From 42c61fb1dbb005871c6d0896e6e85f29e0494f6d Mon Sep 17 00:00:00 2001
From: Yuan Fu <casouri@gmail.com>
Date: Fri, 4 Oct 2019 17:34:28 -0400
Subject: [PATCH] Add filter to regiter display in gdb-mi

lisp/progmode/gdb-mi.el (gdb-display-these-registers,
  gdb-registers-add-to-display, gdb-registers-remove-from-display): new
  (gdb-registers-handler-custom): add conditional check before adding
  each registers to table
---
 lisp/progmodes/gdb-mi.el | 64 +++++++++++++++++++++++++++++++++-------
 1 file changed, 53 insertions(+), 11 deletions(-)

diff --git a/lisp/progmodes/gdb-mi.el b/lisp/progmodes/gdb-mi.el
index 60852e4ad6..5b7e3321f3 100644
--- a/lisp/progmodes/gdb-mi.el
+++ b/lisp/progmodes/gdb-mi.el
@@ -200,6 +200,13 @@ gdb-error
 (defvar gdb-macro-info nil
   "Non-nil if GDB knows that the inferior includes preprocessor macro info.")
 (defvar gdb-register-names nil "List of register names.")
+(defvar gdb-display-these-registers t
+  "Registers that are displayed in register buffer.
+Can be a list, a function or t/nil.
+If a list, registers which names can be found in the list are displayed.
+If a function, it is passed with a register name and should
+return t to display and nil to not display.
+If t/nil, display all registers / none of the registers.")
 (defvar gdb-changed-registers nil
   "List of changed register numbers (strings).")
 (defvar gdb-buffer-fringe-width nil)
@@ -4238,6 +4245,35 @@ gdb-frame-locals-buffer
  'gdb-registers-mode
  'gdb-invalidate-registers)
 
+(defun gdb-registers-add-to-display (register)
+  "Add REGISTER to display in register buffer.
+REGISTER is a string representing the name of the register.
+By default the register buffer displays all the registers.
+REGISTER can also be 'all, which configures gdb to display all registers.
+Also see `gdb-registers-remove-from-display'. "
+  (interactive (list (completing-read "Register: " (append gdb-register-names
+                                                           '("all")))))
+  (if (equal register "all")
+      (setq gdb-display-these-registers t)
+    (if (listp gdb-display-these-registers)
+        (add-to-list 'gdb-display-these-registers register)
+      (setq gdb-display-these-registers (list register)))))
+
+(defun gdb-registers-remove-from-display (register)
+  "Remove REGISTER from display in register buffer.
+REGISTER is a string representing the name of the register.
+By default the register buffer displays all the registers.
+REGISTER can also be 'all, which configures gdb to hide all registers.
+Also see `gdb-registers-add-to-display'."
+  (interactive (list (completing-read "Register: " (append gdb-register-names
+                                                           '("all")))))
+  (if (equal register "all")
+      (setq gdb-display-these-registers nil)
+    (if (listp gdb-display-these-registers)
+        (setq gdb-display-these-registers
+              (remove register gdb-display-these-registers))
+      (user-error "gdb-display-these-registers is not a list, can’t remove anything from it"))))
+
 (defun gdb-registers-handler-custom ()
   (when gdb-register-names
     (let ((register-values
@@ -4248,17 +4284,23 @@ gdb-registers-handler-custom
                (value (bindat-get-field register 'value))
                (register-name (nth (string-to-number register-number)
                                    gdb-register-names)))
-          (gdb-table-add-row
-           table
-           (list
-            (propertize register-name
-                        'font-lock-face font-lock-variable-name-face)
-            (if (member register-number gdb-changed-registers)
-                (propertize value 'font-lock-face font-lock-warning-face)
-              value))
-           `(mouse-face highlight
-                        help-echo "mouse-2: edit value"
-                        gdb-register-name ,register-name))))
+          (when (cond ((and (listp gdb-display-these-registers)
+                            gdb-display-these-registers) ; not nil
+                       (member register-name gdb-display-these-registers))
+                      ((functionp gdb-display-these-registers)
+                       (funcall gdb-display-these-registers register-name))
+                      (t gdb-display-these-registers))
+            (gdb-table-add-row
+             table
+             (list
+              (propertize register-name
+                          'font-lock-face font-lock-variable-name-face)
+              (if (member register-number gdb-changed-registers)
+                  (propertize value 'font-lock-face font-lock-warning-face)
+                value))
+             `(mouse-face highlight
+                          help-echo "mouse-2: edit value"
+                          gdb-register-name ,register-name)))))
       (insert (gdb-table-string table " ")))
     (setq mode-name
           (gdb-current-context-mode-name "Registers"))))
-- 
2.23.0