[llvm-commits] CVS: llvm/lib/Support/DynamicLinker.cpp

[Chris Lattner]

Changes in directory llvm/lib/Support:

DynamicLinker.cpp updated: 1.6 -> 1.7

---
Log message:

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.



---
Diffs of the changes:  (+41 -16)

Index: llvm/lib/Support/DynamicLinker.cpp
diff -u llvm/lib/Support/DynamicLinker.cpp:1.6 llvm/lib/Support/DynamicLinker.cpp:1.7
--- llvm/lib/Support/DynamicLinker.cpp:1.6	Thu May 27 15:53:10 2004
+++ llvm/lib/Support/DynamicLinker.cpp	Fri May 28 18:54:07 2004
@@ -12,8 +12,7 @@
 // provides it.
 //
 // Possible future extensions include support for the HPUX shl_load()
-// interface, the Mac OS X NSLinkModule() interface, and the Windows
-// LoadLibrary() interface.
+// interface, and the Mac OS X NSLinkModule() interface.
 //
 // Note that we assume that if dlopen() is available, then dlsym() is too.
 //
@@ -23,18 +22,36 @@
 #include "Config/dlfcn.h"
 #include "Config/windows.h"
 #include <cassert>
+#include <vector>
 using namespace llvm;
 
-bool llvm::LinkDynamicObject (const char *filename, std::string *ErrorMessage) {
-#if defined (HAVE_DLOPEN)
-  if (dlopen (filename, RTLD_NOW | RTLD_GLOBAL) == 0) {
-    if (ErrorMessage) *ErrorMessage = dlerror ();
-    return true;
+#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 false;
-#elif defined(HAVE_WINDOWS_H)
-  if (LoadLibrary(filename))
+  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
@@ -42,23 +59,31 @@
     *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_DLOPEN)
+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
-#elif defined(HAVE_WINDOWS_H)
-  static HMODULE ModHandle = NULL;
-  if (ModHandle == 0) ModHandle = GetModuleHandle(NULL);
-  return (void*)GetProcAddress(ModHandle, symbolName);
 #else
   assert (0 && "Dynamic symbol lookup not implemented for this platform");
 #endif