forked from OSchip/llvm-project
692 lines
24 KiB
C++
692 lines
24 KiB
C++
//===- InputSection.cpp ---------------------------------------------------===//
|
|
//
|
|
// The LLVM Linker
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "InputSection.h"
|
|
#include "Config.h"
|
|
#include "EhFrame.h"
|
|
#include "Error.h"
|
|
#include "InputFiles.h"
|
|
#include "LinkerScript.h"
|
|
#include "OutputSections.h"
|
|
#include "Target.h"
|
|
#include "Thunks.h"
|
|
|
|
#include "llvm/Support/Compression.h"
|
|
#include "llvm/Support/Endian.h"
|
|
|
|
using namespace llvm;
|
|
using namespace llvm::ELF;
|
|
using namespace llvm::object;
|
|
using namespace llvm::support::endian;
|
|
|
|
using namespace lld;
|
|
using namespace lld::elf;
|
|
|
|
template <class ELFT> bool elf::isDiscarded(InputSectionBase<ELFT> *S) {
|
|
return !S || S == &InputSection<ELFT>::Discarded || !S->Live ||
|
|
Script<ELFT>::X->isDiscarded(S);
|
|
}
|
|
|
|
template <class ELFT>
|
|
InputSectionBase<ELFT>::InputSectionBase(elf::ObjectFile<ELFT> *File,
|
|
const Elf_Shdr *Header,
|
|
Kind SectionKind)
|
|
: Header(Header), File(File), SectionKind(SectionKind), Repl(this),
|
|
Compressed(Header->sh_flags & SHF_COMPRESSED) {
|
|
// The garbage collector sets sections' Live bits.
|
|
// If GC is disabled, all sections are considered live by default.
|
|
Live = !Config->GcSections;
|
|
|
|
// The ELF spec states that a value of 0 means the section has
|
|
// no alignment constraits.
|
|
Alignment = std::max<uintX_t>(Header->sh_addralign, 1);
|
|
}
|
|
|
|
template <class ELFT> size_t InputSectionBase<ELFT>::getSize() const {
|
|
if (auto *D = dyn_cast<InputSection<ELFT>>(this))
|
|
if (D->getThunksSize() > 0)
|
|
return D->getThunkOff() + D->getThunksSize();
|
|
return Header->sh_size;
|
|
}
|
|
|
|
template <class ELFT> StringRef InputSectionBase<ELFT>::getSectionName() const {
|
|
return check(File->getObj().getSectionName(this->Header));
|
|
}
|
|
|
|
template <class ELFT>
|
|
ArrayRef<uint8_t> InputSectionBase<ELFT>::getSectionData() const {
|
|
if (Compressed)
|
|
return ArrayRef<uint8_t>((const uint8_t *)Uncompressed.data(),
|
|
Uncompressed.size());
|
|
return check(this->File->getObj().getSectionContents(this->Header));
|
|
}
|
|
|
|
template <class ELFT>
|
|
typename ELFT::uint InputSectionBase<ELFT>::getOffset(uintX_t Offset) const {
|
|
switch (SectionKind) {
|
|
case Regular:
|
|
return cast<InputSection<ELFT>>(this)->OutSecOff + Offset;
|
|
case EHFrame:
|
|
return cast<EhInputSection<ELFT>>(this)->getOffset(Offset);
|
|
case Merge:
|
|
return cast<MergeInputSection<ELFT>>(this)->getOffset(Offset);
|
|
case MipsReginfo:
|
|
case MipsOptions:
|
|
// MIPS .reginfo and .MIPS.options sections are consumed by the linker,
|
|
// and the linker produces a single output section. It is possible that
|
|
// input files contain section symbol points to the corresponding input
|
|
// section. Redirect it to the produced output section.
|
|
if (Offset != 0)
|
|
fatal("Unsupported reference to the middle of '" + getSectionName() +
|
|
"' section");
|
|
return this->OutSec->getVA();
|
|
}
|
|
llvm_unreachable("invalid section kind");
|
|
}
|
|
|
|
template <class ELFT> void InputSectionBase<ELFT>::uncompress() {
|
|
if (!zlib::isAvailable())
|
|
fatal("build lld with zlib to enable compressed sections support");
|
|
|
|
// A compressed section consists of a header of Elf_Chdr type
|
|
// followed by compressed data.
