llvm-6502/lib/ExecutionEngine/RTDyldMemoryManager.cpp
Andrew Kaylor 8e9ec01534 Adding multiple module support for MCJIT.
Tests to follow.

PIC with small code model and  EH frame handling will not work with multiple modules.  There are also some rough edges to be smoothed out for remote target support.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191722 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 01:47:35 +00:00

129 lines
4.3 KiB
C++

//===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implementation of the runtime dynamic memory manager base class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Config/config.h"
#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
#include "llvm/Support/DynamicLibrary.h"
#include "llvm/Support/ErrorHandling.h"
#include <cstdlib>
#ifdef __linux__
// These includes used by RTDyldMemoryManager::getPointerToNamedFunction()
// for Glibc trickery. See comments in this function for more information.
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <fcntl.h>
#include <unistd.h>
#endif
namespace llvm {
RTDyldMemoryManager::~RTDyldMemoryManager() {}
// Determine whether we can register EH tables.
#if (defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__ia64__) && \
!defined(__USING_SJLJ_EXCEPTIONS__))
#define HAVE_EHTABLE_SUPPORT 1
#else
#define HAVE_EHTABLE_SUPPORT 0
#endif
#if HAVE_EHTABLE_SUPPORT
extern "C" void __register_frame(void*);
static const char *processFDE(const char *Entry) {
const char *P = Entry;
uint32_t Length = *((const uint32_t *)P);
P += 4;
uint32_t Offset = *((const uint32_t *)P);
if (Offset != 0)
__register_frame(const_cast<char *>(Entry));
return P + Length;
}
#endif
void RTDyldMemoryManager::registerEHFrames(StringRef SectionData) {
#if HAVE_EHTABLE_SUPPORT
const char *P = SectionData.data();
const char *End = SectionData.data() + SectionData.size();
do {
P = processFDE(P);
} while(P != End);
#endif
}
static int jit_noop() {
return 0;
}
uint64_t RTDyldMemoryManager::getSymbolAddress(const std::string &Name) {
// This implementation assumes that the host program is the target.
// Clients generating code for a remote target should implement their own
// memory manager.
#if defined(__linux__)
//===--------------------------------------------------------------------===//
// Function stubs that are invoked instead of certain library calls
//
// Force the following functions to be linked in to anything that uses the
// JIT. This is a hack designed to work around the all-too-clever Glibc
// strategy of making these functions work differently when inlined vs. when
// not inlined, and hiding their real definitions in a separate archive file
// that the dynamic linker can't see. For more info, search for
// 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
if (Name == "stat") return (uint64_t)&stat;
if (Name == "fstat") return (uint64_t)&fstat;
if (Name == "lstat") return (uint64_t)&lstat;
if (Name == "stat64") return (uint64_t)&stat64;
if (Name == "fstat64") return (uint64_t)&fstat64;
if (Name == "lstat64") return (uint64_t)&lstat64;
if (Name == "atexit") return (uint64_t)&atexit;
if (Name == "mknod") return (uint64_t)&mknod;
#endif // __linux__
// We should not invoke parent's ctors/dtors from generated main()!
// On Mingw and Cygwin, the symbol __main is resolved to
// callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
// (and register wrong callee's dtors with atexit(3)).
// We expect ExecutionEngine::runStaticConstructorsDestructors()
// is called before ExecutionEngine::runFunctionAsMain() is called.
if (Name == "__main") return (uint64_t)&jit_noop;
const char *NameStr = Name.c_str();
void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
if (Ptr)
return (uint64_t)Ptr;
// If it wasn't found and if it starts with an underscore ('_') character,
// try again without the underscore.
if (NameStr[0] == '_') {
Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
if (Ptr)
return (uint64_t)Ptr;
}
return 0;
}
void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name,
bool AbortOnFailure) {
uint64_t Addr = getSymbolAddress(Name);
if (!Addr && AbortOnFailure)
report_fatal_error("Program used external function '" + Name +
"' which could not be resolved!");
return (void*)Addr;
}
} // namespace llvm