XEmacs 21.2.24 "Hecate".

[chise/xemacs-chise.git.1] / src / ntproc.c

/* Process support for Windows NT port of XEMACS.
   Copyright (C) 1992, 1995 Free Software Foundation, Inc.

This file is part of XEmacs.

XEmacs is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.

   Drew Bliss                   Oct 14, 1993
     Adapted from alarm.c by Tim Fleehart */

/* Adapted for XEmacs by David Hobley <david@spook-le0.cia.com.au> */
/* Synced with FSF Emacs 19.34.6 by Marc Paquette <marcpa@cam.org> */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <io.h>
#include <fcntl.h>
#include <signal.h>

/* must include CRT headers *before* config.h */
/* ### I don't believe it - martin */
#include <config.h>
#undef signal
#undef wait
#undef spawnve
#undef select
#undef kill

#include <windows.h>
#include <sys/socket.h>
#ifdef HAVE_A_OUT_H
#include <a.out.h>
#endif
#include "lisp.h"
#include "sysproc.h"
#include "nt.h"
#include "ntheap.h" /* From 19.34.6 */
#include "systime.h"
#include "syssignal.h"
#include "sysfile.h"
#include "syswait.h"
#include "buffer.h"
#include "process.h"
/*#include "w32term.h"*/ /* From 19.34.6: sync in ? --marcpa */

/* #### I'm not going to play with shit. */
#pragma warning (disable:4013 4024 4090)

/* Control whether spawnve quotes arguments as necessary to ensure
   correct parsing by child process.  Because not all uses of spawnve
   are careful about constructing argv arrays, we make this behavior
   conditional (off by default). */
Lisp_Object Vwin32_quote_process_args;

/* Control whether create_child causes the process' window to be
   hidden.  The default is nil. */
Lisp_Object Vwin32_start_process_show_window;

/* Control whether create_child causes the process to inherit Emacs'
   console window, or be given a new one of its own.  The default is
   nil, to allow multiple DOS programs to run on Win95.  Having separate
   consoles also allows Emacs to cleanly terminate process groups.  */
Lisp_Object Vwin32_start_process_share_console;

/* Time to sleep before reading from a subprocess output pipe - this
   avoids the inefficiency of frequently reading small amounts of data.
   This is primarily necessary for handling DOS processes on Windows 95,
   but is useful for Win32 processes on both Win95 and NT as well.  */
Lisp_Object Vwin32_pipe_read_delay;

/* Control whether stat() attempts to generate fake but hopefully
   "accurate" inode values, by hashing the absolute truenames of files.
   This should detect aliasing between long and short names, but still
   allows the possibility of hash collisions.  */
Lisp_Object Vwin32_generate_fake_inodes;

Lisp_Object Qhigh, Qlow;

extern Lisp_Object Vlisp_EXEC_SUFFIXES;

#ifndef DEBUG_XEMACS
__inline
#endif
void _DebPrint (const char *fmt, ...)
{
#ifdef DEBUG_XEMACS
  char buf[1024];
  va_list args;

  va_start (args, fmt);
  vsprintf (buf, fmt, args);
  va_end (args);
  OutputDebugString (buf);
#endif
}

/* sys_signal moved to nt.c. It's now called msw_signal... */

/* Defined in <process.h> which conflicts with the local copy */
#define _P_NOWAIT 1

/* Child process management list.  */
int child_proc_count = 0;
child_process child_procs[ MAX_CHILDREN ];
child_process *dead_child = NULL;

DWORD WINAPI reader_thread (void *arg);

/* Find an unused process slot.  */
child_process *
new_child (void)
{
  child_process *cp;
  DWORD id;
  
  for (cp = child_procs+(child_proc_count-1); cp >= child_procs; cp--)
    if (!CHILD_ACTIVE (cp))
      goto Initialize;
  if (child_proc_count == MAX_CHILDREN)
    return NULL;
  cp = &child_procs[child_proc_count++];

 Initialize:
  xzero (*cp);
  cp->fd = -1;
  cp->pid = -1;
  if (cp->procinfo.hProcess)
    CloseHandle(cp->procinfo.hProcess);
  cp->procinfo.hProcess = NULL;
  cp->status = STATUS_READ_ERROR;

  /* use manual reset event so that select() will function properly */
  cp->char_avail = CreateEvent (NULL, TRUE, FALSE, NULL);
  if (cp->char_avail)
    {
      cp->char_consumed = CreateEvent (NULL, FALSE, FALSE, NULL);
      if (cp->char_consumed)
        {
          cp->thrd = CreateThread (NULL, 1024, reader_thread, cp, 0, &id);
          if (cp->thrd)
            return cp;
        }
    }
  delete_child (cp);
  return NULL;
}

void 
delete_child (child_process *cp)
{
  int i;

  /* Should not be deleting a child that is still needed. */
  for (i = 0; i < MAXDESC; i++)
    if (fd_info[i].cp == cp)
      abort ();

  if (!CHILD_ACTIVE (cp))
    return;

  /* reap thread if necessary */
  if (cp->thrd)
    {
      DWORD rc;

      if (GetExitCodeThread (cp->thrd, &rc) && rc == STILL_ACTIVE)
        {
          /* let the thread exit cleanly if possible */
          cp->status = STATUS_READ_ERROR;
          SetEvent (cp->char_consumed);
          if (WaitForSingleObject (cp->thrd, 1000) != WAIT_OBJECT_0)
            {
              DebPrint (("delete_child.WaitForSingleObject (thread) failed "
                         "with %lu for fd %ld\n", GetLastError (), cp->fd));
              TerminateThread (cp->thrd, 0);
            }
        }
      CloseHandle (cp->thrd);
      cp->thrd = NULL;
    }
  if (cp->char_avail)
    {
      CloseHandle (cp->char_avail);
      cp->char_avail = NULL;
    }
  if (cp->char_consumed)
    {
      CloseHandle (cp->char_consumed);
      cp->char_consumed = NULL;
    }

