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llvm-for-llvmta/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h

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//===---- RuntimeDyldMachOI386.h ---- MachO/I386 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_RUNTIMEDYLDMACHOI386_H
#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOI386_H
#include "../RuntimeDyldMachO.h"
#include <string>
#define DEBUG_TYPE "dyld"
namespace llvm {
class RuntimeDyldMachOI386
: public RuntimeDyldMachOCRTPBase<RuntimeDyldMachOI386> {
public:
typedef uint32_t TargetPtrT;
RuntimeDyldMachOI386(RuntimeDyld::MemoryManager &MM,
JITSymbolResolver &Resolver)
: RuntimeDyldMachOCRTPBase(MM, Resolver) {}
unsigned getMaxStubSize() const override { return 0; }
unsigned getStubAlignment() override { return 1; }
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 (Obj.isRelocationScattered(RelInfo)) {
if (RelType == MachO::GENERIC_RELOC_SECTDIFF ||
RelType == MachO::GENERIC_RELOC_LOCAL_SECTDIFF)
return processSECTDIFFRelocation(SectionID, RelI, Obj,
ObjSectionToID);
else if (RelType == MachO::GENERIC_RELOC_VANILLA)
return processScatteredVANILLA(SectionID, RelI, Obj, ObjSectionToID);
return make_error<RuntimeDyldError>(("Unhandled I386 scattered relocation "
"type: " + Twine(RelType)).str());
}
switch (RelType) {
UNIMPLEMENTED_RELOC(MachO::GENERIC_RELOC_PAIR);
UNIMPLEMENTED_RELOC(MachO::GENERIC_RELOC_PB_LA_PTR);
UNIMPLEMENTED_RELOC(MachO::GENERIC_RELOC_TLV);
default:
if (RelType > MachO::GENERIC_RELOC_TLV)
return make_error<RuntimeDyldError>(("MachO I386 relocation type " +
Twine(RelType) +
" is out of range").str());
break;
}
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();
// Addends for external, PC-rel relocations on i386 point back to the zero
// offset. Calculate the final offset from the relocation target instead.
// This allows us to use the same logic for both external and internal
// relocations in resolveI386RelocationRef.
// bool IsExtern = Obj.getPlainRelocationExternal(RelInfo);
// if (IsExtern && RE.IsPCRel) {
// uint64_t RelocAddr = 0;
// RelI->getAddress(RelocAddr);
// Value.Addend += RelocAddr + 4;
// }
if (RE.IsPCRel)
makeValueAddendPCRel(Value, RelI, 1 << RE.Size);
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 (RE.IsPCRel) {
uint64_t FinalAddress = Section.getLoadAddressWithOffset(RE.Offset);
Value -= FinalAddress + 4; // see MachOX86_64::resolveRelocation.
}
switch (RE.RelType) {
case MachO::GENERIC_RELOC_VANILLA:
writeBytesUnaligned(Value + RE.Addend, LocalAddress, 1 << RE.Size);
break;
case MachO::GENERIC_RELOC_SECTDIFF:
case MachO::GENERIC_RELOC_LOCAL_SECTDIFF: {
uint64_t SectionABase = Sections[RE.Sections.SectionA].getLoadAddress();
uint64_t SectionBBase = Sections[RE.Sections.SectionB].getLoadAddress();
assert((Value == SectionABase || Value == SectionBBase) &&
"Unexpected SECTDIFF relocation value.");
Value = SectionABase - SectionBBase + RE.Addend;
writeBytesUnaligned(Value, LocalAddress, 1 << RE.Size);
break;
}
default:
llvm_unreachable("Invalid relocation type!");
}
}
Error finalizeSection(const ObjectFile &Obj, unsigned SectionID,
const SectionRef &Section) {
StringRef Name;
if (Expected<StringRef> NameOrErr = Section.getName())
Name = *NameOrErr;
else
consumeError(NameOrErr.takeError());
if (Name == "__jump_table")
return populateJumpTable(cast<MachOObjectFile>(Obj), Section, SectionID);
else if (Name == "__pointers")
return populateIndirectSymbolPointersSection(cast<MachOObjectFile>(Obj),
Section, SectionID);
return Error::success();
}
private:
Expected<relocation_iterator>
