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diff --git a/contrib/llvm-project/lld/ELF/InputSection.cpp b/contrib/llvm-project/lld/ELF/InputSection.cpp
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+++ b/contrib/llvm-project/lld/ELF/InputSection.cpp
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+//===- InputSection.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 "InputSection.h"
+#include "Config.h"
+#include "EhFrame.h"
+#include "InputFiles.h"
+#include "LinkerScript.h"
+#include "OutputSections.h"
+#include "Relocations.h"
+#include "SymbolTable.h"
+#include "Symbols.h"
+#include "SyntheticSections.h"
+#include "Target.h"
+#include "Thunks.h"
+#include "lld/Common/ErrorHandler.h"
+#include "lld/Common/Memory.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Compression.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Threading.h"
+#include "llvm/Support/xxhash.h"
+#include <algorithm>
+#include <mutex>
+#include <set>
+#include <vector>
+
+using namespace llvm;
+using namespace llvm::ELF;
+using namespace llvm::object;
+using namespace llvm::support;
+using namespace llvm::support::endian;
+using namespace llvm::sys;
+
+using namespace lld;
+using namespace lld::elf;
+
+std::vector<InputSectionBase *> elf::inputSections;
+
+// Returns a string to construct an error message.
+std::string lld::toString(const InputSectionBase *sec) {
+ return (toString(sec->file) + ":(" + sec->name + ")").str();
+}
+
+template <class ELFT>
+static ArrayRef<uint8_t> getSectionContents(ObjFile<ELFT> &file,
+ const typename ELFT::Shdr &hdr) {
+ if (hdr.sh_type == SHT_NOBITS)
+ return makeArrayRef<uint8_t>(nullptr, hdr.sh_size);
+ return check(file.getObj().getSectionContents(&hdr));
+}
+
+InputSectionBase::InputSectionBase(InputFile *file, uint64_t flags,
+ uint32_t type, uint64_t entsize,
+ uint32_t link, uint32_t info,
+ uint32_t alignment, ArrayRef<uint8_t> data,
+ StringRef name, Kind sectionKind)
+ : SectionBase(sectionKind, name, flags, entsize, alignment, type, info,
+ link),
+ file(file), rawData(data) {
+ // In order to reduce memory allocation, we assume that mergeable
+ // sections are smaller than 4 GiB, which is not an unreasonable
+ // assumption as of 2017.
+ if (sectionKind == SectionBase::Merge && rawData.size() > UINT32_MAX)
+ error(toString(this) + ": section too large");
+
+ numRelocations = 0;
+ areRelocsRela = false;
+
+ // The ELF spec states that a value of 0 means the section has
+ // no alignment constraits.
+ uint32_t v = std::max<uint32_t>(alignment, 1);
+ if (!isPowerOf2_64(v))
+ fatal(toString(this) + ": sh_addralign is not a power of 2");
+ this->alignment = v;
+
+ // In ELF, each section can be compressed by zlib, and if compressed,
+ // section name may be mangled by appending "z" (e.g. ".zdebug_info").
+ // If that's the case, demangle section name so that we can handle a
+ // section as if it weren't compressed.
+ if ((flags & SHF_COMPRESSED) || name.startswith(".zdebug")) {
+ if (!zlib::isAvailable())
+ error(toString(file) + ": contains a compressed section, " +
+ "but zlib is not available");
+ parseCompressedHeader();
+ }
+}
+
+// Drop SHF_GROUP bit unless we are producing a re-linkable object file.
+// SHF_GROUP is a marker that a section belongs to some comdat group.
+// That flag doesn't make sense in an executable.
+static uint64_t getFlags(uint64_t flags) {
+ flags &= ~(uint64_t)SHF_INFO_LINK;
+ if (!config->relocatable)
+ flags &= ~(uint64_t)SHF_GROUP;
+ return flags;
+}
+
+// GNU assembler 2.24 and LLVM 4.0.0's MC (the newest release as of
+// March 2017) fail to infer section types for sections starting with
+// ".init_array." or ".fini_array.". They set SHT_PROGBITS instead of
+// SHF_INIT_ARRAY. As a result, the following assembler directive
+// creates ".init_array.100" with SHT_PROGBITS, for example.
+//
+// .section .init_array.100, "aw"
+//
+// This function forces SHT_{INIT,FINI}_ARRAY so that we can handle
+// incorrect inputs as if they were correct from the beginning.
+static uint64_t getType(uint64_t type, StringRef name) {
+ if (type == SHT_PROGBITS && name.startswith(".init_array."))
+ return SHT_INIT_ARRAY;
+ if (type == SHT_PROGBITS && name.startswith(".fini_array."))
+ return SHT_FINI_ARRAY;
+ return type;
+}
+
+template <class ELFT>
+InputSectionBase::InputSectionBase(ObjFile<ELFT> &file,
+ const typename ELFT::Shdr &hdr,
+ StringRef name, Kind sectionKind)
+ : InputSectionBase(&file, getFlags(hdr.sh_flags),
+ getType(hdr.sh_type, name), hdr.sh_entsize, hdr.sh_link,
+ hdr.sh_info, hdr.sh_addralign,
+ getSectionContents(file, hdr), name, sectionKind) {
+ // We reject object files having insanely large alignments even though
+ // they are allowed by the spec. I think 4GB is a reasonable limitation.
+ // We might want to relax this in the future.
+ if (hdr.sh_addralign > UINT32_MAX)
+ fatal(toString(&file) + ": section sh_addralign is too large");
+}
+
+size_t InputSectionBase::getSize() const {
+ if (auto *s = dyn_cast<SyntheticSection>(this))
+ return s->getSize();
+ if (uncompressedSize >= 0)
+ return uncompressedSize;
+ return rawData.size();
+}
+
+void InputSectionBase::uncompress() const {
+ size_t size = uncompressedSize;
+ char *uncompressedBuf;
+ {
+ static std::mutex mu;
+ std::lock_guard<std::mutex> lock(mu);
+ uncompressedBuf = bAlloc.Allocate<char>(size);
+ }
+
+ if (Error e = zlib::uncompress(toStringRef(rawData), uncompressedBuf, size))
+ fatal(toString(this) +
+ ": uncompress failed: " + llvm::toString(std::move(e)));
+ rawData = makeArrayRef((uint8_t *)uncompressedBuf, size);
+ uncompressedSize = -1;
+}
+
+uint64_t InputSectionBase::getOffsetInFile() const {
+ const uint8_t *fileStart = (const uint8_t *)file->mb.getBufferStart();
+ const uint8_t *secStart = data().begin();
+ return secStart - fileStart;
+}
+
+uint64_t SectionBase::getOffset(uint64_t offset) const {
+ switch (kind()) {
+ case Output: {
+ auto *os = cast<OutputSection>(this);
+ // For output sections we treat offset -1 as the end of the section.
