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llvm-for-llvmta/lib/ExecutionEngine/JITLink/MachO_x86_64.cpp

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2022-04-25 10:02:23 +02:00
//===---- MachO_x86_64.cpp -JIT linker implementation for MachO/x86-64 ----===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// MachO/x86-64 jit-link implementation.
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/JITLink/MachO_x86_64.h"
#include "BasicGOTAndStubsBuilder.h"
#include "MachOLinkGraphBuilder.h"
#define DEBUG_TYPE "jitlink"
using namespace llvm;
using namespace llvm::jitlink;
using namespace llvm::jitlink::MachO_x86_64_Edges;
namespace {
class MachOLinkGraphBuilder_x86_64 : public MachOLinkGraphBuilder {
public:
MachOLinkGraphBuilder_x86_64(const object::MachOObjectFile &Obj)
: MachOLinkGraphBuilder(Obj, Triple("x86_64-apple-darwin")) {}
private:
static Expected<MachOX86RelocationKind>
getRelocationKind(const MachO::relocation_info &RI) {
switch (RI.r_type) {
case MachO::X86_64_RELOC_UNSIGNED:
if (!RI.r_pcrel) {
if (RI.r_length == 3)
return RI.r_extern ? Pointer64 : Pointer64Anon;
else if (RI.r_extern && RI.r_length == 2)
return Pointer32;
}
break;
case MachO::X86_64_RELOC_SIGNED:
if (RI.r_pcrel && RI.r_length == 2)
return RI.r_extern ? PCRel32 : PCRel32Anon;
break;
case MachO::X86_64_RELOC_BRANCH:
if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return Branch32;
break;
case MachO::X86_64_RELOC_GOT_LOAD:
if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return PCRel32GOTLoad;
break;
case MachO::X86_64_RELOC_GOT:
if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return PCRel32GOT;
break;
case MachO::X86_64_RELOC_SUBTRACTOR:
// SUBTRACTOR must be non-pc-rel, extern, with length 2 or 3.
// Initially represent SUBTRACTOR relocations with 'Delta<W>'. They may
// be turned into NegDelta<W> by parsePairRelocation.
if (!RI.r_pcrel && RI.r_extern) {
if (RI.r_length == 2)
return Delta32;
else if (RI.r_length == 3)
return Delta64;
}
break;
case MachO::X86_64_RELOC_SIGNED_1:
if (RI.r_pcrel && RI.r_length == 2)
return RI.r_extern ? PCRel32Minus1 : PCRel32Minus1Anon;
break;
case MachO::X86_64_RELOC_SIGNED_2:
if (RI.r_pcrel && RI.r_length == 2)
return RI.r_extern ? PCRel32Minus2 : PCRel32Minus2Anon;
break;
case MachO::X86_64_RELOC_SIGNED_4:
if (RI.r_pcrel && RI.r_length == 2)
return RI.r_extern ? PCRel32Minus4 : PCRel32Minus4Anon;
break;
case MachO::X86_64_RELOC_TLV:
if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
return PCRel32TLV;
break;
}
return make_error<JITLinkError>(
"Unsupported x86-64 relocation: address=" +
formatv("{0:x8}", RI.r_address) +
", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) +
", kind=" + formatv("{0:x1}", RI.r_type) +
", pc_rel=" + (RI.r_pcrel ? "true" : "false") +
", extern=" + (RI.r_extern ? "true" : "false") +
", length=" + formatv("{0:d}", RI.r_length));
}
using PairRelocInfo = std::tuple<MachOX86RelocationKind, Symbol *, uint64_t>;
// Parses paired SUBTRACTOR/UNSIGNED relocations and, on success,
// returns the edge kind and addend to be used.
Expected<PairRelocInfo>
parsePairRelocation(Block &BlockToFix, Edge::Kind SubtractorKind,
const MachO::relocation_info &SubRI,
JITTargetAddress FixupAddress, const char *FixupContent,
object::relocation_iterator &UnsignedRelItr,
object::relocation_iterator &RelEnd) {
using namespace support;
assert(((SubtractorKind == Delta32 && SubRI.r_length == 2) ||
(SubtractorKind == Delta64 && SubRI.r_length == 3)) &&
"Subtractor kind should match length");
assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern");
assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel");
if (UnsignedRelItr == RelEnd)
return make_error<JITLinkError>("x86_64 SUBTRACTOR without paired "
"UNSIGNED relocation");
auto UnsignedRI = getRelocationInfo(UnsignedRelItr);
if (SubRI.r_address != UnsignedRI.r_address)
return make_error<JITLinkError>("x86_64 SUBTRACTOR and paired UNSIGNED "
"point to different addresses");
if (SubRI.r_length != UnsignedRI.r_length)
return make_error<JITLinkError>("length of x86_64 SUBTRACTOR and paired "
"UNSIGNED reloc must match");
Symbol *FromSymbol;
if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum))
FromSymbol = FromSymbolOrErr->GraphSymbol;
else
return FromSymbolOrErr.takeError();
// Read the current fixup value.
