Convenient macro to check whether the buffer is live.

* buffer.h (BUFFER_LIVE_P): New macro.
* alloc.c, buffer.c, editfns.c, insdel.c, lread.c, marker.c:
* minibuf.c, print.c, process.c, window.c, xdisp.c: Use it.

13 files changed, 50 insertions, 40 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 362d0b775b0..cecd31ddab4 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2012-09-11  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Convenient macro to check whether the buffer is live.
+        * buffer.h (BUFFER_LIVE_P): New macro.
+        * alloc.c, buffer.c, editfns.c, insdel.c, lread.c, marker.c:
+        * minibuf.c, print.c, process.c, window.c, xdisp.c: Use it.
+
 2012-09-11  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
 
         * xdisp.c (right_overwritten, right_overwriting): Also handle gstring
diff --git a/src/alloc.c b/src/alloc.c
index 33dc68df48e..7bbc0abcd9a 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -3682,7 +3682,7 @@ build_marker (struct buffer *buf, ptrdiff_t charpos, ptrdiff_t bytepos)
   struct Lisp_Marker *m;
 
   /* No dead buffers here.  */
-  eassert (!NILP (BVAR (buf, name)));
+  eassert (BUFFER_LIVE_P (buf));
 
   /* Every character is at least one byte.  */
   eassert (charpos <= bytepos);
diff --git a/src/buffer.c b/src/buffer.c
index 3af45122a0d..d512547d34e 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -388,7 +388,7 @@ DEFUN ("buffer-live-p", Fbuffer_live_p, Sbuffer_live_p, 1, 1, 0,
 Value is nil if OBJECT is not a buffer or if it has been killed.  */)
   (Lisp_Object object)
 {
-  return ((BUFFERP (object) && ! NILP (BVAR (XBUFFER (object), name)))
+  return ((BUFFERP (object) && BUFFER_LIVE_P (XBUFFER (object)))
           ? Qt : Qnil);
 }
 
@@ -776,7 +776,7 @@ CLONE nil means the indirect buffer's state is reset to default values.  */)
   base_buffer = Fget_buffer (base_buffer);
   if (NILP (base_buffer))
     error ("No such buffer: `%s'", SDATA (tem));
-  if (NILP (BVAR (XBUFFER (base_buffer), name)))
+  if (!BUFFER_LIVE_P (XBUFFER (base_buffer)))
     error ("Base buffer has been killed");
 
   if (SCHARS (name) == 0)
@@ -1553,7 +1553,7 @@ exists, return the buffer `*scratch*' (creating it if necessary).  */)
     {
       buf = XCAR (tail);
       if (BUFFERP (buf) && !EQ (buf, buffer)
-          && !NILP (BVAR (XBUFFER (buf), name))
+          && BUFFER_LIVE_P (XBUFFER (buf))
           && (SREF (BVAR (XBUFFER (buf), name), 0) != ' ')
           /* If the frame has a buffer_predicate, disregard buffers that
              don't fit the predicate.  */
@@ -1573,7 +1573,7 @@ exists, return the buffer `*scratch*' (creating it if necessary).  */)
     {
       buf = Fcdr (XCAR (tail));
       if (BUFFERP (buf) && !EQ (buf, buffer)
-          && !NILP (BVAR (XBUFFER (buf), name))
+          && BUFFER_LIVE_P (XBUFFER (buf))
           && (SREF (BVAR (XBUFFER (buf), name), 0) != ' ')
           /* If the frame has a buffer_predicate, disregard buffers that
              don't fit the predicate.  */
@@ -1615,7 +1615,7 @@ other_buffer_safely (Lisp_Object buffer)
     {
       buf = Fcdr (XCAR (tail));
       if (BUFFERP (buf) && !EQ (buf, buffer)
-          && !NILP (BVAR (XBUFFER (buf), name))
+          && BUFFER_LIVE_P (XBUFFER (buf))
           && (SREF (BVAR (XBUFFER (buf), name), 0) != ' '))
         return buf;
     }
@@ -1734,7 +1734,7 @@ cleaning up all windows currently displaying the buffer to be killed. */)
   b = XBUFFER (buffer);
 