+ return offset == uint64_t(-1) ? os->size : offset;
+ }
+ case Regular:
+ case Synthetic:
+ return cast<InputSection>(this)->getOffset(offset);
+ case EHFrame:
+ // 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.
+ return offset;
+ case Merge:
+ const MergeInputSection *ms = cast<MergeInputSection>(this);
+ if (InputSection *isec = ms->getParent())
+ return isec->getOffset(ms->getParentOffset(offset));
+ return ms->getParentOffset(offset);
+ }
+ llvm_unreachable("invalid section kind");
+}
+
+uint64_t SectionBase::getVA(uint64_t offset) const {
+ const OutputSection *out = getOutputSection();
+ return (out ? out->addr : 0) + getOffset(offset);
+}
+
+OutputSection *SectionBase::getOutputSection() {
+ InputSection *sec;
+ if (auto *isec = dyn_cast<InputSection>(this))
+ sec = isec;
+ else if (auto *ms = dyn_cast<MergeInputSection>(this))
+ sec = ms->getParent();
+ else if (auto *eh = dyn_cast<EhInputSection>(this))
+ sec = eh->getParent();
+ else
+ return cast<OutputSection>(this);
+ return sec ? sec->getParent() : nullptr;
+}
+
+// When a section is compressed, `rawData` consists with a header followed
+// by zlib-compressed data. This function parses a header to initialize
+// `uncompressedSize` member and remove the header from `rawData`.
+void InputSectionBase::parseCompressedHeader() {
+ using Chdr64 = typename ELF64LE::Chdr;
+ using Chdr32 = typename ELF32LE::Chdr;
+
+ // Old-style header
+ if (name.startswith(".zdebug")) {
+ if (!toStringRef(rawData).startswith("ZLIB")) {
+ error(toString(this) + ": corrupted compressed section header");
+ return;
+ }
+ rawData = rawData.slice(4);
+
+ if (rawData.size() < 8) {
+ error(toString(this) + ": corrupted compressed section header");
+ return;
+ }
+
+ uncompressedSize = read64be(rawData.data());
+ rawData = rawData.slice(8);
+
+ // Restore the original section name.
+ // (e.g. ".zdebug_info" -> ".debug_info")
+ name = saver.save("." + name.substr(2));
+ return;
+ }
+
+ assert(flags & SHF_COMPRESSED);
+ flags &= ~(uint64_t)SHF_COMPRESSED;
+
+ // New-style 64-bit header
+ if (config->is64) {
+ if (rawData.size() < sizeof(Chdr64)) {
+ error(toString(this) + ": corrupted compressed section");
+ return;
+ }
+
+ auto *hdr = reinterpret_cast<const Chdr64 *>(rawData.data());
+ if (hdr->ch_type != ELFCOMPRESS_ZLIB) {
+ error(toString(this) + ": unsupported compression type");
+ return;
+ }
+
+ uncompressedSize = hdr->ch_size;
+ alignment = std::max<uint32_t>(hdr->ch_addralign, 1);
+ rawData = rawData.slice(sizeof(*hdr));
+ return;
+ }
+
+ // New-style 32-bit header
+ if (rawData.size() < sizeof(Chdr32)) {
+ error(toString(this) + ": corrupted compressed section");
+ return;
+ }
+
+ auto *hdr = reinterpret_cast<const Chdr32 *>(rawData.data());
+ if (hdr->ch_type != ELFCOMPRESS_ZLIB) {
+ error(toString(this) + ": unsupported compression type");
+ return;
+ }
+
+ uncompressedSize = hdr->ch_size;
+ alignment = std::max<uint32_t>(hdr->ch_addralign, 1);
+ rawData = rawData.slice(sizeof(*hdr));
+}
+
+InputSection *InputSectionBase::getLinkOrderDep() const {
+ assert(link);
+ assert(flags & SHF_LINK_ORDER);
+ return cast<InputSection>(file->getSections()[link]);
+}
+
+// Find a function symbol that encloses a given location.
+template <class ELFT>
+Defined *InputSectionBase::getEnclosingFunction(uint64_t offset) {
+ for (Symbol *b : file->getSymbols())
+ if (Defined *d = dyn_cast<Defined>(b))
+ if (d->section == this && d->type == STT_FUNC && d->value <= offset &&
+ offset < d->value + d->size)
+ return d;
+ return nullptr;
+}
+
+// Returns a source location string. Used to construct an error message.
+template <class ELFT>
+std::string InputSectionBase::getLocation(uint64_t offset) {
+ std::string secAndOffset = (name + "+0x" + utohexstr(offset)).str();
+
+ // We don't have file for synthetic sections.
+ if (getFile<ELFT>() == nullptr)
+ return (config->outputFile + ":(" + secAndOffset + ")")
+ .str();
+
+ // First check if we can get desired values from debugging information.
+ if (Optional<DILineInfo> info = getFile<ELFT>()->getDILineInfo(this, offset))
+ return info->FileName + ":" + std::to_string(info->Line) + ":(" +
+ secAndOffset + ")";
+
+ // File->sourceFile contains STT_FILE symbol that contains a
+ // source file name. If it's missing, we use an object file name.
+ std::string srcFile = getFile<ELFT>()->sourceFile;
+ if (srcFile.empty())
+ srcFile = toString(file);
+
+ if (Defined *d = getEnclosingFunction<ELFT>(offset))
+ return srcFile + ":(function " + toString(*d) + ": " + secAndOffset + ")";
+
+ // If there's no symbol, print out the offset in the section.
+ return (srcFile + ":(" + secAndOffset + ")");
+}
+
+// This function is intended to be used for constructing an error message.
+// The returned message looks like this:
+//
+// foo.c:42 (/home/alice/possibly/very/long/path/foo.c:42)
+//
+// Returns an empty string if there's no way to get line info.
+std::string InputSectionBase::getSrcMsg(const Symbol &sym, uint64_t offset) {
+ return file->getSrcMsg(sym, *this, offset);
+}
+
+// Returns a filename string along with an optional section name. This
+// function is intended to be used for constructing an error
+// message. The returned message looks like this:
+//
+// path/to/foo.o:(function bar)
+//
+// or
+//
+// path/to/foo.o:(function bar) in archive path/to/bar.a
+std::string InputSectionBase::getObjMsg(uint64_t off) {
+ std::string filename = file->getName();
+
+ std::string archive;
+ if (!file->archiveName.empty())
+ archive = " in archive " + file->archiveName;
+
+ // Find a symbol that encloses a given location.
+ for (Symbol *b : file->getSymbols())
+ if (auto *d = dyn_cast<Defined>(b))
+ if (d->section == this && d->value <= off && off < d->value + d->size)
+ return filename + ":(" + toString(*d) + ")" + archive;
+
+ // If there's no symbol, print out the offset in the section.