processSECTDIFFRelocation(unsigned SectionID, relocation_iterator RelI,
const ObjectFile &BaseObjT,
ObjSectionToIDMap &ObjSectionToID) {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile&>(BaseObjT);
MachO::any_relocation_info RE =
Obj.getRelocation(RelI->getRawDataRefImpl());
SectionEntry &Section = Sections[SectionID];
uint32_t RelocType = Obj.getAnyRelocationType(RE);
bool IsPCRel = Obj.getAnyRelocationPCRel(RE);
unsigned Size = Obj.getAnyRelocationLength(RE);
uint64_t Offset = RelI->getOffset();
uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
unsigned NumBytes = 1 << Size;
uint64_t Addend = readBytesUnaligned(LocalAddress, NumBytes);
++RelI;
MachO::any_relocation_info RE2 =
Obj.getRelocation(RelI->getRawDataRefImpl());
uint32_t AddrA = Obj.getScatteredRelocationValue(RE);
section_iterator SAI = getSectionByAddress(Obj, AddrA);
assert(SAI != Obj.section_end() && "Can't find section for address A");
uint64_t SectionABase = SAI->getAddress();
uint64_t SectionAOffset = AddrA - SectionABase;
SectionRef SectionA = *SAI;
bool IsCode = SectionA.isText();
uint32_t SectionAID = ~0U;
if (auto SectionAIDOrErr =
findOrEmitSection(Obj, SectionA, IsCode, ObjSectionToID))
SectionAID = *SectionAIDOrErr;
else
return SectionAIDOrErr.takeError();
uint32_t AddrB = Obj.getScatteredRelocationValue(RE2);
section_iterator SBI = getSectionByAddress(Obj, AddrB);
assert(SBI != Obj.section_end() && "Can't find section for address B");
uint64_t SectionBBase = SBI->getAddress();
uint64_t SectionBOffset = AddrB - SectionBBase;
SectionRef SectionB = *SBI;
uint32_t SectionBID = ~0U;
if (auto SectionBIDOrErr =
findOrEmitSection(Obj, SectionB, IsCode, ObjSectionToID))
SectionBID = *SectionBIDOrErr;
else
return SectionBIDOrErr.takeError();
// Compute the addend 'C' from the original expression 'A - B + C'.
Addend -= AddrA - AddrB;
LLVM_DEBUG(dbgs() << "Found SECTDIFF: AddrA: " << AddrA
<< ", AddrB: " << AddrB << ", Addend: " << Addend
<< ", SectionA ID: " << SectionAID << ", SectionAOffset: "
<< SectionAOffset << ", SectionB ID: " << SectionBID
<< ", SectionBOffset: " << SectionBOffset << "\n");
RelocationEntry R(SectionID, Offset, RelocType, Addend, SectionAID,
SectionAOffset, SectionBID, SectionBOffset,
IsPCRel, Size);
addRelocationForSection(R, SectionAID);
return ++RelI;
}
// Populate stubs in __jump_table section.
Error populateJumpTable(const MachOObjectFile &Obj,
const SectionRef &JTSection,
unsigned JTSectionID) {
MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
MachO::section Sec32 = Obj.getSection(JTSection.getRawDataRefImpl());
uint32_t JTSectionSize = Sec32.size;
unsigned FirstIndirectSymbol = Sec32.reserved1;
unsigned JTEntrySize = Sec32.reserved2;
unsigned NumJTEntries = JTSectionSize / JTEntrySize;
uint8_t *JTSectionAddr = getSectionAddress(JTSectionID);
unsigned JTEntryOffset = 0;
if (JTSectionSize % JTEntrySize != 0)
return make_error<RuntimeDyldError>("Jump-table section does not contain "
"a whole number of stubs?");
for (unsigned i = 0; i < NumJTEntries; ++i) {
unsigned SymbolIndex =
Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
Expected<StringRef> IndirectSymbolName = SI->getName();
if (!IndirectSymbolName)
return IndirectSymbolName.takeError();
uint8_t *JTEntryAddr = JTSectionAddr + JTEntryOffset;
createStubFunction(JTEntryAddr);
RelocationEntry RE(JTSectionID, JTEntryOffset + 1,
MachO::GENERIC_RELOC_VANILLA, 0, true, 2);
addRelocationForSymbol(RE, *IndirectSymbolName);
JTEntryOffset += JTEntrySize;
}
return Error::success();
}
};
}
#undef DEBUG_TYPE
#endif
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