Import LLVM, at r72732.

1 files changed, 165 insertions, 0 deletions

diff --git a/lib/System/DynamicLibrary.cpp b/lib/System/DynamicLibrary.cpp
new file mode 100644
index 0000000..3bf172c
--- /dev/null
+++ b/lib/System/DynamicLibrary.cpp
@@ -0,0 +1,165 @@
+//===-- DynamicLibrary.cpp - Runtime link/load libraries --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/System/DynamicLibrary.h"
+#include "llvm/Config/config.h"
+#include <cstdio>
+#include <cstring>
+#include <map>
+
+// Collection of symbol name/value pairs to be searched prior to any libraries.
+std::map<std::string, void *> &g_symbols() {
+  static std::map<std::string, void *> symbols;
+  return symbols;
+}
+
+void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName,
+                                          void *symbolValue) {
+  g_symbols()[symbolName] = symbolValue;
+}
+
+// It is not possible to use ltdl.c on VC++ builds as the terms of its LGPL
+// license and special exception would cause all of LLVM to be placed under
+// the LGPL.  This is because the exception applies only when libtool is
+// used, and obviously libtool is not used with Visual Studio.  An entirely
+// separate implementation is provided in win32/DynamicLibrary.cpp.
+
+#ifdef LLVM_ON_WIN32
+
+#include "Win32/DynamicLibrary.inc"
+
+#else
+
+//#include "ltdl.h"
+#include <dlfcn.h>
+#include <cassert>
+using namespace llvm;
+using namespace llvm::sys;
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only TRULY operating system
+//===          independent code.
+//===----------------------------------------------------------------------===//
+
+//static std::vector<lt_dlhandle> OpenedHandles;
+static std::vector<void *> OpenedHandles;
+
+DynamicLibrary::DynamicLibrary() {}
+
+DynamicLibrary::~DynamicLibrary() {
+  while(!OpenedHandles.empty()) {
+    void *H = OpenedHandles.back();   OpenedHandles.pop_back(); 
+    dlclose(H);
+  }
+}
+
+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;
+  }
+  OpenedHandles.push_back(H);
+  return false;
+}
+
+void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
+  //  check_ltdl_initialization();
+
+  // First check symbols added via AddSymbol().
+  std::map<std::string, void *>::iterator I = g_symbols().find(symbolName);
+  if (I != g_symbols().end())
+    return I->second;
+
+  // Now search the libraries.
+  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
+
+#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
+  // 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
+
+  return 0;
+}
+
+#endif // LLVM_ON_WIN32