1 files changed, 422 insertions, 0 deletions

diff --git a/contrib/llvm-project/llvm/lib/Object/ELFObjectFile.cpp b/contrib/llvm-project/llvm/lib/Object/ELFObjectFile.cpp
new file mode 100644
index 000000000000..347022b8b0b6
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/Object/ELFObjectFile.cpp
@@ -0,0 +1,422 @@
+//===- ELFObjectFile.cpp - ELF object file implementation -----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Part of the ELFObjectFile class implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Object/ELFObjectFile.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/MC/MCInstrAnalysis.h"
+#include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Object/ELF.h"
+#include "llvm/Object/ELFTypes.h"
+#include "llvm/Object/Error.h"
+#include "llvm/Support/ARMAttributeParser.h"
+#include "llvm/Support/ARMBuildAttributes.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/TargetRegistry.h"
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <system_error>
+#include <utility>
+
+using namespace llvm;
+using namespace object;
+
+const EnumEntry<unsigned> llvm::object::ElfSymbolTypes[NumElfSymbolTypes] = {
+    {"None", "NOTYPE", ELF::STT_NOTYPE},
+    {"Object", "OBJECT", ELF::STT_OBJECT},
+    {"Function", "FUNC", ELF::STT_FUNC},
+    {"Section", "SECTION", ELF::STT_SECTION},
+    {"File", "FILE", ELF::STT_FILE},
+    {"Common", "COMMON", ELF::STT_COMMON},
+    {"TLS", "TLS", ELF::STT_TLS},
+    {"GNU_IFunc", "IFUNC", ELF::STT_GNU_IFUNC}};
+
+ELFObjectFileBase::ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source)
+    : ObjectFile(Type, Source) {}
+
+template <class ELFT>
+static Expected<std::unique_ptr<ELFObjectFile<ELFT>>>
+createPtr(MemoryBufferRef Object) {
+  auto Ret = ELFObjectFile<ELFT>::create(Object);
+  if (Error E = Ret.takeError())
+    return std::move(E);
+  return make_unique<ELFObjectFile<ELFT>>(std::move(*Ret));
+}
+
+Expected<std::unique_ptr<ObjectFile>>
+ObjectFile::createELFObjectFile(MemoryBufferRef Obj) {
+  std::pair<unsigned char, unsigned char> Ident =
+      getElfArchType(Obj.getBuffer());
+  std::size_t MaxAlignment =
+      1ULL << countTrailingZeros(uintptr_t(Obj.getBufferStart()));
+
+  if (MaxAlignment < 2)
+    return createError("Insufficient alignment");
+
+  if (Ident.first == ELF::ELFCLASS32) {
+    if (Ident.second == ELF::ELFDATA2LSB)
+      return createPtr<ELF32LE>(Obj);
+    else if (Ident.second == ELF::ELFDATA2MSB)
+      return createPtr<ELF32BE>(Obj);
+    else
+      return createError("Invalid ELF data");
+  } else if (Ident.first == ELF::ELFCLASS64) {
+    if (Ident.second == ELF::ELFDATA2LSB)
+      return createPtr<ELF64LE>(Obj);
+    else if (Ident.second == ELF::ELFDATA2MSB)
+      return createPtr<ELF64BE>(Obj);
+    else
+      return createError("Invalid ELF data");
+  }
+  return createError("Invalid ELF class");
+}
+
+SubtargetFeatures ELFObjectFileBase::getMIPSFeatures() const {
+  SubtargetFeatures Features;
+  unsigned PlatformFlags = getPlatformFlags();
+
+  switch (PlatformFlags & ELF::EF_MIPS_ARCH) {
+  case ELF::EF_MIPS_ARCH_1:
+    break;
+  case ELF::EF_MIPS_ARCH_2:
+    Features.AddFeature("mips2");
+    break;
+  case ELF::EF_MIPS_ARCH_3:
+    Features.AddFeature("mips3");
+    break;
+  case ELF::EF_MIPS_ARCH_4:
+    Features.AddFeature("mips4");
+    break;
+  case ELF::EF_MIPS_ARCH_5:
+    Features.AddFeature("mips5");
+    break;
+  case ELF::EF_MIPS_ARCH_32:
+    Features.AddFeature("mips32");
+    break;
+  case ELF::EF_MIPS_ARCH_64:
+    Features.AddFeature("mips64");
+    break;
+  case ELF::EF_MIPS_ARCH_32R2:
+    Features.AddFeature("mips32r2");
+    break;
+  case ELF::EF_MIPS_ARCH_64R2:
+    Features.AddFeature("mips64r2");
+    break;
+  case ELF::EF_MIPS_ARCH_32R6:
+    Features.AddFeature("mips32r6");
+    break;
+  case ELF::EF_MIPS_ARCH_64R6:
+    Features.AddFeature("mips64r6");
+    break;
+  default:
+    llvm_unreachable("Unknown EF_MIPS_ARCH value");
+  }
+
+  switch (PlatformFlags & ELF::EF_MIPS_MACH) {
+  case ELF::EF_MIPS_MACH_NONE:
+    // No feature associated with this value.