+ return (filename + ":(" + name + "+0x" + utohexstr(off) + ")" + archive)
+ .str();
+}
+
+InputSection InputSection::discarded(nullptr, 0, 0, 0, ArrayRef<uint8_t>(), "");
+
+InputSection::InputSection(InputFile *f, uint64_t flags, uint32_t type,
+ uint32_t alignment, ArrayRef<uint8_t> data,
+ StringRef name, Kind k)
+ : InputSectionBase(f, flags, type,
+ /*Entsize*/ 0, /*Link*/ 0, /*Info*/ 0, alignment, data,
+ name, k) {}
+
+template <class ELFT>
+InputSection::InputSection(ObjFile<ELFT> &f, const typename ELFT::Shdr &header,
+ StringRef name)
+ : InputSectionBase(f, header, name, InputSectionBase::Regular) {}
+
+bool InputSection::classof(const SectionBase *s) {
+ return s->kind() == SectionBase::Regular ||
+ s->kind() == SectionBase::Synthetic;
+}
+
+OutputSection *InputSection::getParent() const {
+ return cast_or_null<OutputSection>(parent);
+}
+
+// Copy SHT_GROUP section contents. Used only for the -r option.
+template <class ELFT> void InputSection::copyShtGroup(uint8_t *buf) {
+ // ELFT::Word is the 32-bit integral type in the target endianness.
+ using u32 = typename ELFT::Word;
+ ArrayRef<u32> from = getDataAs<u32>();
+ auto *to = reinterpret_cast<u32 *>(buf);
+
+ // The first entry is not a section number but a flag.
+ *to++ = from[0];
+
+ // Adjust section numbers because section numbers in an input object
+ // files are different in the output.
+ ArrayRef<InputSectionBase *> sections = file->getSections();
+ for (uint32_t idx : from.slice(1))
+ *to++ = sections[idx]->getOutputSection()->sectionIndex;
+}
+
+InputSectionBase *InputSection::getRelocatedSection() const {
+ if (!file || (type != SHT_RELA && type != SHT_REL))
+ return nullptr;
+ ArrayRef<InputSectionBase *> sections = file->getSections();
+ return sections[info];
+}
+
+// This is used for -r and --emit-relocs. 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, class RelTy>
+void InputSection::copyRelocations(uint8_t *buf, ArrayRef<RelTy> rels) {
+ InputSectionBase *sec = getRelocatedSection();
+
+ for (const RelTy &rel : rels) {
+ RelType type = rel.getType(config->isMips64EL);
+ const ObjFile<ELFT> *file = getFile<ELFT>();
+ Symbol &sym = file->getRelocTargetSym(rel);
+
+ auto *p = reinterpret_cast<typename ELFT::Rela *>(buf);
+ buf += sizeof(RelTy);
+
+ if (RelTy::IsRela)
+ p->r_addend = getAddend<ELFT>(rel);
+
+ // Output section VA is zero for -r, so r_offset is an offset within the
+ // section, but for --emit-relocs it is an virtual address.
+ p->r_offset = sec->getVA(rel.r_offset);
+ p->setSymbolAndType(in.symTab->getSymbolIndex(&sym), type,
+ config->isMips64EL);
+
+ if (sym.type == STT_SECTION) {
+ // We combine multiple section symbols into only one per
+ // section. This means we have to update the addend. That is
+ // trivial for Elf_Rela, but for Elf_Rel we have to write to the
+ // section data. We do that by adding to the Relocation vector.
+
+ // .eh_frame is horribly special and can reference discarded sections. To
+ // avoid having to parse and recreate .eh_frame, we just replace any
+ // relocation in it pointing to discarded sections with R_*_NONE, which
+ // hopefully creates a frame that is ignored at runtime. Also, don't warn
+ // on .gcc_except_table and debug sections.
+ //
+ // See the comment in maybeReportUndefined for PPC64 .toc .
+ auto *d = dyn_cast<Defined>(&sym);
+ if (!d) {
+ if (!sec->name.startswith(".debug") &&
+ !sec->name.startswith(".zdebug") && sec->name != ".eh_frame" &&
+ sec->name != ".gcc_except_table" && sec->name != ".toc") {
+ uint32_t secIdx = cast<Undefined>(sym).discardedSecIdx;
+ Elf_Shdr_Impl<ELFT> sec =
+ CHECK(file->getObj().sections(), file)[secIdx];
+ warn("relocation refers to a discarded section: " +
+ CHECK(file->getObj().getSectionName(&sec), file) +
+ "\n>>> referenced by " + getObjMsg(p->r_offset));
+ }
+ p->setSymbolAndType(0, 0, false);
+ continue;
+ }
+ SectionBase *section = d->section->repl;
+ if (!section->isLive()) {
+ p->setSymbolAndType(0, 0, false);
+ continue;
+ }
+
+ int64_t addend = getAddend<ELFT>(rel);
+ const uint8_t *bufLoc = sec->data().begin() + rel.r_offset;
+ if (!RelTy::IsRela)
+ addend = target->getImplicitAddend(bufLoc, type);
+
+ if (config->emachine == EM_MIPS && config->relocatable &&
+ target->getRelExpr(type, sym, bufLoc) == R_MIPS_GOTREL) {
+ // Some MIPS relocations depend on "gp" value. By default,
+ // this value has 0x7ff0 offset from a .got section. But
+ // relocatable files produced by a complier or a linker
+ // might redefine this default value and we must use it
+ // for a calculation of the relocation result. When we
+ // generate EXE or DSO it's trivial. Generating a relocatable
+ // output is more difficult case because the linker does
+ // not calculate relocations in this mode and loses
+ // individual "gp" values used by each input object file.
+ // As a workaround we add the "gp" value to the relocation
+ // addend and save it back to the file.
+ addend += sec->getFile<ELFT>()->mipsGp0;
+ }
+
+ if (RelTy::IsRela)
+ p->r_addend = sym.getVA(addend) - section->getOutputSection()->addr;
+ else if (config->relocatable && type != target->noneRel)
+ sec->relocations.push_back({R_ABS, type, rel.r_offset, addend, &sym});
+ }
+ }
+}
+
+// The ARM and AArch64 ABI handle pc-relative relocations to undefined weak
+// references specially. The general rule is that the value of the symbol in
+// this context is the address of the place P. A further special case is that
+// branch relocations to an undefined weak reference resolve to the next
+// instruction.
+static uint32_t getARMUndefinedRelativeWeakVA(RelType type, uint32_t a,
+ uint32_t p) {
+ switch (type) {
+ // Unresolved branch relocations to weak references resolve to next
+ // instruction, this will be either 2 or 4 bytes on from P.
+ case R_ARM_THM_JUMP11:
+ return p + 2 + a;
+ case R_ARM_CALL:
+ case R_ARM_JUMP24:
+ case R_ARM_PC24:
+ case R_ARM_PLT32:
+ case R_ARM_PREL31:
+ case R_ARM_THM_JUMP19:
+ case R_ARM_THM_JUMP24:
+ return p + 4 + a;
+ case R_ARM_THM_CALL:
+ // We don't want an interworking BLX to ARM
+ return p + 5 + a;
+ // Unresolved non branch pc-relative relocations
+ // R_ARM_TARGET2 which can be resolved relatively is not present as it never
+ // targets a weak-reference.