   /* Avoid trouble for buffer already dead.  */
-  if (NILP (BVAR (b, name)))
+  if (!BUFFER_LIVE_P (b))
     return Qnil;
 
   /* Query if the buffer is still modified.  */
@@ -1770,7 +1770,7 @@ cleaning up all windows currently displaying the buffer to be killed. */)
   }
 
   /* If the hooks have killed the buffer, exit now.  */
-  if (NILP (BVAR (b, name)))
+  if (!BUFFER_LIVE_P (b))
     return Qt;
 
   /* We have no more questions to ask.  Verify that it is valid
@@ -1802,7 +1802,7 @@ cleaning up all windows currently displaying the buffer to be killed. */)
       UNGCPRO;
 
       /* Exit if we now have killed the base buffer (Bug#11665).  */
-      if (NILP (BVAR (b, name)))
+      if (!BUFFER_LIVE_P (b))
         return Qt;
     }
 
@@ -1813,7 +1813,7 @@ cleaning up all windows currently displaying the buffer to be killed. */)
   replace_buffer_in_windows (buffer);
 
   /* Exit if replacing the buffer in windows has killed our buffer.  */
-  if (NILP (BVAR (b, name)))
+  if (!BUFFER_LIVE_P (b))
     return Qt;
 
   /* Make this buffer not be current.  Exit if it is the sole visible
@@ -1846,7 +1846,7 @@ cleaning up all windows currently displaying the buffer to be killed. */)
 
   /* Killing buffer processes may run sentinels which may have killed
      our buffer.  */
-  if (NILP (BVAR (b, name)))
+  if (!BUFFER_LIVE_P (b))
     return Qt;
 
   /* These may run Lisp code and into infinite loops (if someone
@@ -1878,7 +1878,7 @@ cleaning up all windows currently displaying the buffer to be killed. */)
     }
 
   /* Deleting an auto-save file could have killed our buffer.  */
-  if (NILP (BVAR (b, name)))
+  if (!BUFFER_LIVE_P (b))
     return Qt;
 
   if (b->base_buffer)
@@ -2047,7 +2047,7 @@ the current buffer's major mode.  */)
 
   CHECK_BUFFER (buffer);
 
-  if (NILP (BVAR (XBUFFER (buffer), name)))
+  if (!BUFFER_LIVE_P (XBUFFER (buffer)))
     error ("Attempt to set major mode for a dead buffer");
 
   if (strcmp (SSDATA (BVAR (XBUFFER (buffer), name)), "*scratch*") == 0)
@@ -2183,7 +2183,7 @@ ends when the current command terminates.  Use `switch-to-buffer' or
   buffer = Fget_buffer (buffer_or_name);
   if (NILP (buffer))
     nsberror (buffer_or_name);
-  if (NILP (BVAR (XBUFFER (buffer), name)))
+  if (!BUFFER_LIVE_P (XBUFFER (buffer)))
     error ("Selecting deleted buffer");
   set_buffer_internal (XBUFFER (buffer));
   return buffer;
@@ -2194,7 +2194,7 @@ ends when the current command terminates.  Use `switch-to-buffer' or
 Lisp_Object
 set_buffer_if_live (Lisp_Object buffer)
 {
-  if (! NILP (BVAR (XBUFFER (buffer), name)))
+  if (BUFFER_LIVE_P (XBUFFER (buffer)))
     set_buffer_internal (XBUFFER (buffer));
   return Qnil;
 }
@@ -2289,7 +2289,7 @@ DEFUN ("buffer-swap-text", Fbuffer_swap_text, Sbuffer_swap_text,
   CHECK_BUFFER (buffer);
   other_buffer = XBUFFER (buffer);
 
