elf32_Word *End =
- Word + GroupSec->Contents.size() / sizeof(ELF::Elf32_Word);
- GroupSec->setFlagWord(*Word++);
- for (; Word != End; ++Word) {
- uint32_t Index = support::endian::read32<ELFT::TargetEndianness>(Word);
- GroupSec->addMember(SecTable.getSection(
- Index, "group member index " + Twine(Index) + " in section '" +
- GroupSec->Name + "' is invalid"));
- }
-}
-
-template <class ELFT>
-void ELFBuilder<ELFT>::initSymbolTable(SymbolTableSection *SymTab) {
- const Elf_Shdr &Shdr = *unwrapOrError(ElfFile.getSection(SymTab->Index));
- StringRef StrTabData = unwrapOrError(ElfFile.getStringTableForSymtab(Shdr));
- ArrayRef<Elf_Word> ShndxData;
-
- auto Symbols = unwrapOrError(ElfFile.symbols(&Shdr));
- for (const auto &Sym : Symbols) {
- SectionBase *DefSection = nullptr;
- StringRef Name = unwrapOrError(Sym.getName(StrTabData));
-
- if (Sym.st_shndx == SHN_XINDEX) {
- if (SymTab->getShndxTable() == nullptr)
- error("symbol '" + Name +
- "' has index SHN_XINDEX but no SHT_SYMTAB_SHNDX section exists");
- if (ShndxData.data() == nullptr) {
- const Elf_Shdr &ShndxSec =
- *unwrapOrError(ElfFile.getSection(SymTab->getShndxTable()->Index));
- ShndxData = unwrapOrError(
- ElfFile.template getSectionContentsAsArray<Elf_Word>(&ShndxSec));
- if (ShndxData.size() != Symbols.size())
- error("symbol section index table does not have the same number of "
- "entries as the symbol table");
- }
- Elf_Word Index = ShndxData[&Sym - Symbols.begin()];
- DefSection = Obj.sections().getSection(
- Index,
- "symbol '" + Name + "' has invalid section index " + Twine(Index));
- } else if (Sym.st_shndx >= SHN_LORESERVE) {
- if (!isValidReservedSectionIndex(Sym.st_shndx, Obj.Machine)) {
- error(
- "symbol '" + Name +
- "' has unsupported value greater than or equal to SHN_LORESERVE: " +
- Twine(Sym.st_shndx));
- }
- } else if (Sym.st_shndx != SHN_UNDEF) {
- DefSection = Obj.sections().getSection(
- Sym.st_shndx, "symbol '" + Name +
- "' is defined has invalid section index " +
- Twine(Sym.st_shndx));
- }
-
- SymTab->addSymbol(Name, Sym.getBinding(), Sym.getType(), DefSection,
- Sym.getValue(), Sym.st_other, Sym.st_shndx, Sym.st_size);
- }
-}
-
-template <class ELFT>
-static void getAddend(uint64_t &ToSet, const Elf_Rel_Impl<ELFT, false> &Rel) {}
-
-template <class ELFT>
-static void getAddend(uint64_t &ToSet, const Elf_Rel_Impl<ELFT, true> &Rela) {
- ToSet = Rela.r_addend;
-}
-
-template <class T>
-static void initRelocations(RelocationSection *Relocs,
- SymbolTableSection *SymbolTable, T RelRange) {
- for (const auto &Rel : RelRange) {
- Relocation ToAdd;
- ToAdd.Offset = Rel.r_offset;
- getAddend(ToAdd.Addend, Rel);
- ToAdd.Type = Rel.getType(false);
- ToAdd.RelocSymbol = SymbolTable->getSymbolByIndex(Rel.getSymbol(false));
- Relocs->addRelocation(ToAdd);
- }
-}
-
-SectionBase *SectionTableRef::getSection(uint32_t Index, Twine ErrMsg) {
- if (Index == SHN_UNDEF || Index > Sections.size())
- error(ErrMsg);
- return Sections[Index - 1].get();
-}
-
-template <class T>
-T *SectionTableRef::getSectionOfType(uint32_t Index, Twine IndexErrMsg,
- Twine TypeErrMsg) {
- if (T *Sec = dyn_cast<T>(getSection(Index, IndexErrMsg)))
- return Sec;
- error(TypeErrMsg);
-}
-
-template <class ELFT>
-SectionBase &ELFBuilder<ELFT>::makeSection(const Elf_Shdr &Shdr) {
- ArrayRef<uint8_t> Data;
- switch (Shdr.sh_type) {
- case SHT_REL:
- case SHT_RELA:
- if (Shdr.sh_flags & SHF_ALLOC) {
- Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
- return Obj.addSection<DynamicRelocationSection>(Data);
- }
- return Obj.addSection<RelocationSection>();
- case SHT_STRTAB:
- // If a string table is allocated we don't want to mess with it. That would
- // mean altering the memory image. There are no special link types or
- // anything so we can just use a Section.
- if (Shdr.sh_flags & SHF_ALLOC) {
- Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
- return Obj.addSection<Section>(Data);
- }
- return Obj.addSection<StringTableSection>();
- case SHT_HASH:
- case SHT_GNU_HASH:
- // Hash tables should refer to SHT_DYNSYM which we're not going to change.