|
|
ArrayRef<uint8_t> Data =
|
|
check(this->File->getObj().getSectionContents(this->Header));
|
|
if (Data.size() < sizeof(Elf_Chdr))
|
|
fatal("corrupt compressed section");
|
|
|
|
auto *Hdr = reinterpret_cast<const Elf_Chdr *>(Data.data());
|
|
Data = Data.slice(sizeof(Elf_Chdr));
|
|
|
|
if (Hdr->ch_type != ELFCOMPRESS_ZLIB)
|
|
fatal("unsupported compression type");
|
|
|
|
StringRef Buf((const char *)Data.data(), Data.size());
|
|
if (zlib::uncompress(Buf, Uncompressed, Hdr->ch_size) != zlib::StatusOK)
|
|
fatal("error uncompressing section");
|
|
}
|
|
|
|
template <class ELFT>
|
|
typename ELFT::uint
|
|
InputSectionBase<ELFT>::getOffset(const DefinedRegular<ELFT> &Sym) const {
|
|
return getOffset(Sym.Value);
|
|
}
|
|
|
|
template <class ELFT>
|
|
InputSection<ELFT>::InputSection(elf::ObjectFile<ELFT> *F,
|
|
const Elf_Shdr *Header)
|
|
: InputSectionBase<ELFT>(F, Header, Base::Regular) {}
|
|
|
|
template <class ELFT>
|
|
bool InputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
|
|
return S->SectionKind == Base::Regular;
|
|
}
|
|
|
|
template <class ELFT>
|
|
InputSectionBase<ELFT> *InputSection<ELFT>::getRelocatedSection() {
|
|
assert(this->Header->sh_type == SHT_RELA || this->Header->sh_type == SHT_REL);
|
|
ArrayRef<InputSectionBase<ELFT> *> Sections = this->File->getSections();
|
|
return Sections[this->Header->sh_info];
|
|
}
|
|
|
|
template <class ELFT>
|
|
void InputSection<ELFT>::addThunk(const Thunk<ELFT> *T) {
|
|
Thunks.push_back(T);
|
|
}
|
|
|
|
template <class ELFT> uint64_t InputSection<ELFT>::getThunkOff() const {
|
|
return this->Header->sh_size;
|
|
}
|
|
|
|
template <class ELFT> uint64_t InputSection<ELFT>::getThunksSize() const {
|
|
uint64_t Total = 0;
|
|
for (const Thunk<ELFT> *T : Thunks)
|
|
Total += T->size();
|
|
return Total;
|
|
}
|
|
|
|
// This is used for -r. We can't use memcpy to copy relocations because we need
|
|
// to update symbol table offset and section index for each relocation. So we
|
|
// copy relocations one by one.
|
|
template <class ELFT>
|
|
template <class RelTy>
|
|
void InputSection<ELFT>::copyRelocations(uint8_t *Buf, ArrayRef<RelTy> Rels) {
|
|
InputSectionBase<ELFT> *RelocatedSection = getRelocatedSection();
|
|
|
|
for (const RelTy &Rel : Rels) {
|
|
uint32_t Type = Rel.getType(Config->Mips64EL);
|
|
SymbolBody &Body = this->File->getRelocTargetSym(Rel);
|
|
|
|
RelTy *P = reinterpret_cast<RelTy *>(Buf);
|
|
Buf += sizeof(RelTy);
|
|
|
|
P->r_offset = RelocatedSection->getOffset(Rel.r_offset);
|
|
P->setSymbolAndType(Body.DynsymIndex, Type, Config->Mips64EL);
|
|
}
|
|
}
|
|
|
|
// Page(Expr) is the page address of the expression Expr, defined
|
|
// as (Expr & ~0xFFF). (This applies even if the machine page size
|
|
// supported by the platform has a different value.)
