forked from OSchip/llvm-project
759 lines
26 KiB
C++
759 lines
26 KiB
C++
//===- InputSection.cpp ---------------------------------------------------===//
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//
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// The LLVM Linker
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "InputSection.h"
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#include "Config.h"
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#include "EhFrame.h"
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#include "Error.h"
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#include "InputFiles.h"
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#include "LinkerScript.h"
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#include "OutputSections.h"
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#include "Target.h"
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#include "Thunks.h"
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#include "llvm/Support/Compression.h"
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#include "llvm/Support/Endian.h"
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using namespace llvm;
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using namespace llvm::ELF;
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using namespace llvm::object;
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using namespace llvm::support::endian;
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using namespace lld;
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using namespace lld::elf;
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template <class ELFT>
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InputSectionBase<ELFT>::InputSectionBase(elf::ObjectFile<ELFT> *File,
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const Elf_Shdr *Hdr, Kind SectionKind)
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: InputSectionData(SectionKind, Hdr->sh_flags & SHF_COMPRESSED,
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!Config->GcSections),
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Header(Hdr), File(File), Repl(this) {
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// The ELF spec states that a value of 0 means the section has
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// no alignment constraits.
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Alignment = std::max<uintX_t>(Header->sh_addralign, 1);
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}
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template <class ELFT> size_t InputSectionBase<ELFT>::getSize() const {
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if (auto *D = dyn_cast<InputSection<ELFT>>(this))
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if (D->getThunksSize() > 0)
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return D->getThunkOff() + D->getThunksSize();
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return Header->sh_size;
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}
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template <class ELFT> StringRef InputSectionBase<ELFT>::getSectionName() const {
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return check(File->getObj().getSectionName(this->Header));
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}
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template <class ELFT>
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ArrayRef<uint8_t> InputSectionBase<ELFT>::getSectionData() const {
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if (Compressed)
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return ArrayRef<uint8_t>((const uint8_t *)Uncompressed.data(),
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Uncompressed.size());
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return check(this->File->getObj().getSectionContents(this->Header));
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}
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// Returns a string for an error message.
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template <class SectionT> static std::string getName(SectionT *Sec) {
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return (Sec->getFile()->getName() + "(" + Sec->getSectionName() + ")").str();
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}
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template <class ELFT>
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typename ELFT::uint InputSectionBase<ELFT>::getOffset(uintX_t Offset) const {
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switch (SectionKind) {
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case Regular:
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return cast<InputSection<ELFT>>(this)->OutSecOff + Offset;
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case EHFrame:
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// The file crtbeginT.o has relocations pointing to the start of an empty
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// .eh_frame that is known to be the first in the link. It does that to
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// identify the start of the output .eh_frame.
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return Offset;
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case Merge:
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return cast<MergeInputSection<ELFT>>(this)->getOffset(Offset);
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case MipsReginfo:
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case MipsOptions:
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case MipsAbiFlags:
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// MIPS .reginfo, .MIPS.options, and .MIPS.abiflags sections are consumed
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// by the linker, and the linker produces a single output section. It is
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// possible that input files contain section symbol points to the
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// corresponding input section. Redirect it to the produced output section.
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if (Offset != 0)
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fatal(getName(this) + ": unsupported reference to the middle of '" +
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getSectionName() + "' section");
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return this->OutSec->getVA();
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}
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llvm_unreachable("invalid section kind");
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}
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template <class ELFT> void InputSectionBase<ELFT>::uncompress() {
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if (!zlib::isAvailable())
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fatal(getName(this) +
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": build lld with zlib to enable compressed sections support");
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// A compressed section consists of a header of Elf_Chdr type
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// followed by compressed data.
