mirror of
https://github.com/c64scene-ar/llvm-6502.git
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858143816d
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149967 91177308-0d34-0410-b5e6-96231b3b80d8
599 lines
24 KiB
C++
599 lines
24 KiB
C++
//===-- RuntimeDyldMachO.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-=//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// Implementation of the MC-JIT runtime dynamic linker.
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "dyld"
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#include "llvm/ADT/OwningPtr.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/ADT/STLExtras.h"
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#include "RuntimeDyldMachO.h"
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using namespace llvm;
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using namespace llvm::object;
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namespace llvm {
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bool RuntimeDyldMachO::
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resolveRelocation(uint8_t *Address, uint64_t Value, bool isPCRel,
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unsigned Type, unsigned Size, int64_t Addend) {
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// This just dispatches to the proper target specific routine.
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switch (CPUType) {
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default: llvm_unreachable("Unsupported CPU type!");
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case mach::CTM_x86_64:
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return resolveX86_64Relocation((uintptr_t)Address, (uintptr_t)Value,
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isPCRel, Type, Size, Addend);
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case mach::CTM_ARM:
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return resolveARMRelocation((uintptr_t)Address, (uintptr_t)Value,
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isPCRel, Type, Size, Addend);
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}
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llvm_unreachable("");
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}
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bool RuntimeDyldMachO::
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resolveX86_64Relocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
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unsigned Type, unsigned Size, int64_t Addend) {
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// If the relocation is PC-relative, the value to be encoded is the
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// pointer difference.
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if (isPCRel)
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// FIXME: It seems this value needs to be adjusted by 4 for an effective PC
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// address. Is that expected? Only for branches, perhaps?
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Value -= Address + 4;
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switch(Type) {
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default:
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llvm_unreachable("Invalid relocation type!");
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case macho::RIT_X86_64_Signed1:
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case macho::RIT_X86_64_Signed2:
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case macho::RIT_X86_64_Signed4:
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case macho::RIT_X86_64_Signed:
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case macho::RIT_X86_64_Unsigned:
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case macho::RIT_X86_64_Branch: {
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Value += Addend;
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// Mask in the target value a byte at a time (we don't have an alignment
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// guarantee for the target address, so this is safest).
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uint8_t *p = (uint8_t*)Address;
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for (unsigned i = 0; i < Size; ++i) {
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*p++ = (uint8_t)Value;
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Value >>= 8;
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}
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return false;
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}
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case macho::RIT_X86_64_GOTLoad:
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case macho::RIT_X86_64_GOT:
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case macho::RIT_X86_64_Subtractor:
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case macho::RIT_X86_64_TLV:
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return Error("Relocation type not implemented yet!");
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}
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}
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bool RuntimeDyldMachO::
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resolveARMRelocation(uintptr_t Address, uintptr_t Value, bool isPCRel,
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unsigned Type, unsigned Size, int64_t Addend) {
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// If the relocation is PC-relative, the value to be encoded is the
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// pointer difference.
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if (isPCRel) {
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Value -= Address;
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// ARM PCRel relocations have an effective-PC offset of two instructions
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// (four bytes in Thumb mode, 8 bytes in ARM mode).
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// FIXME: For now, assume ARM mode.
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Value -= 8;
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}
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switch(Type) {
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default:
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llvm_unreachable("Invalid relocation type!");
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case macho::RIT_Vanilla: {
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llvm_unreachable("Invalid relocation type!");
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// Mask in the target value a byte at a time (we don't have an alignment
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// guarantee for the target address, so this is safest).
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uint8_t *p = (uint8_t*)Address;
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for (unsigned i = 0; i < Size; ++i) {
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*p++ = (uint8_t)Value;
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Value >>= 8;
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}
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break;
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}
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case macho::RIT_ARM_Branch24Bit: {
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// Mask the value into the target address. We know instructions are
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// 32-bit aligned, so we can do it all at once.
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uint32_t *p = (uint32_t*)Address;
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// The low two bits of the value are not encoded.
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Value >>= 2;
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// Mask the value to 24 bits.
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Value &= 0xffffff;
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// FIXME: If the destination is a Thumb function (and the instruction
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// is a non-predicated BL instruction), we need to change it to a BLX
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// instruction instead.