|
|
static uint64_t getAArch64Page(uint64_t Expr) {
|
|
return Expr & (~static_cast<uint64_t>(0xFFF));
|
|
}
|
|
|
|
template <class ELFT>
|
|
static typename ELFT::uint getSymVA(uint32_t Type, typename ELFT::uint A,
|
|
typename ELFT::uint P,
|
|
const SymbolBody &Body, RelExpr Expr) {
|
|
typedef typename ELFT::uint uintX_t;
|
|
|
|
switch (Expr) {
|
|
case R_HINT:
|
|
llvm_unreachable("cannot relocate hint relocs");
|
|
case R_TLSLD:
|
|
return Out<ELFT>::Got->getTlsIndexOff() + A -
|
|
Out<ELFT>::Got->getNumEntries() * sizeof(uintX_t);
|
|
case R_TLSLD_PC:
|
|
return Out<ELFT>::Got->getTlsIndexVA() + A - P;
|
|
case R_THUNK_ABS:
|
|
return Body.getThunkVA<ELFT>() + A;
|
|
case R_THUNK_PC:
|
|
case R_THUNK_PLT_PC:
|
|
return Body.getThunkVA<ELFT>() + A - P;
|
|
case R_PPC_TOC:
|
|
return getPPC64TocBase() + A;
|
|
case R_TLSGD:
|
|
return Out<ELFT>::Got->getGlobalDynOffset(Body) + A -
|
|
Out<ELFT>::Got->getNumEntries() * sizeof(uintX_t);
|
|
case R_TLSGD_PC:
|
|
return Out<ELFT>::Got->getGlobalDynAddr(Body) + A - P;
|
|
case R_TLSDESC:
|
|
return Out<ELFT>::Got->getGlobalDynAddr(Body) + A;
|
|
case R_TLSDESC_PAGE:
|
|
return getAArch64Page(Out<ELFT>::Got->getGlobalDynAddr(Body) + A) -
|
|
getAArch64Page(P);
|
|
case R_PLT:
|
|
return Body.getPltVA<ELFT>() + A;
|
|
case R_PLT_PC:
|
|
case R_PPC_PLT_OPD:
|
|
return Body.getPltVA<ELFT>() + A - P;
|
|
case R_SIZE:
|
|
return Body.getSize<ELFT>() + A;
|
|
case R_GOTREL:
|
|
return Body.getVA<ELFT>(A) - Out<ELFT>::Got->getVA();
|
|
case R_RELAX_TLS_GD_TO_IE_END:
|
|
case R_GOT_FROM_END:
|
|
return Body.getGotOffset<ELFT>() + A -
|
|
Out<ELFT>::Got->getNumEntries() * sizeof(uintX_t);
|
|
case R_RELAX_TLS_GD_TO_IE_ABS:
|
|
case R_GOT:
|
|
return Body.getGotVA<ELFT>() + A;
|
|
case R_RELAX_TLS_GD_TO_IE_PAGE_PC:
|
|
case R_GOT_PAGE_PC:
|
|
return getAArch64Page(Body.getGotVA<ELFT>() + A) - getAArch64Page(P);
|
|
case R_RELAX_TLS_GD_TO_IE:
|
|
case R_GOT_PC:
|
|
return Body.getGotVA<ELFT>() + A - P;
|
|
case R_GOTONLY_PC:
|
|
return Out<ELFT>::Got->getVA() + A - P;
|
|
case R_RELAX_TLS_LD_TO_LE:
|
|
case R_RELAX_TLS_IE_TO_LE:
|
|
case R_RELAX_TLS_GD_TO_LE:
|
|
case R_TLS:
|
|
if (Target->TcbSize)
|
|
return Body.getVA<ELFT>(A) +
|
|
alignTo(Target->TcbSize, Out<ELFT>::TlsPhdr->p_align);
|
|
return Body.getVA<ELFT>(A) - Out<ELFT>::TlsPhdr->p_memsz;
|
|
case R_RELAX_TLS_GD_TO_LE_NEG:
|
|
case R_NEG_TLS:
|
|
return Out<ELF32LE>::TlsPhdr->p_memsz - Body.getVA<ELFT>(A);
|
|
case R_ABS:
|
|
case R_RELAX_GOT_PC_NOPIC:
|
|
return Body.getVA<ELFT>(A);
|
|
case R_GOT_OFF:
|
|
return Body.getGotOffset<ELFT>() + A;
|
|
case R_MIPS_GOT_LOCAL_PAGE:
|
|
// If relocation against MIPS local symbol requires GOT entry, this entry
|
|
// should be initialized by 'page address'. This address is high 16-bits
|
|
// of sum the symbol's value and the addend.
|
|
return Out<ELFT>::Got->getMipsLocalPageOffset(Body.getVA<ELFT>(A));
|
|
case R_MIPS_GOT_OFF:
|
|
// In case of MIPS if a GOT relocation has non-zero addend this addend
|
|
// should be applied to the GOT entry content not to the GOT entry offset.
|
|
// That is why we use separate expression type.
