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/Unix/Alarm.inc b/lib/System/Unix/Alarm.inc
new file mode 100644
index 0000000..1480802
--- /dev/null
+++ b/lib/System/Unix/Alarm.inc
@@ -0,0 +1,68 @@
+//===-- Alarm.inc - Implement Unix Alarm Support --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the Reid Spencer and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the UNIX Alarm support.
+//
+//===----------------------------------------------------------------------===//
+
+#include <signal.h>
+#include <unistd.h>
+#include <cassert>
+using namespace llvm;
+
+/// AlarmCancelled - This flag is set by the SIGINT signal handler if the
+/// user presses CTRL-C.
+static volatile bool AlarmCancelled = false;
+
+/// AlarmTriggered - This flag is set by the SIGALRM signal handler if the 
+/// alarm was triggered.
+static volatile bool AlarmTriggered = false;
+
+/// NestedSOI - Sanity check.  Alarms cannot be nested or run in parallel.  
+/// This ensures that they never do.
+static bool NestedSOI = false;
+
+static RETSIGTYPE SigIntHandler(int Sig) {
+  AlarmCancelled = true;
+  signal(SIGINT, SigIntHandler);
+}
+
+static RETSIGTYPE SigAlarmHandler(int Sig) {
+  AlarmTriggered = true;
+}
+
+static void (*OldSigIntHandler) (int);
+
+void sys::SetupAlarm(unsigned seconds) {
+  assert(!NestedSOI && "sys::SetupAlarm calls cannot be nested!");
+  NestedSOI = true;
+  AlarmCancelled = false;
+  AlarmTriggered = false;
+  ::signal(SIGALRM, SigAlarmHandler);
+  OldSigIntHandler = ::signal(SIGINT, SigIntHandler);
+  ::alarm(seconds);
+}
+
+void sys::TerminateAlarm() {
+  assert(NestedSOI && "sys::TerminateAlarm called without sys::SetupAlarm!");
+  ::alarm(0);
+  ::signal(SIGALRM, SIG_DFL);
+  ::signal(SIGINT, OldSigIntHandler);
+  AlarmCancelled = false;
+  AlarmTriggered = false;
+  NestedSOI = false;
+}
+
+int sys::AlarmStatus() {
+  if (AlarmCancelled)
+    return -1;
+  if (AlarmTriggered)
+    return 1;
+  return 0;
+}
diff --git a/lib/System/Unix/MappedFile.inc b/lib/System/Unix/MappedFile.inc
new file mode 100644
index 0000000..91b92ec
--- /dev/null
+++ b/lib/System/Unix/MappedFile.inc
@@ -0,0 +1,154 @@
+//===- Unix/MappedFile.cpp - Unix MappedFile Implementation -----*- 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 provides the generic Unix implementation of the MappedFile concept.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#include "llvm/System/Process.h"
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+
+namespace llvm {
+using namespace sys;
+
+struct sys::MappedFileInfo {
+  int   FD;
+  off_t Size;
+};
+
+bool MappedFile::initialize(std::string* ErrMsg) {
+  int mode = 0;
+  if (options_ & READ_ACCESS) 
+    if (options_ & WRITE_ACCESS)
+      mode = O_RDWR;
+    else
+      mode = O_RDONLY;
+  else if (options_ & WRITE_ACCESS)
+    mode = O_WRONLY;
+
+  int FD = ::open(path_.c_str(), mode);
+  if (FD < 0) {
+    MakeErrMsg(ErrMsg, "can't open file '" + path_.toString() + "'");
+    return true;
+  } 
+  const FileStatus *Status = path_.getFileStatus(false, ErrMsg);
+  if (!Status) {
+    ::close(FD);
+    return true;
+  }
+  info_ = new MappedFileInfo;
+  info_->FD = FD;
+  info_->Size = Status->getSize();
+  return false;
+}
+
+void MappedFile::terminate() {
+  assert(info_ && "MappedFile not initialized");
+  ::close(info_->FD);
+  delete info_;
+  info_ = 0;
+}
+
+void MappedFile::unmap() {
+  assert(info_ && "MappedFile not initialized");
+  if (isMapped()) {
+    if (options_ & WRITE_ACCESS)
+      ::msync(base_, info_->Size, MS_SYNC);
+    ::munmap(base_, info_->Size);
+    base_ = 0;  // Mark this as non-mapped.
+  }
+}
+
+void* MappedFile::map(std::string* ErrMsg) {
+  assert(info_ && "MappedFile not initialized");
+  if (!isMapped()) {
+    int prot = PROT_NONE;
+    int flags = 0;
+#ifdef MAP_FILE
+    flags |= MAP_FILE;
+#endif
+    if (options_ == 0) {
+      prot = PROT_READ;
+      flags = MAP_PRIVATE;
+    } else {
+      if (options_ & READ_ACCESS)
+        prot |= PROT_READ;
+      if (options_ & WRITE_ACCESS)
+        prot |= PROT_WRITE;
+      if (options_ & EXEC_ACCESS)
+        prot |= PROT_EXEC;
+      if (options_ & SHARED_MAPPING)
+        flags |= MAP_SHARED;
+      else
+        flags |= MAP_PRIVATE;
+    }
+    size_t map_size = ((info_->Size / Process::GetPageSize())+1) *
+      Process::GetPageSize();
+
+    base_ = ::mmap(0, map_size, prot, flags, info_->FD, 0);
+    if (base_ == MAP_FAILED) {
+      MakeErrMsg(ErrMsg, "Can't map file:" + path_.toString());
+      return 0;
+    }
+  }
+  return base_;
+}
+
+size_t MappedFile::size() const {
+  assert(info_ && "MappedFile not initialized");
+  return info_->Size;
+}
+
+bool MappedFile::size(size_t new_size, std::string* ErrMsg) {
+  assert(info_ && "MappedFile not initialized");
+
+  // Take the mapping out of memory
+  this->unmap();
+
+  // Adjust the current size to a page boundary
+  size_t cur_size = ((info_->Size / Process::GetPageSize())+1) *
+    Process::GetPageSize();
+
+  // Adjust the new_size to a page boundary
+  new_size = ((new_size / Process::GetPageSize())+1) *
+    Process::GetPageSize();
+
+  // If the file needs to be extended
+  if (new_size > cur_size) {
+    // Ensure we can allocate at least the idodes necessary to handle the
+    // file size requested. 
+    if ((off_t)-1 == ::lseek(info_->FD, new_size, SEEK_SET))
+      return MakeErrMsg(ErrMsg, "Can't lseek: ");
+    if (-1 == ::write(info_->FD, "\0", 1))
+      return MakeErrMsg(ErrMsg, "Can't write: ");
+  }
+
+  // Put the mapping back into memory.
+  return this->map(ErrMsg);
+}
+
+}
+
diff --git a/lib/System/Unix/Memory.inc b/lib/System/Unix/Memory.inc
new file mode 100644
index 0000000..d040416
--- /dev/null
+++ b/lib/System/Unix/Memory.inc
@@ -0,0 +1,76 @@
+//===- Unix/Memory.cpp - Generic UNIX System Configuration ------*- 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 defines some functions for various memory management utilities.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#include "llvm/System/Process.h"
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+/// AllocateRWXMemory - Allocate a slab of memory with read/write/execute
+/// permissions.  This is typically used for JIT applications where we want
+/// to emit code to the memory then jump to it.  Getting this type of memory
+/// is very OS specific.
