[Emacs-diffs] emacs/src process.c

[Nick Roberts]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Nick Roberts <nickrob>  09/08/13 13:22:55

Modified files:
        src            : process.c 

Log message:
        (create_pty): New function.
        (Fstart_process): Use it to allow Emacs to just associate a pty
        with the buffer.  See associated change in gdb-mi.el.
        (list_processes_1): Deal with no program name.
        (start_process_unwind): Use pid == -2 to mean no process.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/emacs/src/process.c?cvsroot=emacs&r1=1.590&r2=1.591

Patches:
Index: process.c
===================================================================
RCS file: /sources/emacs/emacs/src/process.c,v
retrieving revision 1.590
retrieving revision 1.591
diff -u -b -r1.590 -r1.591
--- process.c   18 Jul 2009 21:06:45 -0000      1.590
+++ process.c   13 Aug 2009 13:22:55 -0000      1.591
@@ -284,6 +284,7 @@
 static void deactivate_process P_ ((Lisp_Object));
 static void status_notify P_ ((struct Lisp_Process *));
 static int read_process_output P_ ((Lisp_Object, int));
+static void create_pty P_ ((Lisp_Object));
 
 /* If we support a window system, turn on the code to poll periodically
    to detect C-g.  It isn't actually used when doing interrupt input.  */
@@ -1530,6 +1531,8 @@
          while (1)
            {
              tem1 = Fcar (tem);
+             if (NILP (tem1))
+               break;
              Finsert (1, &tem1);
              tem = Fcdr (tem);
              if (NILP (tem))
@@ -1579,8 +1582,9 @@
 function to handle the output.  BUFFER may also be nil, meaning that
 this process is not associated with any buffer.
 
-PROGRAM is the program file name.  It is searched for in PATH.
-Remaining arguments are strings to give program as arguments.
+PROGRAM is the program file name.  It is searched for in PATH.  If
+nil, just associate a pty with the buffer.  Remaining arguments are
+strings to give program as arguments.
 
 If you want to separate standard output from standard error, invoke
 the command through a shell and redirect one of them using the shell
@@ -1634,6 +1638,7 @@
 
   program = args[2];
 
+  if (!NILP (program))
   CHECK_STRING (program);
 
   proc = make_process (name);
@@ -1680,6 +1685,7 @@
        args2[0] = Qstart_process;
        for (i = 0; i < nargs; i++) args2[i + 1] = args[i];
        GCPRO2 (proc, current_dir);
+       if (!NILP (program))
        coding_systems = Ffind_operation_coding_system (nargs + 1, args2);
        UNGCPRO;
        if (CONSP (coding_systems))
@@ -1698,6 +1704,7 @@
            args2[0] = Qstart_process;
            for (i = 0; i < nargs; i++) args2[i + 1] = args[i];
            GCPRO2 (proc, current_dir);
+           if (!NILP (program))
            coding_systems = Ffind_operation_coding_system (nargs + 1, args2);
            UNGCPRO;
          }
@@ -1709,6 +1716,16 @@
     XPROCESS (proc)->encode_coding_system = val;
   }
 
+
+  XPROCESS (proc)->decoding_buf = make_uninit_string (0);
+  XPROCESS (proc)->decoding_carryover = 0;
+  XPROCESS (proc)->encoding_buf = make_uninit_string (0);
+
+  XPROCESS (proc)->inherit_coding_system_flag
+    = !(NILP (buffer) || !inherit_process_coding_system);
+
+  if (!NILP (program))
+    {
   /* If program file name is not absolute, search our path for it.
      Put the name we will really use in TEM.  */
   if (!IS_DIRECTORY_SEP (SREF (program, 0))
@@ -1775,14 +1792,10 @@
       tem = XCDR (tem);
     }
 