+ case R_ARM_MOVW_PREL_NC:
+ case R_ARM_MOVT_PREL:
+ case R_ARM_REL32:
+ case R_ARM_THM_MOVW_PREL_NC:
+ case R_ARM_THM_MOVT_PREL:
+ return p + a;
+ }
+ llvm_unreachable("ARM pc-relative relocation expected\n");
+}
+
+// The comment above getARMUndefinedRelativeWeakVA applies to this function.
+static uint64_t getAArch64UndefinedRelativeWeakVA(uint64_t type, uint64_t a,
+ uint64_t p) {
+ switch (type) {
+ // Unresolved branch relocations to weak references resolve to next
+ // instruction, this is 4 bytes on from P.
+ case R_AARCH64_CALL26:
+ case R_AARCH64_CONDBR19:
+ case R_AARCH64_JUMP26:
+ case R_AARCH64_TSTBR14:
+ return p + 4 + a;
+ // Unresolved non branch pc-relative relocations
+ case R_AARCH64_PREL16:
+ case R_AARCH64_PREL32:
+ case R_AARCH64_PREL64:
+ case R_AARCH64_ADR_PREL_LO21:
+ case R_AARCH64_LD_PREL_LO19:
+ return p + a;
+ }
+ llvm_unreachable("AArch64 pc-relative relocation expected\n");
+}
+
+// ARM SBREL relocations are of the form S + A - B where B is the static base
+// The ARM ABI defines base to be "addressing origin of the output segment
+// defining the symbol S". We defined the "addressing origin"/static base to be
+// the base of the PT_LOAD segment containing the Sym.
+// The procedure call standard only defines a Read Write Position Independent
+// RWPI variant so in practice we should expect the static base to be the base
+// of the RW segment.
+static uint64_t getARMStaticBase(const Symbol &sym) {
+ OutputSection *os = sym.getOutputSection();
+ if (!os || !os->ptLoad || !os->ptLoad->firstSec)
+ fatal("SBREL relocation to " + sym.getName() + " without static base");
+ return os->ptLoad->firstSec->addr;
+}
+
+// For R_RISCV_PC_INDIRECT (R_RISCV_PCREL_LO12_{I,S}), the symbol actually
+// points the corresponding R_RISCV_PCREL_HI20 relocation, and the target VA
+// is calculated using PCREL_HI20's symbol.
+//
+// This function returns the R_RISCV_PCREL_HI20 relocation from
+// R_RISCV_PCREL_LO12's symbol and addend.
+static Relocation *getRISCVPCRelHi20(const Symbol *sym, uint64_t addend) {
+ const Defined *d = cast<Defined>(sym);
+ if (!d->section) {
+ error("R_RISCV_PCREL_LO12 relocation points to an absolute symbol: " +
+ sym->getName());
+ return nullptr;
+ }
+ InputSection *isec = cast<InputSection>(d->section);
+
+ if (addend != 0)
+ warn("Non-zero addend in R_RISCV_PCREL_LO12 relocation to " +
+ isec->getObjMsg(d->value) + " is ignored");
+
+ // Relocations are sorted by offset, so we can use std::equal_range to do
+ // binary search.
+ Relocation r;
+ r.offset = d->value;
+ auto range =
+ std::equal_range(isec->relocations.begin(), isec->relocations.end(), r,
+ [](const Relocation &lhs, const Relocation &rhs) {
+ return lhs.offset < rhs.offset;
+ });
+
+ for (auto it = range.first; it != range.second; ++it)
+ if (it->type == R_RISCV_PCREL_HI20 || it->type == R_RISCV_GOT_HI20 ||
+ it->type == R_RISCV_TLS_GD_HI20 || it->type == R_RISCV_TLS_GOT_HI20)
+ return &*it;
+
+ error("R_RISCV_PCREL_LO12 relocation points to " + isec->getObjMsg(d->value) +
+ " without an associated R_RISCV_PCREL_HI20 relocation");
+ return nullptr;
+}
+
+// A TLS symbol's virtual address is relative to the TLS segment. Add a
+// target-specific adjustment to produce a thread-pointer-relative offset.
+static int64_t getTlsTpOffset(const Symbol &s) {
+ // On targets that support TLSDESC, _TLS_MODULE_BASE_@tpoff = 0.
+ if (&s == ElfSym::tlsModuleBase)
+ return 0;
+
+ switch (config->emachine) {
+ case EM_ARM:
+ case EM_AARCH64:
+ // Variant 1. The thread pointer points to a TCB with a fixed 2-word size,
+ // followed by a variable amount of alignment padding, followed by the TLS
+ // segment.
+ return s.getVA(0) + alignTo(config->wordsize * 2, Out::tlsPhdr->p_align);
+ case EM_386:
+ case EM_X86_64:
+ // Variant 2. The TLS segment is located just before the thread pointer.
+ return s.getVA(0) - alignTo(Out::tlsPhdr->p_memsz, Out::tlsPhdr->p_align);
+ case EM_PPC:
+ case EM_PPC64:
+ // The thread pointer points to a fixed offset from the start of the
+ // executable's TLS segment. An offset of 0x7000 allows a signed 16-bit
+ // offset to reach 0x1000 of TCB/thread-library data and 0xf000 of the
+ // program's TLS segment.
