bug#63896: [PATCH] Support annotating and sorting the project list during completion

[Spencer Baugh <sbaugh@janestreet.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Spencer Baugh <sbaugh@janestreet.com>
>> Cc: 63896@debbugs.gnu.org
>> Date: Fri, 16 Jun 2023 10:26:05 -0400
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> >
>> > If project.el wants to access data from an exited compilation, it
>> > needs to record that when the compilation exits (via the
>> > compilation-finish-functions hook, for example).  Calling
>> > format-mode-line will not help you, because if the process doesn't
>> > exist, its data cannot be accessed, and relying on what's displayed on
>> > the mode line is a bad idea: it could be outdated or even irrelevant.
>> > So please don't use such kludges, even though they might look
>> > convenient at first sight.
>> 
>> Would it be OK for compile.el to start storing this data in a variable?
>> The number of errors/warnings/infos is already stored; also storing the
>> exit status would probably be useful for all kinds of things.
>
> I think it would be okay to store data about the process in a
> buffer-local variable, but we need to make sure we store everything
> that might be useful.

Sure, how about this?

diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index ccf64fb670b..b1f6d146d01 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -171,6 +171,10 @@ compilation-error
 (defvar compilation-arguments nil
   "Arguments that were given to `compilation-start'.")
 
+(defvar compilation-exit-status nil
+  "The `process-exit-status' of the compilation process, or nil if not exited yet.")
+(defvar compilation-process-status nil
+  "The latest `process-status' of the compilation process.")
 (defvar compilation-num-errors-found 0)
 (defvar compilation-num-warnings-found 0)
 (defvar compilation-num-infos-found 0)
@@ -2457,6 +2461,7 @@ compilation-minor-mode
 
 (defun compilation-handle-exit (process-status exit-status msg)
   "Write MSG in the current buffer and hack its `mode-line-process'."
+  (setq-local compilation-exit-status exit-status)
   (let ((inhibit-read-only t)
 	(status (if compilation-exit-message-function
 		    (funcall compilation-exit-message-function
@@ -2500,6 +2505,7 @@ compilation-handle-exit
 ;; Called when compilation process changes state.
 (defun compilation-sentinel (proc msg)
   "Sentinel for compilation buffers."
+  (setq-local compilation-process-status (process-status proc))
   (if (memq (process-status proc) '(exit signal))
       (unwind-protect
           (let ((buffer (process-buffer proc)))