uint64_t FixupValue = 0;
if (SubRI.r_length == 3)
FixupValue = *(const little64_t *)FixupContent;
else
FixupValue = *(const little32_t *)FixupContent;
// Find 'ToSymbol' using symbol number or address, depending on whether the
// paired UNSIGNED relocation is extern.
Symbol *ToSymbol = nullptr;
if (UnsignedRI.r_extern) {
// Find target symbol by symbol index.
if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum))
ToSymbol = ToSymbolOrErr->GraphSymbol;
else
return ToSymbolOrErr.takeError();
} else {
auto ToSymbolSec = findSectionByIndex(UnsignedRI.r_symbolnum - 1);
if (!ToSymbolSec)
return ToSymbolSec.takeError();
ToSymbol = getSymbolByAddress(ToSymbolSec->Address);
assert(ToSymbol && "No symbol for section");
FixupValue -= ToSymbol->getAddress();
}
MachOX86RelocationKind DeltaKind;
Symbol *TargetSymbol;
uint64_t Addend;
if (&BlockToFix == &FromSymbol->getAddressable()) {
TargetSymbol = ToSymbol;
DeltaKind = (SubRI.r_length == 3) ? Delta64 : Delta32;
Addend = FixupValue + (FixupAddress - FromSymbol->getAddress());
// FIXME: handle extern 'from'.
} else if (&BlockToFix == &ToSymbol->getAddressable()) {
TargetSymbol = FromSymbol;
DeltaKind = (SubRI.r_length == 3) ? NegDelta64 : NegDelta32;
Addend = FixupValue - (FixupAddress - ToSymbol->getAddress());
} else {
// BlockToFix was neither FromSymbol nor ToSymbol.
return make_error<JITLinkError>("SUBTRACTOR relocation must fix up "
"either 'A' or 'B' (or a symbol in one "
"of their alt-entry chains)");
}
return PairRelocInfo(DeltaKind, TargetSymbol, Addend);
}
Error addRelocations() override {
using namespace support;
auto &Obj = getObject();
LLVM_DEBUG(dbgs() << "Processing relocations:\n");
for (auto &S : Obj.sections()) {
JITTargetAddress SectionAddress = S.getAddress();
// Skip relocations virtual sections.
if (S.isVirtual()) {
if (S.relocation_begin() != S.relocation_end())
return make_error<JITLinkError>("Virtual section contains "
"relocations");
continue;
}
// Skip relocations for debug symbols.
{
auto &NSec =
getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl()));
if (!NSec.GraphSection) {
LLVM_DEBUG({
dbgs() << " Skipping relocations for MachO section "
<< NSec.SegName << "/" << NSec.SectName
<< " which has no associated graph section\n";
});
continue;
}
}
// Add relocations for section.
for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end();
RelItr != RelEnd; ++RelItr) {
MachO::relocation_info RI = getRelocationInfo(RelItr);
// Sanity check the relocation kind.
auto Kind = getRelocationKind(RI);
if (!Kind)
return Kind.takeError();
// Find the address of the value to fix up.
JITTargetAddress FixupAddress = SectionAddress + (uint32_t)RI.r_address;
LLVM_DEBUG({
auto &NSec =
getSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl()));
dbgs() << " " << NSec.SectName << " + "
<< formatv("{0:x8}", RI.r_address) << ":\n";
});
// Find the block that the fixup points to.
Block *BlockToFix = nullptr;
{
auto SymbolToFixOrErr = findSymbolByAddress(FixupAddress);
if (!SymbolToFixOrErr)
return SymbolToFixOrErr.takeError();
BlockToFix = &SymbolToFixOrErr->getBlock();
}
if (FixupAddress + static_cast<JITTargetAddress>(1ULL << RI.r_length) >
BlockToFix->getAddress() + BlockToFix->getContent().size())
return make_error<JITLinkError>(
"Relocation extends past end of fixup block");
// Get a pointer to the fixup content.
const char *FixupContent = BlockToFix->getContent().data() +
(FixupAddress - BlockToFix->getAddress());
// The target symbol and addend will be populated by the switch below.
