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/Path.cpp b/lib/System/Path.cpp
new file mode 100644
index 0000000..caf5789
--- /dev/null
+++ b/lib/System/Path.cpp
@@ -0,0 +1,184 @@
+//===-- Path.cpp - Implement OS Path Concept --------------------*- 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 header file implements the operating system Path concept.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/System/Path.h"
+#include "llvm/Config/config.h"
+#include <cassert>
+#include <ostream>
+using namespace llvm;
+using namespace sys;
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only TRULY operating system
+//===          independent code.
+//===----------------------------------------------------------------------===//
+
+std::ostream& llvm::operator<<(std::ostream &strm, const sys::Path &aPath) {
+  strm << aPath.toString();
+  return strm;
+}
+
+Path
+Path::GetLLVMConfigDir() {
+  Path result;
+#ifdef LLVM_ETCDIR
+  if (result.set(LLVM_ETCDIR))
+    return result;
+#endif
+  return GetLLVMDefaultConfigDir();
+}
+
+LLVMFileType
+sys::IdentifyFileType(const char*magic, unsigned length) {
+  assert(magic && "Invalid magic number string");
+  assert(length >=4 && "Invalid magic number length");
+  switch (magic[0]) {
+    case 'B':
+      if (magic[1] == 'C' && magic[2] == (char)0xC0 && magic[3] == (char)0xDE)
+        return Bitcode_FileType;
+      break;
+    case '!':
+      if (length >= 8)
+        if (memcmp(magic,"!<arch>\n",8) == 0)
+          return Archive_FileType;
+      break;
+      
+    case '\177':
+      if (magic[1] == 'E' && magic[2] == 'L' && magic[3] == 'F') {
+        if (length >= 18 && magic[17] == 0)
+          switch (magic[16]) {
+            default: break;
+            case 1: return ELF_Relocatable_FileType;
+            case 2: return ELF_Executable_FileType;
+            case 3: return ELF_SharedObject_FileType;
+            case 4: return ELF_Core_FileType;
+          }
+      }
+      break;
+
+    case 0xCA:
+      // This is complicated by an overlap with Java class files. 
+      // See the Mach-O section in /usr/share/file/magic for details.
+      if (magic[1] == char(0xFE) && magic[2] == char(0xBA) && 
+          magic[3] == char(0xBE)) {
+        return Mach_O_DynamicallyLinkedSharedLib_FileType;
+        
+        // FIXME: How does this work?
+        if (length >= 14 && magic[13] == 0)
+          switch (magic[12]) {
+            default: break;
+            case 1: return Mach_O_Object_FileType;
+            case 2: return Mach_O_Executable_FileType;
+            case 3: return Mach_O_FixedVirtualMemorySharedLib_FileType;
+            case 4: return Mach_O_Core_FileType;
+            case 5: return Mach_O_PreloadExectuable_FileType;
+            case 6: return Mach_O_DynamicallyLinkedSharedLib_FileType;
+            case 7: return Mach_O_DynamicLinker_FileType;
+            case 8: return Mach_O_Bundle_FileType;
+            case 9: return Mach_O_DynamicallyLinkedSharedLibStub_FileType;
+          }
+      }
+      break;
+
+    case 0xF0: // PowerPC Windows
+    case 0x83: // Alpha 32-bit
+    case 0x84: // Alpha 64-bit
+    case 0x66: // MPS R4000 Windows
+    case 0x50: // mc68K
+    case 0x4c: // 80386 Windows
+      if (magic[1] == 0x01)
+        return COFF_FileType;
+
+    case 0x90: // PA-RISC Windows
+    case 0x68: // mc68K Windows
+      if (magic[1] == 0x02)
+        return COFF_FileType;
+      break;
+
+    default:
+      break;
+  }
+  return Unknown_FileType;
+}
+
+bool
+Path::isArchive() const {
+  if (canRead())
+    return hasMagicNumber("!<arch>\012");
+  return false;
+}
+
+bool
+Path::isDynamicLibrary() const {
+  if (canRead()) {
+    std::string Magic;
+    if (getMagicNumber(Magic, 64))
+      switch (IdentifyFileType(Magic.c_str(), Magic.length())) {
+        default: return false;
+        case Mach_O_FixedVirtualMemorySharedLib_FileType:
+        case Mach_O_DynamicallyLinkedSharedLib_FileType:
+        case Mach_O_DynamicallyLinkedSharedLibStub_FileType:
+        case ELF_SharedObject_FileType:
+        case COFF_FileType:  return true;
+      }
+  }
+  return false;
+}
+
+Path
+Path::FindLibrary(std::string& name) {
+  std::vector<sys::Path> LibPaths;
+  GetSystemLibraryPaths(LibPaths);
+  for (unsigned i = 0; i < LibPaths.size(); ++i) {
+    sys::Path FullPath(LibPaths[i]);
+    FullPath.appendComponent("lib" + name + LTDL_SHLIB_EXT);
+    if (FullPath.isDynamicLibrary())
+      return FullPath;
+    FullPath.eraseSuffix();
+    FullPath.appendSuffix("a");
+    if (FullPath.isArchive())
+      return FullPath;
+  }
+  return sys::Path();
+}
+
+std::string Path::GetDLLSuffix() {
+  return LTDL_SHLIB_EXT;
+}
+
+bool
+Path::isBitcodeFile() const {
+  std::string actualMagic;
+  if (!getMagicNumber(actualMagic, 4))
+    return false;
+  return actualMagic == "BC\xC0\xDE";
+}
+
+bool Path::hasMagicNumber(const std::string &Magic) const {
+  std::string actualMagic;
+  if (getMagicNumber(actualMagic, Magic.size()))
+    return Magic == actualMagic;
+  return false;
+}
+
+
+
+// Include the truly platform-specific parts of this class.
+#if defined(LLVM_ON_UNIX)
+#include "Unix/Path.inc"
+#endif
+#if defined(LLVM_ON_WIN32)
+#include "Win32/Path.inc"
+#endif
+
+DEFINING_FILE_FOR(SystemPath)