|
|
return Out<ELFT>::Got->getMipsGotOffset(Body, A);
|
|
case R_MIPS_TLSGD:
|
|
return Out<ELFT>::Got->getGlobalDynOffset(Body) +
|
|
Out<ELFT>::Got->getMipsTlsOffset() - MipsGPOffset;
|
|
case R_MIPS_TLSLD:
|
|
return Out<ELFT>::Got->getTlsIndexOff() +
|
|
Out<ELFT>::Got->getMipsTlsOffset() - MipsGPOffset;
|
|
case R_PPC_OPD: {
|
|
uint64_t SymVA = Body.getVA<ELFT>(A);
|
|
// If we have an undefined weak symbol, we might get here with a symbol
|
|
// address of zero. That could overflow, but the code must be unreachable,
|
|
// so don't bother doing anything at all.
|
|
if (!SymVA)
|
|
return 0;
|
|
if (Out<ELF64BE>::Opd) {
|
|
// If this is a local call, and we currently have the address of a
|
|
// function-descriptor, get the underlying code address instead.
|
|
uint64_t OpdStart = Out<ELF64BE>::Opd->getVA();
|
|
uint64_t OpdEnd = OpdStart + Out<ELF64BE>::Opd->getSize();
|
|
bool InOpd = OpdStart <= SymVA && SymVA < OpdEnd;
|
|
if (InOpd)
|
|
SymVA = read64be(&Out<ELF64BE>::OpdBuf[SymVA - OpdStart]);
|
|
}
|
|
return SymVA - P;
|
|
}
|
|
case R_PC:
|
|
case R_RELAX_GOT_PC:
|
|
return Body.getVA<ELFT>(A) - P;
|
|
case R_PLT_PAGE_PC:
|
|
case R_PAGE_PC:
|
|
return getAArch64Page(Body.getVA<ELFT>(A)) - getAArch64Page(P);
|
|
}
|
|
llvm_unreachable("Invalid expression");
|
|
}
|
|
|
|
// This function applies relocations to sections without SHF_ALLOC bit.
|
|
// Such sections are never mapped to memory at runtime. Debug sections are
|
|
// an example. Relocations in non-alloc sections are much easier to
|
|
// handle than in allocated sections because it will never need complex
|
|
// treatement such as GOT or PLT (because at runtime no one refers them).
|
|
// So, we handle relocations for non-alloc sections directly in this
|
|
// function as a performance optimization.
|
|
template <class ELFT>
|
|
template <class RelTy>
|
|
void InputSection<ELFT>::relocateNonAlloc(uint8_t *Buf, ArrayRef<RelTy> Rels) {
|
|
const unsigned Bits = sizeof(uintX_t) * 8;
|
|
for (const RelTy &Rel : Rels) {
|
|
uint32_t Type = Rel.getType(Config->Mips64EL);
|
|
uintX_t Offset = this->getOffset(Rel.r_offset);
|
|
uint8_t *BufLoc = Buf + Offset;
|
|
uintX_t Addend = getAddend<ELFT>(Rel);
|
|
if (!RelTy::IsRela)
|
|
Addend += Target->getImplicitAddend(BufLoc, Type);
|
|
|
|
SymbolBody &Sym = this->File->getRelocTargetSym(Rel);
|
|
if (Target->getRelExpr(Type, Sym) != R_ABS) {
|
|
error(this->getSectionName() + " has non-ABS reloc");
|
|
return;
|
|
}
|
|
|
|
uintX_t AddrLoc = this->OutSec->getVA() + Offset;
|
|
uint64_t SymVA =
|
|
SignExtend64<Bits>(getSymVA<ELFT>(Type, Addend, AddrLoc, Sym, R_ABS));
|
|
Target->relocateOne(BufLoc, Type, SymVA);
|
|
}
|
|
}
|
|
|
|
template <class ELFT>
|
|
void InputSectionBase<ELFT>::relocate(uint8_t *Buf, uint8_t *BufEnd) {
|
|
// scanReloc function in Writer.cpp constructs Relocations
|
|
// vector only for SHF_ALLOC'ed sections. For other sections,
|
|
// we handle relocations directly here.