Symbol *TargetSymbol = nullptr;
uint64_t Addend = 0;
switch (*Kind) {
case Branch32:
case PCRel32:
case PCRel32GOTLoad:
case PCRel32GOT:
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
Addend = *(const little32_t *)FixupContent;
break;
case Pointer32:
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
Addend = *(const ulittle32_t *)FixupContent;
break;
case Pointer64:
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
Addend = *(const ulittle64_t *)FixupContent;
break;
case Pointer64Anon: {
JITTargetAddress TargetAddress = *(const ulittle64_t *)FixupContent;
if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress))
TargetSymbol = &*TargetSymbolOrErr;
else
return TargetSymbolOrErr.takeError();
Addend = TargetAddress - TargetSymbol->getAddress();
break;
}
case PCRel32Minus1:
case PCRel32Minus2:
case PCRel32Minus4:
if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
TargetSymbol = TargetSymbolOrErr->GraphSymbol;
else
return TargetSymbolOrErr.takeError();
Addend = *(const little32_t *)FixupContent +
(1 << (*Kind - PCRel32Minus1));
break;
case PCRel32Anon: {
JITTargetAddress TargetAddress =
FixupAddress + 4 + *(const little32_t *)FixupContent;
if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress))
TargetSymbol = &*TargetSymbolOrErr;
else
return TargetSymbolOrErr.takeError();
Addend = TargetAddress - TargetSymbol->getAddress();
break;
}
case PCRel32Minus1Anon:
case PCRel32Minus2Anon:
case PCRel32Minus4Anon: {
JITTargetAddress Delta =
static_cast<JITTargetAddress>(1ULL << (*Kind - PCRel32Minus1Anon));
JITTargetAddress TargetAddress =
FixupAddress + 4 + Delta + *(const little32_t *)FixupContent;
if (auto TargetSymbolOrErr = findSymbolByAddress(TargetAddress))
TargetSymbol = &*TargetSymbolOrErr;
else
return TargetSymbolOrErr.takeError();
Addend = TargetAddress - TargetSymbol->getAddress();
break;
}
case Delta32:
case Delta64: {
// We use Delta32/Delta64 to represent SUBTRACTOR relocations.
// parsePairRelocation handles the paired reloc, and returns the
// edge kind to be used (either Delta32/Delta64, or
// NegDelta32/NegDelta64, depending on the direction of the
// subtraction) along with the addend.
auto PairInfo =
parsePairRelocation(*BlockToFix, *Kind, RI, FixupAddress,
FixupContent, ++RelItr, RelEnd);
if (!PairInfo)
return PairInfo.takeError();
std::tie(*Kind, TargetSymbol, Addend) = *PairInfo;
assert(TargetSymbol && "No target symbol from parsePairRelocation?");
break;
}
case PCRel32TLV:
return make_error<JITLinkError>(
"MachO TLV relocations not yet supported");
default:
llvm_unreachable("Special relocation kind should not appear in "
"mach-o file");
}
LLVM_DEBUG({
dbgs() << " ";
Edge GE(*Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol,
Addend);
printEdge(dbgs(), *BlockToFix, GE,
getMachOX86RelocationKindName(*Kind));
dbgs() << "\n";
});
BlockToFix->addEdge(*Kind, FixupAddress - BlockToFix->getAddress(),
*TargetSymbol, Addend);
}
}
return Error::success();
}
};
class MachO_x86_64_GOTAndStubsBuilder
: public BasicGOTAndStubsBuilder<MachO_x86_64_GOTAndStubsBuilder> {
public:
static const uint8_t NullGOTEntryContent[8];
static const uint8_t StubContent[6];
MachO_x86_64_GOTAndStubsBuilder(LinkGraph &G)
: BasicGOTAndStubsBuilder<MachO_x86_64_GOTAndStubsBuilder>(G) {}
bool isGOTEdge(Edge &E) const {
return E.getKind() == PCRel32GOT || E.getKind() == PCRel32GOTLoad;
}
Symbol &createGOTEntry(Symbol &Target) {
auto &GOTEntryBlock = G.createContentBlock(
getGOTSection(), getGOTEntryBlockContent(), 0, 8, 0);
GOTEntryBlock.addEdge(Pointer64, 0, Target, 0);
return G.addAnonymousSymbol(GOTEntryBlock, 0, 8, false, false);
}
void fixGOTEdge(Edge &E, Symbol &GOTEntry) {
assert((E.getKind() == PCRel32GOT || E.getKind() == PCRel32GOTLoad) &&
"Not a GOT edge?");
// If this is a PCRel32GOT then change it to an ordinary PCRel32. If it is
// a PCRel32GOTLoad then leave it as-is for now. We will use the kind to
// check for GOT optimization opportunities in the
// optimizeMachO_x86_64_GOTAndStubs pass below.
if (E.getKind() == PCRel32GOT)
E.setKind(PCRel32);
E.setTarget(GOTEntry);
// Leave the edge addend as-is.
