[patch] delete a range of display numbers

[Guillaume Leconte <guillaume.leconte@gmail.com>]

I often have a bunch of display numbers when I use gdb.  It's pretty
annoying to be unable to remove for example the N first ones I've
previously set.

This patch allow the user to do this:

(gdb) delete display 1-7

Notice that I've change the prototype of delete_display() in order
to have a silent return in case of unknown number.  If you have set
the display numbers 1, 2, 3 and 5, you can remove 2-5 without any
error messages (number 4 is missing in the list).  As a consequence,
you can also remove out of bound numbers, as in 'delete display 5-42'
without having gdb complaining.

diff --git a/gdb/printcmd.c b/gdb/printcmd.c
index 29ffbf5..6f718c4 100644
--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -1420,7 +1420,7 @@ x_command (char *exp, int from_tty)
       val = coerce_ref (val);
      /* In rvalue contexts, such as this, functions are coerced into
         pointers to functions.  This makes "x/i main" work.  */
-      if (/* last_format == 'i'  && */
+      if (/* last_format == 'i'  && */
         TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
          && VALUE_LVAL (val) == lval_memory)
       next_address = value_address (val);
@@ -1558,12 +1558,17 @@ clear_displays (void)
 /* Delete the auto-display number NUM.  */

 static void
-delete_display (int num)
+delete_display (int num,
+                int ignore)
 {
  struct display *d1, *d;

  if (!display_chain)
-    error (_("No display number %d."), num);
+    {
+      if (ignore)
+        return;
+      error (_("No display number %d."), num);
+    }

  if (display_chain->number == num)
    {
@@ -1575,7 +1580,11 @@ delete_display (int num)
    for (d = display_chain;; d = d->next)
      {
       if (d->next == 0)
-         error (_("No display number %d."), num);
+          {
+            if (ignore)
+              return;
+            error (_("No display number %d."), num);
+          }
       if (d->next->number == num)
         {
           d1 = d->next;
@@ -1586,6 +1595,42 @@ delete_display (int num)
      }
 }

+static int
+set_int_from_str(char *str,
+                 int *result,
+                 char *end_delim)
+{
+  char *p;
+  int ret;
+  char *occurrence;
+
+  p = str;
+  ret = -1;
+
+  if (! str)
+    goto err;
+
+  while (p && *p && (' ' == *p || '\t' == *p))
+    p++;
+
+  while (p && *p && *p >= '0' && *p <= '9')
+    p++;
+
+  if (p && *p)
+    {
+      occurrence = strpbrk(p, end_delim);
+      if (! occurrence || occurrence != p)
+        goto err;
+    }
+
+  if (result)
+    *result = atoi(str);
+
+  ret = 0;
+ err:
+  return ret;
+}
+
 /* Delete some values from the auto-display chain.
   Specify the element numbers.  */

@@ -1595,6 +1640,8 @@ undisplay_command (char *args, int from_tty)
  char *p = args;
  char *p1;
  int num;
+  int lower, upper, i;
+  char *dash;

  if (args == 0)
    {
@@ -1604,26 +1651,47 @@ undisplay_command (char *args, int from_tty)
      return;
    }

-  while (*p)
+  dash = strchr(p, '-');
+  if (dash) /* remove all the display IDs within a range */
+    {
+      if (-1 == set_int_from_str(p, &lower, "- \t"))
+        error (_("Arguments must be display numbers."));
+
+      p = dash+1;
+      while (p && *p && (' ' == *p || '\t' == *p))
+        p++;
+
+      if (-1 == set_int_from_str(p, &upper, " \t"))
+        error (_("Arguments must be display numbers."));
+
+      for (i = lower; i <= upper; i++)
+        delete_display(i, 1);
+
+      dont_repeat ();
+    }
+  else
    {
-      p1 = p;
-      while (*p1 >= '0' && *p1 <= '9')
-       p1++;
-      if (*p1 && *p1 != ' ' && *p1 != '\t')
-       error (_("Arguments must be display numbers."));
+      while (*p)
+        {
+          p1 = p;
+          while (*p1 >= '0' && *p1 <= '9')
+            p1++;
+          if (*p1 && *p1 != ' ' && *p1 != '\t')
+            error (_("Arguments must be display numbers."));

-      num = atoi (p);
+          num = atoi (p);

-      delete_display (num);
+          delete_display (num);

-      p = p1;
-      while (*p == ' ' || *p == '\t')
-       p++;
+          p = p1;
+          while (*p == ' ' || *p == '\t')
+            p++;
+        }
+      dont_repeat ();
    }
-  dont_repeat ();
 }

-- 
"A fellow of infinite jest, of most excellent fancy."