  /* update child_proc_count (highest numbered slot in use plus one) */
  if (cp == child_procs + child_proc_count - 1)
    {
      for (i = child_proc_count-1; i >= 0; i--)
        if (CHILD_ACTIVE (&child_procs[i]))
          {
            child_proc_count = i + 1;
            break;
          }
    }
  if (i < 0)
    child_proc_count = 0;
}

/* Find a child by pid.  */
static child_process *
find_child_pid (DWORD pid)
{
  child_process *cp;

  for (cp = child_procs+(child_proc_count-1); cp >= child_procs; cp--)
    if (CHILD_ACTIVE (cp) && pid == cp->pid)
      return cp;
  return NULL;
}

/* Function to do blocking read of one byte, needed to implement
   select.  It is only allowed on sockets and pipes. */
static int
_sys_read_ahead (int fd)
{
  child_process * cp;
  int rc = 0;

  if (fd < 0 || fd >= MAXDESC)
    return STATUS_READ_ERROR;

  cp = fd_info[fd].cp;

  if (cp == NULL || cp->fd != fd || cp->status != STATUS_READ_READY)
    return STATUS_READ_ERROR;

  if ((fd_info[fd].flags & (FILE_PIPE | FILE_SOCKET)) == 0
      || (fd_info[fd].flags & FILE_READ) == 0)
    {
      /* fd is not a pipe or socket */
      abort ();
    }
  
  cp->status = STATUS_READ_IN_PROGRESS;
  
  if (fd_info[fd].flags & FILE_PIPE)
    {
      rc = _read (fd, &cp->chr, sizeof (char));

      /* Give subprocess time to buffer some more output for us before
         reporting that input is available; we need this because Win95
         connects DOS programs to pipes by making the pipe appear to be
         the normal console stdout - as a result most DOS programs will
         write to stdout without buffering, ie.  one character at a
         time.  Even some Win32 programs do this - "dir" in a command
         shell on NT is very slow if we don't do this. */
      if (rc > 0)
        {
          int wait = XINT (Vwin32_pipe_read_delay);

          if (wait > 0)
            Sleep (wait);
          else if (wait < 0)
            while (++wait <= 0)
              /* Yield remainder of our time slice, effectively giving a
                 temporary priority boost to the child process. */
              Sleep (0);
        }
    }

  if (rc == sizeof (char))
    cp->status = STATUS_READ_SUCCEEDED;
  else
    cp->status = STATUS_READ_FAILED;

  return cp->status;
}

/* Thread proc for child process and socket reader threads. Each thread
   is normally blocked until woken by select() to check for input by
   reading one char.  When the read completes, char_avail is signalled
   to wake up the select emulator and the thread blocks itself again. */
DWORD WINAPI 
reader_thread (void *arg)
{
  child_process *cp;
  
  /* Our identity */
  cp = (child_process *)arg;
  
  /* <matts@tibco.com> - I think the test below is wrong - we don't
     want to wait for someone to signal char_consumed, as we haven't
     read anything for them to consume yet! */

  /*
  if (cp == NULL ||
      WaitForSingleObject (cp->char_consumed, INFINITE) != WAIT_OBJECT_0)
  */

  if (cp == NULL)
  {
      return 1;
  }

  for (;;)
    {
      int rc;

      rc = _sys_read_ahead (cp->fd);

      /* The name char_avail is a misnomer - it really just means the
         read-ahead has completed, whether successfully or not. */
      if (!SetEvent (cp->char_avail))
        {
          DebPrint (("reader_thread.SetEvent failed with %lu for fd %ld\n",
                     GetLastError (), cp->fd));
          return 1;
        }

      if (rc == STATUS_READ_ERROR)
      {
        /* We are finished, so clean up handles and set to NULL so
           that CHILD_ACTIVE will see what is going on */
        if (cp->char_avail) {
          CloseHandle (cp->char_avail);
          cp->char_avail = NULL;
        }
        if (cp->thrd) {
          CloseHandle (cp->thrd);
          cp->thrd = NULL;
        }
        if (cp->char_consumed) {
          CloseHandle(cp->char_consumed);
          cp->char_consumed = NULL;
        }
        if (cp->procinfo.hProcess)
        {
          CloseHandle (cp->procinfo.hProcess);
          cp->procinfo.hProcess=NULL;
        }
        return 1;
      }
        
      /* If the read died, the child has died so let the thread die */
      if (rc == STATUS_READ_FAILED)
        break;
        
      /* Wait until our input is acknowledged before reading again */
      if (WaitForSingleObject (cp->char_consumed, INFINITE) != WAIT_OBJECT_0)
        {
          DebPrint (("reader_thread.WaitForSingleObject failed with "
                     "%lu for fd %ld\n", GetLastError (), cp->fd));
          break;
        }
    }
  /* We are finished, so clean up handles and set to NULL so that
     CHILD_ACTIVE will see what is going on */
  if (cp->char_avail) {
    CloseHandle (cp->char_avail);
    cp->char_avail = NULL;
  }
  if (cp->thrd) {
    CloseHandle (cp->thrd);
    cp->thrd = NULL;
  }
  if (cp->char_consumed) {
    CloseHandle(cp->char_consumed);
    cp->char_consumed = NULL;
  }
  if (cp->procinfo.hProcess)
  {
    CloseHandle (cp->procinfo.hProcess);
    cp->procinfo.hProcess=NULL;
  }
  
  return 0;
}

/* To avoid Emacs changing directory, we just record here the directory
   the new process should start in.  This is set just before calling
   sys_spawnve, and is not generally valid at any other time.  */
static const char * process_dir;

static BOOL 
create_child (CONST char *exe, char *cmdline, char *env,
              int * pPid, child_process *cp)
{
  STARTUPINFO start;
  SECURITY_ATTRIBUTES sec_attrs;
  SECURITY_DESCRIPTOR sec_desc;
  char dir[ MAXPATHLEN ];
  
  if (cp == NULL) abort ();
  
  xzero (start);
  start.cb = sizeof (start);
  
