refactor(lib): backport static-{if,when,unless}

And deprecate our eval-{if,when}! macros.

lisp/doom-compat.el

@@ -175,5 +175,47 @@ The functions in the hook are called with one parameter -- the
              enable-local-variables)))
       (funcall fn variables dir-name))))
 
+;; Introduced in 30.1
+(unless (fboundp 'static-if)
+  (defmacro static-if (condition then-form &rest else-forms)
+    "A conditional compilation macro.
+Evaluate CONDITION at macro-expansion time.  If it is non-nil,
+expand the macro to THEN-FORM.  Otherwise expand it to ELSE-FORMS
+enclosed in a `progn' form.  ELSE-FORMS may be empty."
+    (declare (indent 2)
+             (debug (sexp sexp &rest sexp)))
+    (if (eval condition lexical-binding)
+        then-form
+      (cons 'progn else-forms))))
+
+
+;;; From Emacs 31+
+(unless (fboundp 'static-when)
+  (defmacro static-when (condition &rest body)
+    "A conditional compilation macro.
+Evaluate CONDITION at macro-expansion time.  If it is non-nil,
+expand the macro to evaluate all BODY forms sequentially and return
+the value of the last one, or nil if there are none."
+    (declare (indent 1) (debug t))
+    (if body
+        (if (eval condition lexical-binding)
+            (cons 'progn body)
+          nil)
+      (macroexp-warn-and-return (format-message "`static-when' with empty body")
+                                (list 'progn nil nil) '(empty-body static-when) t)))
+
+  (defmacro static-unless (condition &rest body)
+    "A conditional compilation macro.
+Evaluate CONDITION at macro-expansion time.  If it is nil,
+expand the macro to evaluate all BODY forms sequentially and return
+the value of the last one, or nil if there are none."
+    (declare (indent 1) (debug t))
+    (if body
+        (if (eval condition lexical-binding)
+            nil
+          (cons 'progn body))
+      (macroexp-warn-and-return (format-message "`static-unless' with empty body")
+                                (list 'progn nil nil) '(empty-body static-unless) t))))
+
 (provide 'doom-compat)
 ;;; doom-compat.el ends here

lisp/doom-lib.el

@@ -486,22 +486,8 @@ echo-area, but not to *Messages*."
                (save-silently t))
            (prog1 ,@forms (message ""))))))
 
-(defmacro eval-if! (cond then &rest body)
-  "Expands to THEN if COND is non-nil, to BODY otherwise.
-COND is checked at compile/expansion time, allowing BODY to be omitted entirely
-when the elisp is byte-compiled. Use this for forms that contain expensive
-macros that could safely be removed at compile time."
-  (declare (indent 2))
-  (if (eval cond)
-      then
-    (macroexp-progn body)))
-
-(defmacro eval-when! (cond &rest body)
-  "Expands to BODY if CONDITION is non-nil at compile/expansion time.
-See `eval-if!' for details on this macro's purpose."
-  (declare (indent 1))
-  (when (eval cond)
-    (macroexp-progn body)))
+(define-obsolete-function-alias 'eval-if! 'static-if "3.0.0")
+(define-obsolete-function-alias 'eval-when! 'static-when "3.0.0")
 
 (defmacro versionp! (v1 comp v2 &rest comps)
   "Perform compound version checks.

lisp/lib/files.el

@@ -596,7 +596,7 @@ which case it will save it without prompting."
 
 ;; Introduced in Emacs 29.
 ;;;###autoload
-(eval-when! (not (fboundp 'find-sibling-file))
+(static-unless (fboundp 'find-sibling-file)
   (defvar find-sibling-rules nil)
 
   (defun find-sibling-file (file)

modules/checkers/spell/config.el

@@ -70,7 +70,7 @@
 ;;
 ;;; Implementations
 
-(eval-if! (modulep! -flyspell)
+(static-if (modulep! -flyspell)
 
     (use-package! spell-fu
       :when (executable-find "aspell")