+    break;
+  case ELF::EF_MIPS_MACH_OCTEON:
+    Features.AddFeature("cnmips");
+    break;
+  default:
+    llvm_unreachable("Unknown EF_MIPS_ARCH value");
+  }
+
+  if (PlatformFlags & ELF::EF_MIPS_ARCH_ASE_M16)
+    Features.AddFeature("mips16");
+  if (PlatformFlags & ELF::EF_MIPS_MICROMIPS)
+    Features.AddFeature("micromips");
+
+  return Features;
+}
+
+SubtargetFeatures ELFObjectFileBase::getARMFeatures() const {
+  SubtargetFeatures Features;
+  ARMAttributeParser Attributes;
+  if (Error E = getBuildAttributes(Attributes))
+    return SubtargetFeatures();
+
+  // both ARMv7-M and R have to support thumb hardware div
+  bool isV7 = false;
+  if (Attributes.hasAttribute(ARMBuildAttrs::CPU_arch))
+    isV7 = Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch)
+      == ARMBuildAttrs::v7;
+
+  if (Attributes.hasAttribute(ARMBuildAttrs::CPU_arch_profile)) {
+    switch(Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch_profile)) {
+    case ARMBuildAttrs::ApplicationProfile:
+      Features.AddFeature("aclass");
+      break;
+    case ARMBuildAttrs::RealTimeProfile:
+      Features.AddFeature("rclass");
+      if (isV7)
+        Features.AddFeature("hwdiv");
+      break;
+    case ARMBuildAttrs::MicroControllerProfile:
+      Features.AddFeature("mclass");
+      if (isV7)
+        Features.AddFeature("hwdiv");
+      break;
+    }
+  }
+
+  if (Attributes.hasAttribute(ARMBuildAttrs::THUMB_ISA_use)) {
+    switch(Attributes.getAttributeValue(ARMBuildAttrs::THUMB_ISA_use)) {
+    default:
+      break;
+    case ARMBuildAttrs::Not_Allowed:
+      Features.AddFeature("thumb", false);
+      Features.AddFeature("thumb2", false);
+      break;
+    case ARMBuildAttrs::AllowThumb32:
+      Features.AddFeature("thumb2");
+      break;
+    }
+  }
+
+  if (Attributes.hasAttribute(ARMBuildAttrs::FP_arch)) {
+    switch(Attributes.getAttributeValue(ARMBuildAttrs::FP_arch)) {
+    default:
+      break;
+    case ARMBuildAttrs::Not_Allowed:
+      Features.AddFeature("vfp2sp", false);
+      Features.AddFeature("vfp3d16sp", false);
+      Features.AddFeature("vfp4d16sp", false);
+      break;
+    case ARMBuildAttrs::AllowFPv2:
+      Features.AddFeature("vfp2");
+      break;
+    case ARMBuildAttrs::AllowFPv3A:
+    case ARMBuildAttrs::AllowFPv3B:
+      Features.AddFeature("vfp3");
+      break;
+    case ARMBuildAttrs::AllowFPv4A:
+    case ARMBuildAttrs::AllowFPv4B:
+      Features.AddFeature("vfp4");
+      break;
+    }
+  }