#ifdef HAVE_NTGUI
  if (NILP (Vwin32_start_process_show_window))
  start.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
  else
    start.dwFlags = STARTF_USESTDHANDLES;
  start.wShowWindow = SW_HIDE;

  start.hStdInput = GetStdHandle (STD_INPUT_HANDLE);
  start.hStdOutput = GetStdHandle (STD_OUTPUT_HANDLE);
  start.hStdError = GetStdHandle (STD_ERROR_HANDLE);
#endif /* HAVE_NTGUI */

  /* Explicitly specify no security */
  if (!InitializeSecurityDescriptor (&sec_desc, SECURITY_DESCRIPTOR_REVISION))
    goto EH_Fail;
  if (!SetSecurityDescriptorDacl (&sec_desc, TRUE, NULL, FALSE))
    goto EH_Fail;
  sec_attrs.nLength = sizeof (sec_attrs);
  sec_attrs.lpSecurityDescriptor = &sec_desc;
  sec_attrs.bInheritHandle = FALSE;
  
  strcpy (dir, process_dir);
  unixtodos_filename (dir);
  
  if (!CreateProcess (exe, cmdline, &sec_attrs, NULL, TRUE,
                      (!NILP (Vwin32_start_process_share_console)
                       ? CREATE_NEW_PROCESS_GROUP
                       : CREATE_NEW_CONSOLE),
                      env, dir,
                      &start, &cp->procinfo))
    goto EH_Fail;

  cp->pid = (int) cp->procinfo.dwProcessId;

  CloseHandle (cp->procinfo.hThread);
  CloseHandle (cp->procinfo.hProcess);
  cp->procinfo.hThread=NULL;
  cp->procinfo.hProcess=NULL;

  /* pid must fit in a Lisp_Int */


  *pPid = cp->pid;
  
  return TRUE;
  
 EH_Fail:
  DebPrint (("create_child.CreateProcess failed: %ld\n", GetLastError()););
  return FALSE;
}

#ifndef __MINGW32__
/* Return pointer to section header for section containing the given
   relative virtual address. */
static IMAGE_SECTION_HEADER *
rva_to_section (DWORD rva, IMAGE_NT_HEADERS * nt_header)
{
  PIMAGE_SECTION_HEADER section;
  int i;

  section = IMAGE_FIRST_SECTION (nt_header);

  for (i = 0; i < nt_header->FileHeader.NumberOfSections; i++)
    {
      if (rva >= section->VirtualAddress
          && rva < section->VirtualAddress + section->SizeOfRawData)
        return section;
      section++;
    }
  return NULL;
}
#endif

void
win32_executable_type (CONST char * filename, int * is_dos_app, int * is_cygnus_app)
{
  file_data executable;
  char * p;

  /* Default values in case we can't tell for sure.  */
  *is_dos_app = FALSE;
  *is_cygnus_app = FALSE;

  if (!open_input_file (&executable, filename))
    return;

  p = strrchr (filename, '.');

      /* We can only identify DOS .com programs from the extension. */
      if (p && stricmp (p, ".com") == 0)
    *is_dos_app = TRUE;
  else if (p && (stricmp (p, ".bat") == 0 ||
                 stricmp (p, ".cmd") == 0))
    {
      /* A DOS shell script - it appears that CreateProcess is happy to
         accept this (somewhat surprisingly); presumably it looks at
         COMSPEC to determine what executable to actually invoke.
             Therefore, we have to do the same here as well. */
      /* Actually, I think it uses the program association for that
         extension, which is defined in the registry.  */
      p = egetenv ("COMSPEC");
      if (p)
        win32_executable_type (p, is_dos_app, is_cygnus_app);
    }
      else
        {
      /* Look for DOS .exe signature - if found, we must also check that
         it isn't really a 16- or 32-bit Windows exe, since both formats
         start with a DOS program stub.  Note that 16-bit Windows
         executables use the OS/2 1.x format. */

#ifdef __MINGW32__
          /* mingw32 doesn't have enough headers to detect cygwin
             apps, just do what we can. */
          FILHDR * exe_header;

          exe_header = (FILHDR*) executable.file_base;
          if (exe_header->e_magic != DOSMAGIC)
            goto unwind;

          if ((char *) exe_header->e_lfanew > (char *) executable.size)
            {
              /* Some dos headers (pkunzip) have bogus e_lfanew fields.  */
              *is_dos_app = TRUE;
            } 
          else if (exe_header->nt_signature != NT_SIGNATURE)
            {
              *is_dos_app = TRUE;
            }
#else
          IMAGE_DOS_HEADER * dos_header;
          IMAGE_NT_HEADERS * nt_header;

          dos_header = (PIMAGE_DOS_HEADER) executable.file_base;
          if (dos_header->e_magic != IMAGE_DOS_SIGNATURE)
            goto unwind;
          
          nt_header = (PIMAGE_NT_HEADERS) ((char *) dos_header + dos_header->e_lfanew);
          
          if ((char *) nt_header > (char *) dos_header + executable.size) 
            {
              /* Some dos headers (pkunzip) have bogus e_lfanew fields.  */
              *is_dos_app = TRUE;
            } 
          else if (nt_header->Signature != IMAGE_NT_SIGNATURE &&
                   LOWORD (nt_header->Signature) != IMAGE_OS2_SIGNATURE)
            {
              *is_dos_app = TRUE;
            }
          else if (nt_header->Signature == IMAGE_NT_SIGNATURE)
            {
              /* Look for cygwin.dll in DLL import list. */
              IMAGE_DATA_DIRECTORY import_dir =
                nt_header->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT];
              IMAGE_IMPORT_DESCRIPTOR * imports;
              IMAGE_SECTION_HEADER * section;

              section = rva_to_section (import_dir.VirtualAddress, nt_header);
              imports = RVA_TO_PTR (import_dir.VirtualAddress, section, executable);
              