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ArrayRef<uint8_t> Data =
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check(this->File->getObj().getSectionContents(this->Header));
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if (Data.size() < sizeof(Elf_Chdr))
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fatal("corrupt compressed section");
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auto *Hdr = reinterpret_cast<const Elf_Chdr *>(Data.data());
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Data = Data.slice(sizeof(Elf_Chdr));
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if (Hdr->ch_type != ELFCOMPRESS_ZLIB)
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fatal(getName(this) + ": unsupported compression type");
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StringRef Buf((const char *)Data.data(), Data.size());
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if (zlib::uncompress(Buf, Uncompressed, Hdr->ch_size) != zlib::StatusOK)
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fatal(getName(this) + ": error uncompressing section");
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}
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template <class ELFT>
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typename ELFT::uint
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InputSectionBase<ELFT>::getOffset(const DefinedRegular<ELFT> &Sym) const {
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return getOffset(Sym.Value);
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}
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template <class ELFT>
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InputSection<ELFT>::InputSection(elf::ObjectFile<ELFT> *F,
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const Elf_Shdr *Header)
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: InputSectionBase<ELFT>(F, Header, Base::Regular) {}
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template <class ELFT>
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bool InputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
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return S->SectionKind == Base::Regular;
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}
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template <class ELFT>
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InputSectionBase<ELFT> *InputSection<ELFT>::getRelocatedSection() {
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assert(this->Header->sh_type == SHT_RELA || this->Header->sh_type == SHT_REL);
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ArrayRef<InputSectionBase<ELFT> *> Sections = this->File->getSections();
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return Sections[this->Header->sh_info];
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}
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template <class ELFT>
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void InputSection<ELFT>::addThunk(const Thunk<ELFT> *T) {
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Thunks.push_back(T);
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}
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template <class ELFT> uint64_t InputSection<ELFT>::getThunkOff() const {
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return this->Header->sh_size;
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}
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template <class ELFT> uint64_t InputSection<ELFT>::getThunksSize() const {
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uint64_t Total = 0;
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for (const Thunk<ELFT> *T : Thunks)
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Total += T->size();
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return Total;
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}
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// This is used for -r. We can't use memcpy to copy relocations because we need
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// to update symbol table offset and section index for each relocation. So we
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// copy relocations one by one.
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template <class ELFT>
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template <class RelTy>
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void InputSection<ELFT>::copyRelocations(uint8_t *Buf, ArrayRef<RelTy> Rels) {
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InputSectionBase<ELFT> *RelocatedSection = getRelocatedSection();
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for (const RelTy &Rel : Rels) {
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uint32_t Type = Rel.getType(Config->Mips64EL);
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SymbolBody &Body = this->File->getRelocTargetSym(Rel);
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Elf_Rela *P = reinterpret_cast<Elf_Rela *>(Buf);
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Buf += sizeof(RelTy);
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if (Config->Rela)
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P->r_addend = getAddend<ELFT>(Rel);
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P->r_offset = RelocatedSection->getOffset(Rel.r_offset);
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P->setSymbolAndType(Body.DynsymIndex, Type, Config->Mips64EL);
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}
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}
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// Page(Expr) is the page address of the expression Expr, defined
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// as (Expr & ~0xFFF). (This applies even if the machine page size
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// supported by the platform has a different value.)
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static uint64_t getAArch64Page(uint64_t Expr) {
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return Expr & (~static_cast<uint64_t>(0xFFF));
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}
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template <class ELFT>
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static typename ELFT::uint getSymVA(uint32_t Type, typename ELFT::uint A,
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typename ELFT::uint P,
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const SymbolBody &Body, RelExpr Expr) {
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switch (Expr) {
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case R_HINT:
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llvm_unreachable("cannot relocate hint relocs");
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case R_TLSLD:
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return Out<ELFT>::Got->getTlsIndexOff() + A - Out<ELFT>::Got->getSize();
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case R_TLSLD_PC:
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return Out<ELFT>::Got->getTlsIndexVA() + A - P;
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case R_THUNK_ABS:
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return Body.getThunkVA<ELFT>() + A;
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case R_THUNK_PC:
