mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-06-17 04:24:00 +00:00
Library-ize the dyld components of llvm-rtdyld.
Move the dynamic linking functionality of the llvm-rtdyld program into an ExecutionEngine support library. Update llvm-rtdyld to just load an object file into memory, use the library to process it, then run the _main() function, if one is found. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128031 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach
@ -13,6 +13,7 @@
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#include "llvm/ADT/StringMap.h"
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#include "llvm/ADT/OwningPtr.h"
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#include "llvm/ExecutionEngine/RuntimeDyld.h"
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#include "llvm/Object/MachOObject.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/ManagedStatic.h"
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@ -51,157 +52,6 @@ static int Error(const Twine &Msg) {
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}
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/* *** */
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static bool
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loadSegment32(const MachOObject *Obj,
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sys::MemoryBlock &Data,
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const MachOObject::LoadCommandInfo *SegmentLCI,
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const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC,
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StringMap<void*> &SymbolTable) {
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InMemoryStruct<macho::SegmentLoadCommand> Segment32LC;
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Obj->ReadSegmentLoadCommand(*SegmentLCI, Segment32LC);
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if (!Segment32LC)
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return Error("unable to load segment load command");
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// Map the segment into memory.
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std::string ErrorStr;
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Data = sys::Memory::AllocateRWX(Segment32LC->VMSize, 0, &ErrorStr);
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if (!Data.base())
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return Error("unable to allocate memory block: '" + ErrorStr + "'");
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memcpy(Data.base(), Obj->getData(Segment32LC->FileOffset,
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Segment32LC->FileSize).data(),
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Segment32LC->FileSize);
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memset((char*)Data.base() + Segment32LC->FileSize, 0,
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Segment32LC->VMSize - Segment32LC->FileSize);
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// Bind the section indices to address.
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void **SectionBases = new void*[Segment32LC->NumSections];
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for (unsigned i = 0; i != Segment32LC->NumSections; ++i) {
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InMemoryStruct<macho::Section> Sect;
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Obj->ReadSection(*SegmentLCI, i, Sect);
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if (!Sect)
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return Error("unable to load section: '" + Twine(i) + "'");
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// FIXME: We don't support relocations yet.
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if (Sect->NumRelocationTableEntries != 0)
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return Error("not yet implemented: relocations!");
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// FIXME: Improve check.
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if (Sect->Flags != 0x80000400)
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return Error("unsupported section type!");
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SectionBases[i] = (char*) Data.base() + Sect->Address;
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}
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// Bind all the symbols to address.
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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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if (STE->SectionIndex == 0)
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return Error("unexpected undefined symbol!");
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unsigned Index = STE->SectionIndex - 1;
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if (Index >= Segment32LC->NumSections)
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return Error("invalid section index for symbol: '" + Twine() + "'");
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// Get the symbol name.
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StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
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// Get the section base address.
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void *SectionBase = SectionBases[Index];
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// Get the symbol address.
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void *Address = (char*) SectionBase + STE->Value;
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// FIXME: Check the symbol type and flags.
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if (STE->Type != 0xF)
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return Error("unexpected symbol type!");
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if (STE->Flags != 0x0)
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return Error("unexpected symbol type!");
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SymbolTable[Name] = Address;
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}
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delete SectionBases;
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return false;
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}
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static bool
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loadSegment64(const MachOObject *Obj,
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sys::MemoryBlock &Data,
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const MachOObject::LoadCommandInfo *SegmentLCI,
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const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC,
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StringMap<void*> &SymbolTable) {
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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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// Map the segment into memory.
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std::string ErrorStr;
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Data = sys::Memory::AllocateRWX(Segment64LC->VMSize, 0, &ErrorStr);
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if (!Data.base())
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return Error("unable to allocate memory block: '" + ErrorStr + "'");
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memcpy(Data.base(), Obj->getData(Segment64LC->FileOffset,
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Segment64LC->FileSize).data(),
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Segment64LC->FileSize);
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memset((char*)Data.base() + Segment64LC->FileSize, 0,
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Segment64LC->VMSize - Segment64LC->FileSize);
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// Bind the section indices to address.
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void **SectionBases = new void*[Segment64LC->NumSections];
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for (unsigned i = 0; i != Segment64LC->NumSections; ++i) {
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InMemoryStruct<macho::Section64> Sect;
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Obj->ReadSection64(*SegmentLCI, i, Sect);
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if (!Sect)
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return Error("unable to load section: '" + Twine(i) + "'");
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// FIXME: We don't support relocations yet.
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if (Sect->NumRelocationTableEntries != 0)
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return Error("not yet implemented: relocations!");
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// FIXME: Improve check.
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if (Sect->Flags != 0x80000400)
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return Error("unsupported section type!");
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SectionBases[i] = (char*) Data.base() + Sect->Address;
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}
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// Bind all the symbols to address.