|
|
auto *IS = dyn_cast<InputSection<ELFT>>(this);
|
|
if (IS && !(IS->Header->sh_flags & SHF_ALLOC)) {
|
|
for (const Elf_Shdr *RelSec : IS->RelocSections) {
|
|
if (RelSec->sh_type == SHT_RELA)
|
|
IS->relocateNonAlloc(Buf, IS->File->getObj().relas(RelSec));
|
|
else
|
|
IS->relocateNonAlloc(Buf, IS->File->getObj().rels(RelSec));
|
|
}
|
|
return;
|
|
}
|
|
|
|
const unsigned Bits = sizeof(uintX_t) * 8;
|
|
for (const Relocation<ELFT> &Rel : Relocations) {
|
|
uintX_t Offset = Rel.InputSec->getOffset(Rel.Offset);
|
|
uint8_t *BufLoc = Buf + Offset;
|
|
uint32_t Type = Rel.Type;
|
|
uintX_t A = Rel.Addend;
|
|
|
|
uintX_t AddrLoc = OutSec->getVA() + Offset;
|
|
RelExpr Expr = Rel.Expr;
|
|
uint64_t SymVA =
|
|
SignExtend64<Bits>(getSymVA<ELFT>(Type, A, AddrLoc, *Rel.Sym, Expr));
|
|
|
|
switch (Expr) {
|
|
case R_RELAX_GOT_PC:
|
|
case R_RELAX_GOT_PC_NOPIC:
|
|
Target->relaxGot(BufLoc, SymVA);
|
|
break;
|
|
case R_RELAX_TLS_IE_TO_LE:
|
|
Target->relaxTlsIeToLe(BufLoc, Type, SymVA);
|
|
break;
|
|
case R_RELAX_TLS_LD_TO_LE:
|
|
Target->relaxTlsLdToLe(BufLoc, Type, SymVA);
|
|
break;
|
|
case R_RELAX_TLS_GD_TO_LE:
|
|
case R_RELAX_TLS_GD_TO_LE_NEG:
|
|
Target->relaxTlsGdToLe(BufLoc, Type, SymVA);
|
|
break;
|
|
case R_RELAX_TLS_GD_TO_IE:
|
|
case R_RELAX_TLS_GD_TO_IE_ABS:
|
|
case R_RELAX_TLS_GD_TO_IE_PAGE_PC:
|
|
case R_RELAX_TLS_GD_TO_IE_END:
|
|
Target->relaxTlsGdToIe(BufLoc, Type, SymVA);
|
|
break;
|
|
case R_PPC_PLT_OPD:
|
|
// Patch a nop (0x60000000) to a ld.
|
|
if (BufLoc + 8 <= BufEnd && read32be(BufLoc + 4) == 0x60000000)
|
|
write32be(BufLoc + 4, 0xe8410028); // ld %r2, 40(%r1)
|
|
// fallthrough
|
|
default:
|
|
Target->relocateOne(BufLoc, Type, SymVA);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
template <class ELFT> void InputSection<ELFT>::writeTo(uint8_t *Buf) {
|
|
if (this->Header->sh_type == SHT_NOBITS)
|
|
return;
|
|
ELFFile<ELFT> &EObj = this->File->getObj();
|
|
|
|
// If -r is given, then an InputSection may be a relocation section.
|
|
if (this->Header->sh_type == SHT_RELA) {
|
|
copyRelocations(Buf + OutSecOff, EObj.relas(this->Header));
|
|
return;
|
|
}
|
|
if (this->Header->sh_type == SHT_REL) {
|
|
copyRelocations(Buf + OutSecOff, EObj.rels(this->Header));
|
|
return;
|
|
}
|
|
|
|
// Copy section contents from source object file to output file.
|
|
ArrayRef<uint8_t> Data = this->getSectionData();
|
|
memcpy(Buf + OutSecOff, Data.data(), Data.size());
|
|
|
|
// Iterate over all relocation sections that apply to this section.
|
|
uint8_t *BufEnd = Buf + OutSecOff + Data.size();
|
|
this->relocate(Buf, BufEnd);
|
|
|
|
// The section might have a data/code generated by the linker and need
|
|
// to be written after the section. Usually these are thunks - small piece
|
|
// of code used to jump between "incompatible" functions like PIC and non-PIC
|
|
// or if the jump target too far and its address does not fit to the short
|
|
// jump istruction.