}
bool isExternalBranchEdge(Edge &E) {
return E.getKind() == Branch32 && !E.getTarget().isDefined();
}
Symbol &createStub(Symbol &Target) {
auto &StubContentBlock =
G.createContentBlock(getStubsSection(), getStubBlockContent(), 0, 1, 0);
// Re-use GOT entries for stub targets.
auto &GOTEntrySymbol = getGOTEntrySymbol(Target);
StubContentBlock.addEdge(PCRel32, 2, GOTEntrySymbol, 0);
return G.addAnonymousSymbol(StubContentBlock, 0, 6, true, false);
}
void fixExternalBranchEdge(Edge &E, Symbol &Stub) {
assert(E.getKind() == Branch32 && "Not a Branch32 edge?");
assert(E.getAddend() == 0 && "Branch32 edge has non-zero addend?");
// Set the edge kind to Branch32ToStub. We will use this to check for stub
// optimization opportunities in the optimizeMachO_x86_64_GOTAndStubs pass
// below.
E.setKind(Branch32ToStub);
E.setTarget(Stub);
}
private:
Section &getGOTSection() {
if (!GOTSection)
GOTSection = &G.createSection("$__GOT", sys::Memory::MF_READ);
return *GOTSection;
}
Section &getStubsSection() {
if (!StubsSection) {
auto StubsProt = static_cast<sys::Memory::ProtectionFlags>(
sys::Memory::MF_READ | sys::Memory::MF_EXEC);
StubsSection = &G.createSection("$__STUBS", StubsProt);
}
return *StubsSection;
}
StringRef getGOTEntryBlockContent() {
return StringRef(reinterpret_cast<const char *>(NullGOTEntryContent),
sizeof(NullGOTEntryContent));
}
StringRef getStubBlockContent() {
return StringRef(reinterpret_cast<const char *>(StubContent),
sizeof(StubContent));
}
Section *GOTSection = nullptr;
Section *StubsSection = nullptr;
};
const uint8_t MachO_x86_64_GOTAndStubsBuilder::NullGOTEntryContent[8] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
const uint8_t MachO_x86_64_GOTAndStubsBuilder::StubContent[6] = {
0xFF, 0x25, 0x00, 0x00, 0x00, 0x00};
} // namespace
static Error optimizeMachO_x86_64_GOTAndStubs(LinkGraph &G) {
LLVM_DEBUG(dbgs() << "Optimizing GOT entries and stubs:\n");
for (auto *B : G.blocks())
for (auto &E : B->edges())
if (E.getKind() == PCRel32GOTLoad) {
assert(E.getOffset() >= 3 && "GOT edge occurs too early in block");
// Switch the edge kind to PCRel32: Whether we change the edge target
// or not this will be the desired kind.
E.setKind(PCRel32);
// Optimize GOT references.
auto &GOTBlock = E.getTarget().getBlock();
assert(GOTBlock.getSize() == G.getPointerSize() &&
"GOT entry block should be pointer sized");
assert(GOTBlock.edges_size() == 1 &&
"GOT entry should only have one outgoing edge");
auto &GOTTarget = GOTBlock.edges().begin()->getTarget();
JITTargetAddress EdgeAddr = B->getAddress() + E.getOffset();
JITTargetAddress TargetAddr = GOTTarget.getAddress();
// Check that this is a recognized MOV instruction.