- // Because of this we don't need to mess with the hash tables either.
- Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
- return Obj.addSection<Section>(Data);
- case SHT_GROUP:
- Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
- return Obj.addSection<GroupSection>(Data);
- case SHT_DYNSYM:
- Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
- return Obj.addSection<DynamicSymbolTableSection>(Data);
- case SHT_DYNAMIC:
- Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
- return Obj.addSection<DynamicSection>(Data);
- case SHT_SYMTAB: {
- auto &SymTab = Obj.addSection<SymbolTableSection>();
- Obj.SymbolTable = &SymTab;
- return SymTab;
- }
- case SHT_SYMTAB_SHNDX: {
- auto &ShndxSection = Obj.addSection<SectionIndexSection>();
- Obj.SectionIndexTable = &ShndxSection;
- return ShndxSection;
- }
- case SHT_NOBITS:
- return Obj.addSection<Section>(Data);
- default: {
- Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
-
- StringRef Name = unwrapOrError(ElfFile.getSectionName(&Shdr));
- if (Name.startswith(".zdebug") || (Shdr.sh_flags & ELF::SHF_COMPRESSED)) {
- uint64_t DecompressedSize, DecompressedAlign;
- std::tie(DecompressedSize, DecompressedAlign) =
- getDecompressedSizeAndAlignment<ELFT>(Data);
- return Obj.addSection<CompressedSection>(Data, DecompressedSize,
- DecompressedAlign);
- }
-
- return Obj.addSection<Section>(Data);
- }
- }
-}
-
-template <class ELFT> void ELFBuilder<ELFT>::readSectionHeaders() {
- uint32_t Index = 0;
- for (const auto &Shdr : unwrapOrError(ElfFile.sections())) {
- if (Index == 0) {
- ++Index;
- continue;
- }
- auto &Sec = makeSection(Shdr);
- Sec.Name = unwrapOrError(ElfFile.getSectionName(&Shdr));
- Sec.Type = Shdr.sh_type;
- Sec.Flags = Shdr.sh_flags;
- Sec.Addr = Shdr.sh_addr;
- Sec.Offset = Shdr.sh_offset;
- Sec.OriginalOffset = Shdr.sh_offset;
- Sec.Size = Shdr.sh_size;
- Sec.Link = Shdr.sh_link;
- Sec.Info = Shdr.sh_info;
- Sec.Align = Shdr.sh_addralign;
- Sec.EntrySize = Shdr.sh_entsize;
- Sec.Index = Index++;
- Sec.OriginalData =
- ArrayRef<uint8_t>(ElfFile.base() + Shdr.sh_offset,
- (Shdr.sh_type == SHT_NOBITS) ? 0 : Shdr.sh_size);
- }
-}
-
-template <class ELFT> void ELFBuilder<ELFT>::readSections() {
- // If a section index table exists we'll need to initialize it before we
- // initialize the symbol table because the symbol table might need to
- // reference it.
- if (Obj.SectionIndexTable)
- Obj.SectionIndexTable->initialize(Obj.sections());
-
- // Now that all of the sections have been added we can fill out some extra
- // details about symbol tables. We need the symbol table filled out before
- // any relocations.
- if (Obj.SymbolTable) {
- Obj.SymbolTable->initialize(Obj.sections());
- initSymbolTable(Obj.SymbolTable);
- }
-
- // Now that all sections and symbols have been added we can add
- // relocations that reference symbols and set the link and info fields for
- // relocation sections.
- for (auto &Section : Obj.sections()) {
- if (&Section == Obj.SymbolTable)
- continue;
- Section.initialize(Obj.sections());
- if (auto RelSec = dyn_cast<RelocationSection>(&Section)) {
- auto Shdr = unwrapOrError(ElfFile.sections()).begin() + RelSec->Index;
- if (RelSec->Type == SHT_REL)
- initRelocations(RelSec, Obj.SymbolTable,
- unwrapOrError(ElfFile.rels(Shdr)));
- else
- initRelocations(RelSec, Obj.SymbolTable,
- unwrapOrError(ElfFile.relas(Shdr)));
- } else if (auto GroupSec = dyn_cast<GroupSection>(&Section)) {
- initGroupSection(GroupSec);
- }
- }
-
- uint32_t ShstrIndex = ElfFile.getHeader()->e_shstrndx;
- if (ShstrIndex == SHN_XINDEX)
- ShstrIndex = unwrapOrError(ElfFile.getSection(0))->sh_link;
-
- if (ShstrIndex == SHN_UNDEF)
- Obj.HadShdrs = false;
- else
- Obj.SectionNames =
- Obj.sections().template getSectionOfType<StringTableSection>(
- ShstrIndex,
- "e_shstrndx field value " + Twine(ShstrIndex) + " in elf header " +
- " is invalid",
- "e_shstrndx field value " + Twine(ShstrIndex) + " in elf header " +
- " is not a string table");
-}
-
-template <class ELFT> void ELFBuilder<ELFT>::build() {
- readSectionHeaders();
- findEhdrOffset();
-
- // The ELFFile whose ELF headers and program headers are copied into the
- // output file. Normally the same as ElfFile, but if we're extracting a
- // loadable partition it will point to the partition's headers.