|
|
if (!Thunks.empty()) {
|
|
Buf += OutSecOff + getThunkOff();
|
|
for (const Thunk<ELFT> *T : Thunks) {
|
|
T->writeTo(Buf);
|
|
Buf += T->size();
|
|
}
|
|
}
|
|
}
|
|
|
|
template <class ELFT>
|
|
void InputSection<ELFT>::replace(InputSection<ELFT> *Other) {
|
|
this->Alignment = std::max(this->Alignment, Other->Alignment);
|
|
Other->Repl = this->Repl;
|
|
Other->Live = false;
|
|
}
|
|
|
|
template <class ELFT>
|
|
SplitInputSection<ELFT>::SplitInputSection(
|
|
elf::ObjectFile<ELFT> *File, const Elf_Shdr *Header,
|
|
typename InputSectionBase<ELFT>::Kind SectionKind)
|
|
: InputSectionBase<ELFT>(File, Header, SectionKind) {}
|
|
|
|
template <class ELFT>
|
|
EhInputSection<ELFT>::EhInputSection(elf::ObjectFile<ELFT> *F,
|
|
const Elf_Shdr *Header)
|
|
: SplitInputSection<ELFT>(F, Header, InputSectionBase<ELFT>::EHFrame) {
|
|
// Mark .eh_frame sections as live by default because there are
|
|
// usually no relocations that point to .eh_frames. Otherwise,
|
|
// the garbage collector would drop all .eh_frame sections.
|
|
this->Live = true;
|
|
}
|
|
|
|
template <class ELFT>
|
|
bool EhInputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
|
|
return S->SectionKind == InputSectionBase<ELFT>::EHFrame;
|
|
}
|
|
|
|
// .eh_frame is a sequence of CIE or FDE records.
|
|
// This function splits an input section into records and returns them.
|
|
template <class ELFT>
|
|
void EhInputSection<ELFT>::split() {
|
|
ArrayRef<uint8_t> Data = this->getSectionData();
|
|
for (size_t Off = 0, End = Data.size(); Off != End;) {
|
|
size_t Size = readEhRecordSize<ELFT>(Data.slice(Off));
|
|
this->Pieces.emplace_back(Off, Data.slice(Off, Size));
|
|
// The empty record is the end marker.
|
|
if (Size == 4)
|
|
break;
|
|
Off += Size;
|
|
}
|
|
}
|
|
|
|
template <class ELFT>
|
|
typename ELFT::uint EhInputSection<ELFT>::getOffset(uintX_t Offset) const {
|
|
// The file crtbeginT.o has relocations pointing to the start of an empty
|
|
// .eh_frame that is known to be the first in the link. It does that to
|
|
// identify the start of the output .eh_frame. Handle this special case.
|
|
if (this->getSectionHdr()->sh_size == 0)
|
|
return Offset;
|
|
const SectionPiece *Piece = this->getSectionPiece(Offset);
|
|
if (Piece->OutputOff == size_t(-1))
|
|
return -1; // Not in the output
|
|
|
|
uintX_t Addend = Offset - Piece->InputOff;
|
|
return Piece->OutputOff + Addend;
|
|
}
|
|
|
|
static size_t findNull(ArrayRef<uint8_t> A, size_t EntSize) {
|
|
// Optimize the common case.
|
|
StringRef S((const char *)A.data(), A.size());
|
|
if (EntSize == 1)
|
|
return S.find(0);
|
|
|
|
for (unsigned I = 0, N = S.size(); I != N; I += EntSize) {
|
|
const char *B = S.begin() + I;
|
|
if (std::all_of(B, B + EntSize, [](char C) { return C == 0; }))
|
|
return I;
|
|
}
|
|
return StringRef::npos;
|
|
}
|
|
|
|
// Split SHF_STRINGS section. Such section is a sequence of
|
|
// null-terminated strings.
|
|
static std::vector<SectionPiece> splitStrings(ArrayRef<uint8_t> Data,
|
|
size_t EntSize) {
|
|
std::vector<SectionPiece> V;
|
|
size_t Off = 0;
|
|
while (!Data.empty()) {
|
|
size_t End = findNull(Data, EntSize);
|
|
if (End == StringRef::npos)
|
|
fatal("string is not null terminated");
|
|
size_t Size = End + EntSize;
|
|
V.emplace_back(Off, Data.slice(0, Size));
|
|
Data = Data.slice(Size);
|
|
Off += Size;
|
|
}
|
|
return V;
|
|
}
|
|
|
|
// Split non-SHF_STRINGS section. Such section is a sequence of
|
|
// fixed size records.
