llvm/lib/Support/DynamicLinker.cpp
Chris Lattner aafb1c16b4 Thoroughly rehack the dynamic linking mechanisms on Win32. The Win32
dynamic linker does not automatically search libraries when looking up
symbols with GetProcAddress.  Because of this we have to emulate it.  The
only detail is that there doesn't seem to be a way to enumerate the
libraries loaded, so we have a gross hack (tm).

This make the JIT functional on win32 under cygwin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13887 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-28 23:54:07 +00:00

96 lines
3.2 KiB
C++

//===-- DynamicLinker.cpp - Implement DynamicLinker interface -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Lightweight interface to dynamic library linking and loading, and dynamic
// symbol lookup functionality, in whatever form the operating system
// provides it.
//
// Possible future extensions include support for the HPUX shl_load()
// interface, and the Mac OS X NSLinkModule() interface.
//
// Note that we assume that if dlopen() is available, then dlsym() is too.
//
//===----------------------------------------------------------------------===//
#include "Support/DynamicLinker.h"
#include "Config/dlfcn.h"
#include "Config/windows.h"
#include <cassert>
#include <vector>
using namespace llvm;
#if defined(HAVE_WINDOWS_H)
// getLoadedLibs - Keep track of the shared objects that are loaded into the
// process address space, as the windows GetProcAddress function does not
// automatically search an entire address space, it only searches a specific
// object.
static std::vector<HMODULE> &getLoadedLibHandles() {
static std::vector<HMODULE> *LoadedLibHandles = 0;
if (LoadedLibHandles == 0) {
LoadedLibHandles = new std::vector<HMODULE>();
if (HMODULE H = GetModuleHandle(NULL)) // JIT symbols
LoadedLibHandles->push_back(H);
if (HMODULE MH = GetModuleHandle("cygwin1.dll")) // Cygwin symbols OR
LoadedLibHandles->push_back(MH);
else if (HMODULE MH = GetModuleHandle("msvcr80.dll")) // VC++ symbols
LoadedLibHandles->push_back(MH);
}
return *LoadedLibHandles;
}
#endif
bool llvm::LinkDynamicObject(const char *filename, std::string *ErrorMessage) {
#if defined(HAVE_WINDOWS_H)
if (HMODULE Handle = LoadLibrary(filename)) {
// Allow GetProcAddress in this module
getLoadedLibHandles().push_back(Handle);
return false;
}
if (ErrorMessage) {
char Buffer[100];
// FIXME: This should use FormatMessage
sprintf(Buffer, "Windows error code %d\n", GetLastError());
*ErrorMessage = Buffer;
}
return true;
#elif defined (HAVE_DLOPEN)
if (dlopen (filename, RTLD_NOW | RTLD_GLOBAL) == 0) {
if (ErrorMessage) *ErrorMessage = dlerror ();
return true;
}
return false;
#else
assert (0 && "Dynamic object linking not implemented for this platform");
#endif
}
void *llvm::GetAddressOfSymbol(const char *symbolName) {
#if defined(HAVE_WINDOWS_H)
std::vector<HMODULE> &LH = getLoadedLibHandles();
for (unsigned i = 0, e = LH.size(); i != e; ++i)
if (void *Val = (void*)GetProcAddress(LH[i], symbolName))
return Val;
return 0;
#elif defined(HAVE_DLOPEN)
# ifdef RTLD_DEFAULT
return dlsym (RTLD_DEFAULT, symbolName);
# else
static void* CurHandle = dlopen(0, RTLD_LAZY);
return dlsym(CurHandle, symbolName);
# endif
#else
assert (0 && "Dynamic symbol lookup not implemented for this platform");
#endif
}
// soft, cushiony C++ interface.
void *llvm::GetAddressOfSymbol(const std::string &symbolName) {
return GetAddressOfSymbol(symbolName.c_str());
}