+///
+llvm::sys::MemoryBlock 
+llvm::sys::Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock,
+                               std::string *ErrMsg) {
+  if (NumBytes == 0) return MemoryBlock();
+
+  long pageSize = Process::GetPageSize();
+  unsigned NumPages = (NumBytes+pageSize-1)/pageSize;
+
+  int fd = -1;
+#ifdef NEED_DEV_ZERO_FOR_MMAP
+  static int zero_fd = open("/dev/zero", O_RDWR);
+  if (zero_fd == -1) {
+    MakeErrMsg(ErrMsg, "Can't open /dev/zero device");
+    return MemoryBlock();
+  }
+  fd = zero_fd;
+#endif
+
+  int flags = MAP_PRIVATE |
+#ifdef HAVE_MMAP_ANONYMOUS
+  MAP_ANONYMOUS
+#else
+  MAP_ANON
+#endif
+  ;
+
+  void* start = NearBlock ? (unsigned char*)NearBlock->base() + 
+                            NearBlock->size() : 0;
+
+  void *pa = ::mmap(start, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
+                    flags, fd, 0);
+  if (pa == MAP_FAILED) {
+    if (NearBlock) //Try again without a near hint
+      return AllocateRWX(NumBytes, 0);
+
+    MakeErrMsg(ErrMsg, "Can't allocate RWX Memory");
+    return MemoryBlock();
+  }
+  MemoryBlock result;
+  result.Address = pa;
+  result.Size = NumPages*pageSize;
+  return result;
+}
+
+bool llvm::sys::Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
+  if (M.Address == 0 || M.Size == 0) return false;
+  if (0 != ::munmap(M.Address, M.Size))
+    return MakeErrMsg(ErrMsg, "Can't release RWX Memory");
+  return false;
+}
+
diff --git a/lib/System/Unix/Mutex.inc b/lib/System/Unix/Mutex.inc
new file mode 100644
index 0000000..d0984a4
--- /dev/null
+++ b/lib/System/Unix/Mutex.inc
@@ -0,0 +1,49 @@
+//===- llvm/System/Unix/Mutex.inc - Unix Mutex Implementation ---*- 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 implements the Unix specific (non-pthread) Mutex class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+namespace llvm
+{
+using namespace sys;
+
+Mutex::Mutex( bool recursive)
+{
+}
+
+Mutex::~Mutex()
+{
+}
+
+bool 
+Mutex::acquire()
+{
+  return true;
+}
+
+bool 
+Mutex::release()
+{
+  return true;
+}
+
+bool 
+Mutex::tryacquire( void )
+{
+  return true;
+}
+
+}
diff --git a/lib/System/Unix/Path.inc b/lib/System/Unix/Path.inc
new file mode 100644
index 0000000..e4916ba
--- /dev/null
+++ b/lib/System/Unix/Path.inc
@@ -0,0 +1,721 @@
+//===- llvm/System/Unix/Path.cpp - Unix Path Implementation -----*- 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 implements the Unix specific portion of the Path class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Config/alloca.h"
+#include "Unix.h"
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#if HAVE_UTIME_H
+#include <utime.h>
+#endif
+#if HAVE_TIME_H
+#include <time.h>
+#endif
+#if HAVE_DIRENT_H
+# include <dirent.h>
+# define NAMLEN(dirent) strlen((dirent)->d_name)
+#else
+# define dirent direct
+# define NAMLEN(dirent) (dirent)->d_namlen
+# if HAVE_SYS_NDIR_H
+#  include <sys/ndir.h>
+# endif
+# if HAVE_SYS_DIR_H
+#  include <sys/dir.h>
+# endif
+# if HAVE_NDIR_H
+#  include <ndir.h>
+# endif
+#endif
+
+// Put in a hack for Cygwin which falsely reports that the mkdtemp function
+// is available when it is not.
+#ifdef __CYGWIN__
+# undef HAVE_MKDTEMP
+#endif
+
+namespace {
+inline bool lastIsSlash(const std::string& path) {
+  return !path.empty() && path[path.length() - 1] == '/';
+}
+
+}
+
+namespace llvm {
+using namespace sys;
+
+bool 
+Path::isValid() const {
+  // Check some obvious things
+  if (path.empty()) 
+    return false;
+  else if (path.length() >= MAXPATHLEN)
+    return false;
+
+  // Check that the characters are ascii chars
+  size_t len = path.length();
+  unsigned i = 0;
+  while (i < len && isascii(path[i])) 
+    ++i;
+  return i >= len; 
+}
+
+bool 
+Path::isAbsolute() const {
+  if (path.empty())
+    return false;
+  return path[0] == '/';
+} 
+Path
+Path::GetRootDirectory() {
+  Path result;
+  result.set("/");
+  return result;
+}
+
+Path
+Path::GetTemporaryDirectory(std::string* ErrMsg ) {
+#if defined(HAVE_MKDTEMP)
+  // The best way is with mkdtemp but that's not available on many systems, 
+  // Linux and FreeBSD have it. Others probably won't.
+  char pathname[MAXPATHLEN];
+  strcpy(pathname,"/tmp/llvm_XXXXXX");
+  if (0 == mkdtemp(pathname)) {
+    MakeErrMsg(ErrMsg, 
+      std::string(pathname) + ": can't create temporary directory");
+    return Path();
+  }
+  Path result;
+  result.set(pathname);
+  assert(result.isValid() && "mkdtemp didn't create a valid pathname!");
+  return result;
+#elif defined(HAVE_MKSTEMP)
+  // If no mkdtemp is available, mkstemp can be used to create a temporary file
+  // which is then removed and created as a directory. We prefer this over
+  // mktemp because of mktemp's inherent security and threading risks. We still
+  // have a slight race condition from the time the temporary file is created to
+  // the time it is re-created as a directoy. 
+  char pathname[MAXPATHLEN];
+  strcpy(pathname, "/tmp/llvm_XXXXXX");
+  int fd = 0;
+  if (-1 == (fd = mkstemp(pathname))) {
+    MakeErrMsg(ErrMsg, 
+      std::string(pathname) + ": can't create temporary directory");
+    return Path();
+  }
+  ::close(fd);
+  ::unlink(pathname); // start race condition, ignore errors
+  if (-1 == ::mkdir(pathname, S_IRWXU)) { // end race condition
+    MakeErrMsg(ErrMsg, 
+      std::string(pathname) + ": can't create temporary directory");
+    return Path();
+  }
+  Path result;
+  result.set(pathname);
+  assert(result.isValid() && "mkstemp didn't create a valid pathname!");
+  return result;
+#elif defined(HAVE_MKTEMP)
+  // If a system doesn't have mkdtemp(3) or mkstemp(3) but it does have
+  // mktemp(3) then we'll assume that system (e.g. AIX) has a reasonable
+  // implementation of mktemp(3) and doesn't follow BSD 4.3's lead of replacing
+  // the XXXXXX with the pid of the process and a letter. That leads to only
+  // twenty six temporary files that can be generated.
+  char pathname[MAXPATHLEN];
+  strcpy(pathname, "/tmp/llvm_XXXXXX");
+  char *TmpName = ::mktemp(pathname);
+  if (TmpName == 0) {
+    MakeErrMsg(ErrMsg, 
+      std::string(TmpName) + ": can't create unique directory name");
+    return Path();
+  }
+  if (-1 == ::mkdir(TmpName, S_IRWXU)) {
+    MakeErrMsg(ErrMsg, 
+        std::string(TmpName) + ": can't create temporary directory");
+    return Path();
+  }
+  Path result;
+  result.set(TmpName);
+  assert(result.isValid() && "mktemp didn't create a valid pathname!");
+  return result;
+#else
+  // This is the worst case implementation. tempnam(3) leaks memory unless its
+  // on an SVID2 (or later) system. On BSD 4.3 it leaks. tmpnam(3) has thread
+  // issues. The mktemp(3) function doesn't have enough variability in the
+  // temporary name generated. So, we provide our own implementation that 
+  // increments an integer from a random number seeded by the current time. This
+  // should be sufficiently unique that we don't have many collisions between
+  // processes. Generally LLVM processes don't run very long and don't use very
+  // many temporary files so this shouldn't be a big issue for LLVM.