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case R_THUNK_PLT_PC:
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return Body.getThunkVA<ELFT>() + A - P;
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case R_PPC_TOC:
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return getPPC64TocBase() + A;
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case R_TLSGD:
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return Out<ELFT>::Got->getGlobalDynOffset(Body) + A -
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Out<ELFT>::Got->getSize();
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case R_TLSGD_PC:
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return Out<ELFT>::Got->getGlobalDynAddr(Body) + A - P;
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case R_TLSDESC:
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return Out<ELFT>::Got->getGlobalDynAddr(Body) + A;
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case R_TLSDESC_PAGE:
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return getAArch64Page(Out<ELFT>::Got->getGlobalDynAddr(Body) + A) -
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getAArch64Page(P);
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case R_PLT:
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return Body.getPltVA<ELFT>() + A;
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case R_PLT_PC:
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case R_PPC_PLT_OPD:
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return Body.getPltVA<ELFT>() + A - P;
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case R_SIZE:
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return Body.getSize<ELFT>() + A;
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case R_GOTREL:
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return Body.getVA<ELFT>(A) - Out<ELFT>::Got->getVA();
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case R_GOTREL_FROM_END:
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return Body.getVA<ELFT>(A) - Out<ELFT>::Got->getVA() -
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Out<ELFT>::Got->getSize();
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case R_RELAX_TLS_GD_TO_IE_END:
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case R_GOT_FROM_END:
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return Body.getGotOffset<ELFT>() + A - Out<ELFT>::Got->getSize();
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case R_RELAX_TLS_GD_TO_IE_ABS:
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case R_GOT:
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return Body.getGotVA<ELFT>() + A;
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case R_RELAX_TLS_GD_TO_IE_PAGE_PC:
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case R_GOT_PAGE_PC:
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return getAArch64Page(Body.getGotVA<ELFT>() + A) - getAArch64Page(P);
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case R_RELAX_TLS_GD_TO_IE:
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case R_GOT_PC:
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return Body.getGotVA<ELFT>() + A - P;
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case R_GOTONLY_PC:
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return Out<ELFT>::Got->getVA() + A - P;
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case R_GOTONLY_PC_FROM_END:
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return Out<ELFT>::Got->getVA() + A - P + Out<ELFT>::Got->getSize();
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case R_RELAX_TLS_LD_TO_LE:
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case R_RELAX_TLS_IE_TO_LE:
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case R_RELAX_TLS_GD_TO_LE:
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case R_TLS:
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if (Target->TcbSize)
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return Body.getVA<ELFT>(A) +
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alignTo(Target->TcbSize, Out<ELFT>::TlsPhdr->p_align);
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return Body.getVA<ELFT>(A) - Out<ELFT>::TlsPhdr->p_memsz;
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case R_RELAX_TLS_GD_TO_LE_NEG:
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case R_NEG_TLS:
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return Out<ELF32LE>::TlsPhdr->p_memsz - Body.getVA<ELFT>(A);
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case R_ABS:
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case R_RELAX_GOT_PC_NOPIC:
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return Body.getVA<ELFT>(A);
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case R_GOT_OFF:
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return Body.getGotOffset<ELFT>() + A;
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case R_MIPS_GOT_LOCAL_PAGE:
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// If relocation against MIPS local symbol requires GOT entry, this entry
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// should be initialized by 'page address'. This address is high 16-bits
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// of sum the symbol's value and the addend.
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return Out<ELFT>::Got->getMipsLocalPageOffset(Body.getVA<ELFT>(A));
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case R_MIPS_GOT_OFF:
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// In case of MIPS if a GOT relocation has non-zero addend this addend
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// should be applied to the GOT entry content not to the GOT entry offset.
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// That is why we use separate expression type.
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return Out<ELFT>::Got->getMipsGotOffset(Body, A);
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case R_MIPS_TLSGD:
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return Out<ELFT>::Got->getGlobalDynOffset(Body) +
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Out<ELFT>::Got->getMipsTlsOffset() - MipsGPOffset;
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case R_MIPS_TLSLD:
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return Out<ELFT>::Got->getTlsIndexOff() +
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Out<ELFT>::Got->getMipsTlsOffset() - MipsGPOffset;
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case R_PPC_OPD: {
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uint64_t SymVA = Body.getVA<ELFT>(A);
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// If we have an undefined weak symbol, we might get here with a symbol
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// address of zero. That could overflow, but the code must be unreachable,
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// so don't bother doing anything at all.
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if (!SymVA)
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return 0;
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if (Out<ELF64BE>::Opd) {
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// If this is a local call, and we currently have the address of a
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// function-descriptor, get the underlying code address instead.