              for ( ; imports->Name; imports++)
                {
                  char * dllname = RVA_TO_PTR (imports->Name, section, executable);

                  if (strcmp (dllname, "cygwin.dll") == 0)
                    {
                      *is_cygnus_app = TRUE;
                      break;
                    }
                }
            }
#endif
        }

 unwind:
      close_file_data (&executable);
}

int
compare_env (const void *strp1, const void *strp2)
{
  const char *str1 = *(const char**)strp1, *str2 = *(const char**)strp2;

  while (*str1 && *str2 && *str1 != '=' && *str2 != '=')
    {
      if ((*str1) > (*str2))
        return 1;
      else if ((*str1) < (*str2))
        return -1;
      str1++, str2++;
    }

  if (*str1 == '=' && *str2 == '=')
    return 0;
  else if (*str1 == '=')
    return -1;
  else
    return 1;
}

void
merge_and_sort_env (char **envp1, char **envp2, char **new_envp)
{
  char **optr, **nptr;
  int num;

  nptr = new_envp;
  optr = envp1;
  while (*optr)
    *nptr++ = *optr++;
  num = optr - envp1;

  optr = envp2;
  while (*optr)
    *nptr++ = *optr++;
  num += optr - envp2;

  qsort (new_envp, num, sizeof (char *), compare_env);

  *nptr = NULL;
}

/* When a new child process is created we need to register it in our list,
   so intercept spawn requests.  */
int 
sys_spawnve (int mode, CONST char *cmdname,
             CONST char * CONST *argv, CONST char *CONST *envp)
{
  Lisp_Object program, full;
  char *cmdline, *env, *parg, **targ;
  int arglen, numenv;
  int pid;
  child_process *cp;
  int is_dos_app, is_cygnus_app;
  int do_quoting = 0;
  char escape_char = 0;
  /* We pass our process ID to our children by setting up an environment
     variable in their environment.  */
  char ppid_env_var_buffer[64];
  char *extra_env[] = {ppid_env_var_buffer, NULL};
  struct gcpro gcpro1;
    
  /* We don't care about the other modes */
  if (mode != _P_NOWAIT)
    {
      errno = EINVAL;
      return -1;
    }

  /* Handle executable names without an executable suffix.  */
  program = make_string (cmdname, strlen (cmdname));
  GCPRO1 (program);
  if (NILP (Ffile_executable_p (program)))
    {
      full = Qnil;
      locate_file (Vexec_path, program, Vlisp_EXEC_SUFFIXES, &full, 1);
      if (NILP (full))
        {
          UNGCPRO;
          errno = EINVAL;
          return -1;
        }
      GET_C_STRING_FILENAME_DATA_ALLOCA (full, cmdname);
    }
  else
    {
      (char*)cmdname = alloca (strlen (argv[0]) + 1);
      strcpy ((char*)cmdname, argv[0]);
    }
  UNGCPRO;

  /* make sure argv[0] and cmdname are both in DOS format */
  unixtodos_filename ((char*)cmdname);
  /* #### KLUDGE */
  ((CONST char**)argv)[0] = cmdname;

  /* Determine whether program is a 16-bit DOS executable, or a Win32
     executable that is implicitly linked to the Cygnus dll (implying it
     was compiled with the Cygnus GNU toolchain and hence relies on
     cygwin.dll to parse the command line - we use this to decide how to
     escape quote chars in command line args that must be quoted). */
  win32_executable_type (cmdname, &is_dos_app, &is_cygnus_app);

  /* On Windows 95, if cmdname is a DOS app, we invoke a helper
     application to start it by specifying the helper app as cmdname,
     while leaving the real app name as argv[0].  */
  if (is_dos_app)
    {
      cmdname = alloca (MAXPATHLEN);
      if (egetenv ("CMDPROXY"))
        strcpy ((char*)cmdname, egetenv ("CMDPROXY"));
      else
    {
          strcpy ((char*)cmdname, XSTRING_DATA (Vinvocation_directory));
          strcat ((char*)cmdname, "cmdproxy.exe");
        }
      unixtodos_filename ((char*)cmdname);
    }
  
  /* we have to do some conjuring here to put argv and envp into the
     form CreateProcess wants...  argv needs to be a space separated/null
     terminated list of parameters, and envp is a null
     separated/double-null terminated list of parameters.

     Additionally, zero-length args and args containing whitespace or
     quote chars need to be wrapped in double quotes - for this to work,
     embedded quotes need to be escaped as well.  The aim is to ensure
     the child process reconstructs the argv array we start with
     exactly, so we treat quotes at the beginning and end of arguments
     as embedded quotes.

     The Win32 GNU-based library from Cygnus doubles quotes to escape
     them, while MSVC uses backslash for escaping.  (Actually the MSVC
     startup code does attempt to recognize doubled quotes and accept
     them, but gets it wrong and ends up requiring three quotes to get a
     single embedded quote!)  So by default we decide whether to use
     quote or backslash as the escape character based on whether the
     binary is apparently a Cygnus compiled app.

     Note that using backslash to escape embedded quotes requires
     additional special handling if an embedded quote is already
     preceded by backslash, or if an arg requiring quoting ends with
     backslash.  In such cases, the run of escape characters needs to be
     doubled.  For consistency, we apply this special handling as long
     as the escape character is not quote.
   