+  static time_t num = ::time(0);
+  char pathname[MAXPATHLEN];
+  do {
+    num++;
+    sprintf(pathname, "/tmp/llvm_%010u", unsigned(num));
+  } while ( 0 == access(pathname, F_OK ) );
+  if (-1 == ::mkdir(pathname, S_IRWXU)) {
+    MakeErrMsg(ErrMsg, 
+      std::string(pathname) + ": can't create temporary directory");
+    return Path();
+  }
+  Path result;
+  result.set(pathname);
+  assert(result.isValid() && "mkstemp didn't create a valid pathname!");
+  return result;
+#endif
+}
+
+static void getPathList(const char*path, std::vector<sys::Path>& Paths) {
+  const char* at = path;
+  const char* delim = strchr(at, ':');
+  Path tmpPath;
+  while( delim != 0 ) {
+    std::string tmp(at, size_t(delim-at));
+    if (tmpPath.set(tmp))
+      if (tmpPath.canRead())
+        Paths.push_back(tmpPath);
+    at = delim + 1;
+    delim = strchr(at, ':');
+  }
+  if (*at != 0)
+    if (tmpPath.set(std::string(at)))
+      if (tmpPath.canRead())
+        Paths.push_back(tmpPath);
+
+}
+
+void 
+Path::GetSystemLibraryPaths(std::vector<sys::Path>& Paths) {
+#ifdef LTDL_SHLIBPATH_VAR
+  char* env_var = getenv(LTDL_SHLIBPATH_VAR);
+  if (env_var != 0) {
+    getPathList(env_var,Paths);
+  }
+#endif
+  // FIXME: Should this look at LD_LIBRARY_PATH too?
+  Paths.push_back(sys::Path("/usr/local/lib/"));
+  Paths.push_back(sys::Path("/usr/X11R6/lib/"));
+  Paths.push_back(sys::Path("/usr/lib/"));
+  Paths.push_back(sys::Path("/lib/"));
+}
+
+void
+Path::GetBitcodeLibraryPaths(std::vector<sys::Path>& Paths) {
+  char * env_var = getenv("LLVM_LIB_SEARCH_PATH");
+  if (env_var != 0) {
+    getPathList(env_var,Paths);
+  }
+#ifdef LLVM_LIBDIR
+  {
+    Path tmpPath;
+    if (tmpPath.set(LLVM_LIBDIR))
+      if (tmpPath.canRead())
+        Paths.push_back(tmpPath);
+  }
+#endif
+  GetSystemLibraryPaths(Paths);
+}
+
+Path 
+Path::GetLLVMDefaultConfigDir() {
+  return Path("/etc/llvm/");
+}
+
+Path
+Path::GetUserHomeDirectory() {
+  const char* home = getenv("HOME");
+  if (home) {
+    Path result;
+    if (result.set(home))
+      return result;
+  }
+  return GetRootDirectory();
+}
+
+
+std::string
+Path::getBasename() const {
+  // Find the last slash
+  size_t slash = path.rfind('/');
+  if (slash == std::string::npos)
+    slash = 0;
+  else
+    slash++;
+
+  size_t dot = path.rfind('.');
+  if (dot == std::string::npos || dot < slash)
+    return path.substr(slash);
+  else
+    return path.substr(slash, dot - slash);
+}
+
+bool Path::getMagicNumber(std::string& Magic, unsigned len) const {
+  assert(len < 1024 && "Request for magic string too long");
+  char* buf = (char*) alloca(1 + len);
+  int fd = ::open(path.c_str(), O_RDONLY);
+  if (fd < 0)
+    return false;
+  ssize_t bytes_read = ::read(fd, buf, len);
+  ::close(fd);
+  if (ssize_t(len) != bytes_read) {
+    Magic.clear();
+    return false;
+  }
+  Magic.assign(buf,len);
+  return true;
+}
+
+bool
+Path::exists() const {
+  return 0 == access(path.c_str(), F_OK );
+}
+
+bool
+Path::canRead() const {
+  return 0 == access(path.c_str(), F_OK | R_OK );
+}
+
+bool
+Path::canWrite() const {
+  return 0 == access(path.c_str(), F_OK | W_OK );
+}
+
+bool
+Path::canExecute() const {
+  if (0 != access(path.c_str(), R_OK | X_OK ))
+    return false;
+  struct stat buf;
+  if (0 != stat(path.c_str(), &buf))
+    return false;
+  if (!S_ISREG(buf.st_mode))
+    return false;
+  return true;
+}
+
+std::string 
+Path::getLast() const {
+  // Find the last slash
+  size_t pos = path.rfind('/');
+
+  // Handle the corner cases
+  if (pos == std::string::npos)
+    return path;
+
+  // If the last character is a slash
+  if (pos == path.length()-1) {
+    // Find the second to last slash
+    size_t pos2 = path.rfind('/', pos-1);
+    if (pos2 == std::string::npos)
+      return path.substr(0,pos);
+    else
+      return path.substr(pos2+1,pos-pos2-1);
+  }
+  // Return everything after the last slash
+  return path.substr(pos+1);
+}
+
+const FileStatus *
+PathWithStatus::getFileStatus(bool update, std::string *ErrStr) const {
+  if (!fsIsValid || update) {
+    struct stat buf;
+    if (0 != stat(path.c_str(), &buf)) {
+      MakeErrMsg(ErrStr, path + ": can't get status of file");
+      return 0;
+    }
+    status.fileSize = buf.st_size;
+    status.modTime.fromEpochTime(buf.st_mtime);
+    status.mode = buf.st_mode;
+    status.user = buf.st_uid;
+    status.group = buf.st_gid;
+    status.uniqueID = uint64_t(buf.st_ino);
+    status.isDir  = S_ISDIR(buf.st_mode);
+    status.isFile = S_ISREG(buf.st_mode);
+    fsIsValid = true;
+  }
+  return &status;
+}
+
+static bool AddPermissionBits(const Path &File, int bits) {
+  // Get the umask value from the operating system.  We want to use it
+  // when changing the file's permissions. Since calling umask() sets
+  // the umask and returns its old value, we must call it a second
+  // time to reset it to the user's preference.
+  int mask = umask(0777); // The arg. to umask is arbitrary.
+  umask(mask);            // Restore the umask.
+
+  // Get the file's current mode.
+  struct stat buf;
+  if (0 != stat(File.toString().c_str(), &buf)) 
+    return false;
+  // Change the file to have whichever permissions bits from 'bits'
+  // that the umask would not disable.