- ELFFile<ELFT> HeadersFile = unwrapOrError(ELFFile<ELFT>::create(toStringRef(
- {ElfFile.base() + EhdrOffset, ElfFile.getBufSize() - EhdrOffset})));
-
- auto &Ehdr = *HeadersFile.getHeader();
- Obj.OSABI = Ehdr.e_ident[EI_OSABI];
- Obj.ABIVersion = Ehdr.e_ident[EI_ABIVERSION];
- Obj.Type = Ehdr.e_type;
- Obj.Machine = Ehdr.e_machine;
- Obj.Version = Ehdr.e_version;
- Obj.Entry = Ehdr.e_entry;
- Obj.Flags = Ehdr.e_flags;
-
- readSections();
- readProgramHeaders(HeadersFile);
-}
-
-Writer::~Writer() {}
-
-Reader::~Reader() {}
-
-std::unique_ptr<Object> BinaryReader::create() const {
- return BinaryELFBuilder(MInfo.EMachine, MemBuf).build();
-}
-
-Expected<std::vector<IHexRecord>> IHexReader::parse() const {
- SmallVector<StringRef, 16> Lines;
- std::vector<IHexRecord> Records;
- bool HasSections = false;
-
- MemBuf->getBuffer().split(Lines, '\n');
- Records.reserve(Lines.size());
- for (size_t LineNo = 1; LineNo <= Lines.size(); ++LineNo) {
- StringRef Line = Lines[LineNo - 1].trim();
- if (Line.empty())
- continue;
-
- Expected<IHexRecord> R = IHexRecord::parse(Line);
- if (!R)
- return parseError(LineNo, R.takeError());
- if (R->Type == IHexRecord::EndOfFile)
- break;
- HasSections |= (R->Type == IHexRecord::Data);
- Records.push_back(*R);
- }
- if (!HasSections)
- return parseError(-1U, "no sections");
-
- return std::move(Records);
-}
-
-std::unique_ptr<Object> IHexReader::create() const {
- std::vector<IHexRecord> Records = unwrapOrError(parse());
- return IHexELFBuilder(Records).build();
-}
-
-std::unique_ptr<Object> ELFReader::create() const {
- auto Obj = llvm::make_unique<Object>();
- if (auto *O = dyn_cast<ELFObjectFile<ELF32LE>>(Bin)) {
- ELFBuilder<ELF32LE> Builder(*O, *Obj, ExtractPartition);
- Builder.build();
- return Obj;
- } else if (auto *O = dyn_cast<ELFObjectFile<ELF64LE>>(Bin)) {
- ELFBuilder<ELF64LE> Builder(*O, *Obj, ExtractPartition);
- Builder.build();
- return Obj;
- } else if (auto *O = dyn_cast<ELFObjectFile<ELF32BE>>(Bin)) {
- ELFBuilder<ELF32BE> Builder(*O, *Obj, ExtractPartition);
- Builder.build();
- return Obj;
- } else if (auto *O = dyn_cast<ELFObjectFile<ELF64BE>>(Bin)) {
- ELFBuilder<ELF64BE> Builder(*O, *Obj, ExtractPartition);
- Builder.build();
- return Obj;
- }
- error("invalid file type");
-}
-
-template <class ELFT> void ELFWriter<ELFT>::writeEhdr() {
- Elf_Ehdr &Ehdr = *reinterpret_cast<Elf_Ehdr *>(Buf.getBufferStart());
- std::fill(Ehdr.e_ident, Ehdr.e_ident + 16, 0);
- Ehdr.e_ident[EI_MAG0] = 0x7f;
- Ehdr.e_ident[EI_MAG1] = 'E';
- Ehdr.e_ident[EI_MAG2] = 'L';
- Ehdr.e_ident[EI_MAG3] = 'F';
- Ehdr.e_ident[EI_CLASS] = ELFT::Is64Bits ? ELFCLASS64 : ELFCLASS32;
- Ehdr.e_ident[EI_DATA] =
- ELFT::TargetEndianness == support::big ? ELFDATA2MSB : ELFDATA2LSB;
- Ehdr.e_ident[EI_VERSION] = EV_CURRENT;
- Ehdr.e_ident[EI_OSABI] = Obj.OSABI;
- Ehdr.e_ident[EI_ABIVERSION] = Obj.ABIVersion;
-
- Ehdr.e_type = Obj.Type;
- Ehdr.e_machine = Obj.Machine;
- Ehdr.e_version = Obj.Version;
- Ehdr.e_entry = Obj.Entry;
- // We have to use the fully-qualified name llvm::size
- // since some compilers complain on ambiguous resolution.
- Ehdr.e_phnum = llvm::size(Obj.segments());
- Ehdr.e_phoff = (Ehdr.e_phnum != 0) ? Obj.ProgramHdrSegment.Offset : 0;
- Ehdr.e_phentsize = (Ehdr.e_phnum != 0) ? sizeof(Elf_Phdr) : 0;
- Ehdr.e_flags = Obj.Flags;
- Ehdr.e_ehsize = sizeof(Elf_Ehdr);
- if (WriteSectionHeaders && Obj.sections().size() != 0) {
- Ehdr.e_shentsize = sizeof(Elf_Shdr);
- Ehdr.e_shoff = Obj.SHOffset;
- // """
- // If the number of sections is greater than or equal to
- // SHN_LORESERVE (0xff00), this member has the value zero and the actual
- // number of section header table entries is contained in the sh_size field
- // of the section header at index 0.