+
+  if (Attributes.hasAttribute(ARMBuildAttrs::Advanced_SIMD_arch)) {
+    switch(Attributes.getAttributeValue(ARMBuildAttrs::Advanced_SIMD_arch)) {
+    default:
+      break;
+    case ARMBuildAttrs::Not_Allowed:
+      Features.AddFeature("neon", false);
+      Features.AddFeature("fp16", false);
+      break;
+    case ARMBuildAttrs::AllowNeon:
+      Features.AddFeature("neon");
+      break;
+    case ARMBuildAttrs::AllowNeon2:
+      Features.AddFeature("neon");
+      Features.AddFeature("fp16");
+      break;
+    }
+  }
+
+  if (Attributes.hasAttribute(ARMBuildAttrs::MVE_arch)) {
+    switch(Attributes.getAttributeValue(ARMBuildAttrs::MVE_arch)) {
+    default:
+      break;
+    case ARMBuildAttrs::Not_Allowed:
+      Features.AddFeature("mve", false);
+      Features.AddFeature("mve.fp", false);
+      break;
+    case ARMBuildAttrs::AllowMVEInteger:
+      Features.AddFeature("mve.fp", false);
+      Features.AddFeature("mve");
+      break;
+    case ARMBuildAttrs::AllowMVEIntegerAndFloat:
+      Features.AddFeature("mve.fp");
+      break;
+    }
+  }
+
+  if (Attributes.hasAttribute(ARMBuildAttrs::DIV_use)) {
+    switch(Attributes.getAttributeValue(ARMBuildAttrs::DIV_use)) {
+    default:
+      break;
+    case ARMBuildAttrs::DisallowDIV:
+      Features.AddFeature("hwdiv", false);
+      Features.AddFeature("hwdiv-arm", false);
+      break;
+    case ARMBuildAttrs::AllowDIVExt:
+      Features.AddFeature("hwdiv");
+      Features.AddFeature("hwdiv-arm");
+      break;
+    }
+  }
+
+  return Features;
+}
+
+SubtargetFeatures ELFObjectFileBase::getRISCVFeatures() const {
+  SubtargetFeatures Features;
+  unsigned PlatformFlags = getPlatformFlags();
+
+  if (PlatformFlags & ELF::EF_RISCV_RVC) {
+    Features.AddFeature("c");
+  }
+
+  return Features;
+}
+
+SubtargetFeatures ELFObjectFileBase::getFeatures() const {
+  switch (getEMachine()) {
+  case ELF::EM_MIPS:
+    return getMIPSFeatures();
+  case ELF::EM_ARM:
+    return getARMFeatures();
+  case ELF::EM_RISCV:
+    return getRISCVFeatures();
+  default:
+    return SubtargetFeatures();
+  }
+}
+
+// FIXME Encode from a tablegen description or target parser.
+void ELFObjectFileBase::setARMSubArch(Triple &TheTriple) const {
+  if (TheTriple.getSubArch() != Triple::NoSubArch)
+    return;
+
+  ARMAttributeParser Attributes;
+  if (Error E = getBuildAttributes(Attributes))
+    return;
+
+  std::string Triple;
+  // Default to ARM, but use the triple if it's been set.