     Since we have no idea how large argv and envp are likely to be we
     figure out list lengths on the fly and allocate them.  */
  
  if (!NILP (Vwin32_quote_process_args))
    {
      do_quoting = 1;
      /* Override escape char by binding win32-quote-process-args to
         desired character, or use t for auto-selection.  */
      if (INTP (Vwin32_quote_process_args))
        escape_char = XINT (Vwin32_quote_process_args);
      else
        escape_char = is_cygnus_app ? '"' : '\\';
    }
  
  /* do argv...  */
  arglen = 0;
  targ = (char**)argv;
  while (*targ)
    {
      char * p = *targ;
      int need_quotes = 0;
      int escape_char_run = 0;

      if (*p == 0)
        need_quotes = 1;
      for ( ; *p; p++)
        {
          if (*p == '"')
          {
              /* allow for embedded quotes to be escaped */
            arglen++;
              need_quotes = 1;
              /* handle the case where the embedded quote is already escaped */
              if (escape_char_run > 0)
                {
                  /* To preserve the arg exactly, we need to double the
                     preceding escape characters (plus adding one to
                     escape the quote character itself).  */
                  arglen += escape_char_run;
          }
            }
      else if (*p == ' ' || *p == '\t')
            {
              need_quotes = 1;
            }

          if (*p == escape_char && escape_char != '"')
            escape_char_run++;
          else
            escape_char_run = 0;
        }
      if (need_quotes)
        {
        arglen += 2;
          /* handle the case where the arg ends with an escape char - we
             must not let the enclosing quote be escaped.  */
          if (escape_char_run > 0)
            arglen += escape_char_run;
        }
      arglen += strlen (*targ++) + 1;
    }
  cmdline = alloca (arglen);
  targ = (char**)argv;
  parg = cmdline;
  while (*targ)
    {
      char * p = *targ;
      int need_quotes = 0;

      if (*p == 0)
        need_quotes = 1;

      if (do_quoting)
        {
          for ( ; *p; p++)
            if (*p == ' ' || *p == '\t' || *p == '"')
              need_quotes = 1;
        }
      if (need_quotes)
        {
          int escape_char_run = 0;
          char * first;
          char * last;

          p = *targ;
          first = p;
          last = p + strlen (p) - 1;
          *parg++ = '"';
#if 0
          /* This version does not escape quotes if they occur at the
             beginning or end of the arg - this could lead to incorrect
             behavior when the arg itself represents a command line
             containing quoted args.  I believe this was originally done
             as a hack to make some things work, before
             `win32-quote-process-args' was added.  */
          while (*p)
            {
              if (*p == '"' && p > first && p < last)
                *parg++ = escape_char;  /* escape embedded quotes */
              *parg++ = *p++;
            }
#else
          for ( ; *p; p++)
            {
              if (*p == '"')
                {
                  /* double preceding escape chars if any */
                  while (escape_char_run > 0)
                    {
                      *parg++ = escape_char;
                      escape_char_run--;
                    }
                  /* escape all quote chars, even at beginning or end */
                  *parg++ = escape_char;
                }
              *parg++ = *p;

              if (*p == escape_char && escape_char != '"')
                escape_char_run++;
              else
                escape_char_run = 0;
            }
          /* double escape chars before enclosing quote */
          while (escape_char_run > 0)
            {
              *parg++ = escape_char;
              escape_char_run--;
            }
#endif
          *parg++ = '"';
        }
      else
        {
          strcpy (parg, *targ);
          parg += strlen (*targ);
        }
      *parg++ = ' ';
      targ++;
    }
  *--parg = '\0';
  
  /* and envp...  */
  arglen = 1;
  targ = (char**)envp;
  numenv = 1; /* for end null */
  while (*targ)
    {
      arglen += strlen (*targ++) + 1;
      numenv++;
    }
  /* extra env vars... */
  sprintf (ppid_env_var_buffer, "__PARENT_PROCESS_ID=%d", 
           GetCurrentProcessId ());
  arglen += strlen (ppid_env_var_buffer) + 1;
  numenv++;

  /* merge env passed in and extra env into one, and sort it.  */
  targ = (char **) alloca (numenv * sizeof (char *));
  merge_and_sort_env ((char**)envp, extra_env, targ);

  /* concatenate env entries.  */
  env = alloca (arglen);
  parg = env;
  while (*targ)
    {
      strcpy (parg, *targ);
      parg += strlen (*targ++);
      *parg++ = '\0';
    }
  *parg++ = '\0';
  *parg = '\0';

  cp = new_child ();
  if (cp == NULL)
    {
      errno = EAGAIN;
      return -1;
    }
  
  /* Now create the process.  */
  if (!create_child (cmdname, cmdline, env, &pid, cp))
    {
      delete_child (cp);
      errno = ENOEXEC;
      return -1;
    }

  return pid;
}

/* Substitute for certain kill () operations */

static BOOL CALLBACK
find_child_console (HWND hwnd, child_process * cp)
{
  DWORD thread_id;
  DWORD process_id;

  thread_id = GetWindowThreadProcessId (hwnd, &process_id);
  if (process_id == cp->procinfo.dwProcessId)
    {
      char window_class[32];

      GetClassName (hwnd, window_class, sizeof (window_class));
      if (strcmp (window_class,
                  (os_subtype == OS_WIN95)
                  ? "tty"
                  : "ConsoleWindowClass") == 0)
        {
          cp->hwnd = hwnd;
          return FALSE;
        }
    }
  /* keep looking */
  return TRUE;
}

int 
sys_kill (int pid, int sig)
{
  child_process *cp;
  HANDLE proc_hand;
  int need_to_free = 0;
  int rc = 0;
  
  /* Only handle signals that will result in the process dying */
  if (sig != SIGINT && sig != SIGKILL && sig != SIGQUIT && sig != SIGHUP)
    {
      errno = EINVAL;
      return -1;
    }

  cp = find_child_pid (pid);
  if (cp == NULL)
    {
      proc_hand = OpenProcess (PROCESS_TERMINATE, 0, pid);
      if (proc_hand == NULL)
        {
          errno = EPERM;
          return -1;
        }
      need_to_free = 1;
    }
  else
    {
      proc_hand = cp->procinfo.hProcess;
      pid = cp->procinfo.dwProcessId;

      /* Try to locate console window for process. */
      EnumWindows ((WNDENUMPROC)find_child_console, (LPARAM) cp);
    }
  
  if (sig == SIGINT)
    {
      if (NILP (Vwin32_start_process_share_console) && cp && cp->hwnd)
        {
          BYTE control_scan_code = (BYTE) MapVirtualKey (VK_CONTROL, 0);
          BYTE vk_break_code = VK_CANCEL;
          BYTE break_scan_code = (BYTE) MapVirtualKey (vk_break_code, 0);
          HWND foreground_window;

          if (break_scan_code == 0)
            {
              /* Fake Ctrl-C if we can't manage Ctrl-Break. */
              vk_break_code = 'C';
              break_scan_code = (BYTE) MapVirtualKey (vk_break_code, 0);
            }

          foreground_window = GetForegroundWindow ();
          if (foreground_window && SetForegroundWindow (cp->hwnd))
            {
              /* Generate keystrokes as if user had typed Ctrl-Break or Ctrl-C.  */
              keybd_event (VK_CONTROL, control_scan_code, 0, 0);
              keybd_event (vk_break_code, break_scan_code, 0, 0);
              keybd_event (vk_break_code, break_scan_code, KEYEVENTF_KEYUP, 0);
              keybd_event (VK_CONTROL, control_scan_code, KEYEVENTF_KEYUP, 0);

              /* Sleep for a bit to give time for Emacs frame to respond
                 to focus change events (if Emacs was active app).  */
              Sleep (10);

              SetForegroundWindow (foreground_window);
            }
        }
      /* Ctrl-Break is NT equivalent of SIGINT.  */
      else if (!GenerateConsoleCtrlEvent (CTRL_BREAK_EVENT, pid))
        {
          DebPrint (("sys_kill.GenerateConsoleCtrlEvent return %d "
                     "for pid %lu\n", GetLastError (), pid));
          errno = EINVAL;
          rc = -1;
        }
    }
  else
    {
      if (NILP (Vwin32_start_process_share_console) && cp && cp->hwnd)
        {
#if 1
          if (os_subtype == OS_WIN95)
            {
/*
   Another possibility is to try terminating the VDM out-right by
   calling the Shell VxD (id 0x17) V86 interface, function #4
   "SHELL_Destroy_VM", ie.

     mov edx,4
     mov ebx,vm_handle
     call shellapi

   First need to determine the current VM handle, and then arrange for
   the shellapi call to be made from the system vm (by using
   Switch_VM_and_callback).

   Could try to invoke DestroyVM through CallVxD.

*/
#if 0
              /* On Win95, posting WM_QUIT causes the 16-bit subsystem
                 to hang when cmdproxy is used in conjunction with
                 command.com for an interactive shell.  Posting
                 WM_CLOSE pops up a dialog that, when Yes is selected,
                 does the same thing.  TerminateProcess is also less
                 than ideal in that subprocesses tend to stick around
                 until the machine is shutdown, but at least it
                 doesn't freeze the 16-bit subsystem.  */
              PostMessage (cp->hwnd, WM_QUIT, 0xff, 0);
#endif
              if (!TerminateProcess (proc_hand, 0xff))
                {
                  DebPrint (("sys_kill.TerminateProcess returned %d "
                             "for pid %lu\n", GetLastError (), pid));
                  errno = EINVAL;
                  rc = -1;
                }
            }
          else
#endif
            PostMessage (cp->hwnd, WM_CLOSE, 0, 0);
        }
      /* Kill the process.  On Win32 this doesn't kill child processes
         so it doesn't work very well for shells which is why it's not
         used in every case.  */
      else if (!TerminateProcess (proc_hand, 0xff))
        {
          DebPrint (("sys_kill.TerminateProcess returned %d "
                     "for pid %lu\n", GetLastError (), pid));
          errno = EINVAL;
          rc = -1;
        }
    }

  if (need_to_free)
    CloseHandle (proc_hand);

  return rc;
}

#if 0
/* Sync with FSF Emacs 19.34.6 note: ifdef'ed out in XEmacs */
extern int report_file_error (CONST char *, Lisp_Object);
#endif
/* The following two routines are used to manipulate stdin, stdout, and
   stderr of our child processes.

   Assuming that in, out, and err are *not* inheritable, we make them
   stdin, stdout, and stderr of the child as follows:

   - Save the parent's current standard handles.
   - Set the std handles to inheritable duplicates of the ones being passed in.
     (Note that _get_osfhandle() is an io.h procedure that retrieves the
     NT file handle for a crt file descriptor.)
   - Spawn the child, which inherits in, out, and err as stdin,
     stdout, and stderr. (see Spawnve)
   - Close the std handles passed to the child.
   - Reset the parent's standard handles to the saved handles.
     (see reset_standard_handles)
   We assume that the caller closes in, out, and err after calling us.  */

void
prepare_standard_handles (int in, int out, int err, HANDLE handles[3])
{
  HANDLE parent;
  HANDLE newstdin, newstdout, newstderr;

  parent = GetCurrentProcess ();

  handles[0] = GetStdHandle (STD_INPUT_HANDLE);
  handles[1] = GetStdHandle (STD_OUTPUT_HANDLE);
  handles[2] = GetStdHandle (STD_ERROR_HANDLE);

  /* make inheritable copies of the new handles */
  if (!DuplicateHandle (parent, 
                       (HANDLE) _get_osfhandle (in),
                       parent,
                       &newstdin, 
                       0, 
                       TRUE, 
                       DUPLICATE_SAME_ACCESS))
    report_file_error ("Duplicating input handle for child", Qnil);
  
  if (!DuplicateHandle (parent,
                       (HANDLE) _get_osfhandle (out),
                       parent,
                       &newstdout,
                       0,
                       TRUE,
                       DUPLICATE_SAME_ACCESS))
    report_file_error ("Duplicating output handle for child", Qnil);
  
  if (!DuplicateHandle (parent,
                       (HANDLE) _get_osfhandle (err),
                       parent,
                       &newstderr,
                       0,
                       TRUE,
                       DUPLICATE_SAME_ACCESS))
    report_file_error ("Duplicating error handle for child", Qnil);

  /* and store them as our std handles */
  if (!SetStdHandle (STD_INPUT_HANDLE, newstdin))
    report_file_error ("Changing stdin handle", Qnil);
  
  if (!SetStdHandle (STD_OUTPUT_HANDLE, newstdout))
    report_file_error ("Changing stdout handle", Qnil);

  if (!SetStdHandle (STD_ERROR_HANDLE, newstderr))
    report_file_error ("Changing stderr handle", Qnil);
}

void
reset_standard_handles (int in, int out, int err, HANDLE handles[3])
{
  /* close the duplicated handles passed to the child */
  CloseHandle (GetStdHandle (STD_INPUT_HANDLE));
  CloseHandle (GetStdHandle (STD_OUTPUT_HANDLE));
  CloseHandle (GetStdHandle (STD_ERROR_HANDLE));

  /* now restore parent's saved std handles */
  SetStdHandle (STD_INPUT_HANDLE, handles[0]);
  SetStdHandle (STD_OUTPUT_HANDLE, handles[1]);
  SetStdHandle (STD_ERROR_HANDLE, handles[2]);
}

void
set_process_dir (const char * dir)
{
  process_dir = dir;
}
\f
/* Some miscellaneous functions that are Windows specific, but not GUI
   specific (ie. are applicable in terminal or batch mode as well).  */

/* lifted from fileio.c  */
#define CORRECT_DIR_SEPS(s) \
  do { if ('/' == DIRECTORY_SEP) dostounix_filename (s); \
       else unixtodos_filename (s); \
  } while (0)

DEFUN ("win32-short-file-name", Fwin32_short_file_name, 1, 1, "", /*
  Return the short file name version (8.3) of the full path of FILENAME.
If FILENAME does not exist, return nil.
All path elements in FILENAME are converted to their short names.
*/
       (filename))
{
  char shortname[MAX_PATH];

  CHECK_STRING (filename);

  /* first expand it.  */
  filename = Fexpand_file_name (filename, Qnil);

  /* luckily, this returns the short version of each element in the path.  */
  if (GetShortPathName (XSTRING_DATA (filename), shortname, MAX_PATH) == 0)
    return Qnil;

  CORRECT_DIR_SEPS (shortname);

  return build_string (shortname);
}


DEFUN ("win32-long-file-name", Fwin32_long_file_name, 1, 1, "", /*
  Return the long file name version of the full path of FILENAME.
If FILENAME does not exist, return nil.
All path elements in FILENAME are converted to their long names.
*/
       (filename))
{
  char longname[ MAX_PATH ];

  CHECK_STRING (filename);

  /* first expand it.  */
  filename = Fexpand_file_name (filename, Qnil);

  if (!win32_get_long_filename (XSTRING_DATA (filename), longname, MAX_PATH))
    return Qnil;

  CORRECT_DIR_SEPS (longname);

  return build_string (longname);
}

DEFUN ("win32-set-process-priority", Fwin32_set_process_priority, 2, 2, "", /*
  Set the priority of PROCESS to PRIORITY.
If PROCESS is nil, the priority of Emacs is changed, otherwise the
priority of the process whose pid is PROCESS is changed.
PRIORITY should be one of the symbols high, normal, or low;
any other symbol will be interpreted as normal.

If successful, the return value is t, otherwise nil.
*/
       (process, priority))
{
  HANDLE proc_handle = GetCurrentProcess ();
  DWORD  priority_class = NORMAL_PRIORITY_CLASS;
  Lisp_Object result = Qnil;

  CHECK_SYMBOL (priority);

  if (!NILP (process))
    {
      DWORD pid;
      child_process *cp;

      CHECK_INT (process);

      /* Allow pid to be an internally generated one, or one obtained
         externally.  This is necessary because real pids on Win95 are
         negative.  */

      pid = XINT (process);
      cp = find_child_pid (pid);
      if (cp != NULL)
        pid = cp->procinfo.dwProcessId;

      proc_handle = OpenProcess (PROCESS_SET_INFORMATION, FALSE, pid);
    }

  if (EQ (priority, Qhigh))
    priority_class = HIGH_PRIORITY_CLASS;
  else if (EQ (priority, Qlow))
    priority_class = IDLE_PRIORITY_CLASS;

  if (proc_handle != NULL)
    {
      if (SetPriorityClass (proc_handle, priority_class))
        result = Qt;
      if (!NILP (process))
        CloseHandle (proc_handle);
    }

  return result;
}


DEFUN ("win32-get-locale-info", Fwin32_get_locale_info, 1, 2, "", /*
  "Return information about the Windows locale LCID.
By default, return a three letter locale code which encodes the default
language as the first two characters, and the country or regional variant
as the third letter.  For example, ENU refers to `English (United States)',
while ENC means `English (Canadian)'.

If the optional argument LONGFORM is non-nil, the long form of the locale
name is returned, e.g. `English (United States)' instead.

If LCID (a 16-bit number) is not a valid locale, the result is nil.
*/
     (lcid, longform))
{
  int got_abbrev;
  int got_full;
  char abbrev_name[32] = { 0 };
  char full_name[256] = { 0 };

  CHECK_INT (lcid);

  if (!IsValidLocale (XINT (lcid), LCID_SUPPORTED))
    return Qnil;

  if (NILP (longform))
    {
      got_abbrev = GetLocaleInfo (XINT (lcid),
                                  LOCALE_SABBREVLANGNAME | LOCALE_USE_CP_ACP,
                                  abbrev_name, sizeof (abbrev_name));
      if (got_abbrev)
        return build_string (abbrev_name);
    }
  else
    {
      got_full = GetLocaleInfo (XINT (lcid),
                                LOCALE_SLANGUAGE | LOCALE_USE_CP_ACP,
                                full_name, sizeof (full_name));
      if (got_full)
        return build_string (full_name);
    }

  return Qnil;
}


DEFUN ("win32-get-current-locale-id", Fwin32_get_current_locale_id, 0, 0, "", /*
  "Return Windows locale id for current locale setting.
This is a numerical value; use `win32-get-locale-info' to convert to a
human-readable form.
*/
       ())
{
  return make_int (GetThreadLocale ());
}