// FIXME: Can we assume this?
constexpr uint8_t MOVQRIPRel[] = {0x48, 0x8b};
if (strncmp(B->getContent().data() + E.getOffset() - 3,
reinterpret_cast<const char *>(MOVQRIPRel), 2) != 0)
continue;
int64_t Displacement = TargetAddr - EdgeAddr + 4;
if (Displacement >= std::numeric_limits<int32_t>::min() &&
Displacement <= std::numeric_limits<int32_t>::max()) {
E.setTarget(GOTTarget);
auto *BlockData = reinterpret_cast<uint8_t *>(
const_cast<char *>(B->getContent().data()));
BlockData[E.getOffset() - 2] = 0x8d;
LLVM_DEBUG({
dbgs() << " Replaced GOT load wih LEA:\n ";
printEdge(dbgs(), *B, E,
getMachOX86RelocationKindName(E.getKind()));
dbgs() << "\n";
});
}
} else if (E.getKind() == Branch32ToStub) {
// Switch the edge kind to PCRel32: Whether we change the edge target
// or not this will be the desired kind.
E.setKind(Branch32);
auto &StubBlock = E.getTarget().getBlock();
assert(StubBlock.getSize() ==
sizeof(MachO_x86_64_GOTAndStubsBuilder::StubContent) &&
"Stub block should be stub sized");
assert(StubBlock.edges_size() == 1 &&
"Stub block should only have one outgoing edge");
auto &GOTBlock = StubBlock.edges().begin()->getTarget().getBlock();
assert(GOTBlock.getSize() == G.getPointerSize() &&
"GOT block should be pointer sized");
assert(GOTBlock.edges_size() == 1 &&
"GOT block should only have one outgoing edge");
auto &GOTTarget = GOTBlock.edges().begin()->getTarget();
JITTargetAddress EdgeAddr = B->getAddress() + E.getOffset();
JITTargetAddress TargetAddr = GOTTarget.getAddress();
int64_t Displacement = TargetAddr - EdgeAddr + 4;
if (Displacement >= std::numeric_limits<int32_t>::min() &&
Displacement <= std::numeric_limits<int32_t>::max()) {
E.setTarget(GOTTarget);
LLVM_DEBUG({
dbgs() << " Replaced stub branch with direct branch:\n ";
printEdge(dbgs(), *B, E,
getMachOX86RelocationKindName(E.getKind()));
dbgs() << "\n";
});
}
}
return Error::success();
}
namespace llvm {
namespace jitlink {
class MachOJITLinker_x86_64 : public JITLinker<MachOJITLinker_x86_64> {
friend class JITLinker<MachOJITLinker_x86_64>;
public:
MachOJITLinker_x86_64(std::unique_ptr<JITLinkContext> Ctx,
std::unique_ptr<LinkGraph> G,
PassConfiguration PassConfig)
: JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {}
private:
StringRef getEdgeKindName(Edge::Kind R) const override {
return getMachOX86RelocationKindName(R);
}
static Error targetOutOfRangeError(const Block &B, const Edge &E) {
std::string ErrMsg;
{
raw_string_ostream ErrStream(ErrMsg);
ErrStream << "Relocation target out of range: ";
printEdge(ErrStream, B, E, getMachOX86RelocationKindName(E.getKind()));
ErrStream << "\n";
}
return make_error<JITLinkError>(std::move(ErrMsg));
}
Error applyFixup(Block &B, const Edge &E, char *BlockWorkingMem) const {
using namespace support;
char *FixupPtr = BlockWorkingMem + E.getOffset();
JITTargetAddress FixupAddress = B.getAddress() + E.getOffset();
switch (E.getKind()) {
case Branch32:
case PCRel32:
case PCRel32Anon: {
int64_t Value =
E.getTarget().getAddress() - (FixupAddress + 4) + E.getAddend();
if (Value < std::numeric_limits<int32_t>::min() ||
Value > std::numeric_limits<int32_t>::max())
return targetOutOfRangeError(B, E);
*(little32_t *)FixupPtr = Value;
break;
}
case Pointer64:
case Pointer64Anon: {
uint64_t Value = E.getTarget().getAddress() + E.getAddend();
*(ulittle64_t *)FixupPtr = Value;
break;
}
case PCRel32Minus1:
case PCRel32Minus2:
case PCRel32Minus4: {
int Delta = 4 + (1 << (E.getKind() - PCRel32Minus1));
int64_t Value =
E.getTarget().getAddress() - (FixupAddress + Delta) + E.getAddend();
if (Value < std::numeric_limits<int32_t>::min() ||
Value > std::numeric_limits<int32_t>::max())
return targetOutOfRangeError(B, E);