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uint64_t OpdStart = Out<ELF64BE>::Opd->getVA();
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uint64_t OpdEnd = OpdStart + Out<ELF64BE>::Opd->getSize();
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bool InOpd = OpdStart <= SymVA && SymVA < OpdEnd;
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if (InOpd)
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SymVA = read64be(&Out<ELF64BE>::OpdBuf[SymVA - OpdStart]);
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}
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return SymVA - P;
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}
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case R_PC:
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case R_RELAX_GOT_PC:
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return Body.getVA<ELFT>(A) - P;
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case R_PLT_PAGE_PC:
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case R_PAGE_PC:
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return getAArch64Page(Body.getVA<ELFT>(A)) - getAArch64Page(P);
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}
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llvm_unreachable("Invalid expression");
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}
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// This function applies relocations to sections without SHF_ALLOC bit.
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// Such sections are never mapped to memory at runtime. Debug sections are
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// an example. Relocations in non-alloc sections are much easier to
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// handle than in allocated sections because it will never need complex
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// treatement such as GOT or PLT (because at runtime no one refers them).
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// So, we handle relocations for non-alloc sections directly in this
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// function as a performance optimization.
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template <class ELFT>
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template <class RelTy>
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void InputSection<ELFT>::relocateNonAlloc(uint8_t *Buf, ArrayRef<RelTy> Rels) {
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const unsigned Bits = sizeof(uintX_t) * 8;
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for (const RelTy &Rel : Rels) {
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uint32_t Type = Rel.getType(Config->Mips64EL);
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uintX_t Offset = this->getOffset(Rel.r_offset);
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uint8_t *BufLoc = Buf + Offset;
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uintX_t Addend = getAddend<ELFT>(Rel);
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if (!RelTy::IsRela)
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Addend += Target->getImplicitAddend(BufLoc, Type);
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SymbolBody &Sym = this->File->getRelocTargetSym(Rel);
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if (Target->getRelExpr(Type, Sym) != R_ABS) {
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error(getName(this) + " has non-ABS reloc");
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return;
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}
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uintX_t AddrLoc = this->OutSec->getVA() + Offset;
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uint64_t SymVA =
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SignExtend64<Bits>(getSymVA<ELFT>(Type, Addend, AddrLoc, Sym, R_ABS));
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Target->relocateOne(BufLoc, Type, SymVA);
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}
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}
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template <class ELFT>
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void InputSectionBase<ELFT>::relocate(uint8_t *Buf, uint8_t *BufEnd) {
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// scanReloc function in Writer.cpp constructs Relocations
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// vector only for SHF_ALLOC'ed sections. For other sections,
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// we handle relocations directly here.
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auto *IS = dyn_cast<InputSection<ELFT>>(this);
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if (IS && !(IS->Header->sh_flags & SHF_ALLOC)) {
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for (const Elf_Shdr *RelSec : IS->RelocSections) {
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if (RelSec->sh_type == SHT_RELA)
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IS->relocateNonAlloc(Buf, IS->File->getObj().relas(RelSec));
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else
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IS->relocateNonAlloc(Buf, IS->File->getObj().rels(RelSec));
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}
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return;
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}
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const unsigned Bits = sizeof(uintX_t) * 8;
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for (const Relocation<ELFT> &Rel : Relocations) {
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uintX_t Offset = getOffset(Rel.Offset);
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uint8_t *BufLoc = Buf + Offset;
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uint32_t Type = Rel.Type;
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uintX_t A = Rel.Addend;
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uintX_t AddrLoc = OutSec->getVA() + Offset;
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RelExpr Expr = Rel.Expr;
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uint64_t SymVA =
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SignExtend64<Bits>(getSymVA<ELFT>(Type, A, AddrLoc, *Rel.Sym, Expr));
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switch (Expr) {
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case R_RELAX_GOT_PC:
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case R_RELAX_GOT_PC_NOPIC:
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Target->relaxGot(BufLoc, SymVA);
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break;
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case R_RELAX_TLS_IE_TO_LE:
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Target->relaxTlsIeToLe(BufLoc, Type, SymVA);
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break;
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case R_RELAX_TLS_LD_TO_LE:
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Target->relaxTlsLdToLe(BufLoc, Type, SymVA);
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break;
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case R_RELAX_TLS_GD_TO_LE:
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case R_RELAX_TLS_GD_TO_LE_NEG:
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Target->relaxTlsGdToLe(BufLoc, Type, SymVA);
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break;
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case R_RELAX_TLS_GD_TO_IE:
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case R_RELAX_TLS_GD_TO_IE_ABS:
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case R_RELAX_TLS_GD_TO_IE_PAGE_PC:
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case R_RELAX_TLS_GD_TO_IE_END:
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Target->relaxTlsGdToIe(BufLoc, Type, SymVA);
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break;
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case R_PPC_PLT_OPD:
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// Patch a nop (0x60000000) to a ld.