-  XPROCESS (proc)->decoding_buf = make_uninit_string (0);
-  XPROCESS (proc)->decoding_carryover = 0;
-  XPROCESS (proc)->encoding_buf = make_uninit_string (0);
-
-  XPROCESS (proc)->inherit_coding_system_flag
-    = !(NILP (buffer) || !inherit_process_coding_system);
-
   create_process (proc, (char **) new_argv, current_dir);
+    }
+  else
+    create_pty (proc);
 
   return unbind_to (count, proc);
 }
@@ -1799,7 +1812,7 @@
     abort ();
 
   /* Was PROC started successfully?  */
-  if (XPROCESS (proc)->pid <= 0)
+  if (XPROCESS (proc)->pid == -1)
     remove_process (proc);
 
   return Qnil;
@@ -2268,6 +2281,83 @@
     report_file_error ("Doing vfork", Qnil);
 }
 
+void
+create_pty (process)
+     Lisp_Object process;
+{
+  int inchannel, outchannel;
+
+  /* Use volatile to protect variables from being clobbered by longjmp.  */
+  volatile int forkin, forkout;
+  volatile int pty_flag = 0;
+
+  inchannel = outchannel = -1;
+
+#ifdef HAVE_PTYS
+  if (!NILP (Vprocess_connection_type))
+    outchannel = inchannel = allocate_pty ();
+
+  if (inchannel >= 0)
+    {
+#if ! defined (USG) || defined (USG_SUBTTY_WORKS)
+      /* On most USG systems it does not work to open the pty's tty here,
+        then close it and reopen it in the child.  */
+#ifdef O_NOCTTY
+      /* Don't let this terminal become our controlling terminal
+        (in case we don't have one).  */
+      forkout = forkin = emacs_open (pty_name, O_RDWR | O_NOCTTY, 0);
+#else
+      forkout = forkin = emacs_open (pty_name, O_RDWR, 0);
+#endif
+      if (forkin < 0)
+       report_file_error ("Opening pty", Qnil);
+#if defined (RTU) || defined (UNIPLUS) || defined (DONT_REOPEN_PTY)
+      /* In the case that vfork is defined as fork, the parent process
+        (Emacs) may send some data before the child process completes
+        tty options setup.  So we setup tty before forking.  */
+      child_setup_tty (forkout);
+#endif /* RTU or UNIPLUS or DONT_REOPEN_PTY */
+#else
+      forkin = forkout = -1;
+#endif /* not USG, or USG_SUBTTY_WORKS */
+      pty_flag = 1;
+    }
+#endif /* HAVE_PTYS */
+
+#ifdef O_NONBLOCK
+  fcntl (inchannel, F_SETFL, O_NONBLOCK);
+  fcntl (outchannel, F_SETFL, O_NONBLOCK);
+#else
+#ifdef O_NDELAY
+  fcntl (inchannel, F_SETFL, O_NDELAY);
+  fcntl (outchannel, F_SETFL, O_NDELAY);
+#endif
+#endif
+
+  /* Record this as an active process, with its channels.
+     As a result, child_setup will close Emacs's side of the pipes.  */
+  chan_process[inchannel] = process;
+  XPROCESS (process)->infd = inchannel;
+  XPROCESS (process)->outfd = outchannel;
+
+  /* Previously we recorded the tty descriptor used in the subprocess.
+     It was only used for getting the foreground tty process, so now
+     we just reopen the device (see emacs_get_tty_pgrp) as this is
+     more portable (see USG_SUBTTY_WORKS above).  */
+
+  XPROCESS (process)->pty_flag = pty_flag;
+  XPROCESS (process)->status = Qrun;
+  setup_process_coding_systems (process);
+
+  FD_SET (inchannel, &input_wait_mask);
+  FD_SET (inchannel, &non_keyboard_wait_mask);
+  if (inchannel > max_process_desc)
+    max_process_desc = inchannel;
+
+  XPROCESS (process)->pid = -2;
+  XPROCESS (process)->tty_name = build_string (pty_name);
+}
+
 
 #ifdef HAVE_SOCKETS