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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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if (STE->SectionIndex == 0)
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return Error("unexpected undefined symbol!");
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unsigned Index = STE->SectionIndex - 1;
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if (Index >= Segment64LC->NumSections)
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return Error("invalid section index for symbol: '" + Twine() + "'");
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// Get the symbol name.
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StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
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// Get the section base address.
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void *SectionBase = SectionBases[Index];
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// Get the symbol address.
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void *Address = (char*) SectionBase + STE->Value;
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// FIXME: Check the symbol type and flags.
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if (STE->Type != 0xF)
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return Error("unexpected symbol type!");
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if (STE->Flags != 0x0)
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return Error("unexpected symbol type!");
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SymbolTable[Name] = Address;
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}
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delete SectionBases;
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return false;
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}
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static int executeInput() {
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// Load the input memory buffer.
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@ -209,94 +59,28 @@ static int executeInput() {
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if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFile, InputBuffer))
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return Error("unable to read input: '" + ec.message() + "'");
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// Load the Mach-O wrapper object.
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std::string ErrorStr;
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OwningPtr<MachOObject> Obj(
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MachOObject::LoadFromBuffer(InputBuffer.take(), &ErrorStr));
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if (!Obj)
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return Error("unable to load object: '" + ErrorStr + "'");
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// Instantiate a dynamic linker.
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RuntimeDyld Dyld;
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// Validate that the load commands match what we expect.
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const MachOObject::LoadCommandInfo *SegmentLCI = 0, *SymtabLCI = 0,
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*DysymtabLCI = 0;
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for (unsigned i = 0; i != Obj->getHeader().NumLoadCommands; ++i) {
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const MachOObject::LoadCommandInfo &LCI = Obj->getLoadCommandInfo(i);
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switch (LCI.Command.Type) {
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case macho::LCT_Segment:
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case macho::LCT_Segment64:
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if (SegmentLCI)
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return Error("unexpected input object (multiple segments)");
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SegmentLCI = &LCI;
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break;
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case macho::LCT_Symtab:
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if (SymtabLCI)
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return Error("unexpected input object (multiple symbol tables)");
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SymtabLCI = &LCI;
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break;
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case macho::LCT_Dysymtab:
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if (DysymtabLCI)
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return Error("unexpected input object (multiple symbol tables)");
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DysymtabLCI = &LCI;
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break;
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default:
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return Error("unexpected input object (unexpected load command");
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}
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}
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if (!SymtabLCI)
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return Error("no symbol table found in object");
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if (!SegmentLCI)
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return Error("no symbol table found in object");
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// Read and register the symbol table data.
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InMemoryStruct<macho::SymtabLoadCommand> SymtabLC;
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Obj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC);
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if (!SymtabLC)
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return Error("unable to load symbol table load command");
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Obj->RegisterStringTable(*SymtabLC);
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// Read the dynamic link-edit information, if present (not present in static
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// objects).
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if (DysymtabLCI) {
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InMemoryStruct<macho::DysymtabLoadCommand> DysymtabLC;
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Obj->ReadDysymtabLoadCommand(*DysymtabLCI, DysymtabLC);
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if (!DysymtabLC)
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return Error("unable to load dynamic link-exit load command");
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// FIXME: We don't support anything interesting yet.
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if (DysymtabLC->LocalSymbolsIndex != 0)
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return Error("NOT YET IMPLEMENTED: local symbol entries");
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if (DysymtabLC->ExternalSymbolsIndex != 0)
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return Error("NOT YET IMPLEMENTED: non-external symbol entries");
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if (DysymtabLC->UndefinedSymbolsIndex != SymtabLC->NumSymbolTableEntries)
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return Error("NOT YET IMPLEMENTED: undefined symbol entries");
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}
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// Load the segment load command.
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sys::MemoryBlock Data;
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StringMap<void*> SymbolTable;
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if (SegmentLCI->Command.Type == macho::LCT_Segment) {
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if (loadSegment32(Obj.get(), Data, SegmentLCI, SymtabLC, SymbolTable))
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return true;
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} else {
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if (loadSegment64(Obj.get(), Data, SegmentLCI, SymtabLC, SymbolTable))
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return true;
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}
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// Load the object file into it.
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if (Dyld.loadObject(InputBuffer.take()))
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return true;
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// Get the address of "_main".
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StringMap<void*>::iterator it = SymbolTable.find("_main");
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if (it == SymbolTable.end())
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void *MainAddress = Dyld.getSymbolAddress("_main");
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if (MainAddress == 0)
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return Error("no definition for '_main'");
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// Invalidate the instruction cache.
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sys::MemoryBlock Data = Dyld.getMemoryBlock();
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sys::Memory::InvalidateInstructionCache(Data.base(), Data.size());
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// Make sure the memory is executable.
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std::string ErrorStr;
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if (!sys::Memory::setExecutable(Data, &ErrorStr))
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return Error("unable to mark function executable: '" + ErrorStr + "'");
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// Dispatch to _main().
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void *MainAddress = it->second;
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errs() << "loaded '_main' at: " << MainAddress << "\n";
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int (*Main)(int, const char**) =
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