+  if ((chmod(File.c_str(), (buf.st_mode | (bits & ~mask)))) == -1)
+      return false;
+  return true;
+}
+
+bool Path::makeReadableOnDisk(std::string* ErrMsg) {
+  if (!AddPermissionBits(*this, 0444)) 
+    return MakeErrMsg(ErrMsg, path + ": can't make file readable");
+  return false;
+}
+
+bool Path::makeWriteableOnDisk(std::string* ErrMsg) {
+  if (!AddPermissionBits(*this, 0222))
+    return MakeErrMsg(ErrMsg, path + ": can't make file writable");
+  return false;
+}
+
+bool Path::makeExecutableOnDisk(std::string* ErrMsg) {
+  if (!AddPermissionBits(*this, 0111))
+    return MakeErrMsg(ErrMsg, path + ": can't make file executable");
+  return false;
+}
+
+bool
+Path::getDirectoryContents(std::set<Path>& result, std::string* ErrMsg) const {
+  DIR* direntries = ::opendir(path.c_str());
+  if (direntries == 0)
+    return MakeErrMsg(ErrMsg, path + ": can't open directory");
+
+  std::string dirPath = path;
+  if (!lastIsSlash(dirPath))
+    dirPath += '/';
+
+  result.clear();
+  struct dirent* de = ::readdir(direntries);
+  for ( ; de != 0; de = ::readdir(direntries)) {
+    if (de->d_name[0] != '.') {
+      Path aPath(dirPath + (const char*)de->d_name);
+      struct stat st;
+      if (0 != lstat(aPath.path.c_str(), &st)) {
+        if (S_ISLNK(st.st_mode))
+          continue; // dangling symlink -- ignore
+        return MakeErrMsg(ErrMsg, 
+                          aPath.path +  ": can't determine file object type");
+      }
+      result.insert(aPath);
+    }
+  }
+  
+  closedir(direntries);
+  return false;
+}
+
+bool
+Path::set(const std::string& a_path) {
+  if (a_path.empty())
+    return false;
+  std::string save(path);
+  path = a_path;
+  if (!isValid()) {
+    path = save;
+    return false;
+  }
+  return true;
+}
+
+bool
+Path::appendComponent(const std::string& name) {
+  if (name.empty())
+    return false;
+  std::string save(path);
+  if (!lastIsSlash(path))
+    path += '/';
+  path += name;
+  if (!isValid()) {
+    path = save;
+    return false;
+  }
+  return true;
+}
+
+bool
+Path::eraseComponent() {
+  size_t slashpos = path.rfind('/',path.size());
+  if (slashpos == 0 || slashpos == std::string::npos) {
+    path.erase();
+    return true;
+  }
+  if (slashpos == path.size() - 1)
+    slashpos = path.rfind('/',slashpos-1);
+  if (slashpos == std::string::npos) {
+    path.erase();
+    return true;
+  }
+  path.erase(slashpos);
+  return true;
+}
+
+bool
+Path::appendSuffix(const std::string& suffix) {
+  std::string save(path);
+  path.append(".");
+  path.append(suffix);
+  if (!isValid()) {
+    path = save;
+    return false;
+  }
+  return true;
+}
+
+bool
+Path::eraseSuffix() {
+  std::string save = path;
+  size_t dotpos = path.rfind('.',path.size());
+  size_t slashpos = path.rfind('/',path.size());
+  if (dotpos != std::string::npos) {
+    if (slashpos == std::string::npos || dotpos > slashpos+1) {
+      path.erase(dotpos, path.size()-dotpos);
+      return true;
+    }
+  }
+  if (!isValid())
+    path = save;
+  return false;
+}
+
+bool
+Path::createDirectoryOnDisk( bool create_parents, std::string* ErrMsg ) {
+  // Get a writeable copy of the path name
+  char pathname[MAXPATHLEN];
+  path.copy(pathname,MAXPATHLEN);
+
+  // Null-terminate the last component
+  int lastchar = path.length() - 1 ; 
+  if (pathname[lastchar] == '/') 
+    pathname[lastchar] = 0;
+  else 
+    pathname[lastchar+1] = 0;
+
+  // If we're supposed to create intermediate directories
+  if ( create_parents ) {
+    // Find the end of the initial name component
+    char * next = strchr(pathname,'/');
+    if ( pathname[0] == '/') 
+      next = strchr(&pathname[1],'/');
+
+    // Loop through the directory components until we're done 
+    while ( next != 0 ) {
+      *next = 0;
+      if (0 != access(pathname, F_OK | R_OK | W_OK))
+        if (0 != mkdir(pathname, S_IRWXU | S_IRWXG)) {
+          return MakeErrMsg(ErrMsg, 
+                            std::string(pathname) + ": can't create directory");
+        }
+      char* save = next;
+      next = strchr(next+1,'/');
+      *save = '/';
+    }
+  } 
+
+  if (0 != access(pathname, F_OK | R_OK))
+    if (0 != mkdir(pathname, S_IRWXU | S_IRWXG)) {
+      return MakeErrMsg(ErrMsg, 
+                        std::string(pathname) + ": can't create directory");
+    }
+  return false;
+}
+
+bool
+Path::createFileOnDisk(std::string* ErrMsg) {
+  // Create the file
+  int fd = ::creat(path.c_str(), S_IRUSR | S_IWUSR);
+  if (fd < 0)
+    return MakeErrMsg(ErrMsg, path + ": can't create file");
+  ::close(fd);
+  return false;
+}
+
+bool
+Path::createTemporaryFileOnDisk(bool reuse_current, std::string* ErrMsg) {
+  // Make this into a unique file name
+  if (makeUnique( reuse_current, ErrMsg ))
+    return true;
+
+  // create the file
+  int fd = ::open(path.c_str(), O_WRONLY|O_CREAT|O_TRUNC, 0666);
+  if (fd < 0) 
+    return MakeErrMsg(ErrMsg, path + ": can't create temporary file");
+  ::close(fd);
+  return false;
+}
+
+bool
+Path::eraseFromDisk(bool remove_contents, std::string *ErrStr) const {
+  // Get the status so we can determin if its a file or directory
+  struct stat buf;
+  if (0 != stat(path.c_str(), &buf)) {
+    MakeErrMsg(ErrStr, path + ": can't get status of file");
+    return true;
+  }
+
+  // Note: this check catches strange situations. In all cases, LLVM should 
+  // only be involved in the creation and deletion of regular files.  This 
+  // check ensures that what we're trying to erase is a regular file. It 
+  // effectively prevents LLVM from erasing things like /dev/null, any block 
+  // special file, or other things that aren't "regular" files. 
+  if (S_ISREG(buf.st_mode)) {
+    if (unlink(path.c_str()) != 0)
+      return MakeErrMsg(ErrStr, path + ": can't destroy file");
+    return false;
+  }
+  
+  if (!S_ISDIR(buf.st_mode)) {
+    if (ErrStr) *ErrStr = "not a file or directory";
+    return true;
+  }
+
+  if (remove_contents) {
+    // Recursively descend the directory to remove its contents.
+    std::string cmd = "/bin/rm -rf " + path;
+    system(cmd.c_str());
+    return false;
+  }
+
+  // Otherwise, try to just remove the one directory.
+  char pathname[MAXPATHLEN];
+  path.copy(pathname, MAXPATHLEN);
+  int lastchar = path.length() - 1 ; 
+  if (pathname[lastchar] == '/') 
+    pathname[lastchar] = 0;
+  else
+    pathname[lastchar+1] = 0;
+    
+  if (rmdir(pathname) != 0)
+    return MakeErrMsg(ErrStr, 
+      std::string(pathname) + ": can't erase directory");
+  return false;
+}
+
+bool
+Path::renamePathOnDisk(const Path& newName, std::string* ErrMsg) {
+  if (0 != ::rename(path.c_str(), newName.c_str()))
+    return MakeErrMsg(ErrMsg, std::string("can't rename '") + path + "' as '" + 
+               newName.toString() + "' ");
+  return false;
+}
+
+bool 
+Path::setStatusInfoOnDisk(const FileStatus &si, std::string *ErrStr) const {
+  struct utimbuf utb;
+  utb.actime = si.modTime.toPosixTime();
+  utb.modtime = utb.actime;
+  if (0 != ::utime(path.c_str(),&utb))
+    return MakeErrMsg(ErrStr, path + ": can't set file modification time");
+  if (0 != ::chmod(path.c_str(),si.mode))
+    return MakeErrMsg(ErrStr, path + ": can't set mode");
+  return false;
+}
+
+bool 
+sys::CopyFile(const sys::Path &Dest, const sys::Path &Src, std::string* ErrMsg){
+  int inFile = -1;
+  int outFile = -1;
+  inFile = ::open(Src.c_str(), O_RDONLY);
+  if (inFile == -1)
+    return MakeErrMsg(ErrMsg, Src.toString() + 
+      ": can't open source file to copy");
+
+  outFile = ::open(Dest.c_str(), O_WRONLY|O_CREAT, 0666);
+  if (outFile == -1) {
+    ::close(inFile);
+    return MakeErrMsg(ErrMsg, Dest.toString() +
+      ": can't create destination file for copy");
+  }
+
+  char Buffer[16*1024];
+  while (ssize_t Amt = ::read(inFile, Buffer, 16*1024)) {
+    if (Amt == -1) {
+      if (errno != EINTR && errno != EAGAIN) {
+        ::close(inFile);
+        ::close(outFile);
+        return MakeErrMsg(ErrMsg, Src.toString()+": can't read source file: ");
+      }
+    } else {
+      char *BufPtr = Buffer;
+      while (Amt) {
+        ssize_t AmtWritten = ::write(outFile, BufPtr, Amt);
+        if (AmtWritten == -1) {
+          if (errno != EINTR && errno != EAGAIN) {
+            ::close(inFile);
+            ::close(outFile);
+            return MakeErrMsg(ErrMsg, Dest.toString() + 
+              ": can't write destination file: ");
+          }
+        } else {
+          Amt -= AmtWritten;
+          BufPtr += AmtWritten;
+        }
+      }
+    }
+  }
+  ::close(inFile);
+  ::close(outFile);
+  return false;
+}
+
+bool 
+Path::makeUnique(bool reuse_current, std::string* ErrMsg) {
+  if (reuse_current && !exists())
+    return false; // File doesn't exist already, just use it!
+
+  // Append an XXXXXX pattern to the end of the file for use with mkstemp, 
+  // mktemp or our own implementation.
+  char *FNBuffer = (char*) alloca(path.size()+8);
+  path.copy(FNBuffer,path.size());
+  strcpy(FNBuffer+path.size(), "-XXXXXX");
+
+#if defined(HAVE_MKSTEMP)
+  int TempFD;
+  if ((TempFD = mkstemp(FNBuffer)) == -1)
+    return MakeErrMsg(ErrMsg, path + ": can't make unique filename");
+
+  // We don't need to hold the temp file descriptor... we will trust that no one
+  // will overwrite/delete the file before we can open it again.
+  close(TempFD);
+
+  // Save the name
+  path = FNBuffer;
+#elif defined(HAVE_MKTEMP)
+  // If we don't have mkstemp, use the old and obsolete mktemp function.
+  if (mktemp(FNBuffer) == 0)
+    return MakeErrMsg(ErrMsg, path + ": can't make unique filename");
+
+  // Save the name
+  path = FNBuffer;
+#else
+  // Okay, looks like we have to do it all by our lonesome.
+  static unsigned FCounter = 0;
+  unsigned offset = path.size() + 1;
+  while ( FCounter < 999999 && exists()) {
+    sprintf(FNBuffer+offset,"%06u",++FCounter);
+    path = FNBuffer;
+  }
+  if (FCounter > 999999)
+    return MakeErrMsg(ErrMsg, 
+      path + ": can't make unique filename: too many files");
+#endif
+  return false;
+}
+
+} // end llvm namespace
+
diff --git a/lib/System/Unix/Process.inc b/lib/System/Unix/Process.inc
new file mode 100644
index 0000000..6b9b2b3
--- /dev/null
+++ b/lib/System/Unix/Process.inc
@@ -0,0 +1,185 @@
+//===- Unix/Process.cpp - Unix Process Implementation --------- -*- 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 provides the generic Unix implementation of the Process class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+#ifdef HAVE_MALLOC_H
+#include <malloc.h>
+#endif
+#ifdef HAVE_MALLOC_MALLOC_H
+#include <malloc/malloc.h>
+#endif
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+using namespace llvm;
+using namespace sys;
+
+unsigned 
+Process::GetPageSize() 
+{
+#if defined(HAVE_GETPAGESIZE)
+  static const int page_size = ::getpagesize();
+#elif defined(HAVE_SYSCONF)
+  static long page_size = ::sysconf(_SC_PAGE_SIZE);
+#else
+#warning Cannot get the page size on this machine
+#endif
+  return static_cast<unsigned>(page_size);
+}
+
+size_t Process::GetMallocUsage() {
+#if defined(HAVE_MALLINFO)
+  struct mallinfo mi;
+  mi = ::mallinfo();
+  return mi.uordblks;
+#elif defined(HAVE_MALLOC_ZONE_STATISTICS) && defined(HAVE_MALLOC_MALLOC_H)
+  malloc_statistics_t Stats;
+  malloc_zone_statistics(malloc_default_zone(), &Stats);
+  return Stats.size_in_use;   // darwin
+#elif defined(HAVE_SBRK)
+  // Note this is only an approximation and more closely resembles
+  // the value returned by mallinfo in the arena field.
+  static char *StartOfMemory = reinterpret_cast<char*>(::sbrk(0));
+  char *EndOfMemory = (char*)sbrk(0);
+  if (EndOfMemory != ((char*)-1) && StartOfMemory != ((char*)-1))
+    return EndOfMemory - StartOfMemory;
+  else
+    return 0;
+#else
+#warning Cannot get malloc info on this platform
+  return 0;
+#endif
+}
+
+size_t
+Process::GetTotalMemoryUsage()
+{
+#if defined(HAVE_MALLINFO)
+  struct mallinfo mi = ::mallinfo();
+  return mi.uordblks + mi.hblkhd;
+#elif defined(HAVE_MALLOC_ZONE_STATISTICS) && defined(HAVE_MALLOC_MALLOC_H)
+  malloc_statistics_t Stats;
+  malloc_zone_statistics(malloc_default_zone(), &Stats);
+  return Stats.size_allocated;   // darwin
+#elif defined(HAVE_GETRUSAGE)
+  struct rusage usage;
+  ::getrusage(RUSAGE_SELF, &usage);
+  return usage.ru_maxrss;
+#else
+#warning Cannot get total memory size on this platform
+  return 0;
+#endif
+}
+
+void
+Process::GetTimeUsage(TimeValue& elapsed, TimeValue& user_time, 
+                      TimeValue& sys_time)
+{
+  elapsed = TimeValue::now();
+#if defined(HAVE_GETRUSAGE)
+  struct rusage usage;
+  ::getrusage(RUSAGE_SELF, &usage);
+  user_time = TimeValue( 
+    static_cast<TimeValue::SecondsType>( usage.ru_utime.tv_sec ), 
+    static_cast<TimeValue::NanoSecondsType>( usage.ru_utime.tv_usec * 
+      TimeValue::NANOSECONDS_PER_MICROSECOND ) );
+  sys_time = TimeValue( 
+    static_cast<TimeValue::SecondsType>( usage.ru_stime.tv_sec ), 
+    static_cast<TimeValue::NanoSecondsType>( usage.ru_stime.tv_usec * 
+      TimeValue::NANOSECONDS_PER_MICROSECOND ) );
+#else
+#warning Cannot get usage times on this platform
+  user_time.seconds(0);
+  user_time.microseconds(0);
+  sys_time.seconds(0);
+  sys_time.microseconds(0);
+#endif
+}
+
+int Process::GetCurrentUserId() {
+  return getuid();
+}
+
+int Process::GetCurrentGroupId() {
+  return getgid();
+}
+
+#ifdef HAVE_MACH_MACH_H
+#include <mach/mach.h>
+#endif
+
+// Some LLVM programs such as bugpoint produce core files as a normal part of
+// their operation. To prevent the disk from filling up, this function
+// does what's necessary to prevent their generation.
+void Process::PreventCoreFiles() {
+#if HAVE_SETRLIMIT
+  struct rlimit rlim;
+  rlim.rlim_cur = rlim.rlim_max = 0;
+  setrlimit(RLIMIT_CORE, &rlim);
+#endif
+
+#ifdef HAVE_MACH_MACH_H
+  // Disable crash reporting on Mac OS/X.
