Conditional compilation to avoid "assignment to free variable"

Conditional compilation to avoid "assignment to free variable"

[Michael Hoffman]

I use the same .emacs file on multiple systems, and each have various 
packages installed. There are various forms in my .emacs to only 
interact with these packages if they are actually installed:

(when (locate-library "auctex")
   (load "auctex.el" nil t t)
   (setq TeX-auto-save t))

When I byte-compile, however, I get a warning like this:

emacs.el:320:9:Warning: assignment to free variable `TeX-auto-save'

Is there a way to skip over that form at compile time if the library 
cannot be found? I tried various permutations of using 
eval-when-compile, but I still get the warning.

I suppose the other solution is to wrap the setq in a boundp check, but 
this seems silly as the result of the boundp check will be the same as 
the result of locate-library.

In this case, I may be able to use a custom variable instead but I am 
looking for a more general solution.

Re: Conditional compilation to avoid "assignment to free variable"

[Joost Diepenmaat]

Michael Hoffman <4g4trz802@sneakemail.com> writes:

> I use the same .emacs file on multiple systems, and each have various
> packages installed. There are various forms in my .emacs to only
> interact with these packages if they are actually installed:
>
> (when (locate-library "auctex")
>   (load "auctex.el" nil t t)
>   (setq TeX-auto-save t))
>
> When I byte-compile, however, I get a warning like this:
>
> emacs.el:320:9:Warning: assignment to free variable `TeX-auto-save'
>
> Is there a way to skip over that form at compile time if the library
> cannot be found? I tried various permutations of using
> eval-when-compile, but I still get the warning.

Did you try the following?

(eval-when-compile
  (require 'my-macro-package))

(when (locate-library "auctex")
  (setq TeX-auto-save t))

HTH,
Joost.

-- 
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/

Re: Conditional compilation to avoid "assignment to free variable"

[Chetan]

Michael Hoffman <4g4trz802@sneakemail.com> writes:

> I use the same .emacs file on multiple systems, and each have various packages
> installed. There are various forms in my .emacs to only interact with these
> packages if they are actually installed:
>
> (when (locate-library "auctex")
>   (load "auctex.el" nil t t)
>   (setq TeX-auto-save t))
>
> When I byte-compile, however, I get a warning like this:
>
> emacs.el:320:9:Warning: assignment to free variable `TeX-auto-save'
>
> Is there a way to skip over that form at compile time if the library cannot be
> found? I tried various permutations of using eval-when-compile, but I still get
> the warning.
>
> I suppose the other solution is to wrap the setq in a boundp check, but this
> seems silly as the result of the boundp check will be the same as the result of
> locate-library.
>
> In this case, I may be able to use a custom variable instead but I am looking
> for a more general solution.
C-h f eval-when-compile

Re: Conditional compilation to avoid "assignment to free variable"

[Glenn Morris]

Michael Hoffman wrote:

> (when (locate-library "auctex")
>   (load "auctex.el" nil t t)
>   (setq TeX-auto-save t))
>
> When I byte-compile, however, I get a warning like this:
>
> emacs.el:320:9:Warning: assignment to free variable `TeX-auto-save'

Byte-compiling your .emacs is pretty much a waste of time (you've
probably already invested more time in it than it might ever save you).
Worry about warnings while doing so is really a waste of time; but the 
standard method of suppressing free variable warnings is

(defvar TeX-auto-save)
(setq TeX-auto-save t)

Re: Conditional compilation to avoid "assignment to free variable"

[Chetan]

Michael Hoffman <4g4trz802@sneakemail.com> writes:

> I use the same .emacs file on multiple systems, and each have various packages
> installed. There are various forms in my .emacs to only interact with these
> packages if they are actually installed:
>
> (when (locate-library "auctex")
>   (load "auctex.el" nil t t)
>   (setq TeX-auto-save t))
>
> When I byte-compile, however, I get a warning like this:
>
> emacs.el:320:9:Warning: assignment to free variable `TeX-auto-save'
>
> Is there a way to skip over that form at compile time if the library cannot be
> found? I tried various permutations of using eval-when-compile, but I still get
> the warning.
>
> I suppose the other solution is to wrap the setq in a boundp check, but this
> seems silly as the result of the boundp check will be the same as the result of
> locate-library.
>
> In this case, I may be able to use a custom variable instead but I am looking
> for a more general solution.
I don't have auctex installed, so I cannot check. However, I am
wondering, what is this variable used for? Does tex mode not use
auto-save-mode? Or if it is for saving file before running tex, does is
not use the compile infrastructure?

Chetan