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if (BufLoc + 8 <= BufEnd && read32be(BufLoc + 4) == 0x60000000)
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write32be(BufLoc + 4, 0xe8410028); // ld %r2, 40(%r1)
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// fallthrough
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default:
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Target->relocateOne(BufLoc, Type, SymVA);
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break;
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}
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}
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}
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template <class ELFT> void InputSection<ELFT>::writeTo(uint8_t *Buf) {
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if (this->Header->sh_type == SHT_NOBITS)
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return;
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ELFFile<ELFT> &EObj = this->File->getObj();
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// If -r is given, then an InputSection may be a relocation section.
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if (this->Header->sh_type == SHT_RELA) {
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copyRelocations(Buf + OutSecOff, EObj.relas(this->Header));
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return;
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}
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if (this->Header->sh_type == SHT_REL) {
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copyRelocations(Buf + OutSecOff, EObj.rels(this->Header));
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return;
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}
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// Copy section contents from source object file to output file.
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ArrayRef<uint8_t> Data = this->getSectionData();
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memcpy(Buf + OutSecOff, Data.data(), Data.size());
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// Iterate over all relocation sections that apply to this section.
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uint8_t *BufEnd = Buf + OutSecOff + Data.size();
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this->relocate(Buf, BufEnd);
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// The section might have a data/code generated by the linker and need
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// to be written after the section. Usually these are thunks - small piece
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// of code used to jump between "incompatible" functions like PIC and non-PIC
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// or if the jump target too far and its address does not fit to the short
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// jump istruction.
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if (!Thunks.empty()) {
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Buf += OutSecOff + getThunkOff();
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for (const Thunk<ELFT> *T : Thunks) {
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T->writeTo(Buf);
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Buf += T->size();
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}
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}
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}
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template <class ELFT>
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void InputSection<ELFT>::replace(InputSection<ELFT> *Other) {
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this->Alignment = std::max(this->Alignment, Other->Alignment);
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Other->Repl = this->Repl;
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|
Other->Live = false;
|
|
}
|
|
|
|
template <class ELFT>
|
|
EhInputSection<ELFT>::EhInputSection(elf::ObjectFile<ELFT> *F,
|
|
const Elf_Shdr *Header)
|
|
: InputSectionBase<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;
|
|
}
|
|
|
|
// Returns the index of the first relocation that points to a region between
|
|
// Begin and Begin+Size.
|
|
template <class IntTy, class RelTy>
|
|
static unsigned getReloc(IntTy Begin, IntTy Size, const ArrayRef<RelTy> &Rels,
|
|
unsigned &RelocI) {
|
|
// Start search from RelocI for fast access. That works because the
|
|
// relocations are sorted in .eh_frame.
|
|
for (unsigned N = Rels.size(); RelocI < N; ++RelocI) {
|
|
const RelTy &Rel = Rels[RelocI];
|
|
if (Rel.r_offset < Begin)
|
|
continue;
|
|
|
|
if (Rel.r_offset < Begin + Size)
|
|
return RelocI;
|
|
return -1;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
// .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() {
|
|
// Early exit if already split.
|
|
if (!this->Pieces.empty())
|
|
return;
|
|
|
|
if (RelocSection) {
|
|
ELFFile<ELFT> &Obj = this->File->getObj();
|
|
if (RelocSection->sh_type == SHT_RELA)
|
|
split(Obj.relas(RelocSection));
|
|
else
|
|
split(Obj.rels(RelocSection));
|
|
return;
|
|
}
|
|
split(makeArrayRef<typename ELFT::Rela>(nullptr, nullptr));
|
|
}
|
|
|
|
template <class ELFT>
|
|
template <class RelTy>
|
|
void EhInputSection<ELFT>::split(ArrayRef<RelTy> Rels) {
|
|
ArrayRef<uint8_t> Data = this->getSectionData();
|
|
unsigned RelI = 0;
|
|
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),
|
|
getReloc(Off, Size, Rels, RelI));
|
|
// The empty record is the end marker.