- // """
- auto Shnum = Obj.sections().size() + 1;
- if (Shnum >= SHN_LORESERVE)
- Ehdr.e_shnum = 0;
- else
- Ehdr.e_shnum = Shnum;
- // """
- // If the section name string table section index is greater than or equal
- // to SHN_LORESERVE (0xff00), this member has the value SHN_XINDEX (0xffff)
- // and the actual index of the section name string table section is
- // contained in the sh_link field of the section header at index 0.
- // """
- if (Obj.SectionNames->Index >= SHN_LORESERVE)
- Ehdr.e_shstrndx = SHN_XINDEX;
- else
- Ehdr.e_shstrndx = Obj.SectionNames->Index;
- } else {
- Ehdr.e_shentsize = 0;
- Ehdr.e_shoff = 0;
- Ehdr.e_shnum = 0;
- Ehdr.e_shstrndx = 0;
- }
-}
-
-template <class ELFT> void ELFWriter<ELFT>::writePhdrs() {
- for (auto &Seg : Obj.segments())
- writePhdr(Seg);
-}
-
-template <class ELFT> void ELFWriter<ELFT>::writeShdrs() {
- // This reference serves to write the dummy section header at the begining
- // of the file. It is not used for anything else
- Elf_Shdr &Shdr =
- *reinterpret_cast<Elf_Shdr *>(Buf.getBufferStart() + Obj.SHOffset);
- Shdr.sh_name = 0;
- Shdr.sh_type = SHT_NULL;
- Shdr.sh_flags = 0;
- Shdr.sh_addr = 0;
- Shdr.sh_offset = 0;
- // See writeEhdr for why we do this.
- uint64_t Shnum = Obj.sections().size() + 1;
- if (Shnum >= SHN_LORESERVE)
- Shdr.sh_size = Shnum;
- else
- Shdr.sh_size = 0;
- // See writeEhdr for why we do this.
- if (Obj.SectionNames != nullptr && Obj.SectionNames->Index >= SHN_LORESERVE)
- Shdr.sh_link = Obj.SectionNames->Index;
- else
- Shdr.sh_link = 0;
- Shdr.sh_info = 0;
- Shdr.sh_addralign = 0;
- Shdr.sh_entsize = 0;
-
- for (SectionBase &Sec : Obj.sections())
- writeShdr(Sec);
-}
-
-template <class ELFT> void ELFWriter<ELFT>::writeSectionData() {
- for (SectionBase &Sec : Obj.sections())
- // Segments are responsible for writing their contents, so only write the
- // section data if the section is not in a segment. Note that this renders
- // sections in segments effectively immutable.
- if (Sec.ParentSegment == nullptr)
- Sec.accept(*SecWriter);
-}
-
-template <class ELFT> void ELFWriter<ELFT>::writeSegmentData() {
- for (Segment &Seg : Obj.segments()) {
- uint8_t *B = Buf.getBufferStart() + Seg.Offset;
- assert(Seg.FileSize == Seg.getContents().size() &&
- "Segment size must match contents size");
- std::memcpy(B, Seg.getContents().data(), Seg.FileSize);
- }
-
- // Iterate over removed sections and overwrite their old data with zeroes.
- for (auto &Sec : Obj.removedSections()) {
- Segment *Parent = Sec.ParentSegment;
- if (Parent == nullptr || Sec.Type == SHT_NOBITS || Sec.Size == 0)
- continue;
- uint64_t Offset =
- Sec.OriginalOffset - Parent->OriginalOffset + Parent->Offset;
- std::memset(Buf.getBufferStart() + Offset, 0, Sec.Size);
- }
-}
-
-template <class ELFT>
-ELFWriter<ELFT>::ELFWriter(Object &Obj, Buffer &Buf, bool WSH)
- : Writer(Obj, Buf), WriteSectionHeaders(WSH && Obj.HadShdrs) {}
-
-Error Object::removeSections(bool AllowBrokenLinks,
- std::function<bool(const SectionBase &)> ToRemove) {
-
- auto Iter = std::stable_partition(
- std::begin(Sections), std::end(Sections), [=](const SecPtr &Sec) {
- if (ToRemove(*Sec))
- return false;
- if (auto RelSec = dyn_cast<RelocationSectionBase>(Sec.get())) {
- if (auto ToRelSec = RelSec->getSection())
- return !ToRemove(*ToRelSec);
- }
- return true;
- });
- if (SymbolTable != nullptr && ToRemove(*SymbolTable))
- SymbolTable = nullptr;
- if (SectionNames != nullptr && ToRemove(*SectionNames))
- SectionNames = nullptr;
- if (SectionIndexTable != nullptr && ToRemove(*SectionIndexTable))
- SectionIndexTable = nullptr;
- // Now make sure there are no remaining references to the sections that will
- // be removed. Sometimes it is impossible to remove a reference so we emit
- // an error here instead.