*(little32_t *)FixupPtr = Value;
break;
}
case PCRel32Minus1Anon:
case PCRel32Minus2Anon:
case PCRel32Minus4Anon: {
int Delta = 4 + (1 << (E.getKind() - PCRel32Minus1Anon));
int64_t Value =
E.getTarget().getAddress() - (FixupAddress + Delta) + E.getAddend();
if (Value < std::numeric_limits<int32_t>::min() ||
Value > std::numeric_limits<int32_t>::max())
return targetOutOfRangeError(B, E);
*(little32_t *)FixupPtr = Value;
break;
}
case Delta32:
case Delta64:
case NegDelta32:
case NegDelta64: {
int64_t Value;
if (E.getKind() == Delta32 || E.getKind() == Delta64)
Value = E.getTarget().getAddress() - FixupAddress + E.getAddend();
else
Value = FixupAddress - E.getTarget().getAddress() + E.getAddend();
if (E.getKind() == Delta32 || E.getKind() == NegDelta32) {
if (Value < std::numeric_limits<int32_t>::min() ||
Value > std::numeric_limits<int32_t>::max())
return targetOutOfRangeError(B, E);
*(little32_t *)FixupPtr = Value;
} else
*(little64_t *)FixupPtr = Value;
break;
}
case Pointer32: {
uint64_t Value = E.getTarget().getAddress() + E.getAddend();
if (Value > std::numeric_limits<uint32_t>::max())
return targetOutOfRangeError(B, E);
*(ulittle32_t *)FixupPtr = Value;
break;
}
default:
llvm_unreachable("Unrecognized edge kind");
}
return Error::success();
}
uint64_t NullValue = 0;
};
Expected<std::unique_ptr<LinkGraph>>
createLinkGraphFromMachOObject_x86_64(MemoryBufferRef ObjectBuffer) {
auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjectBuffer);
if (!MachOObj)
return MachOObj.takeError();
return MachOLinkGraphBuilder_x86_64(**MachOObj).buildGraph();
}
void link_MachO_x86_64(std::unique_ptr<LinkGraph> G,
std::unique_ptr<JITLinkContext> Ctx) {
PassConfiguration Config;
if (Ctx->shouldAddDefaultTargetPasses(G->getTargetTriple())) {
// Add eh-frame passses.
Config.PrePrunePasses.push_back(EHFrameSplitter("__eh_frame"));
Config.PrePrunePasses.push_back(EHFrameEdgeFixer(
"__eh_frame", G->getPointerSize(), Delta64, Delta32, NegDelta32));
// Add a mark-live pass.
if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple()))
Config.PrePrunePasses.push_back(std::move(MarkLive));
else
Config.PrePrunePasses.push_back(markAllSymbolsLive);
// Add an in-place GOT/Stubs pass.
Config.PostPrunePasses.push_back([](LinkGraph &G) -> Error {
MachO_x86_64_GOTAndStubsBuilder(G).run();
return Error::success();
});
// Add GOT/Stubs optimizer pass.
Config.PreFixupPasses.push_back(optimizeMachO_x86_64_GOTAndStubs);
}
if (auto Err = Ctx->modifyPassConfig(G->getTargetTriple(), Config))
return Ctx->notifyFailed(std::move(Err));
// Construct a JITLinker and run the link function.
MachOJITLinker_x86_64::link(std::move(Ctx), std::move(G), std::move(Config));
}
StringRef getMachOX86RelocationKindName(Edge::Kind R) {
switch (R) {
case Branch32:
return "Branch32";
case Branch32ToStub:
return "Branch32ToStub";
case Pointer32:
return "Pointer32";
case Pointer64:
return "Pointer64";
case Pointer64Anon:
return "Pointer64Anon";
case PCRel32:
return "PCRel32";
case PCRel32Minus1:
return "PCRel32Minus1";
case PCRel32Minus2:
return "PCRel32Minus2";
case PCRel32Minus4:
return "PCRel32Minus4";
case PCRel32Anon:
return "PCRel32Anon";
case PCRel32Minus1Anon:
return "PCRel32Minus1Anon";
case PCRel32Minus2Anon:
return "PCRel32Minus2Anon";
case PCRel32Minus4Anon:
return "PCRel32Minus4Anon";
case PCRel32GOTLoad:
return "PCRel32GOTLoad";
case PCRel32GOT:
return "PCRel32GOT";
case PCRel32TLV:
return "PCRel32TLV";
case Delta32:
return "Delta32";
case Delta64:
return "Delta64";
case NegDelta32:
return "NegDelta32";
case NegDelta64:
return "NegDelta64";
default:
return getGenericEdgeKindName(static_cast<Edge::Kind>(R));
}
}
} // end namespace jitlink
} // end namespace llvm