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//===-- llvm-rtdyld.cpp - MCJIT Testing Tool ------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This is a testing tool for use with the MC-JIT LLVM components.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/Object/MachOObject.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/Memory.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/system_error.h"
using namespace llvm;
using namespace llvm::object;
static cl::opt<std::string>
InputFile(cl::Positional, cl::desc("<input file>"), cl::init("-"));
enum ActionType {
AC_Execute
};
static cl::opt<ActionType>
Action(cl::desc("Action to perform:"),
cl::init(AC_Execute),
cl::values(clEnumValN(AC_Execute, "execute",
"Load, link, and execute the inputs."),
clEnumValEnd));
/* *** */
static const char *ProgramName;
static void Message(const char *Type, const Twine &Msg) {
errs() << ProgramName << ": " << Type << ": " << Msg << "\n";
}
static int Error(const Twine &Msg) {
Message("error", Msg);
return 1;
}
/* *** */
static int executeInput() {
// Load the input memory buffer.
OwningPtr<MemoryBuffer> InputBuffer;
if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFile, InputBuffer))
return Error("unable to read input: '" + ec.message() + "'");
// Load the Mach-O wrapper object.
std::string ErrorStr;
OwningPtr<MachOObject> Obj(
MachOObject::LoadFromBuffer(InputBuffer.take(), &ErrorStr));
if (!Obj)
return Error("unable to load object: '" + ErrorStr + "'");
// Validate that the load commands match what we expect.
const MachOObject::LoadCommandInfo *SegmentLCI = 0, *SymtabLCI = 0,
*DysymtabLCI = 0;
for (unsigned i = 0; i != Obj->getHeader().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 symbol table 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_Segment64)
return Error("Segment32 not yet implemented!");
InMemoryStruct<macho::Segment64LoadCommand> Segment64LC;
Obj->ReadSegment64LoadCommand(*SegmentLCI, Segment64LC);
if (!Segment64LC)
return Error("unable to load segment load command");
// Map the segment into memory.
sys::MemoryBlock Data = sys::Memory::AllocateRWX(Segment64LC->VMSize,
0, &ErrorStr);
if (!Data.base())
return Error("unable to allocate memory block: '" + ErrorStr + "'");
memcpy(Data.base(), Obj->getData(Segment64LC->FileOffset,
Segment64LC->FileSize).data(),
Segment64LC->FileSize);
memset((char*)Data.base() + Segment64LC->FileSize, 0,
Segment64LC->VMSize - Segment64LC->FileSize);
// Bind the section indices to address.
void **SectionBases = new void*[Segment64LC->NumSections];
for (unsigned i = 0; i != Segment64LC->NumSections; ++i) {
InMemoryStruct<macho::Section64> Sect;
Obj->ReadSection64(*SegmentLCI, i, Sect);
if (!Sect)
return Error("unable to load section: '" + Twine(i) + "'");
// FIXME: We don't support relocations yet.
if (Sect->NumRelocationTableEntries != 0)
return Error("not yet implemented: relocations!");
// FIXME: Improve check.
if (Sect->Flags != 0x80000400)
return Error("unsupported section type!");
SectionBases[i] = (char*) Data.base() + Sect->Address;
}
// Bind all the symbols to address.
StringMap<void*> SymbolTable;
for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
InMemoryStruct<macho::Symbol64TableEntry> STE;
Obj->ReadSymbol64TableEntry(SymtabLC->SymbolTableOffset, i, STE);
if (!STE)
return Error("unable to read symbol: '" + Twine(i) + "'");
if (STE->SectionIndex == 0)
return Error("unexpected undefined symbol!");
unsigned Index = STE->SectionIndex - 1;
if (Index >= Segment64LC->NumSections)
return Error("invalid section index for symbol: '" + Twine() + "'");
// Get the symbol name.
StringRef Name = Obj->getStringAtIndex(STE->StringIndex);
// Get the section base address.
void *SectionBase = SectionBases[Index];
// Get the symbol address.
void *Address = (char*) SectionBase + STE->Value;
// FIXME: Check the symbol type and flags.
if (STE->Type != 0xF)
return Error("unexpected symbol type!");
if (STE->Flags != 0x0)
return Error("unexpected symbol type!");
SymbolTable[Name] = Address;
}
// Get the address of "_main".
StringMap<void*>::iterator it = SymbolTable.find("_main");
if (it == SymbolTable.end())
return Error("no definition for '_main'");
// Invalidate the instruction cache.
sys::Memory::InvalidateInstructionCache(Data.base(), Data.size());
// Make sure the memory is executable.
if (!sys::Memory::setExecutable(Data, &ErrorStr))
return Error("unable to mark function executable: '" + ErrorStr + "'");
// Dispatch to _main().
void *MainAddress = it->second;
errs() << "loaded '_main' at: " << MainAddress << "\n";
int (*Main)(int, const char**) =
(int(*)(int,const char**)) uintptr_t(MainAddress);
const char **Argv = new const char*[2];
Argv[0] = InputFile.c_str();
Argv[1] = 0;
return Main(1, Argv);
}
int main(int argc, char **argv) {
ProgramName = argv[0];
llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
cl::ParseCommandLineOptions(argc, argv, "llvm MC-JIT tool\n");
switch (Action) {
default:
case AC_Execute:
return executeInput();
}
return 0;
}
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