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// Insert the value into the instruction.
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*p = (*p & ~0xffffff) | Value;
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break;
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}
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case macho::RIT_ARM_ThumbBranch22Bit:
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case macho::RIT_ARM_ThumbBranch32Bit:
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case macho::RIT_ARM_Half:
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case macho::RIT_ARM_HalfDifference:
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case macho::RIT_Pair:
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case macho::RIT_Difference:
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case macho::RIT_ARM_LocalDifference:
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case macho::RIT_ARM_PreboundLazyPointer:
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return Error("Relocation type not implemented yet!");
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}
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return false;
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}
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bool RuntimeDyldMachO::
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loadSegment32(const MachOObject *Obj,
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const MachOObject::LoadCommandInfo *SegmentLCI,
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const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
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// FIXME: This should really be combined w/ loadSegment64. Templatized
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// function on the 32/64 datatypes maybe?
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InMemoryStruct<macho::SegmentLoadCommand> SegmentLC;
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Obj->ReadSegmentLoadCommand(*SegmentLCI, SegmentLC);
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if (!SegmentLC)
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return Error("unable to load segment load command");
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SmallVector<unsigned, 16> SectionMap;
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for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) {
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InMemoryStruct<macho::Section> Sect;
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Obj->ReadSection(*SegmentLCI, SectNum, Sect);
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if (!Sect)
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return Error("unable to load section: '" + Twine(SectNum) + "'");
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// Allocate memory via the MM for the section.
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uint8_t *Buffer;
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uint32_t SectionID = Sections.size();
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if (Sect->Flags != 0x80000400)
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Buffer = MemMgr->allocateCodeSection(Sect->Size, Sect->Align, SectionID);
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else
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Buffer = MemMgr->allocateDataSection(Sect->Size, Sect->Align, SectionID);
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DEBUG(dbgs() << "Loading "
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<< ((Sect->Flags == 0x80000400) ? "text" : "data")
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<< " (ID #" << SectionID << ")"
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<< " '" << Sect->SegmentName << ","
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<< Sect->Name << "' of size " << Sect->Size
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<< " to address " << Buffer << ".\n");
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// Copy the payload from the object file into the allocated buffer.
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uint8_t *Base = (uint8_t*)Obj->getData(SegmentLC->FileOffset,
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SegmentLC->FileSize).data();
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memcpy(Buffer, Base + Sect->Address, Sect->Size);
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// Remember what got allocated for this SectionID.
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Sections.push_back(sys::MemoryBlock(Buffer, Sect->Size));
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SectionLocalMemToID[Buffer] = SectionID;
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// By default, the load address of a section is its memory buffer.
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SectionLoadAddress.push_back((uint64_t)Buffer);
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// Keep a map of object file section numbers to corresponding SectionIDs
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// while processing the file.
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SectionMap.push_back(SectionID);
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}
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// Process the symbol table.
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SmallVector<StringRef, 64> SymbolNames;
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processSymbols32(Obj, SectionMap, SymbolNames, SymtabLC);
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// Process the relocations for each section we're loading.
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Relocations.grow(Relocations.size() + SegmentLC->NumSections);
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for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) {
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InMemoryStruct<macho::Section> Sect;
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Obj->ReadSection(*SegmentLCI, SectNum, Sect);
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if (!Sect)
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return Error("unable to load section: '" + Twine(SectNum) + "'");
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for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
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InMemoryStruct<macho::RelocationEntry> RE;
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Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
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if (RE->Word0 & macho::RF_Scattered)
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return Error("NOT YET IMPLEMENTED: scattered relocations.");
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// Word0 of the relocation is the offset into the section where the
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// relocation should be applied. We need to translate that into an
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// offset into a function since that's our atom.
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uint32_t Offset = RE->Word0;
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bool isExtern = (RE->Word1 >> 27) & 1;
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// FIXME: Get the relocation addend from the target address.
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// FIXME: VERY imporant for internal relocations.
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// Figure out the source symbol of the relocation. If isExtern is true,
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// this relocation references the symbol table, otherwise it references
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// a section in the same object, numbered from 1 through NumSections
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// (SectionBases is [0, NumSections-1]).