+  if (TheTriple.isThumb())
+    Triple = "thumb";
+  else
+    Triple = "arm";
+
+  if (Attributes.hasAttribute(ARMBuildAttrs::CPU_arch)) {
+    switch(Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch)) {
+    case ARMBuildAttrs::v4:
+      Triple += "v4";
+      break;
+    case ARMBuildAttrs::v4T:
+      Triple += "v4t";
+      break;
+    case ARMBuildAttrs::v5T:
+      Triple += "v5t";
+      break;
+    case ARMBuildAttrs::v5TE:
+      Triple += "v5te";
+      break;
+    case ARMBuildAttrs::v5TEJ:
+      Triple += "v5tej";
+      break;
+    case ARMBuildAttrs::v6:
+      Triple += "v6";
+      break;
+    case ARMBuildAttrs::v6KZ:
+      Triple += "v6kz";
+      break;
+    case ARMBuildAttrs::v6T2:
+      Triple += "v6t2";
+      break;
+    case ARMBuildAttrs::v6K:
+      Triple += "v6k";
+      break;
+    case ARMBuildAttrs::v7:
+      Triple += "v7";
+      break;
+    case ARMBuildAttrs::v6_M:
+      Triple += "v6m";
+      break;
+    case ARMBuildAttrs::v6S_M:
+      Triple += "v6sm";
+      break;
+    case ARMBuildAttrs::v7E_M:
+      Triple += "v7em";
+      break;
+    }
+  }
+  if (!isLittleEndian())
+    Triple += "eb";
+
+  TheTriple.setArchName(Triple);
+}
+
+std::vector<std::pair<DataRefImpl, uint64_t>>
+ELFObjectFileBase::getPltAddresses() const {
+  std::string Err;
+  const auto Triple = makeTriple();
+  const auto *T = TargetRegistry::lookupTarget(Triple.str(), Err);
+  if (!T)
+    return {};
+  uint64_t JumpSlotReloc = 0;
+  switch (Triple.getArch()) {
+    case Triple::x86:
+      JumpSlotReloc = ELF::R_386_JUMP_SLOT;
+      break;
+    case Triple::x86_64:
+      JumpSlotReloc = ELF::R_X86_64_JUMP_SLOT;
+      break;
+    case Triple::aarch64:
+      JumpSlotReloc = ELF::R_AARCH64_JUMP_SLOT;
+      break;
+    default:
+      return {};
+  }
+  std::unique_ptr<const MCInstrInfo> MII(T->createMCInstrInfo());
+  std::unique_ptr<const MCInstrAnalysis> MIA(
+      T->createMCInstrAnalysis(MII.get()));
+  if (!MIA)
+    return {};
+  Optional<SectionRef> Plt = None, RelaPlt = None, GotPlt = None;
+  for (const SectionRef &Section : sections()) {
+    StringRef Name;
+    if (Section.getName(Name))
+      continue;
+    if (Name == ".plt")
+      Plt = Section;
+    else if (Name == ".rela.plt" || Name == ".rel.plt")
+      RelaPlt = Section;
+    else if (Name == ".got.plt")
+      GotPlt = Section;
+  }
+  if (!Plt || !RelaPlt || !GotPlt)
+    return {};
+  Expected<StringRef> PltContents = Plt->getContents();
+  if (!PltContents) {
+    consumeError(PltContents.takeError());
+    return {};
+  }
+  auto PltEntries = MIA->findPltEntries(Plt->getAddress(),
+                                        arrayRefFromStringRef(*PltContents),
+                                        GotPlt->getAddress(), Triple);
+  // Build a map from GOT entry virtual address to PLT entry virtual address.
+  DenseMap<uint64_t, uint64_t> GotToPlt;
+  for (const auto &Entry : PltEntries)
+    GotToPlt.insert(std::make_pair(Entry.second, Entry.first));
+  // Find the relocations in the dynamic relocation table that point to
+  // locations in the GOT for which we know the corresponding PLT entry.
+  std::vector<std::pair<DataRefImpl, uint64_t>> Result;
+  for (const auto &Relocation : RelaPlt->relocations()) {
+    if (Relocation.getType() != JumpSlotReloc)
+      continue;
+    auto PltEntryIter = GotToPlt.find(Relocation.getOffset());
+    if (PltEntryIter != GotToPlt.end())
+      Result.push_back(std::make_pair(
+          Relocation.getSymbol()->getRawDataRefImpl(), PltEntryIter->second));
+  }
+  return Result;
+}