+ return s.getVA(0) - 0x7000;
+ case EM_RISCV:
+ return s.getVA(0);
+ default:
+ llvm_unreachable("unhandled Config->EMachine");
+ }
+}
+
+static uint64_t getRelocTargetVA(const InputFile *file, RelType type, int64_t a,
+ uint64_t p, const Symbol &sym, RelExpr expr) {
+ switch (expr) {
+ case R_ABS:
+ case R_DTPREL:
+ case R_RELAX_TLS_LD_TO_LE_ABS:
+ case R_RELAX_GOT_PC_NOPIC:
+ case R_RISCV_ADD:
+ return sym.getVA(a);
+ case R_ADDEND:
+ return a;
+ case R_ARM_SBREL:
+ return sym.getVA(a) - getARMStaticBase(sym);
+ case R_GOT:
+ case R_RELAX_TLS_GD_TO_IE_ABS:
+ return sym.getGotVA() + a;
+ case R_GOTONLY_PC:
+ return in.got->getVA() + a - p;
+ case R_GOTPLTONLY_PC:
+ return in.gotPlt->getVA() + a - p;
+ case R_GOTREL:
+ case R_PPC64_RELAX_TOC:
+ return sym.getVA(a) - in.got->getVA();
+ case R_GOTPLTREL:
+ return sym.getVA(a) - in.gotPlt->getVA();
+ case R_GOTPLT:
+ case R_RELAX_TLS_GD_TO_IE_GOTPLT:
+ return sym.getGotVA() + a - in.gotPlt->getVA();
+ case R_TLSLD_GOT_OFF:
+ case R_GOT_OFF:
+ case R_RELAX_TLS_GD_TO_IE_GOT_OFF:
+ return sym.getGotOffset() + a;
+ case R_AARCH64_GOT_PAGE_PC:
+ case R_AARCH64_RELAX_TLS_GD_TO_IE_PAGE_PC:
+ return getAArch64Page(sym.getGotVA() + a) - getAArch64Page(p);
+ case R_GOT_PC:
+ case R_RELAX_TLS_GD_TO_IE:
+ return sym.getGotVA() + a - p;
+ case R_HEXAGON_GOT:
+ return sym.getGotVA() - in.gotPlt->getVA();
+ case R_MIPS_GOTREL:
+ return sym.getVA(a) - in.mipsGot->getGp(file);
+ case R_MIPS_GOT_GP:
+ return in.mipsGot->getGp(file) + a;
+ case R_MIPS_GOT_GP_PC: {
+ // R_MIPS_LO16 expression has R_MIPS_GOT_GP_PC type iif the target
+ // is _gp_disp symbol. In that case we should use the following
+ // formula for calculation "AHL + GP - P + 4". For details see p. 4-19 at
+ // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
+ // microMIPS variants of these relocations use slightly different
+ // expressions: AHL + GP - P + 3 for %lo() and AHL + GP - P - 1 for %hi()
+ // to correctly handle less-sugnificant bit of the microMIPS symbol.
+ uint64_t v = in.mipsGot->getGp(file) + a - p;
+ if (type == R_MIPS_LO16 || type == R_MICROMIPS_LO16)
+ v += 4;
+ if (type == R_MICROMIPS_LO16 || type == R_MICROMIPS_HI16)
+ v -= 1;
+ return v;
+ }
+ 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 in.mipsGot->getVA() + in.mipsGot->getPageEntryOffset(file, sym, a) -
+ in.mipsGot->getGp(file);
+ case R_MIPS_GOT_OFF:
+ case R_MIPS_GOT_OFF32:
+ // 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 in.mipsGot->getVA() + in.mipsGot->getSymEntryOffset(file, sym, a) -
+ in.mipsGot->getGp(file);
+ case R_MIPS_TLSGD:
+ return in.mipsGot->getVA() + in.mipsGot->getGlobalDynOffset(file, sym) -
+ in.mipsGot->getGp(file);
+ case R_MIPS_TLSLD:
+ return in.mipsGot->getVA() + in.mipsGot->getTlsIndexOffset(file) -
+ in.mipsGot->getGp(file);
+ case R_AARCH64_PAGE_PC: {
+ uint64_t val = sym.isUndefWeak() ? p + a : sym.getVA(a);
+ return getAArch64Page(val) - getAArch64Page(p);
+ }
+ case R_RISCV_PC_INDIRECT: {
+ if (const Relocation *hiRel = getRISCVPCRelHi20(&sym, a))
+ return getRelocTargetVA(file, hiRel->type, hiRel->addend, sym.getVA(),
+ *hiRel->sym, hiRel->expr);
+ return 0;
+ }
+ case R_PC: {
+ uint64_t dest;
+ if (sym.isUndefWeak()) {
+ // On ARM and AArch64 a branch to an undefined weak resolves to the
+ // next instruction, otherwise the place.
+ if (config->emachine == EM_ARM)
+ dest = getARMUndefinedRelativeWeakVA(type, a, p);
+ else if (config->emachine == EM_AARCH64)
+ dest = getAArch64UndefinedRelativeWeakVA(type, a, p);
+ else if (config->emachine == EM_PPC)
+ dest = p;
+ else
+ dest = sym.getVA(a);
+ } else {
+ dest = sym.getVA(a);
+ }
+ return dest - p;
+ }
+ case R_PLT:
+ return sym.getPltVA() + a;
+ case R_PLT_PC:
+ case R_PPC64_CALL_PLT:
+ return sym.getPltVA() + a - p;
+ case R_PPC32_PLTREL:
+ // R_PPC_PLTREL24 uses the addend (usually 0 or 0x8000) to indicate r30
+ // stores _GLOBAL_OFFSET_TABLE_ or .got2+0x8000. The addend is ignored for
+ // target VA compuation.
+ return sym.getPltVA() - p;
+ case R_PPC64_CALL: {
+ uint64_t symVA = sym.getVA(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;
+
+ // PPC64 V2 ABI describes two entry points to a function. The global entry
+ // point is used for calls where the caller and callee (may) have different
+ // TOC base pointers and r2 needs to be modified to hold the TOC base for
+ // the callee. For local calls the caller and callee share the same
+ // TOC base and so the TOC pointer initialization code should be skipped by
+ // branching to the local entry point.
+ return symVA - p + getPPC64GlobalEntryToLocalEntryOffset(sym.stOther);
+ }
+ case R_PPC64_TOCBASE:
+ return getPPC64TocBase() + a;
+ case R_RELAX_GOT_PC:
+ return sym.getVA(a) - p;
+ case R_RELAX_TLS_GD_TO_LE:
+ case R_RELAX_TLS_IE_TO_LE:
+ case R_RELAX_TLS_LD_TO_LE:
+ case R_TLS:
+ // It is not very clear what to return if the symbol is undefined. With
+ // --noinhibit-exec, even a non-weak undefined reference may reach here.
+ // Just return A, which matches R_ABS, and the behavior of some dynamic
+ // loaders.
+ if (sym.isUndefined())
+ return a;
+ return getTlsTpOffset(sym) + a;
+ case R_RELAX_TLS_GD_TO_LE_NEG:
+ case R_NEG_TLS:
+ if (sym.isUndefined())
+ return a;
+ return -getTlsTpOffset(sym) + a;
+ case R_SIZE:
+ return sym.getSize() + a;
+ case R_TLSDESC:
+ return in.got->getGlobalDynAddr(sym) + a;
+ case R_TLSDESC_PC:
+ return in.got->getGlobalDynAddr(sym) + a - p;
+ case R_AARCH64_TLSDESC_PAGE:
+ return getAArch64Page(in.got->getGlobalDynAddr(sym) + a) -
+ getAArch64Page(p);
+ case R_TLSGD_GOT:
+ return in.got->getGlobalDynOffset(sym) + a;
+ case R_TLSGD_GOTPLT:
+ return in.got->getVA() + in.got->getGlobalDynOffset(sym) + a - in.gotPlt->getVA();
+ case R_TLSGD_PC:
+ return in.got->getGlobalDynAddr(sym) + a - p;
+ case R_TLSLD_GOTPLT:
+ return in.got->getVA() + in.got->getTlsIndexOff() + a - in.gotPlt->getVA();
+ case R_TLSLD_GOT:
+ return in.got->getTlsIndexOff() + a;
+ case R_TLSLD_PC:
+ return in.got->getTlsIndexVA() + a - p;
+ default:
+ 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, class RelTy>
+void InputSection::relocateNonAlloc(uint8_t *buf, ArrayRef<RelTy> rels) {
+ const unsigned bits = sizeof(typename ELFT::uint) * 8;
+
+ for (const RelTy &rel : rels) {
+ RelType type = rel.getType(config->isMips64EL);
+
+ // GCC 8.0 or earlier have a bug that they emit R_386_GOTPC relocations
+ // against _GLOBAL_OFFSET_TABLE_ for .debug_info. The bug has been fixed
+ // in 2017 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82630), but we
+ // need to keep this bug-compatible code for a while.