-  if (NILP (BVAR (other_buffer, name)))
+  if (!BUFFER_LIVE_P (other_buffer))
     error ("Cannot swap a dead buffer's text");
 
   /* Actually, it probably works just fine.
@@ -2685,7 +2685,7 @@ current buffer is cleared.  */)
   /* Copy this buffer's new multibyte status
      into all of its indirect buffers.  */
   FOR_EACH_BUFFER (other)
-    if (other->base_buffer == current_buffer && !NILP (BVAR (other, name)))
+    if (other->base_buffer == current_buffer && BUFFER_LIVE_P (other))
       {
         BVAR (other, enable_multibyte_characters)
           = BVAR (current_buffer, enable_multibyte_characters);
diff --git a/src/buffer.h b/src/buffer.h
index da40a7ce3d8..d18ef30ea38 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -959,7 +959,10 @@ bset_width_table (struct buffer *b, Lisp_Object val)
   b->INTERNAL_FIELD (width_table) = val;
 }
 
-
+/* Convenient check whether buffer B is live.  */
+
+#define BUFFER_LIVE_P(b) (!NILP (BVAR (b, name)))
+
 /* Chain of all buffers, including killed ones.  */
 
 extern struct buffer *all_buffers;
diff --git a/src/editfns.c b/src/editfns.c
index 65baaf4e3f8..299cad07fd7 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -2613,7 +2613,7 @@ They default to the values of (point-min) and (point-max) in BUFFER.  */)
   if (NILP (buf))
     nsberror (buffer);
   bp = XBUFFER (buf);
-  if (NILP (BVAR (bp, name)))
+  if (!BUFFER_LIVE_P (bp))
     error ("Selecting deleted buffer");
 
   if (NILP (start))
@@ -2677,7 +2677,7 @@ determines whether case is significant or ignored.  */)
       if (NILP (buf1))
         nsberror (buffer1);
       bp1 = XBUFFER (buf1);
-      if (NILP (BVAR (bp1, name)))
+      if (!BUFFER_LIVE_P (bp1))
         error ("Selecting deleted buffer");
     }
 
@@ -2715,7 +2715,7 @@ determines whether case is significant or ignored.  */)
       if (NILP (buf2))
         nsberror (buffer2);
       bp2 = XBUFFER (buf2);
-      if (NILP (BVAR (bp2, name)))
+      if (!BUFFER_LIVE_P (bp2))
         error ("Selecting deleted buffer");
     }
 
diff --git a/src/insdel.c b/src/insdel.c
index 604a9bbf3df..b12a390633e 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -2107,7 +2107,7 @@ DEFUN ("combine-after-change-execute", Fcombine_after_change_execute,
      non-nil, and insertion calls a file handler (e.g. through
      lock_file) which scribbles into a temp file -- cyd  */
   if (!BUFFERP (combine_after_change_buffer)
-      || NILP (BVAR (XBUFFER (combine_after_change_buffer), name)))
+      || !BUFFER_LIVE_P (XBUFFER (combine_after_change_buffer)))
     {
       combine_after_change_list = Qnil;
       return Qnil;
diff --git a/src/lread.c b/src/lread.c
index 02b13affb6a..08a2e856c00 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -1734,7 +1734,7 @@ readevalloop (Lisp_Object readcharfun,
     {
       ptrdiff_t count1 = SPECPDL_INDEX ();
 
