llvm-6502/tools/llvm-rtdyld/llvm-rtdyld.cpp

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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/ExecutionEngine/RuntimeDyld.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::list<std::string>
InputFileList(cl::Positional, cl::ZeroOrMore,
cl::desc("<input file>"));
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 cl::opt<std::string>
EntryPoint("entry",
cl::desc("Function to call as entry point."),
cl::init("_main"));
/* *** */
// A trivial memory manager that doesn't do anything fancy, just uses the
// support library allocation routines directly.
class TrivialMemoryManager : public RTDyldMemoryManager {
public:
SmallVector<sys::MemoryBlock, 16> FunctionMemory;
SmallVector<sys::MemoryBlock, 16> DataMemory;
uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID);
uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID);
virtual void *getPointerToNamedFunction(const std::string &Name,
bool AbortOnFailure = true) {
return 0;
}
// Invalidate instruction cache for sections with execute permissions.
// Some platforms with separate data cache and instruction cache require
// explicit cache flush, otherwise JIT code manipulations (like resolved
// relocations) will get to the data cache but not to the instruction cache.
virtual void invalidateInstructionCache();
};
uint8_t *TrivialMemoryManager::allocateCodeSection(uintptr_t Size,
unsigned Alignment,
unsigned SectionID) {
sys::MemoryBlock MB = sys::Memory::AllocateRWX(Size, 0, 0);
FunctionMemory.push_back(MB);
return (uint8_t*)MB.base();
}
uint8_t *TrivialMemoryManager::allocateDataSection(uintptr_t Size,
unsigned Alignment,
unsigned SectionID) {
sys::MemoryBlock MB = sys::Memory::AllocateRWX(Size, 0, 0);
DataMemory.push_back(MB);
return (uint8_t*)MB.base();
}
void TrivialMemoryManager::invalidateInstructionCache() {
for (int i = 0, e = FunctionMemory.size(); i != e; ++i)
sys::Memory::InvalidateInstructionCache(FunctionMemory[i].base(),
FunctionMemory[i].size());
for (int i = 0, e = DataMemory.size(); i != e; ++i)
sys::Memory::InvalidateInstructionCache(DataMemory[i].base(),
DataMemory[i].size());
}
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() {
// Instantiate a dynamic linker.
TrivialMemoryManager *MemMgr = new TrivialMemoryManager;
RuntimeDyld Dyld(MemMgr);
// If we don't have any input files, read from stdin.
if (!InputFileList.size())
InputFileList.push_back("-");
for(unsigned i = 0, e = InputFileList.size(); i != e; ++i) {
// Load the input memory buffer.
OwningPtr<MemoryBuffer> InputBuffer;
if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFileList[i],
InputBuffer))
return Error("unable to read input: '" + ec.message() + "'");
// Load the object file into it.
if (Dyld.loadObject(InputBuffer.take())) {
return Error(Dyld.getErrorString());
}
}
MCJIT lazy relocation resolution and symbol address re-assignment. Add handling for tracking the relocations on symbols and resolving them. Keep track of the relocations even after they are resolved so that if the RuntimeDyld client moves the object, it can update the address and any relocations to that object will be updated. For our trival object file load/run test harness (llvm-rtdyld), this enables relocations between functions located in the same object module. It should be trivially extendable to load multiple objects with mutual references. As a simple example, the following now works (running on x86_64 Darwin 10.6): $ cat t.c int bar() { return 65; } int main() { return bar(); } $ clang t.c -fno-asynchronous-unwind-tables -o t.o -c $ otool -vt t.o t.o: (__TEXT,__text) section _bar: 0000000000000000 pushq %rbp 0000000000000001 movq %rsp,%rbp 0000000000000004 movl $0x00000041,%eax 0000000000000009 popq %rbp 000000000000000a ret 000000000000000b nopl 0x00(%rax,%rax) _main: 0000000000000010 pushq %rbp 0000000000000011 movq %rsp,%rbp 0000000000000014 subq $0x10,%rsp 0000000000000018 movl $0x00000000,0xfc(%rbp) 000000000000001f callq 0x00000024 0000000000000024 addq $0x10,%rsp 0000000000000028 popq %rbp 0000000000000029 ret $ llvm-rtdyld t.o -debug-only=dyld ; echo $? Function sym: '_bar' @ 0 Function sym: '_main' @ 16 Extracting function: _bar from [0, 15] allocated to 0x100153000 Extracting function: _main from [16, 41] allocated to 0x100154000 Relocation at '_main' + 16 from '_bar(Word1: 0x2d000000) Resolving relocation at '_main' + 16 (0x100154010) from '_bar (0x100153000)(pcrel, type: 2, Size: 4). loaded '_main' at: 0x100154000 65 $ git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129388 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-12 21:20:41 +00:00
// Resolve all the relocations we can.
Dyld.resolveRelocations();
// Clear instruction cache before code will be executed.
MemMgr->invalidateInstructionCache();
// FIXME: Error out if there are unresolved relocations.
// Get the address of the entry point (_main by default).
void *MainAddress = Dyld.getSymbolAddress(EntryPoint);
if (MainAddress == 0)
return Error("no definition for '" + EntryPoint + "'");
// Invalidate the instruction cache for each loaded function.
for (unsigned i = 0, e = MemMgr->FunctionMemory.size(); i != e; ++i) {
sys::MemoryBlock &Data = MemMgr->FunctionMemory[i];
// Make sure the memory is executable.
std::string ErrorStr;
sys::Memory::InvalidateInstructionCache(Data.base(), Data.size());
if (!sys::Memory::setExecutable(Data, &ErrorStr))
return Error("unable to mark function executable: '" + ErrorStr + "'");
}
// Dispatch to _main().
errs() << "loaded '" << EntryPoint << "' at: " << (void*)MainAddress << "\n";
int (*Main)(int, const char**) =
(int(*)(int,const char**)) uintptr_t(MainAddress);
const char **Argv = new const char*[2];
// Use the name of the first input object module as argv[0] for the target.
Argv[0] = InputFileList[0].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) {
case AC_Execute:
return executeInput();
}
}