+ if (config->emachine == EM_386 && type == R_386_GOTPC)
+ continue;
+
+ uint64_t offset = getOffset(rel.r_offset);
+ uint8_t *bufLoc = buf + offset;
+ int64_t addend = getAddend<ELFT>(rel);
+ if (!RelTy::IsRela)
+ addend += target->getImplicitAddend(bufLoc, type);
+
+ Symbol &sym = getFile<ELFT>()->getRelocTargetSym(rel);
+ RelExpr expr = target->getRelExpr(type, sym, bufLoc);
+ if (expr == R_NONE)
+ continue;
+
+ if (expr != R_ABS && expr != R_DTPREL && expr != R_RISCV_ADD) {
+ std::string msg = getLocation<ELFT>(offset) +
+ ": has non-ABS relocation " + toString(type) +
+ " against symbol '" + toString(sym) + "'";
+ if (expr != R_PC) {
+ error(msg);
+ return;
+ }
+
+ // If the control reaches here, we found a PC-relative relocation in a
+ // non-ALLOC section. Since non-ALLOC section is not loaded into memory
+ // at runtime, the notion of PC-relative doesn't make sense here. So,
+ // this is a usage error. However, GNU linkers historically accept such
+ // relocations without any errors and relocate them as if they were at
+ // address 0. For bug-compatibilty, we accept them with warnings. We
+ // know Steel Bank Common Lisp as of 2018 have this bug.
+ warn(msg);
+ target->relocateOne(bufLoc, type,
+ SignExtend64<bits>(sym.getVA(addend - offset)));
+ continue;
+ }
+
+ if (sym.isTls() && !Out::tlsPhdr)
+ target->relocateOne(bufLoc, type, 0);
+ else
+ target->relocateOne(bufLoc, type, SignExtend64<bits>(sym.getVA(addend)));
+ }
+}
+
+// This is used when '-r' is given.
+// For REL targets, InputSection::copyRelocations() may store artificial
+// relocations aimed to update addends. They are handled in relocateAlloc()
+// for allocatable sections, and this function does the same for
+// non-allocatable sections, such as sections with debug information.
+static void relocateNonAllocForRelocatable(InputSection *sec, uint8_t *buf) {
+ const unsigned bits = config->is64 ? 64 : 32;
+
+ for (const Relocation &rel : sec->relocations) {
+ // InputSection::copyRelocations() adds only R_ABS relocations.
+ assert(rel.expr == R_ABS);
+ uint8_t *bufLoc = buf + rel.offset + sec->outSecOff;
+ uint64_t targetVA = SignExtend64(rel.sym->getVA(rel.addend), bits);
+ target->relocateOne(bufLoc, rel.type, targetVA);
+ }
+}
+
+template <class ELFT>
+void InputSectionBase::relocate(uint8_t *buf, uint8_t *bufEnd) {
+ if (flags & SHF_EXECINSTR)
+ adjustSplitStackFunctionPrologues<ELFT>(buf, bufEnd);
+
+ if (flags & SHF_ALLOC) {
+ relocateAlloc(buf, bufEnd);
+ return;
+ }
+
+ auto *sec = cast<InputSection>(this);
+ if (config->relocatable)
+ relocateNonAllocForRelocatable(sec, buf);
+ else if (sec->areRelocsRela)
+ sec->relocateNonAlloc<ELFT>(buf, sec->template relas<ELFT>());
+ else
+ sec->relocateNonAlloc<ELFT>(buf, sec->template rels<ELFT>());
+}
+
+void InputSectionBase::relocateAlloc(uint8_t *buf, uint8_t *bufEnd) {
+ assert(flags & SHF_ALLOC);
+ const unsigned bits = config->wordsize * 8;
+
+ for (const Relocation &rel : relocations) {
+ uint64_t offset = rel.offset;
+ if (auto *sec = dyn_cast<InputSection>(this))
+ offset += sec->outSecOff;
+ uint8_t *bufLoc = buf + offset;
+ RelType type = rel.type;
+
+ uint64_t addrLoc = getOutputSection()->addr + offset;
+ RelExpr expr = rel.expr;
+ uint64_t targetVA = SignExtend64(
+ getRelocTargetVA(file, type, rel.addend, addrLoc, *rel.sym, expr),
+ bits);
+
+ switch (expr) {
+ case R_RELAX_GOT_PC:
+ case R_RELAX_GOT_PC_NOPIC:
+ target->relaxGot(bufLoc, type, targetVA);
+ break;
+ case R_PPC64_RELAX_TOC:
+ if (!tryRelaxPPC64TocIndirection(type, rel, bufLoc))
+ target->relocateOne(bufLoc, type, targetVA);
+ break;
+ case R_RELAX_TLS_IE_TO_LE:
+ target->relaxTlsIeToLe(bufLoc, type, targetVA);
+ break;
+ case R_RELAX_TLS_LD_TO_LE:
+ case R_RELAX_TLS_LD_TO_LE_ABS:
+ target->relaxTlsLdToLe(bufLoc, type, targetVA);
+ break;
+ case R_RELAX_TLS_GD_TO_LE:
+ case R_RELAX_TLS_GD_TO_LE_NEG:
+ target->relaxTlsGdToLe(bufLoc, type, targetVA);
+ break;
+ case R_AARCH64_RELAX_TLS_GD_TO_IE_PAGE_PC:
+ case R_RELAX_TLS_GD_TO_IE:
+ case R_RELAX_TLS_GD_TO_IE_ABS:
+ case R_RELAX_TLS_GD_TO_IE_GOT_OFF:
+ case R_RELAX_TLS_GD_TO_IE_GOTPLT:
+ target->relaxTlsGdToIe(bufLoc, type, targetVA);
+ break;
+ case R_PPC64_CALL:
+ // If this is a call to __tls_get_addr, it may be part of a TLS
+ // sequence that has been relaxed and turned into a nop. In this
+ // case, we don't want to handle it as a call.
+ if (read32(bufLoc) == 0x60000000) // nop
+ break;
+
+ // Patch a nop (0x60000000) to a ld.