-      if (b != 0 && NILP (BVAR (b, name)))
+      if (b != 0 && !BUFFER_LIVE_P (b))
         error ("Reading from killed buffer");
 
       if (!NILP (start))
diff --git a/src/marker.c b/src/marker.c
index de3c19c3bcb..bfbb161a71d 100644
--- a/src/marker.c
+++ b/src/marker.c
@@ -407,7 +407,7 @@ Returns nil if MARKER points into a dead buffer.  */)
          does not preserve the buffer from being GC'd (it's weak), so
          markers have to be unlinked from their buffer as soon as the buffer
          is killed.  */
-      eassert (!NILP (BVAR (XBUFFER (buf), name)));
+      eassert (BUFFER_LIVE_P (XBUFFER (buf)));
       return buf;
     }
   return Qnil;
@@ -462,13 +462,13 @@ live_buffer (Lisp_Object buffer)
   if (NILP (buffer))
     {
       b = current_buffer;
-      eassert (!NILP (BVAR (b, name)));
+      eassert (BUFFER_LIVE_P (b));
     }
   else
     {
       CHECK_BUFFER (buffer);
       b = XBUFFER (buffer);
-      if (NILP (BVAR (b, name)))
+      if (!BUFFER_LIVE_P (b))
        b = NULL;
     }
   return b;
@@ -595,7 +595,7 @@ unchain_marker (register struct Lisp_Marker *marker)
       register struct Lisp_Marker *tail, **prev;
 
       /* No dead buffers here.  */
-      eassert (!NILP (BVAR (b, name)));
+      eassert (BUFFER_LIVE_P (b));
 
       marker->buffer = NULL;
       prev = &BUF_MARKERS (b);
diff --git a/src/minibuf.c b/src/minibuf.c
index 655a02f5eca..4ed480a8408 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -798,7 +798,7 @@ get_minibuffer (EMACS_INT depth)
       Vminibuffer_list = nconc2 (Vminibuffer_list, tail);
     }
   buf = Fcar (tail);
-  if (NILP (buf) || NILP (BVAR (XBUFFER (buf), name)))
+  if (NILP (buf) || !BUFFER_LIVE_P (XBUFFER (buf)))
     {
       buf = Fget_buffer_create
         (make_formatted_string (name, " *Minibuf-%"pI"d*", depth));
diff --git a/src/print.c b/src/print.c
index ab86ee1a8b5..16116643ad0 100644
--- a/src/print.c
+++ b/src/print.c
@@ -1873,7 +1873,7 @@ print_object (Lisp_Object obj, register Lisp_Object printcharfun, int escapeflag
         }
       else if (BUFFERP (obj))
         {
-          if (NILP (BVAR (XBUFFER (obj), name)))
+          if (!BUFFER_LIVE_P (XBUFFER (obj)))
             strout ("#<killed buffer>", -1, -1, printcharfun);
           else if (escapeflag)
             {
diff --git a/src/process.c b/src/process.c
index 0cc9bc353a1..0ae68567d6b 100644
--- a/src/process.c
+++ b/src/process.c
@@ -5298,7 +5298,7 @@ read_process_output (Lisp_Object proc, register int channel)
     }
 
   /* If no filter, write into buffer if it isn't dead.  */
-  else if (!NILP (p->buffer) && !NILP (BVAR (XBUFFER (p->buffer), name)))
+  else if (!NILP (p->buffer) && BUFFER_LIVE_P (XBUFFER (p->buffer)))
     {
       Lisp_Object old_read_only;
       ptrdiff_t old_begv, old_zv;
@@ -6722,7 +6722,7 @@ status_notify (struct Lisp_Process *deleting_process)
 
               /* Avoid error if buffer is deleted
                  (probably that's why the process is dead, too) */
-              if (NILP (BVAR (XBUFFER (buffer), name)))
+              if (!BUFFER_LIVE_P (XBUFFER (buffer)))
                 continue;
               Fset_buffer (buffer);
 
diff --git a/src/window.c b/src/window.c
index 1869a3b65cf..4a833a120b3 100644
--- a/src/window.c
+++ b/src/window.c
@@ -2668,7 +2668,7 @@ window_loop (enum window_loop type, Lisp_Object obj, int mini, Lisp_Object frame
             /* Check for a window that has a killed buffer.  */
           case CHECK_ALL_WINDOWS:
             if (! NILP (w->buffer)
-                && NILP (BVAR (XBUFFER (w->buffer), name)))
+                && !BUFFER_LIVE_P (XBUFFER (w->buffer)))
               emacs_abort ();
             break;
 
