Fix byte compiler and native compiler warnings (#848)

* Fix compiler warning: fix defcustom type

* Instead of the 'list :type, the '(repeat string) :type
  does not generate the warning and provide a set of lines to enter/edit
  each string separately, providing buttons to add/delete entries.

* Fix compiler warnings on potentially undefined functions

* Both dap-launch and dap-tasks are required by dap-mode and cannot
  require dap-utils outside of functions because that would cause recursive
  loading.  However, the state of Emacs compiler AFAIK is not yet able to
  determine that the functions are present and generate a function "not known
  to be defined" warning in the byte compilation and native compilation, which
  is annoying.  The work around is to add a check that the required functions
  are bound.  They should always be bound, but just in case, the added code
  raises and error if they are not bound (instead of silently failing).

* Fix compiler warnings on potentially undefined functions - better

* Instead of checking that the functions are loaded, use the declare-function
  form, a better way that does not incur any overhead.

Author: pierre-rouleau

dap-launch.el

@@ -34,45 +34,47 @@ Yields nil if it cannot be found or there is no project."
 	(require 'dap-variables)
 	(dap-variables-find-vscode-config "launch.json" root)))
 
+
+(declare-function dap-utils-sanitize-json "dap-utils")
 (defun dap-launch-get-launch-json ()
   "Parse the project's launch.json as json data and return the result."
   (require 'dap-utils)
   (when-let ((launch-json (dap-launch-find-launch-json))
-			 (json-object-type 'plist)
-			 ;; Use 'vector instead of 'list. With 'list for array type,
-			 ;; json-encode-list interpreted a list with one plist element as
-			 ;; an alist. Using 'list, it turned the following value of
-			 ;; pathMappings:
-			 ;;
-			 ;;     "pathMappings": [
-			 ;;         {
-			 ;;             "localRoot": "${workspaceFolder}",
-			 ;;             "remoteRoot": "."
-			 ;;         }
-			 ;;     ]
-			 ;;
-			 ;; into:
-			 ;;
-			 ;;     ((:localRoot "${workspaceFolder}" :remoteRoot "."))
-			 ;;
-			 ;; and then into:
-			 ;;
-			 ;;     "pathMappings": {
-			 ;;         "localRoot": [
-			 ;;             "${workspaceFolder}",
-			 ;;             "remoteRoot",
-			 ;;             "."
-			 ;;         ]
-			 ;;     }
-			 (json-array-type 'vector))
-	(with-temp-buffer
-	  ;; NOTE: insert-file-contents does not move point
-	  (insert-file-contents launch-json)
-	  (dap-utils-sanitize-json)
-	  ;; dap-launch-remove-comments does move point
-	  (goto-char (point-min))
-
-	  (json-read))))
+	     (json-object-type 'plist)
+	     ;; Use 'vector instead of 'list. With 'list for array type,
+	     ;; json-encode-list interpreted a list with one plist element as
+	     ;; an alist. Using 'list, it turned the following value of
+	     ;; pathMappings:
+	     ;;
+	     ;;     "pathMappings": [
+	     ;;         {
+	     ;;             "localRoot": "${workspaceFolder}",
+	     ;;             "remoteRoot": "."
+	     ;;         }
+	     ;;     ]
+	     ;;
+	     ;; into:
+	     ;;
+	     ;;     ((:localRoot "${workspaceFolder}" :remoteRoot "."))
+	     ;;
+	     ;; and then into:
+	     ;;
+	     ;;     "pathMappings": {
+	     ;;         "localRoot": [
+	     ;;             "${workspaceFolder}",
+	     ;;             "remoteRoot",
+	     ;;             "."
+	     ;;         ]
+	     ;;     }
+	     (json-array-type 'vector))
+    (with-temp-buffer
+      ;; NOTE: insert-file-contents does not move point
+      (insert-file-contents launch-json)
+      (dap-utils-sanitize-json)
+      ;; dap-launch-remove-comments does move point
+      (goto-char (point-min))
+
+      (json-read))))
 
 (defun dap-launch-configuration-get-name (conf)
   "Return the name of launch configuration CONF."

dap-mode.el

@@ -120,7 +120,7 @@ also `dap--make-terminal-buffer'."
 (defcustom dap-output-buffer-filter '("stdout" "stderr")
   "If non-nil, a list of output types to display in the debug output buffer."
   :group 'dap-mode
-  :type 'list)
+  :type '(repeat string))
 
 (defcustom dap-label-output-buffer-category nil
   "If non-nil, content that is printed to the output buffer will be labelled

dap-tasks.el

@@ -34,6 +34,8 @@ Yields nil if it cannot be found or there is no project."
     (require 'dap-variables)
     (dap-variables-find-vscode-config "tasks.json" root)))
 
+
+(declare-function dap-utils-sanitize-json "dap-utils")
 (defun dap-tasks-get-tasks-json ()
   "Parse the project's launch.json as json data and return the result."
   (when-let ((tasks-json (dap-tasks-find-tasks-json))
@@ -74,6 +76,8 @@ Yields nil if it cannot be found or there is no project."
 
       (json-read))))
 
+(declare-function dap-utils-string-to-keyword "dap-utils")
+(declare-function dap-utils-get-os-key "dap-utils")
 (defun dap-tasks--get-key (key conf)
   "Given a KEY, attempt to get a value from a debug CONF.
 The order of presedence within vscode is: