bug#8647: since lexical merge, declare-function in subr.el no longer works

bug#8647: since lexical merge, declare-function in subr.el no longer works

[Glenn Morris]

Package: emacs
Version: 24.0.50
Severity: minor

Since the merge of the lexical branch, `declare-function' statements in
subr.el no longer have the desired effect. Eg compiling subr.el warns:

In end of data:
subr.el:4015:1:Warning: the function `w32-shell-dos-semantics' is not
  known to be defined.

despite the presence of

  (declare-function w32-shell-dos-semantics "w32-fns" nil)

in the file.

bug#8647: since lexical merge, declare-function in subr.el no longer works

[Glenn Morris]

Moving the definition to the end of subr.el does not work, because
subr.el is loaded uncompiled during bootstrap.

IMO, conceptually the right fix is for an element in
byte-compile-initial-macro-environment to _always_ take precedence
during compilation, even if the file being compiled contains a
redefinition.

*** lisp/emacs-lisp/bytecomp.el	2011-05-11 17:32:38 +0000
--- lisp/emacs-lisp/bytecomp.el	2011-05-11 17:57:12 +0000
***************
*** 2166,2172 ****
  	      byte-compile-output nil))))
  
  (defun byte-compile-preprocess (form &optional _for-effect)
!   (setq form (macroexpand-all form byte-compile-macro-environment))
    ;; FIXME: We should run byte-optimize-form here, but it currently does not
    ;; recurse through all the code, so we'd have to fix this first.
    ;; Maybe a good fix would be to merge byte-optimize-form into
--- 2174,2183 ----
  	      byte-compile-output nil))))
  
  (defun byte-compile-preprocess (form &optional _for-effect)
!   ;; b-c-initial-m-e should take precedence during compilation.  (Bug#8647)
!   (setq form (macroexpand-all form
! 			      (append byte-compile-initial-macro-environment
! 				      byte-compile-macro-environment)))
    ;; FIXME: We should run byte-optimize-form here, but it currently does not
    ;; recurse through all the code, so we'd have to fix this first.
    ;; Maybe a good fix would be to merge byte-optimize-form into

bug#8647: since lexical merge, declare-function in subr.el no longer works

[Stefan Monnier]

> IMO, conceptually the right fix is for an element in
> byte-compile-initial-macro-environment to _always_ take precedence
> during compilation, even if the file being compiled contains a
> redefinition.

Agreed.
Another way to get that result is to change the place where we add
elements to byte-compile-macro-environment (so as not to add it if it's
in byte-compile-initial-macro-environment), but the one you showed
seems fine.  Feel free to install it.


        Stefan

bug#8647: since lexical merge, declare-function in subr.el no longer works

[Glenn Morris]

Stefan Monnier wrote:

> Another way to get that result is to change the place where we add
> elements to byte-compile-macro-environment (so as not to add it if it's
> in byte-compile-initial-macro-environment),

I like that idea better. Done.