@@ -3273,7 +3273,7 @@ This function runs `window-scroll-functions' before running
   XSETWINDOW (window, w);
   buffer = Fget_buffer (buffer_or_name);
   CHECK_BUFFER (buffer);
-  if (NILP (BVAR (XBUFFER (buffer), name)))
+  if (!BUFFER_LIVE_P (XBUFFER (buffer)))
     error ("Attempt to display deleted buffer");
 
   tem = w->buffer;
@@ -3338,7 +3338,7 @@ displaying that buffer.  */)
 
   if (STRINGP (object))
     object = Fget_buffer (object);
-  if (BUFFERP (object) && !NILP (BVAR (XBUFFER (object), name)))
+  if (BUFFERP (object) && BUFFER_LIVE_P (XBUFFER (object)))
     {
       /* Walk all windows looking for buffer, and force update
          of each of those windows.  */
@@ -5549,7 +5549,7 @@ the return value is nil.  Otherwise the value is t.  */)
   saved_windows = XVECTOR (data->saved_windows);
 
   new_current_buffer = data->current_buffer;
-  if (NILP (BVAR (XBUFFER (new_current_buffer), name)))
+  if (!BUFFER_LIVE_P (XBUFFER (new_current_buffer)))
     new_current_buffer = Qnil;
   else
     {
@@ -5624,7 +5624,7 @@ the return value is nil.  Otherwise the value is t.  */)
           w = XWINDOW (window);
           if (!NILP (w->buffer)
               && !EQ (w->buffer, p->buffer)
-              && !NILP (BVAR (XBUFFER (p->buffer), name)))
+              && BUFFER_LIVE_P (XBUFFER (p->buffer)))
             /* If a window we restore gets another buffer, record the
                window's old buffer.  */
             call1 (Qrecord_window_buffer, window);
@@ -5774,7 +5774,7 @@ the return value is nil.  Otherwise the value is t.  */)
           if (NILP (p->buffer))
             /* An internal window.  */
             wset_buffer (w, p->buffer);
-          else if (!NILP (BVAR (XBUFFER (p->buffer), name)))
+          else if (BUFFER_LIVE_P (XBUFFER (p->buffer)))
             /* If saved buffer is alive, install it.  */
             {
               wset_buffer (w, p->buffer);
@@ -5793,7 +5793,7 @@ the return value is nil.  Otherwise the value is t.  */)
                 Fgoto_char (w->pointm);
              }
            else if (!NILP (w->buffer)
-                    && !NILP (BVAR (XBUFFER (w->buffer), name)))
+                    && BUFFER_LIVE_P (XBUFFER (w->buffer)))
              /* Keep window's old buffer; make sure the markers are
                 real.  */
              {
diff --git a/src/xdisp.c b/src/xdisp.c
index 1deda682192..c1e05d6df15 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -3667,7 +3667,7 @@ handle_fontified_prop (struct it *it)
         }
       /* There isn't much we can reasonably do to protect against
          misbehaving fontification, but here's a fig leaf.  */
-      else if (!NILP (BVAR (obuf, name)))
+      else if (BUFFER_LIVE_P (obuf))
         set_buffer_internal_1 (obuf);
 
       /* The fontification code may have added/removed text.
@@ -9910,7 +9910,7 @@ ensure_echo_area_buffers (void)
 
   for (i = 0; i < 2; ++i)
     if (!BUFFERP (echo_buffer[i])
-        || NILP (BVAR (XBUFFER (echo_buffer[i]), name)))
+        || !BUFFER_LIVE_P (XBUFFER (echo_buffer[i])))
       {
         char name[30];
         Lisp_Object old_buffer;