It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Win32/DynamicLibrary.inc b/lib/System/Win32/DynamicLibrary.inc
new file mode 100644
index 0000000..251131e
--- /dev/null
+++ b/lib/System/Win32/DynamicLibrary.inc
@@ -0,0 +1,169 @@
+//===- Win32/DynamicLibrary.cpp - Win32 DL Implementation -------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Jeff Cohen and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file provides the Win32 specific implementation of DynamicLibrary.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Win32.h"
+
+#ifdef __MINGW32__
+ #include <imagehlp.h>
+#else
+ #include <dbghelp.h>
+#endif
+
+#ifdef __MINGW32__
+ #if (HAVE_LIBIMAGEHLP != 1)
+  #error "libimagehlp.a should be present"
+ #endif
+#else
+ #pragma comment(lib, "dbghelp.lib")
+#endif
+
+namespace llvm {
+using namespace sys;
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only Win32 specific code 
+//===          and must not be UNIX code.
+//===----------------------------------------------------------------------===//
+
+static std::vector<HMODULE> OpenedHandles;
+
+extern "C" {
+  static BOOL CALLBACK ELM_Callback(PSTR  ModuleName,
+                                    ULONG ModuleBase,
+                                    ULONG ModuleSize,
+                                    PVOID UserContext)
+  {
+    // Ignore VC++ runtimes prior to 7.1.  Somehow some of them get loaded
+    // into the process.
+    if (stricmp(ModuleName, "msvci70") != 0 &&
+        stricmp(ModuleName, "msvcirt") != 0 &&
+        stricmp(ModuleName, "msvcp50") != 0 &&
+        stricmp(ModuleName, "msvcp60") != 0 &&
+        stricmp(ModuleName, "msvcp70") != 0 &&
+        stricmp(ModuleName, "msvcr70") != 0 &&
+#ifndef __MINGW32__
+        // Mingw32 uses msvcrt.dll by default. Don't ignore it.
+        // Otherwise, user should be aware, what he's doing :)
+        stricmp(ModuleName, "msvcrt") != 0 &&
+#endif        
+        stricmp(ModuleName, "msvcrt20") != 0 &&
+        stricmp(ModuleName, "msvcrt40") != 0) {
+      OpenedHandles.push_back((HMODULE)ModuleBase);
+    }
+    return TRUE;
+  }
+}
+
+DynamicLibrary::DynamicLibrary() : handle(0) {
+  handle = GetModuleHandle(NULL);
+  OpenedHandles.push_back((HMODULE)handle);
+}
+
+DynamicLibrary::~DynamicLibrary() {
+  if (handle == 0)
+    return;
+
+  // GetModuleHandle() does not increment the ref count, so we must not free
+  // the handle to the executable.
+  if (handle != GetModuleHandle(NULL))
+    FreeLibrary((HMODULE)handle);
+  handle = 0;
+
+  for (std::vector<HMODULE>::iterator I = OpenedHandles.begin(),
+       E = OpenedHandles.end(); I != E; ++I) {
+    if (*I == handle) {
+      // Note: don't use the swap/pop_back trick here. Order is important.
+      OpenedHandles.erase(I);
+    }
+  }
+}
+
+// Stack probing routines are in the support library (e.g. libgcc), but we don't
+// have dynamic linking on windows. Provide a hook.
+#if defined(__MINGW32__) || defined (_MSC_VER)
+  #define EXPLICIT_SYMBOL(SYM)                    \
+    if (!strcmp(symbolName, #SYM)) return (void*)&SYM
+  #define EXPLICIT_SYMBOL2(SYMFROM, SYMTO)        \
+    if (!strcmp(symbolName, #SYMFROM)) return (void*)&SYMTO
+  #define EXPLICIT_SYMBOL_DEF(SYM)                \
+    extern "C" { extern void *SYM; }
+
+  #if defined(__MINGW32__)
+    EXPLICIT_SYMBOL_DEF(_alloca);
+  #elif defined(_MSC_VER)
+    EXPLICIT_SYMBOL_DEF(_alloca_probe);
+  #endif
+#endif
+ 
+bool DynamicLibrary::LoadLibraryPermanently(const char *filename,
+                                            std::string *ErrMsg) {
+  if (filename) {
+    HMODULE a_handle = LoadLibrary(filename);
+
+    if (a_handle == 0)
+      return MakeErrMsg(ErrMsg, std::string(filename) + ": Can't open : ");
+
+    OpenedHandles.push_back(a_handle);
+  } else {
+    // When no file is specified, enumerate all DLLs and EXEs in the
+    // process.
+    EnumerateLoadedModules(GetCurrentProcess(), ELM_Callback, 0);
+  }
+
+  // Because we don't remember the handle, we will never free it; hence,
+  // it is loaded permanently.
+  return false;
+}
+
+void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
+  // 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<HMODULE>::iterator I = OpenedHandles.begin(),
+       E = OpenedHandles.end(); I != E; ++I) {
+    FARPROC ptr = GetProcAddress((HMODULE)*I, symbolName);
+    if (ptr)
+      return (void *) ptr;
+  }
+
+#if defined(__MINGW32__)
+  {
+    EXPLICIT_SYMBOL(_alloca);
+    EXPLICIT_SYMBOL2(alloca, _alloca);
+#undef EXPLICIT_SYMBOL
+#undef EXPLICIT_SYMBOL2
+#undef EXPLICIT_SYMBOL_DEF    
+  }
+#elif defined(_MSC_VER)
+  {
+    EXPLICIT_SYMBOL2(alloca, _alloca_probe);
+    EXPLICIT_SYMBOL2(_alloca, _alloca_probe);
+#undef EXPLICIT_SYMBOL
+#undef EXPLICIT_SYMBOL2
+#undef EXPLICIT_SYMBOL_DEF    
+  }  
+#endif
+
+  return 0;
+}
+
+void *DynamicLibrary::GetAddressOfSymbol(const char *symbolName) {
+  assert(handle != 0 && "Invalid DynamicLibrary handle");
+  return (void *) GetProcAddress((HMODULE)handle, symbolName);
+}
+
+}
+