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uint32_t SourceNum = RE->Word1 & 0xffffff; // 24-bit value
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if (!isExtern) {
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assert(SourceNum > 0 && "Invalid relocation section number!");
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unsigned SectionID = SectionMap[SourceNum - 1];
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unsigned TargetID = SectionMap[SectNum];
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DEBUG(dbgs() << "Internal relocation at Section #"
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<< TargetID << " + " << Offset
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<< " from Section #"
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<< SectionID << " (Word1: "
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<< format("0x%x", RE->Word1) << ")\n");
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// Store the relocation information. It will get resolved when
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// the section addresses are assigned.
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Relocations[SectionID].push_back(RelocationEntry(TargetID,
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Offset,
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RE->Word1,
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0 /*Addend*/));
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} else {
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StringRef SourceName = SymbolNames[SourceNum];
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// Now store the relocation information. Associate it with the source
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// symbol. Just add it to the unresolved list and let the general
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// path post-load resolve it if we know where the symbol is.
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UnresolvedRelocations[SourceName].push_back(RelocationEntry(SectNum,
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Offset,
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RE->Word1,
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0 /*Addend*/));
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DEBUG(dbgs() << "Relocation at Section #" << SectNum << " + " << Offset
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<< " from '" << SourceName << "(Word1: "
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<< format("0x%x", RE->Word1) << ")\n");
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}
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}
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}
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// Resolve the addresses of any symbols that were defined in this segment.
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for (int i = 0, e = SymbolNames.size(); i != e; ++i)
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resolveSymbol(SymbolNames[i]);
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return false;
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}
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bool RuntimeDyldMachO::
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loadSegment64(const MachOObject *Obj,
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const MachOObject::LoadCommandInfo *SegmentLCI,
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const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
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InMemoryStruct<macho::Segment64LoadCommand> Segment64LC;
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Obj->ReadSegment64LoadCommand(*SegmentLCI, Segment64LC);
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if (!Segment64LC)
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return Error("unable to load segment load command");
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SmallVector<unsigned, 16> SectionMap;
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for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; ++SectNum) {
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InMemoryStruct<macho::Section64> Sect;
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Obj->ReadSection64(*SegmentLCI, SectNum, Sect);
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if (!Sect)
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return Error("unable to load section: '" + Twine(SectNum) + "'");
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// Allocate memory via the MM for the section.
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uint8_t *Buffer;
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uint32_t SectionID = Sections.size();
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unsigned Align = 1 << Sect->Align; // .o file has log2 alignment.
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if (Sect->Flags == 0x80000400)
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Buffer = MemMgr->allocateCodeSection(Sect->Size, Align, SectionID);
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else
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Buffer = MemMgr->allocateDataSection(Sect->Size, Align, SectionID);
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DEBUG(dbgs() << "Loading "
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<< ((Sect->Flags == 0x80000400) ? "text" : "data")
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<< " (ID #" << SectionID << ")"
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<< " '" << Sect->SegmentName << ","
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<< Sect->Name << "' of size " << Sect->Size
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<< " (align " << Align << ")"
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<< " to address " << Buffer << ".\n");
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// Copy the payload from the object file into the allocated buffer.
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uint8_t *Base = (uint8_t*)Obj->getData(Segment64LC->FileOffset,
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Segment64LC->FileSize).data();
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memcpy(Buffer, Base + Sect->Address, Sect->Size);
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// Remember what got allocated for this SectionID.
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Sections.push_back(sys::MemoryBlock(Buffer, Sect->Size));
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SectionLocalMemToID[Buffer] = SectionID;
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// By default, the load address of a section is its memory buffer.
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SectionLoadAddress.push_back((uint64_t)Buffer);
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// Keep a map of object file section numbers to corresponding SectionIDs
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// while processing the file.
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SectionMap.push_back(SectionID);
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}
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// Process the symbol table.
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SmallVector<StringRef, 64> SymbolNames;
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processSymbols64(Obj, SectionMap, SymbolNames, SymtabLC);
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// Process the relocations for each section we're loading.