|
|
if (Size == 4)
|
|
break;
|
|
Off += Size;
|
|
}
|
|
}
|
|
|
|
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.
|
|
template <class ELFT>
|
|
std::vector<SectionPiece>
|
|
MergeInputSection<ELFT>::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(getName(this) + ": 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.
|
|
template <class ELFT>
|
|
std::vector<SectionPiece>
|
|
MergeInputSection<ELFT>::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)
|
|
: InputSectionBase<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 *MergeInputSection<ELFT>::getSectionPiece(uintX_t Offset) {
|
|
auto *This = static_cast<const MergeInputSection<ELFT> *>(this);
|
|
return const_cast<SectionPiece *>(This->getSectionPiece(Offset));
|
|
}
|
|
|
|
template <class ELFT>
|
|
const SectionPiece *
|
|
MergeInputSection<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(getName(this) + ": 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(getName(this) + ": 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(getName(this) + ": 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 <class ELFT>
|
|
MipsAbiFlagsInputSection<ELFT>::MipsAbiFlagsInputSection(
|
|
elf::ObjectFile<ELFT> *F, const Elf_Shdr *Hdr)
|
|
: InputSectionBase<ELFT>(F, Hdr, InputSectionBase<ELFT>::MipsAbiFlags) {
|
|
// Initialize this->Flags.
|
|
ArrayRef<uint8_t> D = this->getSectionData();
|
|
if (D.size() != sizeof(Elf_Mips_ABIFlags<ELFT>)) {
|
|
error("invalid size of .MIPS.abiflags section");
|
|
return;
|
|
}
|
|
Flags = reinterpret_cast<const Elf_Mips_ABIFlags<ELFT> *>(D.data());
|
|
}
|
|
|
|
template <class ELFT>
|
|
bool MipsAbiFlagsInputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
|
|
return S->SectionKind == InputSectionBase<ELFT>::MipsAbiFlags;
|
|
}
|
|
|
|
template <class ELFT>
|
|
CommonInputSection<ELFT>::CommonInputSection(std::vector<DefinedCommon *> Syms)
|
|
: InputSection<ELFT>(nullptr, &Hdr) {
|
|
Hdr.sh_size = 0;
|
|
Hdr.sh_type = SHT_NOBITS;
|
|
Hdr.sh_flags = SHF_ALLOC | SHF_WRITE;
|
|
this->Live = true;
|
|
|
|
// Sort the common symbols by alignment as an heuristic to pack them better.
|
|
std::stable_sort(Syms.begin(), Syms.end(),
|
|
[](const DefinedCommon *A, const DefinedCommon *B) {
|
|
return A->Alignment > B->Alignment;
|
|
});
|
|
|
|
for (DefinedCommon *Sym : Syms) {
|
|
this->Alignment = std::max<uintX_t>(this->Alignment, Sym->Alignment);
|
|
Hdr.sh_size = alignTo(Hdr.sh_size, Sym->Alignment);
|
|
|
|
// Compute symbol offset relative to beginning of input section.
|
|
Sym->Offset = Hdr.sh_size;
|
|
Hdr.sh_size += Sym->Size;
|
|
}
|
|
}
|
|
|
|
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::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>;
|
|
|
|
template class elf::MipsAbiFlagsInputSection<ELF32LE>;
|
|
template class elf::MipsAbiFlagsInputSection<ELF32BE>;
|
|
template class elf::MipsAbiFlagsInputSection<ELF64LE>;
|
|
template class elf::MipsAbiFlagsInputSection<ELF64BE>;
|
|
|
|
template class elf::CommonInputSection<ELF32LE>;
|
|
template class elf::CommonInputSection<ELF32BE>;
|
|
template class elf::CommonInputSection<ELF64LE>;
|
|
template class elf::CommonInputSection<ELF64BE>;
|