+
+  // get information about the original set of exception ports for the task
+  mach_msg_type_number_t Count = 0;
+  exception_mask_t OriginalMasks[EXC_TYPES_COUNT];
+  exception_port_t OriginalPorts[EXC_TYPES_COUNT];
+  exception_behavior_t OriginalBehaviors[EXC_TYPES_COUNT];
+  thread_state_flavor_t OriginalFlavors[EXC_TYPES_COUNT];
+  kern_return_t err = 
+    task_get_exception_ports(mach_task_self(), EXC_MASK_ALL, OriginalMasks,
+                             &Count, OriginalPorts, OriginalBehaviors,
+                             OriginalFlavors);
+  if (err == KERN_SUCCESS) {
+    // replace each with MACH_PORT_NULL.
+    for (unsigned i = 0; i != Count; ++i)
+      task_set_exception_ports(mach_task_self(), OriginalMasks[i], 
+                               MACH_PORT_NULL, OriginalBehaviors[i],
+                               OriginalFlavors[i]);
+  }
+#endif
+}
+
+bool Process::StandardInIsUserInput() {
+#if HAVE_ISATTY
+  return isatty(0);
+#endif
+  // If we don't have isatty, just return false.
+  return false;
+}
+
+bool Process::StandardOutIsDisplayed() {
+#if HAVE_ISATTY
+  return isatty(1);
+#endif
+  // If we don't have isatty, just return false.
+  return false;
+}
+
+bool Process::StandardErrIsDisplayed() {
+#if HAVE_ISATTY
+  return isatty(2);
+#endif
+  // If we don't have isatty, just return false.
+  return false;
+}
diff --git a/lib/System/Unix/Program.inc b/lib/System/Unix/Program.inc
new file mode 100644
index 0000000..896e809
--- /dev/null
+++ b/lib/System/Unix/Program.inc
@@ -0,0 +1,286 @@
+//===- llvm/System/Unix/Program.cpp -----------------------------*- 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 implements the Unix specific portion of the Program class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include <llvm/Config/config.h>
+#include "Unix.h"
+#include <iostream>
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+#if HAVE_SIGNAL_H
+#include <signal.h>
+#endif
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+namespace llvm {
+using namespace sys;
+
+// This function just uses the PATH environment variable to find the program.
+Path
+Program::FindProgramByName(const std::string& progName) {
+
+  // Check some degenerate cases
+  if (progName.length() == 0) // no program
+    return Path();
+  Path temp;
+  if (!temp.set(progName)) // invalid name
+    return Path();
+  // FIXME: have to check for absolute filename - we cannot assume anything
+  // about "." being in $PATH
+  if (temp.canExecute()) // already executable as is
+    return temp;
+
+  // At this point, the file name is valid and its not executable
+ 
+  // Get the path. If its empty, we can't do anything to find it.
+  const char *PathStr = getenv("PATH");
+  if (PathStr == 0) 
+    return Path();
+
+  // Now we have a colon separated list of directories to search; try them.
+  unsigned PathLen = strlen(PathStr);
+  while (PathLen) {
+    // Find the first colon...
+    const char *Colon = std::find(PathStr, PathStr+PathLen, ':');
+
+    // Check to see if this first directory contains the executable...
+    Path FilePath;
+    if (FilePath.set(std::string(PathStr,Colon))) {
+      FilePath.appendComponent(progName);
+      if (FilePath.canExecute())
+        return FilePath;                    // Found the executable!
+    }
+
+    // Nope it wasn't in this directory, check the next path in the list!
+    PathLen -= Colon-PathStr;
+    PathStr = Colon;
+
+    // Advance past duplicate colons
+    while (*PathStr == ':') {
+      PathStr++;
+      PathLen--;
+    }
+  }
+  return Path();
+}
+
+static bool RedirectFD(const std::string &File, int FD, std::string* ErrMsg) {
+  if (File.empty()) return false;  // Noop
+
+  // Open the file
+  int InFD = open(File.c_str(), FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666);
+  if (InFD == -1) {
+    MakeErrMsg(ErrMsg, "Cannot open file '" + File + "' for "
+              + (FD == 0 ? "input" : "output") + "!\n");
+    return true;
+  }
+
+  // Install it as the requested FD
+  if (-1 == dup2(InFD, FD)) {
+    MakeErrMsg(ErrMsg, "Cannot dup2");
+    return true;
+  }
+  close(InFD);      // Close the original FD
+  return false;
+}
+
+static bool Timeout = false;
+static void TimeOutHandler(int Sig) {
+  Timeout = true;
+}
+
+static void SetMemoryLimits (unsigned size)
+{
+#if HAVE_SYS_RESOURCE_H
+  struct rlimit r;
+  __typeof__ (r.rlim_cur) limit = (__typeof__ (r.rlim_cur)) (size) * 1048576;
+
+  // Heap size
+  getrlimit (RLIMIT_DATA, &r);
+  r.rlim_cur = limit;
+  setrlimit (RLIMIT_DATA, &r);
+#ifdef RLIMIT_RSS
+  // Resident set size.
+  getrlimit (RLIMIT_RSS, &r);
+  r.rlim_cur = limit;
+  setrlimit (RLIMIT_RSS, &r);
+#endif
+#ifdef RLIMIT_AS  // e.g. NetBSD doesn't have it.
+  // Virtual memory.
+  getrlimit (RLIMIT_AS, &r);
+  r.rlim_cur = limit;
+  setrlimit (RLIMIT_AS, &r);
+#endif
+#endif
+}
+
+int 
+Program::ExecuteAndWait(const Path& path, 
+                        const char** args,
+                        const char** envp,
+                        const Path** redirects,
+                        unsigned secondsToWait,
+                        unsigned memoryLimit,
+                        std::string* ErrMsg) 
+{
+  if (!path.canExecute()) {
+    if (ErrMsg)
+      *ErrMsg = path.toString() + " is not executable";
+    return -1;
+  }
+
+#ifdef HAVE_SYS_WAIT_H
+  // Create a child process.
+  int child = fork();
+  switch (child) {
+    // An error occured:  Return to the caller.
+    case -1:
+      MakeErrMsg(ErrMsg, "Couldn't fork");
+      return -1;
+
+    // Child process: Execute the program.
+    case 0: {
+      // Redirect file descriptors...
+      if (redirects) {
+        if (redirects[0]) {
+          if (redirects[0]->isEmpty()) {
+            if (RedirectFD("/dev/null",0,ErrMsg)) { return -1; }
+          } else {
+            if (RedirectFD(redirects[0]->toString(), 0,ErrMsg)) { return -1; }
+          }
+        }
+        if (redirects[1]) {
+          if (redirects[1]->isEmpty()) {
+            if (RedirectFD("/dev/null",1,ErrMsg)) { return -1; }
+          } else {
+            if (RedirectFD(redirects[1]->toString(),1,ErrMsg)) { return -1; }
+          }
+        }
+        if (redirects[1] && redirects[2] && 
+            *(redirects[1]) != *(redirects[2])) {
+          if (redirects[2]->isEmpty()) {
+            if (RedirectFD("/dev/null",2,ErrMsg)) { return -1; }
+          } else {
+            if (RedirectFD(redirects[2]->toString(), 2,ErrMsg)) { return -1; }
+          }
+        } else if (-1 == dup2(1,2)) {
+          MakeErrMsg(ErrMsg, "Can't redirect");
+          return -1;
+        }
+      }
+
+      // Set memory limits
+      if (memoryLimit!=0) {
+        SetMemoryLimits(memoryLimit);
+      }
+      
+      // Execute!
+      if (envp != 0)
+        execve (path.c_str(), (char** const)args, (char**)envp);
+      else
+        execv (path.c_str(), (char** const)args);
+      // If the execve() failed, we should exit and let the parent pick up
+      // our non-zero exit status.
