gdb/breakpoint: display "N" on MI for disabled-by-condition locations

For breakpoint locations that are disabled because of an invalid
condition, CLI displays "N*" in the 'enabled' field, where '*' refers
to the footnote below the table:

  (*): Breakpoint condition is invalid at this location.

This is not necessary for MI, where we shall simply print "N" without
the footnote.

Update the document to mention the "N" value for the MI.  Also remove
the line about the 'enable' field, because there is no such field for
locations.

gdb/ChangeLog:
2021-04-21  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	* breakpoint.c (print_one_breakpoint_location): Display "N" for
	disabled-by-condition locations on MI-like output.
	(breakpoint_1): Do not display the disabled-by-condition footnote
	if the output is MI-like.

gdb/doc/ChangeLog:
2021-04-21  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	* gdb.texinfo (GDB/MI Breakpoint Information): Update the
	description for the 'enabled' field of breakpoint locations.

4 files changed, 28 insertions, 5 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 13d0bc2..a900a1d 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2021-04-21  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+	* breakpoint.c (print_one_breakpoint_location): Display "N" for
+	disabled-by-condition locations on MI-like output.
+	(breakpoint_1): Do not display the disabled-by-condition footnote
+	if the output is MI-like.
+
 2021-04-21  Frederic Cambus  <fred@statdns.com>
 
 	* syscalls/update-netbsd.sh: Fix script name display in usage, and
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 16cf797..0136019 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -6190,8 +6190,12 @@ print_one_breakpoint_location (struct breakpoint *b,
 
   /* 4 */
   annotate_field (3);
+  /* For locations that are disabled because of an invalid condition,
+     display "N*" on CLI, where "*" refers to a footnote below the
+     table.  For MI, simply display a "N" without a footnote.  */
+  const char *N = (uiout->is_mi_like_p ()) ? "N" : "N*";
   if (part_of_multiple)
-    uiout->field_string ("enabled", (loc->disabled_by_cond ? "N*"
+    uiout->field_string ("enabled", (loc->disabled_by_cond ? N
 				     : (loc->enabled ? "y" : "n")));
   else
     uiout->field_fmt ("enabled", "%c", bpenables[(int) b->enable_state]);
@@ -6716,7 +6720,7 @@ breakpoint_1 (const char *bp_num_list, bool show_internal,
       if (last_loc && !server_command)
 	set_next_address (last_loc->gdbarch, last_loc->address);
 
-      if (has_disabled_by_cond_location)
+      if (has_disabled_by_cond_location && !uiout->is_mi_like_p ())
 	uiout->message (_("(*): Breakpoint condition is invalid at this "
 			  "location.\n"));
     }
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 32801bf..08e3182 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2021-04-21  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+	* gdb.texinfo (GDB/MI Breakpoint Information): Update the
+	description for the 'enabled' field of breakpoint locations.
+
 2021-04-15  Tom Tromey  <tom@tromey.com>
 	    Andrew Burgess  <andrew.burgess@embecosm.com>
 
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index d13cbda..fd04aee 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -30154,9 +30154,16 @@ number of the parent breakpoint.  The second digit is the number of the
 location within that breakpoint.
 
 @item enabled
-This indicates whether the location is enabled, in which case the
-value is @samp{y}, or disabled, in which case the value is @samp{n}.
-Note that this is not the same as the field @code{enable}.
+There are three possible values, with the following meanings:
+@table @code
+@item y
+The location is enabled.
+@item n
+The location is disabled by the user.
+@item N
+The location is disabled because the breakpoint condition is invalid
+at this location.
+@end table
 
 @item addr
 The address of this location as an hexidecimal number.