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//===-- RuntimeDyldMachOX86_64.h ---- MachO/X86_64 specific code. -*- C++ -*-=//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOX86_64_H
#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOX86_64_H
#include "../RuntimeDyldMachO.h"
#include <string>
#define DEBUG_TYPE "dyld"
namespace llvm {
class RuntimeDyldMachOX86_64
: public RuntimeDyldMachOCRTPBase<RuntimeDyldMachOX86_64> {
public:
typedef uint64_t TargetPtrT;
RuntimeDyldMachOX86_64(RuntimeDyld::MemoryManager &MM,
JITSymbolResolver &Resolver)
: RuntimeDyldMachOCRTPBase(MM, Resolver) {}
unsigned getMaxStubSize() const override { return 8; }
unsigned getStubAlignment() override { return 8; }
Expected<relocation_iterator>
processRelocationRef(unsigned SectionID, relocation_iterator RelI,
const ObjectFile &BaseObjT,
ObjSectionToIDMap &ObjSectionToID,
StubMap &Stubs) override {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile &>(BaseObjT);
MachO::any_relocation_info RelInfo =
Obj.getRelocation(RelI->getRawDataRefImpl());
uint32_t RelType = Obj.getAnyRelocationType(RelInfo);
if (RelType == MachO::X86_64_RELOC_SUBTRACTOR)
return processSubtractRelocation(SectionID, RelI, Obj, ObjSectionToID);
assert(!Obj.isRelocationScattered(RelInfo) &&
"Scattered relocations not supported on X86_64");
RelocationEntry RE(getRelocationEntry(SectionID, Obj, RelI));
RE.Addend = memcpyAddend(RE);
RelocationValueRef Value;
if (auto ValueOrErr = getRelocationValueRef(Obj, RelI, RE, ObjSectionToID))
Value = *ValueOrErr;
else
return ValueOrErr.takeError();
bool IsExtern = Obj.getPlainRelocationExternal(RelInfo);
if (!IsExtern && RE.IsPCRel)
makeValueAddendPCRel(Value, RelI, 1 << RE.Size);
switch (RelType) {
UNIMPLEMENTED_RELOC(MachO::X86_64_RELOC_TLV);
default:
if (RelType > MachO::X86_64_RELOC_TLV)
return make_error<RuntimeDyldError>(("MachO X86_64 relocation type " +
Twine(RelType) +
" is out of range").str());
break;
}
if (RE.RelType == MachO::X86_64_RELOC_GOT ||
RE.RelType == MachO::X86_64_RELOC_GOT_LOAD)
processGOTRelocation(RE, Value, Stubs);
else {
RE.Addend = Value.Offset;
if (Value.SymbolName)
addRelocationForSymbol(RE, Value.SymbolName);
else
addRelocationForSection(RE, Value.SectionID);
}
return ++RelI;
}
void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override {
LLVM_DEBUG(dumpRelocationToResolve(RE, Value));
const SectionEntry &Section = Sections[RE.SectionID];
uint8_t *LocalAddress = Section.getAddressWithOffset(RE.Offset);
// If the relocation is PC-relative, the value to be encoded is the
// pointer difference.
if (RE.IsPCRel) {
// FIXME: It seems this value needs to be adjusted by 4 for an effective
// PC address. Is that expected? Only for branches, perhaps?