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Relocations.grow(Relocations.size() + Segment64LC->NumSections);
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for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; ++SectNum) {
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InMemoryStruct<macho::Section64> Sect;
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Obj->ReadSection64(*SegmentLCI, SectNum, Sect);
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if (!Sect)
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return Error("unable to load section: '" + Twine(SectNum) + "'");
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for (unsigned j = 0; j != Sect->NumRelocationTableEntries; ++j) {
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InMemoryStruct<macho::RelocationEntry> RE;
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Obj->ReadRelocationEntry(Sect->RelocationTableOffset, j, RE);
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if (RE->Word0 & macho::RF_Scattered)
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return Error("NOT YET IMPLEMENTED: scattered relocations.");
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// Word0 of the relocation is the offset into the section where the
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// relocation should be applied. We need to translate that into an
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// offset into a function since that's our atom.
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uint32_t Offset = RE->Word0;
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bool isExtern = (RE->Word1 >> 27) & 1;
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// FIXME: Get the relocation addend from the target address.
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// FIXME: VERY imporant for internal relocations.
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// Figure out the source symbol of the relocation. If isExtern is true,
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// this relocation references the symbol table, otherwise it references
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// a section in the same object, numbered from 1 through NumSections
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// (SectionBases is [0, NumSections-1]).
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uint32_t SourceNum = RE->Word1 & 0xffffff; // 24-bit value
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if (!isExtern) {
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assert(SourceNum > 0 && "Invalid relocation section number!");
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unsigned SectionID = SectionMap[SourceNum - 1];
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unsigned TargetID = SectionMap[SectNum];
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DEBUG(dbgs() << "Internal relocation at Section #"
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<< TargetID << " + " << Offset
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<< " from Section #"
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<< SectionID << " (Word1: "
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<< format("0x%x", RE->Word1) << ")\n");
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// Store the relocation information. It will get resolved when
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// the section addresses are assigned.
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Relocations[SectionID].push_back(RelocationEntry(TargetID,
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Offset,
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RE->Word1,
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0 /*Addend*/));
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} else {
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StringRef SourceName = SymbolNames[SourceNum];
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// Now store the relocation information. Associate it with the source
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// symbol. Just add it to the unresolved list and let the general
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// path post-load resolve it if we know where the symbol is.
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UnresolvedRelocations[SourceName].push_back(RelocationEntry(SectNum,
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Offset,
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RE->Word1,
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0 /*Addend*/));
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DEBUG(dbgs() << "Relocation at Section #" << SectNum << " + " << Offset
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<< " from '" << SourceName << "(Word1: "
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<< format("0x%x", RE->Word1) << ")\n");
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}
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}
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}
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// Resolve the addresses of any symbols that were defined in this segment.
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for (int i = 0, e = SymbolNames.size(); i != e; ++i)
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resolveSymbol(SymbolNames[i]);
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return false;
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}
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bool RuntimeDyldMachO::
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processSymbols32(const MachOObject *Obj,
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SmallVectorImpl<unsigned> &SectionMap,
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SmallVectorImpl<StringRef> &SymbolNames,
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const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
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// FIXME: Combine w/ processSymbols64. Factor 64/32 datatype and such.
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for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
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InMemoryStruct<macho::SymbolTableEntry> STE;
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Obj->ReadSymbolTableEntry(SymtabLC->SymbolTableOffset, i, STE);
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if (!STE)
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return Error("unable to read symbol: '" + Twine(i) + "'");
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// Get the symbol name.
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StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
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SymbolNames.push_back(Name);
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// FIXME: Check the symbol type and flags.
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if (STE->Type != 0xF) // external, defined in this segment.
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continue;
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// Flags in the upper nibble we don't care about.
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if ((STE->Flags & 0xf) != 0x0)
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continue;
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// Remember the symbol.
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uint32_t SectionID = SectionMap[STE->SectionIndex - 1];
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SymbolTable[Name] = SymbolLoc(SectionID, STE->Value);
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DEBUG(dbgs() << "Symbol: '" << Name << "' @ "
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<< (getSectionAddress(SectionID) + STE->Value)
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<< "\n");
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}
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return false;
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}
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bool RuntimeDyldMachO::
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processSymbols64(const MachOObject *Obj,
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SmallVectorImpl<unsigned> &SectionMap,
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SmallVectorImpl<StringRef> &SymbolNames,
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const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC) {
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for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
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InMemoryStruct<macho::Symbol64TableEntry> STE;
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Obj->ReadSymbol64TableEntry(SymtabLC->SymbolTableOffset, i, STE);
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if (!STE)
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return Error("unable to read symbol: '" + Twine(i) + "'");
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// Get the symbol name.