DEFUN ("win32-get-default-locale-id", Fwin32_get_default_locale_id, 0, 1, "", /*
  "Return Windows locale id for default locale setting.
By default, the system default locale setting is returned; if the optional
parameter USERP is non-nil, the user default locale setting is returned.
This is a numerical value; use `win32-get-locale-info' to convert to a
human-readable form.
*/
       (userp))
{
  if (NILP (userp))
    return make_int (GetSystemDefaultLCID ());
  return make_int (GetUserDefaultLCID ());
}

DWORD int_from_hex (char * s)
{
  DWORD val = 0;
  static char hex[] = "0123456789abcdefABCDEF";
  char * p;

  while (*s && (p = strchr(hex, *s)) != NULL)
    {
      unsigned digit = p - hex;
      if (digit > 15)
        digit -= 6;
      val = val * 16 + digit;
      s++;
    }
  return val;
}

/* We need to build a global list, since the EnumSystemLocale callback
   function isn't given a context pointer.  */
Lisp_Object Vwin32_valid_locale_ids;

BOOL CALLBACK enum_locale_fn (LPTSTR localeNum)
{
  DWORD id = int_from_hex (localeNum);
  Vwin32_valid_locale_ids = Fcons (make_int (id), Vwin32_valid_locale_ids);
  return TRUE;
}

DEFUN ("win32-get-valid-locale-ids", Fwin32_get_valid_locale_ids, 0, 0, "", /*
  Return list of all valid Windows locale ids.
Each id is a numerical value; use `win32-get-locale-info' to convert to a
human-readable form.
*/
       ())
{
  Vwin32_valid_locale_ids = Qnil;

  EnumSystemLocales (enum_locale_fn, LCID_SUPPORTED);

  Vwin32_valid_locale_ids = Fnreverse (Vwin32_valid_locale_ids);
  return Vwin32_valid_locale_ids;
}


DEFUN ("win32-set-current-locale", Fwin32_set_current_locale, 1, 1, "", /*
  Make Windows locale LCID be the current locale setting for Emacs.
If successful, the new locale id is returned, otherwise nil.
*/
     (lcid))
{
  CHECK_INT (lcid);

  if (!IsValidLocale (XINT (lcid), LCID_SUPPORTED))
    return Qnil;

  if (!SetThreadLocale (XINT (lcid)))
    return Qnil;

/* Sync with FSF Emacs 19.34.6 note: dwWinThreadId declared in
   w32term.h and defined in w32fns.c, both of which are not in current
   XEmacs.  ### Check what we lose by ifdef'ing out these. --marcpa */
#if 0
  /* Need to set input thread locale if present.  */
  if (dwWinThreadId)
    /* Reply is not needed.  */
    PostThreadMessage (dwWinThreadId, WM_EMACS_SETLOCALE, XINT (lcid), 0);
#endif

  return make_int (GetThreadLocale ());
}

\f
void
syms_of_ntproc ()
{
  DEFSUBR (Fwin32_short_file_name);
  DEFSUBR (Fwin32_long_file_name);
  DEFSUBR (Fwin32_set_process_priority);
  DEFSUBR (Fwin32_get_locale_info);
  DEFSUBR (Fwin32_get_current_locale_id);
  DEFSUBR (Fwin32_get_default_locale_id);
  DEFSUBR (Fwin32_get_valid_locale_ids);
  DEFSUBR (Fwin32_set_current_locale);
}


void
vars_of_ntproc (void)
{
  defsymbol (&Qhigh, "high");
  defsymbol (&Qlow, "low");

  DEFVAR_LISP ("win32-quote-process-args", &Vwin32_quote_process_args /*
    Non-nil enables quoting of process arguments to ensure correct parsing.
Because Windows does not directly pass argv arrays to child processes,
programs have to reconstruct the argv array by parsing the command
line string.  For an argument to contain a space, it must be enclosed
in double quotes or it will be parsed as multiple arguments.

If the value is a character, that character will be used to escape any
quote characters that appear, otherwise a suitable escape character
will be chosen based on the type of the program.
*/ );
  Vwin32_quote_process_args = Qt;

  DEFVAR_LISP ("win32-start-process-show-window",
               &Vwin32_start_process_show_window /*
    When nil, processes started via start-process hide their windows.
When non-nil, they show their window in the method of their choice.
*/ );
  Vwin32_start_process_show_window = Qnil;

  DEFVAR_LISP ("win32-start-process-share-console",
               &Vwin32_start_process_share_console /*
    When nil, processes started via start-process are given a new console.
When non-nil, they share the Emacs console; this has the limitation of
allowing only only DOS subprocess to run at a time (whether started directly
or indirectly by Emacs), and preventing Emacs from cleanly terminating the
subprocess group, but may allow Emacs to interrupt a subprocess that doesn't
otherwise respond to interrupts from Emacs.
*/ );
  Vwin32_start_process_share_console = Qt;

  DEFVAR_LISP ("win32-pipe-read-delay", &Vwin32_pipe_read_delay /*
    Forced delay before reading subprocess output.
This is done to improve the buffering of subprocess output, by
avoiding the inefficiency of frequently reading small amounts of data.

If positive, the value is the number of milliseconds to sleep before
reading the subprocess output.  If negative, the magnitude is the number
of time slices to wait (effectively boosting the priority of the child
process temporarily).  A value of zero disables waiting entirely.
*/ );
  Vwin32_pipe_read_delay = make_int (50);

#if 0
  DEFVAR_LISP ("win32-generate-fake-inodes", &Vwin32_generate_fake_inodes /*
    "Non-nil means attempt to fake realistic inode values.
This works by hashing the truename of files, and should detect 
aliasing between long and short (8.3 DOS) names, but can have
false positives because of hash collisions.  Note that determining
the truename of a file can be slow.
*/ );
  Vwin32_generate_fake_inodes = Qnil;
#endif
}

/* end of ntproc.c */