Reapply 91184 with fixes and an addition to the testcase to cover the problem
[oota-llvm.git] / lib / System / DynamicLibrary.cpp
index ca7bee661a661471ed393f9cf1f0b7b206fc696c..7eb9f5f3ef8e1439679f1647341723483d237310 100644 (file)
 //===-- DynamicLibrary.cpp - Runtime link/load libraries --------*- C++ -*-===//
-// 
+//
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by Reid Spencer and is distributed under the 
-// University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
 //===----------------------------------------------------------------------===//
 //
 //  This header file implements the operating system DynamicLibrary concept.
 //
+// FIXME: This file leaks the ExplicitSymbols and OpenedHandles vector, and is
+// not thread safe!
+//
 //===----------------------------------------------------------------------===//
 
 #include "llvm/System/DynamicLibrary.h"
-#include "llvm/Config/dlfcn.h"
-#include <cassert>
-
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only TRULY operating system
-//===          independent code. 
-//===----------------------------------------------------------------------===//
+#include "llvm/Config/config.h"
+#include <cstdio>
+#include <cstring>
+#include <map>
+#include <vector>
+
+// Collection of symbol name/value pairs to be searched prior to any libraries.
+static std::map<std::string, void*> *ExplicitSymbols = 0;
+
+static struct ExplicitSymbolsDeleter {
+  ~ExplicitSymbolsDeleter() {
+    if (ExplicitSymbols)
+      delete ExplicitSymbols;
+  }
+} Dummy;
+
+void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName,
+                                          void *symbolValue) {
+  if (ExplicitSymbols == 0)
+    ExplicitSymbols = new std::map<std::string, void*>();
+  (*ExplicitSymbols)[symbolName] = symbolValue;
+}
 
-#ifdef HAVE_LTDL_H
+#ifdef LLVM_ON_WIN32
 
-namespace llvm {
+#include "Win32/DynamicLibrary.inc"
 
-using namespace sys;
+#else
 
-#ifdef HAVE_LT_DLOPEN
+#include <dlfcn.h>
+using namespace llvm;
+using namespace llvm::sys;
 
-DynamicLibrary::DynamicLibrary(const char*filename) : handle(0) {
-  if (0 != lt_dlinit())
-    throw std::string(lt_dlerror());
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only TRULY operating system
+//===          independent code.
+//===----------------------------------------------------------------------===//
 
-  handle = lt_dlopen(filename);
+static std::vector<void *> *OpenedHandles = 0;
 
-  if (handle == 0)
-    handle = lt_dlopenext(filename);
 
-  if (handle == 0)
-    throw std::string("Can't open dynamic library:") + filename;
+bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
+                                            std::string *ErrMsg) {
+  void *H = dlopen(Filename, RTLD_LAZY|RTLD_GLOBAL);
+  if (H == 0) {
+    if (ErrMsg) *ErrMsg = dlerror();
+    return true;
+  }
+  if (OpenedHandles == 0)
+    OpenedHandles = new std::vector<void *>();
+  OpenedHandles->push_back(H);
+  return false;
 }
 
-DynamicLibrary::~DynamicLibrary() {
-  if (handle)
-    lt_dlclose((lt_dlhandle)handle);
-
-  lt_dlexit();
-}
+void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
+  // First check symbols added via AddSymbol().
+  if (ExplicitSymbols) {
+    std::map<std::string, void *>::iterator I =
+      ExplicitSymbols->find(symbolName);
+    std::map<std::string, void *>::iterator E = ExplicitSymbols->end();
+  
+    if (I != E)
+      return I->second;
+  }
+
+  // Now search the libraries.
+  if (OpenedHandles) {
+    for (std::vector<void *>::iterator I = OpenedHandles->begin(),
+         E = OpenedHandles->end(); I != E; ++I) {
+      //lt_ptr ptr = lt_dlsym(*I, symbolName);
+      void *ptr = dlsym(*I, symbolName);
+      if (ptr) {
+        return ptr;
+      }
+    }
+  }
+
+#define EXPLICIT_SYMBOL(SYM) \
+   extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM
+
+  // If this is darwin, it has some funky issues, try to solve them here.  Some
+  // important symbols are marked 'private external' which doesn't allow
+  // SearchForAddressOfSymbol to find them.  As such, we special case them here,
+  // there is only a small handful of them.
+
+#ifdef __APPLE__
+  {
+    EXPLICIT_SYMBOL(__ashldi3);
+    EXPLICIT_SYMBOL(__ashrdi3);
+    EXPLICIT_SYMBOL(__cmpdi2);
+    EXPLICIT_SYMBOL(__divdi3);
+    EXPLICIT_SYMBOL(__eprintf);
+    EXPLICIT_SYMBOL(__fixdfdi);
+    EXPLICIT_SYMBOL(__fixsfdi);
+    EXPLICIT_SYMBOL(__fixunsdfdi);
+    EXPLICIT_SYMBOL(__fixunssfdi);
+    EXPLICIT_SYMBOL(__floatdidf);
+    EXPLICIT_SYMBOL(__floatdisf);
+    EXPLICIT_SYMBOL(__lshrdi3);
+    EXPLICIT_SYMBOL(__moddi3);
+    EXPLICIT_SYMBOL(__udivdi3);
+    EXPLICIT_SYMBOL(__umoddi3);
+  }
+#endif
 
-void *DynamicLibrary::GetAddressOfSymbol(const char *symbolName) {
-  assert(handle != 0 && "Invalid DynamicLibrary handle");
-  return lt_dlsym((lt_dlhandle) handle,symbolName);
-}
+#ifdef __CYGWIN__
+  {
+    EXPLICIT_SYMBOL(_alloca);
+    EXPLICIT_SYMBOL(__main);
+  }
+#endif
 
+#undef EXPLICIT_SYMBOL
+
+// This macro returns the address of a well-known, explicit symbol
+#define EXPLICIT_SYMBOL(SYM) \
+   if (!strcmp(symbolName, #SYM)) return &SYM
+
+// On linux we have a weird situation. The stderr/out/in symbols are both
+// macros and global variables because of standards requirements. So, we 
+// boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
+#if defined(__linux__)
+  {
+    EXPLICIT_SYMBOL(stderr);
+    EXPLICIT_SYMBOL(stdout);
+    EXPLICIT_SYMBOL(stdin);
+  }
 #else
-DynamicLibrary::DynamicLibrary(const char*filename) : handle(0) {
-  assert(!"Have ltdl.h but not libltdl.a!");
-}
-
-DynamicLibrary::~DynamicLibrary() {
-  assert(!"Have ltdl.h but not libltdl.a!");
-}
+  // For everything else, we want to check to make sure the symbol isn't defined
+  // as a macro before using EXPLICIT_SYMBOL.
+  {
+#ifndef stdin
+    EXPLICIT_SYMBOL(stdin);
+#endif
+#ifndef stdout
+    EXPLICIT_SYMBOL(stdout);
+#endif
+#ifndef stderr
+    EXPLICIT_SYMBOL(stderr);
+#endif
+  }
+#endif
+#undef EXPLICIT_SYMBOL
 
-void *DynamicLibrary::GetAddressOfSymbol(const char *symbolName) {
-  assert(!"Have ltdl.h but not libltdl.a!");
   return 0;
 }
 
-#endif // HAVE_DLOPEN
-
-} // namespace llvm
-
-#else // HAVE_LTDL_H
-
-#include "platform/DynamicLibrary.cpp"
-
-#endif
+#endif // LLVM_ON_WIN32