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StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
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SymbolNames.push_back(Name);
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// FIXME: Check the symbol type and flags.
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if (STE->Type != 0xF) // external, defined in this segment.
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continue;
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// Flags in the upper nibble we don't care about.
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if ((STE->Flags & 0xf) != 0x0)
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continue;
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// Remember the symbol.
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uint32_t SectionID = SectionMap[STE->SectionIndex - 1];
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SymbolTable[Name] = SymbolLoc(SectionID, STE->Value);
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DEBUG(dbgs() << "Symbol: '" << Name << "' @ "
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<< (getSectionAddress(SectionID) + STE->Value)
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<< "\n");
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}
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return false;
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}
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// resolveSymbol - Resolve any relocations to the specified symbol if
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// we know where it lives.
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void RuntimeDyldMachO::resolveSymbol(StringRef Name) {
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StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(Name);
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if (Loc == SymbolTable.end())
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return;
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RelocationList &Relocs = UnresolvedRelocations[Name];
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DEBUG(dbgs() << "Resolving symbol '" << Name << "'\n");
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for (int i = 0, e = Relocs.size(); i != e; ++i) {
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// Change the relocation to be section relative rather than symbol
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// relative and move it to the resolved relocation list.
|
|
RelocationEntry Entry = Relocs[i];
|
|
Entry.Addend += Loc->second.second;
|
|
Relocations[Loc->second.first].push_back(Entry);
|
|
}
|
|
// FIXME: Keep a worklist of the relocations we've added so that we can
|
|
// resolve more selectively later.
|
|
Relocs.clear();
|
|
}
|
|
|
|
bool RuntimeDyldMachO::loadObject(MemoryBuffer *InputBuffer) {
|
|
// If the linker is in an error state, don't do anything.
|
|
if (hasError())
|
|
return true;
|
|
// Load the Mach-O wrapper object.
|
|
std::string ErrorStr;
|
|
OwningPtr<MachOObject> Obj(
|
|
MachOObject::LoadFromBuffer(InputBuffer, &ErrorStr));
|
|
if (!Obj)
|
|
return Error("unable to load object: '" + ErrorStr + "'");
|
|
|
|
// Get the CPU type information from the header.
|
|
const macho::Header &Header = Obj->getHeader();
|
|
|
|
// FIXME: Error checking that the loaded object is compatible with
|
|
// the system we're running on.
|
|
CPUType = Header.CPUType;
|
|
CPUSubtype = Header.CPUSubtype;
|
|
|
|
// Validate that the load commands match what we expect.
|
|
const MachOObject::LoadCommandInfo *SegmentLCI = 0, *SymtabLCI = 0,
|
|
*DysymtabLCI = 0;
|
|
for (unsigned i = 0; i != Header.NumLoadCommands; ++i) {
|
|
const MachOObject::LoadCommandInfo &LCI = Obj->getLoadCommandInfo(i);
|
|
switch (LCI.Command.Type) {
|
|
case macho::LCT_Segment:
|
|
case macho::LCT_Segment64:
|
|
if (SegmentLCI)
|
|
return Error("unexpected input object (multiple segments)");
|
|
SegmentLCI = &LCI;
|
|
break;
|
|
case macho::LCT_Symtab:
|
|
if (SymtabLCI)
|
|
return Error("unexpected input object (multiple symbol tables)");
|
|
SymtabLCI = &LCI;
|
|
break;
|
|
case macho::LCT_Dysymtab:
|
|
if (DysymtabLCI)
|
|
return Error("unexpected input object (multiple symbol tables)");
|
|
DysymtabLCI = &LCI;
|
|
break;
|
|
default:
|
|
return Error("unexpected input object (unexpected load command");
|
|
}
|
|
}
|
|
|
|
if (!SymtabLCI)
|
|
return Error("no symbol table found in object");
|
|
if (!SegmentLCI)
|
|
return Error("no segments found in object");
|
|
|
|
// Read and register the symbol table data.
|
|
InMemoryStruct<macho::SymtabLoadCommand> SymtabLC;
|
|
Obj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC);
|
|
if (!SymtabLC)
|
|
return Error("unable to load symbol table load command");
|
|
Obj->RegisterStringTable(*SymtabLC);
|
|
|
|
// Read the dynamic link-edit information, if present (not present in static
|
|
// objects).