+      exit (errno);
+    }
+
+    // Parent process: Break out of the switch to do our processing.
+    default:
+      break;
+  }
+
+  // Make sure stderr and stdout have been flushed
+  std::cerr << std::flush;
+  std::cout << std::flush;
+  fsync(1);
+  fsync(2);
+
+  struct sigaction Act, Old;
+
+  // Install a timeout handler.
+  if (secondsToWait) {
+    Timeout = false;
+    Act.sa_sigaction = 0;
+    Act.sa_handler = TimeOutHandler;
+    sigemptyset(&Act.sa_mask);
+    Act.sa_flags = 0;
+    sigaction(SIGALRM, &Act, &Old);
+    alarm(secondsToWait);
+  }
+
+  // Parent process: Wait for the child process to terminate.
+  int status;
+  while (wait(&status) != child)
+    if (secondsToWait && errno == EINTR) {
+      // Kill the child.
+      kill(child, SIGKILL);
+        
+      // Turn off the alarm and restore the signal handler
+      alarm(0);
+      sigaction(SIGALRM, &Old, 0);
+
+      // Wait for child to die
+      if (wait(&status) != child)
+        MakeErrMsg(ErrMsg, "Child timed out but wouldn't die");
+        
+      return -1;   // Timeout detected
+    } else {
+      MakeErrMsg(ErrMsg, "Error waiting for child process");
+      return -1;
+    }
+
+  // We exited normally without timeout, so turn off the timer.
+  if (secondsToWait) {
+    alarm(0);
+    sigaction(SIGALRM, &Old, 0);
+  }
+
+  // Return the proper exit status. 0=success, >0 is programs' exit status,
+  // <0 means a signal was returned, -9999999 means the program dumped core.
+  int result = 0;
+  if (WIFEXITED(status))
+    result = WEXITSTATUS(status);
+  else if (WIFSIGNALED(status))
+    result = 0 - WTERMSIG(status);
+#ifdef WCOREDUMP
+  else if (WCOREDUMP(status))
+    result |= 0x01000000;
+#endif
+  return result;
+#else
+  return -99;
+#endif
+    
+}
+
+bool Program::ChangeStdinToBinary(){
+  // Do nothing, as Unix doesn't differentiate between text and binary.
+  return false;
+}
+
+bool Program::ChangeStdoutToBinary(){
+  // Do nothing, as Unix doesn't differentiate between text and binary.
+  return false;
+}
+
+}
diff --git a/lib/System/Unix/README.txt b/lib/System/Unix/README.txt
new file mode 100644
index 0000000..b3bace4
--- /dev/null
+++ b/lib/System/Unix/README.txt
@@ -0,0 +1,16 @@
+llvm/lib/System/Unix README
+===========================
+
+This directory provides implementations of the lib/System classes that
+are common to two or more variants of UNIX. For example, the directory 
+structure underneath this directory could look like this:
+
+Unix           - only code that is truly generic to all UNIX platforms
+  Posix        - code that is specific to Posix variants of UNIX
+  SUS          - code that is specific to the Single Unix Specification 
+  SysV         - code that is specific to System V variants of UNIX
+
+As a rule, only those directories actually needing to be created should be
+created. Also, further subdirectories could be created to reflect versions of
+the various standards. For example, under SUS there could be v1, v2, and v3
+subdirectories to reflect the three major versions of SUS.
diff --git a/lib/System/Unix/SUS/Process.cpp b/lib/System/Unix/SUS/Process.cpp
new file mode 100644
index 0000000..fb462b4
--- /dev/null
+++ b/lib/System/Unix/SUS/Process.cpp
@@ -0,0 +1,30 @@
+//===- Unix/SUS/Process.cpp - Linux Process Implementation ---- -*- 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 provides the Linux specific implementation of the Process class.
+//
+//===----------------------------------------------------------------------===//
+
+#include <unistd.h>
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only code specific to the
+//===          SUS (Single Unix Specification).
+//===----------------------------------------------------------------------===//
+
+namespace llvm {
+using namespace sys;
+
+unsigned
+Process::GetPageSize() {
+  static const long page_size = sysconf(_SC_PAGE_SIZE);
+  return static_cast<unsigned>(page_size);
+}
+
+}
diff --git a/lib/System/Unix/Signals.inc b/lib/System/Unix/Signals.inc
new file mode 100644
index 0000000..d1493a2
--- /dev/null
+++ b/lib/System/Unix/Signals.inc
@@ -0,0 +1,201 @@
+//===- Signals.cpp - Generic Unix Signals Implementation -----*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file defines some helpful functions for dealing with the possibility of
+// Unix signals occuring while your program is running.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#include <vector>
+#include <algorithm>
+#if HAVE_EXECINFO_H
+# include <execinfo.h>         // For backtrace().
+#endif
+#if HAVE_SIGNAL_H
+#include <signal.h>
+#endif
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+using namespace llvm;
+
+namespace {
+
+bool StackTraceRequested = false; 
+
+/// InterruptFunction - The function to call if ctrl-c is pressed.
+void (*InterruptFunction)() = 0;
+
+std::vector<sys::Path> *FilesToRemove = 0 ;
+std::vector<sys::Path> *DirectoriesToRemove = 0;
+
+// IntSigs - Signals that may interrupt the program at any time.
+const int IntSigs[] = {
+  SIGHUP, SIGINT, SIGQUIT, SIGPIPE, SIGTERM, SIGUSR1, SIGUSR2
+};
+const int *IntSigsEnd = IntSigs + sizeof(IntSigs)/sizeof(IntSigs[0]);
+
+// KillSigs - Signals that are synchronous with the program that will cause it
+// to die.
+const int KillSigs[] = {
+  SIGILL, SIGTRAP, SIGABRT, SIGFPE, SIGBUS, SIGSEGV, SIGSYS, SIGXCPU, SIGXFSZ
+#ifdef SIGEMT
+  , SIGEMT
+#endif
+};
+const int *KillSigsEnd = KillSigs + sizeof(KillSigs)/sizeof(KillSigs[0]);
+
+#ifdef HAVE_BACKTRACE
+void* StackTrace[256];
+#endif
+
+// PrintStackTrace - In the case of a program crash or fault, print out a stack
+// trace so that the user has an indication of why and where we died.
+//
+// On glibc systems we have the 'backtrace' function, which works nicely, but
+// doesn't demangle symbols.  In order to backtrace symbols, we fork and exec a
+// 'c++filt' process to do the demangling.  This seems like the simplest and
+// most robust solution when we can't allocate memory (such as in a signal
+// handler).  If we can't find 'c++filt', we fallback to printing mangled names.
+//
+void PrintStackTrace() {
+#ifdef HAVE_BACKTRACE
+  // Use backtrace() to output a backtrace on Linux systems with glibc.
+  int depth = backtrace(StackTrace, sizeof(StackTrace)/sizeof(StackTrace[0]));
+  
+  // Create a one-way unix pipe.  The backtracing process writes to PipeFDs[1],
+  // the c++filt process reads from PipeFDs[0].
+  int PipeFDs[2];
+  if (pipe(PipeFDs)) {
+    backtrace_symbols_fd(StackTrace, depth, STDERR_FILENO);
+    return;
+  }
+
+  switch (pid_t ChildPID = fork()) {
+  case -1:        // Error forking, print mangled stack trace
+    close(PipeFDs[0]);
+    close(PipeFDs[1]);
+    backtrace_symbols_fd(StackTrace, depth, STDERR_FILENO);
+    return;
+  default:        // backtracing process
+    close(PipeFDs[0]);  // Close the reader side.
+
+    // Print the mangled backtrace into the pipe.
+    backtrace_symbols_fd(StackTrace, depth, PipeFDs[1]);
+    close(PipeFDs[1]);   // We are done writing.
