Using the content of a dynamic variable in a macro

[Damien Cassou <damien@cassou.me>]

I tried to send the mail below to help-gnu-emacs@gnu.org (without being
subscribed) but it never reached the archive:
https://lists.gnu.org/archive/html/help-gnu-emacs/2023-02/threads.html.

Hi,

I'm wondering why the code below works but won't compile.

foo.el:
  (defvar foo-var '((message "hello world")))
  
  (defmacro foo-macro ()
    `(progn
       ,@foo-var))
  
  (defun foo-fun ()
    (foo-macro))


$ emacs --batch -l foo.el --eval '(foo-fun)'
hello world

$ emacs --batch --eval '(find-file "foo.el")' --eval '(emacs-lisp-byte-compile)'
In toplevel form:
foo.el:32:1: Error: Symbol’s value as variable is void: foo-var

Why isn't the compiler aware of the foo-var variable?

-- 
Damien Cassou

"Success is the ability to go from one failure to another without
losing enthusiasm." --Winston Churchill