- std::unordered_set<const SectionBase *> RemoveSections;
- RemoveSections.reserve(std::distance(Iter, std::end(Sections)));
- for (auto &RemoveSec : make_range(Iter, std::end(Sections))) {
- for (auto &Segment : Segments)
- Segment->removeSection(RemoveSec.get());
- RemoveSections.insert(RemoveSec.get());
- }
-
- // For each section that remains alive, we want to remove the dead references.
- // This either might update the content of the section (e.g. remove symbols
- // from symbol table that belongs to removed section) or trigger an error if
- // a live section critically depends on a section being removed somehow
- // (e.g. the removed section is referenced by a relocation).
- for (auto &KeepSec : make_range(std::begin(Sections), Iter)) {
- if (Error E = KeepSec->removeSectionReferences(AllowBrokenLinks,
- [&RemoveSections](const SectionBase *Sec) {
- return RemoveSections.find(Sec) != RemoveSections.end();
- }))
- return E;
- }
-
- // Transfer removed sections into the Object RemovedSections container for use
- // later.
- std::move(Iter, Sections.end(), std::back_inserter(RemovedSections));
- // Now finally get rid of them all together.
- Sections.erase(Iter, std::end(Sections));
- return Error::success();
-}
-
-Error Object::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
- if (SymbolTable)
- for (const SecPtr &Sec : Sections)
- if (Error E = Sec->removeSymbols(ToRemove))
- return E;
- return Error::success();
-}
-
-void Object::sortSections() {
- // Use stable_sort to maintain the original ordering as closely as possible.
- llvm::stable_sort(Sections, [](const SecPtr &A, const SecPtr &B) {
- // Put SHT_GROUP sections first, since group section headers must come
- // before the sections they contain. This also matches what GNU objcopy
- // does.
- if (A->Type != B->Type &&
- (A->Type == ELF::SHT_GROUP || B->Type == ELF::SHT_GROUP))
- return A->Type == ELF::SHT_GROUP;
- // For all other sections, sort by offset order.
- return A->OriginalOffset < B->OriginalOffset;
- });
-}
-
-static uint64_t alignToAddr(uint64_t Offset, uint64_t Addr, uint64_t Align) {
- // Calculate Diff such that (Offset + Diff) & -Align == Addr & -Align.
- if (Align == 0)
- Align = 1;
- auto Diff =
- static_cast<int64_t>(Addr % Align) - static_cast<int64_t>(Offset % Align);
- // We only want to add to Offset, however, so if Diff < 0 we can add Align and
- // (Offset + Diff) & -Align == Addr & -Align will still hold.
- if (Diff < 0)
- Diff += Align;
- return Offset + Diff;
-}
-
-// Orders segments such that if x = y->ParentSegment then y comes before x.
-static void orderSegments(std::vector<Segment *> &Segments) {
- llvm::stable_sort(Segments, compareSegmentsByOffset);
-}
-
-// This function finds a consistent layout for a list of segments starting from
-// an Offset. It assumes that Segments have been sorted by OrderSegments and
-// returns an Offset one past the end of the last segment.
-static uint64_t layoutSegments(std::vector<Segment *> &Segments,
- uint64_t Offset) {
- assert(std::is_sorted(std::begin(Segments), std::end(Segments),
- compareSegmentsByOffset));
- // The only way a segment should move is if a section was between two
- // segments and that section was removed. If that section isn't in a segment
- // then it's acceptable, but not ideal, to simply move it to after the
- // segments. So we can simply layout segments one after the other accounting
- // for alignment.
- for (Segment *Seg : Segments) {
- // We assume that segments have been ordered by OriginalOffset and Index
- // such that a parent segment will always come before a child segment in
- // OrderedSegments. This means that the Offset of the ParentSegment should
- // already be set and we can set our offset relative to it.
- if (Seg->ParentSegment != nullptr) {
- Segment *Parent = Seg->ParentSegment;
- Seg->Offset =
- Parent->Offset + Seg->OriginalOffset - Parent->OriginalOffset;
- } else {
- Offset = alignToAddr(Offset, Seg->VAddr, Seg->Align);
- Seg->Offset = Offset;
- }
- Offset = std::max(Offset, Seg->Offset + Seg->FileSize);
- }
- return Offset;
-}
-
-// This function finds a consistent layout for a list of sections. It assumes
-// that the ->ParentSegment of each section has already been laid out. The
-// supplied starting Offset is used for the starting offset of any section that
-// does not have a ParentSegment. It returns either the offset given if all
-// sections had a ParentSegment or an offset one past the last section if there
-// was a section that didn't have a ParentSegment.
-template <class Range>
-static uint64_t layoutSections(Range Sections, uint64_t Offset) {
- // Now the offset of every segment has been set we can assign the offsets
- // of each section. For sections that are covered by a segment we should use
- // the segment's original offset and the section's original offset to compute
- // the offset from the start of the segment. Using the offset from the start
- // of the segment we can assign a new offset to the section. For sections not
- // covered by segments we can just bump Offset to the next valid location.