+ if (rel.sym->needsTocRestore) {
+ if (bufLoc + 8 > bufEnd || read32(bufLoc + 4) != 0x60000000) {
+ error(getErrorLocation(bufLoc) + "call lacks nop, can't restore toc");
+ break;
+ }
+ write32(bufLoc + 4, 0xe8410018); // ld %r2, 24(%r1)
+ }
+ target->relocateOne(bufLoc, type, targetVA);
+ break;
+ default:
+ target->relocateOne(bufLoc, type, targetVA);
+ break;
+ }
+ }
+}
+
+// For each function-defining prologue, find any calls to __morestack,
+// and replace them with calls to __morestack_non_split.
+static void switchMorestackCallsToMorestackNonSplit(
+ DenseSet<Defined *> &prologues, std::vector<Relocation *> &morestackCalls) {
+
+ // If the target adjusted a function's prologue, all calls to
+ // __morestack inside that function should be switched to
+ // __morestack_non_split.
+ Symbol *moreStackNonSplit = symtab->find("__morestack_non_split");
+ if (!moreStackNonSplit) {
+ error("Mixing split-stack objects requires a definition of "
+ "__morestack_non_split");
+ return;
+ }
+
+ // Sort both collections to compare addresses efficiently.
+ llvm::sort(morestackCalls, [](const Relocation *l, const Relocation *r) {
+ return l->offset < r->offset;
+ });
+ std::vector<Defined *> functions(prologues.begin(), prologues.end());
+ llvm::sort(functions, [](const Defined *l, const Defined *r) {
+ return l->value < r->value;
+ });
+
+ auto it = morestackCalls.begin();
+ for (Defined *f : functions) {
+ // Find the first call to __morestack within the function.
+ while (it != morestackCalls.end() && (*it)->offset < f->value)
+ ++it;
+ // Adjust all calls inside the function.
+ while (it != morestackCalls.end() && (*it)->offset < f->value + f->size) {
+ (*it)->sym = moreStackNonSplit;
+ ++it;
+ }
+ }
+}
+
+static bool enclosingPrologueAttempted(uint64_t offset,
+ const DenseSet<Defined *> &prologues) {
+ for (Defined *f : prologues)
+ if (f->value <= offset && offset < f->value + f->size)
+ return true;
+ return false;
+}
+
+// If a function compiled for split stack calls a function not
+// compiled for split stack, then the caller needs its prologue
+// adjusted to ensure that the called function will have enough stack
+// available. Find those functions, and adjust their prologues.
+template <class ELFT>
+void InputSectionBase::adjustSplitStackFunctionPrologues(uint8_t *buf,
+ uint8_t *end) {
+ if (!getFile<ELFT>()->splitStack)
+ return;
+ DenseSet<Defined *> prologues;
+ std::vector<Relocation *> morestackCalls;
+
+ for (Relocation &rel : relocations) {
+ // Local symbols can't possibly be cross-calls, and should have been
+ // resolved long before this line.
+ if (rel.sym->isLocal())
+ continue;
+
+ // Ignore calls into the split-stack api.
+ if (rel.sym->getName().startswith("__morestack")) {
+ if (rel.sym->getName().equals("__morestack"))
+ morestackCalls.push_back(&rel);
+ continue;
+ }
+
+ // A relocation to non-function isn't relevant. Sometimes
+ // __morestack is not marked as a function, so this check comes
+ // after the name check.
+ if (rel.sym->type != STT_FUNC)
+ continue;
+
+ // If the callee's-file was compiled with split stack, nothing to do. In
+ // this context, a "Defined" symbol is one "defined by the binary currently
+ // being produced". So an "undefined" symbol might be provided by a shared
+ // library. It is not possible to tell how such symbols were compiled, so be
+ // conservative.
+ if (Defined *d = dyn_cast<Defined>(rel.sym))
+ if (InputSection *isec = cast_or_null<InputSection>(d->section))
+ if (!isec || !isec->getFile<ELFT>() || isec->getFile<ELFT>()->splitStack)
+ continue;
+
+ if (enclosingPrologueAttempted(rel.offset, prologues))
+ continue;
+
+ if (Defined *f = getEnclosingFunction<ELFT>(rel.offset)) {
+ prologues.insert(f);
+ if (target->adjustPrologueForCrossSplitStack(buf + getOffset(f->value),
+ end, f->stOther))
+ continue;
+ if (!getFile<ELFT>()->someNoSplitStack)
+ error(lld::toString(this) + ": " + f->getName() +
+ " (with -fsplit-stack) calls " + rel.sym->getName() +
+ " (without -fsplit-stack), but couldn't adjust its prologue");
+ }
+ }
+
+ if (target->needsMoreStackNonSplit)
+ switchMorestackCallsToMorestackNonSplit(prologues, morestackCalls);
+}
+
+template <class ELFT> void InputSection::writeTo(uint8_t *buf) {
+ if (type == SHT_NOBITS)
+ return;
+
+ if (auto *s = dyn_cast<SyntheticSection>(this)) {
+ s->writeTo(buf + outSecOff);
+ return;
+ }
+
+ // If -r or --emit-relocs is given, then an InputSection
+ // may be a relocation section.
+ if (type == SHT_RELA) {
+ copyRelocations<ELFT>(buf + outSecOff, getDataAs<typename ELFT::Rela>());
+ return;
+ }
+ if (type == SHT_REL) {
+ copyRelocations<ELFT>(buf + outSecOff, getDataAs<typename ELFT::Rel>());
+ return;
+ }
+
+ // If -r is given, we may have a SHT_GROUP section.
+ if (type == SHT_GROUP) {
+ copyShtGroup<ELFT>(buf + outSecOff);
+ return;
+ }
+
+ // If this is a compressed section, uncompress section contents directly
+ // to the buffer.
+ if (uncompressedSize >= 0) {
+ size_t size = uncompressedSize;
+ if (Error e = zlib::uncompress(toStringRef(rawData),
+ (char *)(buf + outSecOff), size))
+ fatal(toString(this) +
+ ": uncompress failed: " + llvm::toString(std::move(e)));
+ uint8_t *bufEnd = buf + outSecOff + size;
+ relocate<ELFT>(buf, bufEnd);
+ return;
+ }
+
+ // Copy section contents from source object file to output file
+ // and then apply relocations.
+ memcpy(buf + outSecOff, data().data(), data().size());
+ uint8_t *bufEnd = buf + outSecOff + data().size();
+ relocate<ELFT>(buf, bufEnd);
+}
+
+void InputSection::replace(InputSection *other) {
+ alignment = std::max(alignment, other->alignment);
+
+ // When a section is replaced with another section that was allocated to
+ // another partition, the replacement section (and its associated sections)
+ // need to be placed in the main partition so that both partitions will be
+ // able to access it.