|
|
if (DysymtabLCI) {
|
|
InMemoryStruct<macho::DysymtabLoadCommand> DysymtabLC;
|
|
Obj->ReadDysymtabLoadCommand(*DysymtabLCI, DysymtabLC);
|
|
if (!DysymtabLC)
|
|
return Error("unable to load dynamic link-exit load command");
|
|
|
|
// FIXME: We don't support anything interesting yet.
|
|
// if (DysymtabLC->LocalSymbolsIndex != 0)
|
|
// return Error("NOT YET IMPLEMENTED: local symbol entries");
|
|
// if (DysymtabLC->ExternalSymbolsIndex != 0)
|
|
// return Error("NOT YET IMPLEMENTED: non-external symbol entries");
|
|
// if (DysymtabLC->UndefinedSymbolsIndex != SymtabLC->NumSymbolTableEntries)
|
|
// return Error("NOT YET IMPLEMENTED: undefined symbol entries");
|
|
}
|
|
|
|
// Load the segment load command.
|
|
if (SegmentLCI->Command.Type == macho::LCT_Segment) {
|
|
if (loadSegment32(Obj.get(), SegmentLCI, SymtabLC))
|
|
return true;
|
|
} else {
|
|
if (loadSegment64(Obj.get(), SegmentLCI, SymtabLC))
|
|
return true;
|
|
}
|
|
|
|
// Assign the addresses of the sections from the object so that any
|
|
// relocations to them get set properly.
|
|
// FIXME: This is done directly from the client at the moment. We should
|
|
// default the values to the local storage, at least when the target arch
|
|
// is the same as the host arch.
|
|
|
|
return false;
|
|
}
|
|
|
|
// Assign an address to a symbol name and resolve all the relocations
|
|
// associated with it.
|
|
void RuntimeDyldMachO::reassignSectionAddress(unsigned SectionID,
|
|
uint64_t Addr) {
|
|
// The address to use for relocation resolution is not
|
|
// the address of the local section buffer. We must be doing
|
|
// a remote execution environment of some sort. Re-apply any
|
|
// relocations referencing this section with the given address.
|
|
//
|
|
// Addr is a uint64_t because we can't assume the pointer width
|
|
// of the target is the same as that of the host. Just use a generic
|
|
// "big enough" type.
|
|
|
|
SectionLoadAddress[SectionID] = Addr;
|
|
|
|
RelocationList &Relocs = Relocations[SectionID];
|
|
for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
|
|
RelocationEntry &RE = Relocs[i];
|
|
uint8_t *Target = (uint8_t*)Sections[RE.SectionID].base() + RE.Offset;
|
|
bool isPCRel = (RE.Data >> 24) & 1;
|
|
unsigned Type = (RE.Data >> 28) & 0xf;
|
|
unsigned Size = 1 << ((RE.Data >> 25) & 3);
|
|
|
|
DEBUG(dbgs() << "Resolving relocation at Section #" << RE.SectionID
|
|
<< " + " << RE.Offset << " (" << format("%p", Target) << ")"
|
|
<< " from Section #" << SectionID << " (" << format("%p", Addr) << ")"
|
|
<< "(" << (isPCRel ? "pcrel" : "absolute")
|
|
<< ", type: " << Type << ", Size: " << Size << ", Addend: "
|
|
<< RE.Addend << ").\n");
|
|
|
|
resolveRelocation(Target, Addr, isPCRel, Type, Size, RE.Addend);
|
|
}
|
|
}
|
|
|
|
bool RuntimeDyldMachO::isKnownFormat(const MemoryBuffer *InputBuffer) {
|
|
StringRef Magic = InputBuffer->getBuffer().slice(0, 4);
|
|
if (Magic == "\xFE\xED\xFA\xCE") return true;
|
|
if (Magic == "\xCE\xFA\xED\xFE") return true;
|
|
if (Magic == "\xFE\xED\xFA\xCF") return true;
|
|
if (Magic == "\xCF\xFA\xED\xFE") return true;
|
|
return false;
|
|
}
|
|
|
|
} // end namespace llvm
|