- uint32_t Index = 1;
- for (auto &Section : Sections) {
- Section.Index = Index++;
- if (Section.ParentSegment != nullptr) {
- auto Segment = *Section.ParentSegment;
- Section.Offset =
- Segment.Offset + (Section.OriginalOffset - Segment.OriginalOffset);
- } else {
- Offset = alignTo(Offset, Section.Align == 0 ? 1 : Section.Align);
- Section.Offset = Offset;
- if (Section.Type != SHT_NOBITS)
- Offset += Section.Size;
- }
- }
- return Offset;
-}
-
-template <class ELFT> void ELFWriter<ELFT>::initEhdrSegment() {
- Segment &ElfHdr = Obj.ElfHdrSegment;
- ElfHdr.Type = PT_PHDR;
- ElfHdr.Flags = 0;
- ElfHdr.VAddr = 0;
- ElfHdr.PAddr = 0;
- ElfHdr.FileSize = ElfHdr.MemSize = sizeof(Elf_Ehdr);
- ElfHdr.Align = 0;
-}
-
-template <class ELFT> void ELFWriter<ELFT>::assignOffsets() {
- // We need a temporary list of segments that has a special order to it
- // so that we know that anytime ->ParentSegment is set that segment has
- // already had its offset properly set.
- std::vector<Segment *> OrderedSegments;
- for (Segment &Segment : Obj.segments())
- OrderedSegments.push_back(&Segment);
- OrderedSegments.push_back(&Obj.ElfHdrSegment);
- OrderedSegments.push_back(&Obj.ProgramHdrSegment);
- orderSegments(OrderedSegments);
- // Offset is used as the start offset of the first segment to be laid out.
- // Since the ELF Header (ElfHdrSegment) must be at the start of the file,
- // we start at offset 0.
- uint64_t Offset = 0;
- Offset = layoutSegments(OrderedSegments, Offset);
- Offset = layoutSections(Obj.sections(), Offset);
- // If we need to write the section header table out then we need to align the
- // Offset so that SHOffset is valid.
- if (WriteSectionHeaders)
- Offset = alignTo(Offset, sizeof(Elf_Addr));
- Obj.SHOffset = Offset;
-}
-
-template <class ELFT> size_t ELFWriter<ELFT>::totalSize() const {
- // We already have the section header offset so we can calculate the total
- // size by just adding up the size of each section header.
- if (!WriteSectionHeaders)
- return Obj.SHOffset;
- size_t ShdrCount = Obj.sections().size() + 1; // Includes null shdr.
- return Obj.SHOffset + ShdrCount * sizeof(Elf_Shdr);
-}
-
-template <class ELFT> Error ELFWriter<ELFT>::write() {
- // Segment data must be written first, so that the ELF header and program
- // header tables can overwrite it, if covered by a segment.
- writeSegmentData();
- writeEhdr();
- writePhdrs();
- writeSectionData();
- if (WriteSectionHeaders)
- writeShdrs();
- return Buf.commit();
-}
-
-template <class ELFT> Error ELFWriter<ELFT>::finalize() {
- // It could happen that SectionNames has been removed and yet the user wants
- // a section header table output. We need to throw an error if a user tries
- // to do that.
- if (Obj.SectionNames == nullptr && WriteSectionHeaders)
- return createStringError(llvm::errc::invalid_argument,
- "cannot write section header table because "
- "section header string table was removed");
-
- Obj.sortSections();
-
- // We need to assign indexes before we perform layout because we need to know
- // if we need large indexes or not. We can assign indexes first and check as
- // we go to see if we will actully need large indexes.
- bool NeedsLargeIndexes = false;
- if (Obj.sections().size() >= SHN_LORESERVE) {
- SectionTableRef Sections = Obj.sections();
- NeedsLargeIndexes =
- std::any_of(Sections.begin() + SHN_LORESERVE, Sections.end(),
- [](const SectionBase &Sec) { return Sec.HasSymbol; });
- // TODO: handle case where only one section needs the large index table but
- // only needs it because the large index table hasn't been removed yet.
- }
-
- if (NeedsLargeIndexes) {
- // This means we definitely need to have a section index table but if we
- // already have one then we should use it instead of making a new one.
- if (Obj.SymbolTable != nullptr && Obj.SectionIndexTable == nullptr) {
- // Addition of a section to the end does not invalidate the indexes of
- // other sections and assigns the correct index to the new section.
- auto &Shndx = Obj.addSection<SectionIndexSection>();
- Obj.SymbolTable->setShndxTable(&Shndx);
- Shndx.setSymTab(Obj.SymbolTable);
- }
- } else {
- // Since we don't need SectionIndexTable we should remove it and all
- // references to it.
- if (Obj.SectionIndexTable != nullptr) {
- // We do not support sections referring to the section index table.
- if (Error E = Obj.removeSections(false /*AllowBrokenLinks*/,
- [this](const SectionBase &Sec) {
- return &Sec == Obj.SectionIndexTable;
- }))
- return E;
- }
- }
-
- // Make sure we add the names of all the sections. Importantly this must be
- // done after we decide to add or remove SectionIndexes.
- if (Obj.SectionNames != nullptr)
- for (const auto &Section : Obj.sections()) {
- Obj.SectionNames->addString(Section.Name);
- }
-
- initEhdrSegment();
-
- // Before we can prepare for layout the indexes need to be finalized.
