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llvm-6502/tools/llvm-rtdyld/llvm-rtdyld.cpp
Jim Grosbach 4f9f41f2f9 Load multiple object files and link them via RuntimeDyld in llvm-rtdyld.
Relocations between the object modules are properly resolved, as in the
following trivial example:

$ cat t.c
int foo();
int main() {
    return foo();
}
$ cat foo.c
int foo() {
    return 65;
}
$ clang -c t.c -fno-asynchronous-unwind-tables
$ clang -c foo.c -fno-asynchronous-unwind-tables
$ llvm-rtdyld t.o foo.o ; echo $?
loaded '_main' at: 0x10015c000
65



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129448 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-13 15:49:40 +00:00

152 lines
4.8 KiB
C++

//===-- 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;
uint8_t *startFunctionBody(const char *Name, uintptr_t &Size);
void endFunctionBody(const char *Name, uint8_t *FunctionStart,
uint8_t *FunctionEnd);
};
uint8_t *TrivialMemoryManager::startFunctionBody(const char *Name,
uintptr_t &Size) {
return (uint8_t*)sys::Memory::AllocateRWX(Size, 0, 0).base();
}
void TrivialMemoryManager::endFunctionBody(const char *Name,
uint8_t *FunctionStart,
uint8_t *FunctionEnd) {
uintptr_t Size = FunctionEnd - FunctionStart + 1;
FunctionMemory.push_back(sys::MemoryBlock(FunctionStart, 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());
}
}
// Resolve all the relocations we can.
Dyld.resolveRelocations();
// 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) {
default:
case AC_Execute:
return executeInput();
}
return 0;
}