[PATCH] Project out of sources compilation

[Ergus <spacibba@aol.com>]

[-- Attachment #1: Type: text/plain, Size: 6361 bytes --]

Hi:

Here I attach a very simple patch to allow project out of sources
compilation and project build detection.

So far I already implemented a very primitive backend [1] for project.el
using these features to detect and compile autotools and cmake projects;
and, at some point I will propose it for elpa.

But I need to work a bit more on it; and, of course, the functionalities
in the attached patch need to go to vanilla this way or some other
equivalent.

Best,
Ergus

[1] https://github.com/Ergus/project-multi-mode/blob/master/project-multi-mode.el



On Tue, Mar 19, 2024 at 07:36:35PM +0100, Ergus wrote:
>Hi Dmitry:
>
>Here I attach a very simple approach to add support for out of sources
>compilation in project.el
>
>This is just a POC, but to have some starting point to discuss.
>
>Best,
>Ergus
>
>
>
>On Sun, Mar 17, 2024 at 06:47:43PM +0100, Ergus wrote:
>>On Sun, Mar 17, 2024 at 12:36:44PM +0100, Augusto Stoffel wrote:
>>>On Sat, 16 Mar 2024 at 14:12, Ergus wrote:
>>>
>>>>5. Project local variables (a man can dream, a man can dream)
>>>>
>>>>There are some situations where we want to have variables shared among a
>>>>project. (i.e some output directory, logging option when executing,
>>>>flags, environment variables).
>>>>
>>>>At the moment these options work partially by using directory
>>>>variables. If we have the concept of a "project", maybe it is logical to
>>>>have some sort of project scope concept, specially for projects sharing
>>>>a common root.
>>>
>>>For Emacs variables, why you think dir-local variables only works
>>>“partially”?
>>>
>>>As to environment variables, they are generally assumed to be global in
>>>Emacs and it goes a bit against the grain to make them buffer-local /
>>>project dependent.  Nonetheless, there are packages for that (one is
>>>buffer-env, which I wrote) and they work fine (at least for me).
>>>
>>They work for one directory, but when the project includes multiple
>>roots (project-external-roots) the variables are somehow missing just
>>when jumping with xref to a definition.
>>
>>However, we can ignore this as I mentioned before.
>>
>>>>For example vs-code adds a subdirectory with project variables that the
>>>>user (but also any plugin) can refer to in the project's scope.
>>>
>>>Is this meant to store editor configuration or environment variables?  I
>>>guess turning VSCode configuration variables into Emacs alternatives
>>>would be tricky.
>>
>>No please. No interaction-importing from other editors will be
>>maintainable in the long path.
>>
>>>But if this is about env vars and the directory
>>>organization is sensible, then one could configure buffer-env to
>>>interoperate.
>>
>>This is it. The idea is to extend project.el in order to bring more
>>project-oriented features.
>>
>>Lets say:
>>
>>The user (or project.el backend) could specify the `build` directory and
>>the environment that needs to be set to execute the program from the
>>build or bin directory.
>>
>>So with a simple modification of dir-locals.el the user may be capable
>>to run M-x compile (or project-compile), M-x gud-gdb... or being more
>>ambitious M-x project-generate (to call autogen.sh and ./configure or
>>cmake depending of the project-backend)
>>
>>For sure we wont cover the 100% of the projects, but wuth automake and
>>autotools we will be very close (and in the future someone could add
>>other backends for it)
>>
>>
>>
>>
>>

>commit cfa10dfeac01ae25a7acd6857fae0b377b625779
>Author: Jimmy Aguilar Mena <kratsbinovish@gmail.com>
>Date:   Tue Mar 19 17:57:25 2024 +0100
>
>    Add basic project-build-dir implementation
>
>    This is just a dummy prototype to discuss about alternatives.
>
>diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
>index ac18aceadcf..0ca4ca85566 100644
>--- a/lisp/progmodes/project.el
>+++ b/lisp/progmodes/project.el
>@@ -51,6 +51,9 @@
> ;; files inside the root must not be considered a part of it).  It
> ;; should be consistent with `project-files'.
> ;;
>+;; `project-build-dir' can be overridden if the project backend has some
>+;; extra information about the project build directory.
>+;;
> ;; This list can change in future versions.
> ;;
> ;; Transient project:
>@@ -208,6 +211,12 @@ project-prompter
>   :group 'project
>   :version "30.1")
>
>+(defcustom project-build-dir nil
>+  "Build directory for current project."
>+  :type 'directory
>+  :safe t
>+  :version "30.1")
>+
> ;;;###autoload
> (defun project-current (&optional maybe-prompt directory)
>   "Return the project instance in DIRECTORY, defaulting to `default-directory'.
>@@ -289,8 +298,30 @@ project-external-roots
> headers search path, load path, class path, and so on."
>   nil)
>
>+(cl-defgeneric project-build-dir (_project)
>+  "Return build directory of the current PROJECT.
>+
>+This function is intended to be defined by the backend when possible.
>+Otherwise this returns nil and the `project-compile' command will be
>+called in the project-root.
>+If the user defines the directory-local variable `project-build-dir' it
>+will have precedence over the result of this function."
>+ nil)
>+
>+(defun project-get-build-dir (project)
>+  "Return build directory of the current PROJECT.
>+If the variable `project-build-dir' is defined, this function returns
>+it, otherwise it returns the project root.  If the defined path is
>+relative, this expands it relatively to the project's root"
>+  (let ((dir (or project-build-dir
>+                 (project-build-dir project)
>+                 (project-root project)))) ;; I assume project-root is absolute
>+    (if (file-name-absolute-p dir)
>+        dir
>+      (expand-file-name dir (project-root project)))))
>+
> (cl-defgeneric project-name (project)
>-  "A human-readable name for the project.
>+  "A human-readable name for the PROJECT.
> Nominally unique, but not enforced."
>   (file-name-nondirectory (directory-file-name (project-root project))))
>
>@@ -1391,7 +1422,7 @@ project-compile
>   "Run `compile' in the project root."
>   (declare (interactive-only compile))
>   (interactive)
>-  (let ((default-directory (project-root (project-current t)))
>+  (let ((default-directory (project-get-build-dir (project-current t)))
>         (compilation-buffer-name-function
>          (or project-compilation-buffer-name-function
>              compilation-buffer-name-function)))


[-- Attachment #2: project-compile.patch --]
[-- Type: text/plain, Size: 4160 bytes --]

diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index ac18aceadcf..5a4274d6f68 100644
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -51,6 +51,9 @@
 ;; files inside the root must not be considered a part of it).  It
 ;; should be consistent with `project-files'.
 ;;
+;; `project-build-dir' can be overridden if the project backend has some
+;; extra information about the project build directory.
+;;
 ;; This list can change in future versions.
 ;;
 ;; Transient project:
@@ -208,6 +211,22 @@ project-prompter
   :group 'project
   :version "30.1")
 
+(defcustom project-build-dir nil
+  "Build directory for current project.
+This is the custom that the user could specify in dir-locals to override
+the option specified by the project's backend."
+  :type 'directory
+  :safe t
+  :version "30.1")
+
+(defcustom project-compile-command nil
+  "Build command for current project.
+This is the custom that the user could specify in dir-locals to override
+the option specified by the project's backend."
+  :type 'directory
+  :safe t
+  :version "30.1")
+
 ;;;###autoload
 (defun project-current (&optional maybe-prompt directory)
   "Return the project instance in DIRECTORY, defaulting to `default-directory'.
@@ -289,8 +308,42 @@ project-external-roots
 headers search path, load path, class path, and so on."
   nil)
 
+(cl-defgeneric project-build-dir (_project)
+  "Return build directory of the current PROJECT.
+
+This function is intended to be defined by the backend when possible.
+Otherwise this returns nil and the `project-compile' command will be
+called in the project-root.
+If the user defines the directory-local variable `project-build-dir' it
+will have precedence over the result of this function."
+ nil)
+
+(defun project-get-build-dir (project)
+  "Return build directory of the current PROJECT.
+1. If the variable `project-build-dir' is defined, this function returns
+it.  2. Else if the function `project-build-dir' return non-nil.
+3. else it return the project-root.
+If the defined path is relative, this expands it relatively to the
+project's root."
+  (let ((dir (or project-build-dir           ;; variable for dir-locals or connection local vars
+                 (project-build-dir project) ;; backend function
+                 (project-root project))))   ;; I assume project-root is always absolute
+    (if (file-name-absolute-p dir)
+        dir
+      (expand-file-name dir (project-root project)))))
+
+(cl-defgeneric project-compile-command (_project)
+  "Return build command of the current PROJECT.
+
+This function is intended to be defined by the backend when possible.
+Otherwise this returns nil and the `project-compile' command will use
+the default `compile-command' value.  If the user defines the
+directory-local variable `project-build-command' it will have preference
+over this function and this will be never called."
+ nil)
+
 (cl-defgeneric project-name (project)
-  "A human-readable name for the project.
+  "A human-readable name for the PROJECT.
 Nominally unique, but not enforced."
   (file-name-nondirectory (directory-file-name (project-root project))))
 
@@ -1391,10 +1444,16 @@ project-compile
   "Run `compile' in the project root."
   (declare (interactive-only compile))
   (interactive)
-  (let ((default-directory (project-root (project-current t)))
-        (compilation-buffer-name-function
-         (or project-compilation-buffer-name-function
-             compilation-buffer-name-function)))
+  ;; I am wondering whenever we need to expand connection local
+  ;; variables at this point... maybe before or inside the let.
+  (let* ((project (project-current t))
+         (default-directory (project-get-build-dir project))
+         (compile-command (or project-compile-command
+                              (project-compile-command project)
+                              compile-command))
+         (compilation-buffer-name-function
+          (or project-compilation-buffer-name-function
+              compilation-buffer-name-function)))
     (call-interactively #'compile)))
 
 (defun project-recompile (&optional edit-command)