- // Also, the output arch may not be the same as the input arch, so fix up
- // size-related fields before doing layout calculations.
- uint64_t Index = 0;
- auto SecSizer = llvm::make_unique<ELFSectionSizer<ELFT>>();
- for (auto &Sec : Obj.sections()) {
- Sec.Index = Index++;
- Sec.accept(*SecSizer);
- }
-
- // The symbol table does not update all other sections on update. For
- // instance, symbol names are not added as new symbols are added. This means
- // that some sections, like .strtab, don't yet have their final size.
- if (Obj.SymbolTable != nullptr)
- Obj.SymbolTable->prepareForLayout();
-
- // Now that all strings are added we want to finalize string table builders,
- // because that affects section sizes which in turn affects section offsets.
- for (SectionBase &Sec : Obj.sections())
- if (auto StrTab = dyn_cast<StringTableSection>(&Sec))
- StrTab->prepareForLayout();
-
- assignOffsets();
-
- // layoutSections could have modified section indexes, so we need
- // to fill the index table after assignOffsets.
- if (Obj.SymbolTable != nullptr)
- Obj.SymbolTable->fillShndxTable();
-
- // Finally now that all offsets and indexes have been set we can finalize any
- // remaining issues.
- uint64_t Offset = Obj.SHOffset + sizeof(Elf_Shdr);
- for (SectionBase &Section : Obj.sections()) {
- Section.HeaderOffset = Offset;
- Offset += sizeof(Elf_Shdr);
- if (WriteSectionHeaders)
- Section.NameIndex = Obj.SectionNames->findIndex(Section.Name);
- Section.finalize();
- }
-
- if (Error E = Buf.allocate(totalSize()))
- return E;
- SecWriter = llvm::make_unique<ELFSectionWriter<ELFT>>(Buf);
- return Error::success();
-}
-
-Error BinaryWriter::write() {
- for (auto &Section : Obj.sections())
- if (Section.Flags & SHF_ALLOC)
- Section.accept(*SecWriter);
- return Buf.commit();
-}
-
-Error BinaryWriter::finalize() {
- // TODO: Create a filter range to construct OrderedSegments from so that this
- // code can be deduped with assignOffsets above. This should also solve the
- // todo below for LayoutSections.
- // We need a temporary list of segments that has a special order to it
- // so that we know that anytime ->ParentSegment is set that segment has
- // already had it's offset properly set. We only want to consider the segments
- // that will affect layout of allocated sections so we only add those.
- std::vector<Segment *> OrderedSegments;
- for (SectionBase &Section : Obj.sections())
- if ((Section.Flags & SHF_ALLOC) != 0 && Section.ParentSegment != nullptr)
- OrderedSegments.push_back(Section.ParentSegment);
-
- // For binary output, we're going to use physical addresses instead of
- // virtual addresses, since a binary output is used for cases like ROM
- // loading and physical addresses are intended for ROM loading.
- // However, if no segment has a physical address, we'll fallback to using
- // virtual addresses for all.
- if (all_of(OrderedSegments,
- [](const Segment *Seg) { return Seg->PAddr == 0; }))
- for (Segment *Seg : OrderedSegments)
- Seg->PAddr = Seg->VAddr;
-
- llvm::stable_sort(OrderedSegments, compareSegmentsByPAddr);
-
- // Because we add a ParentSegment for each section we might have duplicate
- // segments in OrderedSegments. If there were duplicates then LayoutSegments
- // would do very strange things.
- auto End =
- std::unique(std::begin(OrderedSegments), std::end(OrderedSegments));
- OrderedSegments.erase(End, std::end(OrderedSegments));
-
- uint64_t Offset = 0;
-
- // Modify the first segment so that there is no gap at the start. This allows
- // our layout algorithm to proceed as expected while not writing out the gap
- // at the start.
- if (!OrderedSegments.empty()) {
- Segment *Seg = OrderedSegments[0];
- const SectionBase *Sec = Seg->firstSection();
- auto Diff = Sec->OriginalOffset - Seg->OriginalOffset;
- Seg->OriginalOffset += Diff;
- // The size needs to be shrunk as well.
- Seg->FileSize -= Diff;
- // The PAddr needs to be increased to remove the gap before the first
- // section.
- Seg->PAddr += Diff;
- uint64_t LowestPAddr = Seg->PAddr;
- for (Segment *Segment : OrderedSegments) {
- Segment->Offset = Segment->PAddr - LowestPAddr;
- Offset = std::max(Offset, Segment->Offset + Segment->FileSize);
- }
- }
-
- // TODO: generalize LayoutSections to take a range. Pass a special range
- // constructed from an iterator that skips values for which a predicate does
- // not hold. Then pass such a range to LayoutSections instead of constructing
- // AllocatedSections here.
- std::vector<SectionBase *> AllocatedSections;
- for (SectionBase &Section : Obj.sections())
- if (Section.Flags & SHF_ALLOC)
- AllocatedSections.push_back(&Section);
- layoutSections(make_pointee_range(AllocatedSections), Offset);
-
- // Now that every section has been laid out we just need to compute the total
- // file size. This might not be the same as the offset returned by
- // LayoutSections, because we want to truncate the last segment to the end of
- // its last section, to match GNU objcopy's behaviour.
- TotalSize = 0;
- for (SectionBase *Section : AllocatedSections)
- if (Section->Type != SHT_NOBITS)
- TotalSize = std::max(TotalSize, Section->Offset + Section->Size);
-
- if (Error E = Buf.allocate(TotalSize))
- return E;
- SecWriter = llvm::make_unique<BinarySectionWriter>(Buf);
- return Error::success();
-}
-
-bool IHexWriter::SectionCompare::operator()(const SectionBase *Lhs,
- const SectionBase *Rhs) const {
- return (sectionPhysicalAddr(Lhs) & 0xFFFFFFFFU) <
- (sectionPhysicalAddr(Rhs) & 0xFFFFFFFFU);
-}
-
-uint64_t IHexWriter::writeEntryPointRecord(uint8_t *Buf) {
- IHexLineData HexData;
- uint8_t Data[4] = {};
- // We don't write entry point record if entry is zero.
- if (Obj.Entry == 0)
- return 0;
-
- if (Obj.Entry <= 0xFFFFFU) {
- Data[0] = ((Obj.Entry & 0xF0000U) >> 12) & 0xFF;
- support::endian::write(&Data[2], static_cast<uint16_t>(Obj.Entry),
- support::big);
- HexData = IHexRecord::getLine(IHexRecord::StartAddr80x86, 0, Data);
- } else {
- support::endian::write(Data, static_cast<uint32_t>(Obj.Entry),
- support::big);
- HexData = IHexRecord::getLine(IHexRecord::StartAddr, 0, Data);
- }
- memcpy(Buf, HexData.data(), HexData.size());
- return HexData.size();
-}
-
-uint64_t IHexWriter::writeEndOfFileRecord(uint8_t *Buf) {
- IHexLineData HexData = IHexRecord::getLine(IHexRecord::EndOfFile, 0, {});
- memcpy(Buf, HexData.data(), HexData.size());
- return HexData.size();
-}
-
-Error IHexWriter::write() {
- IHexSectionWriter Writer(Buf);
- // Write sections.
- for (const SectionBase *Sec : Sections)
- Sec->accept(Writer);
-
- uint64_t Offset = Writer.getBufferOffset();
- // Write entry point address.
- Offset += writeEntryPointRecord(Buf.getBufferStart() + Offset);
- // Write EOF.
- Offset += writeEndOfFileRecord(Buf.getBufferStart() + Offset);
- assert(Offset == TotalSize);
- return Buf.commit();
-}
-
-Error IHexWriter::checkSection(const SectionBase &Sec) {
- uint64_t Addr = sectionPhysicalAddr(&Sec);
- if (addressOverflows32bit(Addr) || addressOverflows32bit(Addr + Sec.Size - 1))
- return createStringError(
- errc::invalid_argument,
- "Section '%s' address range [0x%llx, 0x%llx] is not 32 bit", Sec.Name.c_str(),
- Addr, Addr + Sec.Size - 1);
- return Error::success();
-}
-
-Error IHexWriter::finalize() {
- bool UseSegments = false;
- auto ShouldWrite = [](const SectionBase &Sec) {
- return (Sec.Flags & ELF::SHF_ALLOC) && (Sec.Type != ELF::SHT_NOBITS);
- };
- auto IsInPtLoad = [](const SectionBase &Sec) {
- return Sec.ParentSegment && Sec.ParentSegment->Type == ELF::PT_LOAD;
- };
-
- // We can't write 64-bit addresses.
- if (addressOverflows32bit(Obj.Entry))
- return createStringError(errc::invalid_argument,
- "Entry point address 0x%llx overflows 32 bits.",
- Obj.Entry);
-
- // If any section we're to write has segment then we
- // switch to using physical addresses. Otherwise we
- // use section virtual address.
- for (auto &Section : Obj.sections())
- if (ShouldWrite(Section) && IsInPtLoad(Section)) {
- UseSegments = true;
- break;
- }
-
- for (auto &Section : Obj.sections())
- if (ShouldWrite(Section) && (!UseSegments || IsInPtLoad(Section))) {
- if (Error E = checkSection(Section))
- return E;
- Sections.insert(&Section);
- }
-
- IHexSectionWriterBase LengthCalc(Buf);
- for (const SectionBase *Sec : Sections)
- Sec->accept(LengthCalc);
-
- // We need space to write section records + StartAddress record
- // (if start adress is not zero) + EndOfFile record.
- TotalSize = LengthCalc.getBufferOffset() +
- (Obj.Entry ? IHexRecord::getLineLength(4) : 0) +
- IHexRecord::getLineLength(0);
- if (Error E = Buf.allocate(TotalSize))
- return E;
- return Error::success();
-}
-
-template class ELFBuilder<ELF64LE>;
-template class ELFBuilder<ELF64BE>;
-template class ELFBuilder<ELF32LE>;
-template class ELFBuilder<ELF32BE>;
-
-template class ELFWriter<ELF64LE>;
-template class ELFWriter<ELF64BE>;
-template class ELFWriter<ELF32LE>;
-template class ELFWriter<ELF32BE>;
-
-} // end namespace elf
-} // end namespace objcopy
-} // end namespace llvm