uint64_t FinalAddress = Section.getLoadAddressWithOffset(RE.Offset);
Value -= FinalAddress + 4;
}
switch (RE.RelType) {
default:
llvm_unreachable("Invalid relocation type!");
case MachO::X86_64_RELOC_SIGNED_1:
case MachO::X86_64_RELOC_SIGNED_2:
case MachO::X86_64_RELOC_SIGNED_4:
case MachO::X86_64_RELOC_SIGNED:
case MachO::X86_64_RELOC_UNSIGNED:
case MachO::X86_64_RELOC_BRANCH:
writeBytesUnaligned(Value + RE.Addend, LocalAddress, 1 << RE.Size);
break;
case MachO::X86_64_RELOC_SUBTRACTOR: {
uint64_t SectionABase = Sections[RE.Sections.SectionA].getLoadAddress();
uint64_t SectionBBase = Sections[RE.Sections.SectionB].getLoadAddress();
assert((Value == SectionABase || Value == SectionBBase) &&
"Unexpected SUBTRACTOR relocation value.");
Value = SectionABase - SectionBBase + RE.Addend;
writeBytesUnaligned(Value, LocalAddress, 1 << RE.Size);
break;
}
}
}
Error finalizeSection(const ObjectFile &Obj, unsigned SectionID,
const SectionRef &Section) {
return Error::success();
}
private:
void processGOTRelocation(const RelocationEntry &RE,
RelocationValueRef &Value, StubMap &Stubs) {
SectionEntry &Section = Sections[RE.SectionID];
assert(RE.IsPCRel);
assert(RE.Size == 2);
Value.Offset -= RE.Addend;
RuntimeDyldMachO::StubMap::const_iterator i = Stubs.find(Value);
uint8_t *Addr;
if (i != Stubs.end()) {
Addr = Section.getAddressWithOffset(i->second);
} else {
Stubs[Value] = Section.getStubOffset();
uint8_t *GOTEntry = Section.getAddressWithOffset(Section.getStubOffset());
RelocationEntry GOTRE(RE.SectionID, Section.getStubOffset(),
MachO::X86_64_RELOC_UNSIGNED, Value.Offset, false,
3);
if (Value.SymbolName)
addRelocationForSymbol(GOTRE, Value.SymbolName);
else
addRelocationForSection(GOTRE, Value.SectionID);
Section.advanceStubOffset(8);
Addr = GOTEntry;
}
RelocationEntry TargetRE(RE.SectionID, RE.Offset,
MachO::X86_64_RELOC_UNSIGNED, RE.Addend, true, 2);
resolveRelocation(TargetRE, (uint64_t)Addr);
}
Expected<relocation_iterator>
processSubtractRelocation(unsigned SectionID, relocation_iterator RelI,
const MachOObjectFile &BaseObj,
ObjSectionToIDMap &ObjSectionToID) {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile&>(BaseObj);
MachO::any_relocation_info RE =
Obj.getRelocation(RelI->getRawDataRefImpl());
unsigned Size = Obj.getAnyRelocationLength(RE);
uint64_t Offset = RelI->getOffset();
uint8_t *LocalAddress = Sections[SectionID].getAddressWithOffset(Offset);
unsigned NumBytes = 1 << Size;
int64_t Addend =
SignExtend64(readBytesUnaligned(LocalAddress, NumBytes), NumBytes * 8);
unsigned SectionBID = ~0U;
uint64_t SectionBOffset = 0;
MachO::any_relocation_info RelInfo =
Obj.getRelocation(RelI->getRawDataRefImpl());
bool AIsExternal = BaseObj.getPlainRelocationExternal(RelInfo);
if (AIsExternal) {
Expected<StringRef> SubtrahendNameOrErr = RelI->getSymbol()->getName();
if (!SubtrahendNameOrErr)
return SubtrahendNameOrErr.takeError();
auto SubtrahendI = GlobalSymbolTable.find(*SubtrahendNameOrErr);
SectionBID = SubtrahendI->second.getSectionID();
SectionBOffset = SubtrahendI->second.getOffset();
} else {
SectionRef SecB = Obj.getAnyRelocationSection(RelInfo);
bool IsCode = SecB.isText();
Expected<unsigned> SectionBIDOrErr =
findOrEmitSection(Obj, SecB, IsCode, ObjSectionToID);
if (!SectionBIDOrErr)
return SectionBIDOrErr.takeError();
SectionBID = *SectionBIDOrErr;
Addend += SecB.getAddress();
}
++RelI;
unsigned SectionAID = ~0U;
uint64_t SectionAOffset = 0;
RelInfo = Obj.getRelocation(RelI->getRawDataRefImpl());
bool BIsExternal = BaseObj.getPlainRelocationExternal(RelInfo);
if (BIsExternal) {
Expected<StringRef> MinuendNameOrErr = RelI->getSymbol()->getName();
if (!MinuendNameOrErr)
return MinuendNameOrErr.takeError();
auto MinuendI = GlobalSymbolTable.find(*MinuendNameOrErr);
SectionAID = MinuendI->second.getSectionID();
SectionAOffset = MinuendI->second.getOffset();
} else {
SectionRef SecA = Obj.getAnyRelocationSection(RelInfo);
bool IsCode = SecA.isText();
Expected<unsigned> SectionAIDOrErr =
findOrEmitSection(Obj, SecA, IsCode, ObjSectionToID);
if (!SectionAIDOrErr)
return SectionAIDOrErr.takeError();
SectionAID = *SectionAIDOrErr;
Addend -= SecA.getAddress();
}
RelocationEntry R(SectionID, Offset, MachO::X86_64_RELOC_SUBTRACTOR, (uint64_t)Addend,
SectionAID, SectionAOffset, SectionBID, SectionBOffset,
false, Size);
addRelocationForSection(R, SectionAID);
return ++RelI;
}
};
}
#undef DEBUG_TYPE
#endif
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