+ if (partition != other->partition) {
+ partition = 1;
+ for (InputSection *isec : dependentSections)
+ isec->partition = 1;
+ }
+
+ other->repl = repl;
+ other->markDead();
+}
+
+template <class ELFT>
+EhInputSection::EhInputSection(ObjFile<ELFT> &f,
+ const typename ELFT::Shdr &header,
+ StringRef name)
+ : InputSectionBase(f, header, name, InputSectionBase::EHFrame) {}
+
+SyntheticSection *EhInputSection::getParent() const {
+ return cast_or_null<SyntheticSection>(parent);
+}
+
+// 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::split() {
+ if (areRelocsRela)
+ split<ELFT>(relas<ELFT>());
+ else
+ split<ELFT>(rels<ELFT>());
+}
+
+template <class ELFT, class RelTy>
+void EhInputSection::split(ArrayRef<RelTy> rels) {
+ unsigned relI = 0;
+ for (size_t off = 0, end = data().size(); off != end;) {
+ size_t size = readEhRecordSize(this, off);
+ pieces.emplace_back(off, this, size, getReloc(off, size, rels, relI));
+ // The empty record is the end marker.
+ if (size == 4)
+ break;
+ off += size;
+ }
+}
+
+static size_t findNull(StringRef s, size_t entSize) {
+ // Optimize the common case.
+ 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;
+}
+
+SyntheticSection *MergeInputSection::getParent() const {
+ return cast_or_null<SyntheticSection>(parent);
+}
+
+// Split SHF_STRINGS section. Such section is a sequence of
+// null-terminated strings.
+void MergeInputSection::splitStrings(ArrayRef<uint8_t> data, size_t entSize) {
+ size_t off = 0;
+ bool isAlloc = flags & SHF_ALLOC;
+ StringRef s = toStringRef(data);
+
+ while (!s.empty()) {
+ size_t end = findNull(s, entSize);
+ if (end == StringRef::npos)
+ fatal(toString(this) + ": string is not null terminated");
+ size_t size = end + entSize;
+
+ pieces.emplace_back(off, xxHash64(s.substr(0, size)), !isAlloc);
+ s = s.substr(size);
+ off += size;
+ }
+}
+
+// Split non-SHF_STRINGS section. Such section is a sequence of
+// fixed size records.
+void MergeInputSection::splitNonStrings(ArrayRef<uint8_t> data,
+ size_t entSize) {
+ size_t size = data.size();
+ assert((size % entSize) == 0);
+ bool isAlloc = flags & SHF_ALLOC;
+
+ for (size_t i = 0; i != size; i += entSize)
+ pieces.emplace_back(i, xxHash64(data.slice(i, entSize)), !isAlloc);
+}
+
+template <class ELFT>
+MergeInputSection::MergeInputSection(ObjFile<ELFT> &f,
+ const typename ELFT::Shdr &header,
+ StringRef name)
+ : InputSectionBase(f, header, name, InputSectionBase::Merge) {}
+
+MergeInputSection::MergeInputSection(uint64_t flags, uint32_t type,
+ uint64_t entsize, ArrayRef<uint8_t> data,
+ StringRef name)
+ : InputSectionBase(nullptr, flags, type, entsize, /*Link*/ 0, /*Info*/ 0,
+ /*Alignment*/ entsize, data, name, SectionBase::Merge) {}
+
+// This function is called after we obtain a complete list of input sections
+// that need to be linked. This is responsible to split section contents
+// into small chunks for further processing.
+//
+// Note that this function is called from parallelForEach. This must be
+// thread-safe (i.e. no memory allocation from the pools).
+void MergeInputSection::splitIntoPieces() {
+ assert(pieces.empty());
+
+ if (flags & SHF_STRINGS)
+ splitStrings(data(), entsize);
+ else
+ splitNonStrings(data(), entsize);
+}
+
+SectionPiece *MergeInputSection::getSectionPiece(uint64_t offset) {
+ if (this->data().size() <= offset)
+ fatal(toString(this) + ": offset is outside the section");
+
+ // If Offset is not at beginning of a section piece, it is not in the map.
+ // In that case we need to do a binary search of the original section piece vector.
+ auto it = partition_point(
+ pieces, [=](SectionPiece p) { return p.inputOff <= offset; });
+ return &it[-1];
+}
+
+// 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.
+uint64_t MergeInputSection::getParentOffset(uint64_t offset) const {
+ // 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 =
+ *(const_cast<MergeInputSection *>(this)->getSectionPiece (offset));
+ uint64_t addend = offset - piece.inputOff;
+ return piece.outputOff + addend;
+}
+
+template InputSection::InputSection(ObjFile<ELF32LE> &, const ELF32LE::Shdr &,
+ StringRef);
+template InputSection::InputSection(ObjFile<ELF32BE> &, const ELF32BE::Shdr &,
+ StringRef);
+template InputSection::InputSection(ObjFile<ELF64LE> &, const ELF64LE::Shdr &,
+ StringRef);
+template InputSection::InputSection(ObjFile<ELF64BE> &, const ELF64BE::Shdr &,
+ StringRef);
+
+template std::string InputSectionBase::getLocation<ELF32LE>(uint64_t);
+template std::string InputSectionBase::getLocation<ELF32BE>(uint64_t);
+template std::string InputSectionBase::getLocation<ELF64LE>(uint64_t);
+template std::string InputSectionBase::getLocation<ELF64BE>(uint64_t);
+
+template void InputSection::writeTo<ELF32LE>(uint8_t *);
+template void InputSection::writeTo<ELF32BE>(uint8_t *);
+template void InputSection::writeTo<ELF64LE>(uint8_t *);
+template void InputSection::writeTo<ELF64BE>(uint8_t *);
+
+template MergeInputSection::MergeInputSection(ObjFile<ELF32LE> &,
+ const ELF32LE::Shdr &, StringRef);
+template MergeInputSection::MergeInputSection(ObjFile<ELF32BE> &,
+ const ELF32BE::Shdr &, StringRef);
+template MergeInputSection::MergeInputSection(ObjFile<ELF64LE> &,
+ const ELF64LE::Shdr &, StringRef);
+template MergeInputSection::MergeInputSection(ObjFile<ELF64BE> &,
+ const ELF64BE::Shdr &, StringRef);
+
+template EhInputSection::EhInputSection(ObjFile<ELF32LE> &,
+ const ELF32LE::Shdr &, StringRef);
+template EhInputSection::EhInputSection(ObjFile<ELF32BE> &,
+ const ELF32BE::Shdr &, StringRef);
+template EhInputSection::EhInputSection(ObjFile<ELF64LE> &,
+ const ELF64LE::Shdr &, StringRef);
+template EhInputSection::EhInputSection(ObjFile<ELF64BE> &,
+ const ELF64BE::Shdr &, StringRef);
+
+template void EhInputSection::split<ELF32LE>();
+template void EhInputSection::split<ELF32BE>();
+template void EhInputSection::split<ELF64LE>();
+template void EhInputSection::split<ELF64BE>();
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-09 09:21:28 +0000