+    while (waitpid(ChildPID, 0, 0) == -1)
+      if (errno != EINTR) break;
+    return;
+
+  case 0:         // c++filt process
+    close(PipeFDs[1]);    // Close the writer side.
+    dup2(PipeFDs[0], 0);  // Read from standard input
+    close(PipeFDs[0]);    // Close the old descriptor
+    dup2(2, 1);           // Revector stdout -> stderr
+
+    // Try to run c++filt or gc++filt.  If neither is found, call back on 'cat'
+    // to print the mangled stack trace.  If we can't find cat, just exit.
+    execlp("c++filt", "c++filt", (char*)NULL);
+    execlp("gc++filt", "gc++filt", (char*)NULL);
+    execlp("cat", "cat", (char*)NULL);
+    execlp("/bin/cat", "cat", (char*)NULL);
+    exit(0);
+  }
+#endif
+}
+
+// SignalHandler - The signal handler that runs...
+RETSIGTYPE SignalHandler(int Sig) {
+  if (FilesToRemove != 0)
+    while (!FilesToRemove->empty()) {
+      FilesToRemove->back().eraseFromDisk(true);
+      FilesToRemove->pop_back();
+    }
+
+  if (DirectoriesToRemove != 0)
+    while (!DirectoriesToRemove->empty()) {
+      DirectoriesToRemove->back().eraseFromDisk(true);
+      DirectoriesToRemove->pop_back();
+    }
+
+  if (std::find(IntSigs, IntSigsEnd, Sig) != IntSigsEnd) {
+    if (InterruptFunction) {
+      void (*IF)() = InterruptFunction;
+      InterruptFunction = 0;
+      IF();        // run the interrupt function.
+      return;
+    } else {
+      exit(1);   // If this is an interrupt signal, exit the program
+    }
+  }
+
+  // Otherwise if it is a fault (like SEGV) output the stacktrace to
+  // STDERR (if we can) and reissue the signal to die...
+  if (StackTraceRequested)
+    PrintStackTrace();
+  signal(Sig, SIG_DFL);
+}
+
+// Just call signal
+void RegisterHandler(int Signal) { 
+  signal(Signal, SignalHandler); 
+}
+
+}
+
+
+void sys::SetInterruptFunction(void (*IF)()) {
+  InterruptFunction = IF;
+  RegisterHandler(SIGINT);
+}
+
+// RemoveFileOnSignal - The public API
+bool sys::RemoveFileOnSignal(const sys::Path &Filename, std::string* ErrMsg) {
+  if (FilesToRemove == 0)
+    FilesToRemove = new std::vector<sys::Path>;
+
+  FilesToRemove->push_back(Filename);
+
+  std::for_each(IntSigs, IntSigsEnd, RegisterHandler);
+  std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
+  return false;
+}
+
+// RemoveDirectoryOnSignal - The public API
+bool sys::RemoveDirectoryOnSignal(const sys::Path& path, std::string* ErrMsg) {
+  // Not a directory?
+  struct stat buf;
+  if (0 != stat(path.c_str(), &buf)) {
+    MakeErrMsg(ErrMsg, path.toString() + ": can't get status of file");
+    return true;
+  }
+
+  if (!S_ISDIR(buf.st_mode)) {
+    if (ErrMsg)
+      *ErrMsg = path.toString() + " is not a directory";
+    return true;
+  }
+
+  if (DirectoriesToRemove == 0)
+    DirectoriesToRemove = new std::vector<sys::Path>;
+
+  DirectoriesToRemove->push_back(path);
+
+  std::for_each(IntSigs, IntSigsEnd, RegisterHandler);
+  std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
+  return false;
+}
+
+/// PrintStackTraceOnErrorSignal - When an error signal (such as SIBABRT or
+/// SIGSEGV) is delivered to the process, print a stack trace and then exit.
+void sys::PrintStackTraceOnErrorSignal() {
+  StackTraceRequested = true;
+  std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
+}
diff --git a/lib/System/Unix/TimeValue.inc b/lib/System/Unix/TimeValue.inc
new file mode 100644
index 0000000..77fc9ab
--- /dev/null
+++ b/lib/System/Unix/TimeValue.inc
@@ -0,0 +1,56 @@
+//===- Unix/TimeValue.cpp - Unix TimeValue Implementation -------*- 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 implements the Unix specific portion of the TimeValue class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+
+namespace llvm {
+  using namespace sys;
+
+std::string TimeValue::toString() const {
+  char buffer[32];
+
+  time_t ourTime = time_t(this->toEpochTime());
+#ifdef __hpux
+// note that the following line needs -D_REENTRANT on HP-UX to be picked up 
+  asctime_r(localtime(&ourTime), buffer);
+#else
+  ::asctime_r(::localtime(&ourTime), buffer);
+#endif
+
+  std::string result(buffer);
+  return result.substr(0,24);
+}
+
+TimeValue TimeValue::now() {
+  struct timeval the_time;
+  timerclear(&the_time);
+  if (0 != ::gettimeofday(&the_time,0)) {
+    // This is *really* unlikely to occur because the only gettimeofday
+    // errors concern the timezone parameter which we're passing in as 0.
+    // In the unlikely case it does happen, just return MinTime, no error
+    // message needed. 
+    return MinTime;
+  }
+
+  return TimeValue(
+    static_cast<TimeValue::SecondsType>( the_time.tv_sec ), 
+    static_cast<TimeValue::NanoSecondsType>( the_time.tv_usec * 
+      NANOSECONDS_PER_MICROSECOND ) );
+}
+
+}
diff --git a/lib/System/Unix/Unix.h b/lib/System/Unix/Unix.h
new file mode 100644
index 0000000..c38c652
--- /dev/null
+++ b/lib/System/Unix/Unix.h
@@ -0,0 +1,101 @@
+//===- llvm/System/Unix/Unix.h - Common Unix Include File -------*- 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 defines things specific to Unix implementations.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SYSTEM_UNIX_UNIX_H
+#define LLVM_SYSTEM_UNIX_UNIX_H
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on all UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Config/config.h"     // Get autoconf configuration settings
+#include <cstdlib>
+#include <cstdio>
+#include <cstring>
+#include <cerrno>
+#include <string>
+#include <algorithm>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
+
+#ifdef HAVE_ASSERT_H
+#include <assert.h>
+#endif
+
+#ifdef TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else
+# ifdef HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else
+#  include <time.h>
+# endif
+#endif
+
+#ifdef HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
+
+#ifndef WEXITSTATUS
+# define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
+#endif
+
+#ifndef WIFEXITED
+# define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
+#endif
+
+/// This function builds an error message into \p ErrMsg using the \p prefix
+/// string and the Unix error number given by \p errnum. If errnum is -1, the
+/// default then the value of errno is used.
+/// @brief Make an error message
+inline bool MakeErrMsg(
+  std::string* ErrMsg, const std::string& prefix, int errnum = -1) {
+  if (!ErrMsg)
+    return true;
+  char buffer[MAXPATHLEN];
+  buffer[0] = 0;
+  if (errnum == -1)
+    errnum = errno;
+#ifdef HAVE_STRERROR_R
+  // strerror_r is thread-safe.
+  if (errnum)
+    strerror_r(errnum,buffer,MAXPATHLEN-1);
+#elif HAVE_STRERROR
+  // Copy the thread un-safe result of strerror into
+  // the buffer as fast as possible to minimize impact
+  // of collision of strerror in multiple threads.
+  if (errnum)
+    strncpy(buffer,strerror(errnum),MAXPATHLEN-1);
+  buffer[MAXPATHLEN-1] = 0;
+#else
+  // Strange that this system doesn't even have strerror
+  // but, oh well, just use a generic message
+  sprintf(buffer, "Error #%d", errnum);
+#endif
+  *ErrMsg = prefix + buffer;
+  return true;
+}
+
+#endif