|
|
static std::vector<SectionPiece> splitNonStrings(ArrayRef<uint8_t> Data,
|
|
size_t EntSize) {
|
|
std::vector<SectionPiece> V;
|
|
size_t Size = Data.size();
|
|
assert((Size % EntSize) == 0);
|
|
for (unsigned I = 0, N = Size; I != N; I += EntSize)
|
|
V.emplace_back(I, Data.slice(I, EntSize));
|
|
return V;
|
|
}
|
|
|
|
template <class ELFT>
|
|
MergeInputSection<ELFT>::MergeInputSection(elf::ObjectFile<ELFT> *F,
|
|
const Elf_Shdr *Header)
|
|
: SplitInputSection<ELFT>(F, Header, InputSectionBase<ELFT>::Merge) {}
|
|
|
|
template <class ELFT> void MergeInputSection<ELFT>::splitIntoPieces() {
|
|
ArrayRef<uint8_t> Data = this->getSectionData();
|
|
uintX_t EntSize = this->Header->sh_entsize;
|
|
if (this->Header->sh_flags & SHF_STRINGS)
|
|
this->Pieces = splitStrings(Data, EntSize);
|
|
else
|
|
this->Pieces = splitNonStrings(Data, EntSize);
|
|
|
|
if (Config->GcSections)
|
|
for (uintX_t Off : LiveOffsets)
|
|
this->getSectionPiece(Off)->Live = true;
|
|
}
|
|
|
|
template <class ELFT>
|
|
bool MergeInputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
|
|
return S->SectionKind == InputSectionBase<ELFT>::Merge;
|
|
}
|
|
|
|
// Do binary search to get a section piece at a given input offset.
|
|
template <class ELFT>
|
|
SectionPiece *SplitInputSection<ELFT>::getSectionPiece(uintX_t Offset) {
|
|
auto *This = static_cast<const SplitInputSection<ELFT> *>(this);
|
|
return const_cast<SectionPiece *>(This->getSectionPiece(Offset));
|
|
}
|
|
|
|
template <class ELFT>
|
|
const SectionPiece *
|
|
SplitInputSection<ELFT>::getSectionPiece(uintX_t Offset) const {
|
|
ArrayRef<uint8_t> D = this->getSectionData();
|
|
StringRef Data((const char *)D.data(), D.size());
|
|
uintX_t Size = Data.size();
|
|
if (Offset >= Size)
|
|
fatal("entry is past the end of the section");
|
|
|
|
// Find the element this offset points to.
|
|
auto I = std::upper_bound(
|
|
Pieces.begin(), Pieces.end(), Offset,
|
|
[](const uintX_t &A, const SectionPiece &B) { return A < B.InputOff; });
|
|
--I;
|
|
return &*I;
|
|
}
|
|
|
|
// Returns the offset in an output section for a given input offset.
|
|
// Because contents of a mergeable section is not contiguous in output,
|
|
// it is not just an addition to a base output offset.
|
|
template <class ELFT>
|
|
typename ELFT::uint MergeInputSection<ELFT>::getOffset(uintX_t Offset) const {
|
|
auto It = OffsetMap.find(Offset);
|
|
if (It != OffsetMap.end())
|
|
return It->second;
|
|
|
|
// If Offset is not at beginning of a section piece, it is not in the map.
|
|
// In that case we need to search from the original section piece vector.
|
|
const SectionPiece &Piece = *this->getSectionPiece(Offset);
|
|
assert(Piece.Live);
|
|
uintX_t Addend = Offset - Piece.InputOff;
|
|
return Piece.OutputOff + Addend;
|
|
}
|
|
|
|
// Create a map from input offsets to output offsets for all section pieces.
|
|
// It is called after finalize().
|
|
template <class ELFT> void MergeInputSection<ELFT>::finalizePieces() {
|
|
OffsetMap.grow(this->Pieces.size());
|
|
for (SectionPiece &Piece : this->Pieces) {
|
|
if (!Piece.Live)
|
|
continue;
|
|
if (Piece.OutputOff == size_t(-1)) {
|
|
// Offsets of tail-merged strings are computed lazily.
|
|
auto *OutSec = static_cast<MergeOutputSection<ELFT> *>(this->OutSec);
|
|
ArrayRef<uint8_t> D = Piece.data();
|
|
StringRef S((const char *)D.data(), D.size());
|
|
Piece.OutputOff = OutSec->getOffset(S);
|
|
}
|
|
OffsetMap[Piece.InputOff] = Piece.OutputOff;
|
|
}
|
|
}
|
|
|
|
template <class ELFT>
|
|
MipsReginfoInputSection<ELFT>::MipsReginfoInputSection(elf::ObjectFile<ELFT> *F,
|
|
const Elf_Shdr *Hdr)
|
|
: InputSectionBase<ELFT>(F, Hdr, InputSectionBase<ELFT>::MipsReginfo) {
|
|
// Initialize this->Reginfo.
|
|
ArrayRef<uint8_t> D = this->getSectionData();
|
|
if (D.size() != sizeof(Elf_Mips_RegInfo<ELFT>)) {
|
|
error("invalid size of .reginfo section");
|
|
return;
|
|
}
|
|
Reginfo = reinterpret_cast<const Elf_Mips_RegInfo<ELFT> *>(D.data());
|
|
}
|
|
|
|
template <class ELFT>
|
|
bool MipsReginfoInputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
|
|
return S->SectionKind == InputSectionBase<ELFT>::MipsReginfo;
|
|
}
|
|
|
|
template <class ELFT>
|
|
MipsOptionsInputSection<ELFT>::MipsOptionsInputSection(elf::ObjectFile<ELFT> *F,
|
|
const Elf_Shdr *Hdr)
|
|
: InputSectionBase<ELFT>(F, Hdr, InputSectionBase<ELFT>::MipsOptions) {
|
|
// Find ODK_REGINFO option in the section's content.
|
|
ArrayRef<uint8_t> D = this->getSectionData();
|
|
while (!D.empty()) {
|
|
if (D.size() < sizeof(Elf_Mips_Options<ELFT>)) {
|
|
error("invalid size of .MIPS.options section");
|
|
break;
|
|
}
|
|
auto *O = reinterpret_cast<const Elf_Mips_Options<ELFT> *>(D.data());
|
|
if (O->kind == ODK_REGINFO) {
|
|
Reginfo = &O->getRegInfo();
|
|
break;
|
|
}
|
|
D = D.slice(O->size);
|
|
}
|
|
}
|
|
|
|
template <class ELFT>
|
|
bool MipsOptionsInputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
|
|
return S->SectionKind == InputSectionBase<ELFT>::MipsOptions;
|
|
}
|
|
|
|
template bool elf::isDiscarded<ELF32LE>(InputSectionBase<ELF32LE> *);
|
|
template bool elf::isDiscarded<ELF32BE>(InputSectionBase<ELF32BE> *);
|
|
template bool elf::isDiscarded<ELF64LE>(InputSectionBase<ELF64LE> *);
|
|
template bool elf::isDiscarded<ELF64BE>(InputSectionBase<ELF64BE> *);
|
|
|
|
template class elf::InputSectionBase<ELF32LE>;
|
|
template class elf::InputSectionBase<ELF32BE>;
|
|
template class elf::InputSectionBase<ELF64LE>;
|
|
template class elf::InputSectionBase<ELF64BE>;
|
|
|
|
template class elf::InputSection<ELF32LE>;
|
|
template class elf::InputSection<ELF32BE>;
|
|
template class elf::InputSection<ELF64LE>;
|
|
template class elf::InputSection<ELF64BE>;
|
|
|
|
template class elf::SplitInputSection<ELF32LE>;
|
|
template class elf::SplitInputSection<ELF32BE>;
|
|
template class elf::SplitInputSection<ELF64LE>;
|
|
template class elf::SplitInputSection<ELF64BE>;
|
|
|
|
template class elf::EhInputSection<ELF32LE>;
|
|
template class elf::EhInputSection<ELF32BE>;
|
|
template class elf::EhInputSection<ELF64LE>;
|
|
template class elf::EhInputSection<ELF64BE>;
|
|
|
|
template class elf::MergeInputSection<ELF32LE>;
|
|
template class elf::MergeInputSection<ELF32BE>;
|
|
template class elf::MergeInputSection<ELF64LE>;
|
|
template class elf::MergeInputSection<ELF64BE>;
|
|
|
|
template class elf::MipsReginfoInputSection<ELF32LE>;
|
|
template class elf::MipsReginfoInputSection<ELF32BE>;
|
|
template class elf::MipsReginfoInputSection<ELF64LE>;
|
|
template class elf::MipsReginfoInputSection<ELF64BE>;
|
|
|
|
template class elf::MipsOptionsInputSection<ELF32LE>;
|
|
template class elf::MipsOptionsInputSection<ELF32BE>;
|
|
template class elf::MipsOptionsInputSection<ELF64LE>;
|
|
template class elf::MipsOptionsInputSection<ELF64BE>;
|