diff options
Diffstat (limited to 'lisp/emacs-lisp/byte-opt.el')
| -rw-r--r-- | lisp/emacs-lisp/byte-opt.el | 33 |
1 files changed, 15 insertions, 18 deletions
diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el index a4254bfeca1..b07d61ae0d1 100644 --- a/lisp/emacs-lisp/byte-opt.el +++ b/lisp/emacs-lisp/byte-opt.el @@ -308,9 +308,9 @@ ;; ((lambda ...) ...) (defun byte-compile-unfold-lambda (form &optional name) ;; In lexical-binding mode, let and functions don't bind vars in the same way - ;; (let obey special-variable-p, but functions don't). This doesn't matter - ;; here, because function's behavior is underspecified so it can safely be - ;; turned into a `let', even though the reverse is not true. + ;; (let obey special-variable-p, but functions don't). But luckily, this + ;; doesn't matter here, because function's behavior is underspecified so it + ;; can safely be turned into a `let', even though the reverse is not true. (or name (setq name "anonymous lambda")) (let ((lambda (car form)) (values (cdr form))) @@ -378,9 +378,7 @@ ;;; implementing source-level optimizers -(defvar for-effect) - -(defun byte-optimize-form-code-walker (form for-effect-arg) +(defun byte-optimize-form-code-walker (form for-effect) ;; ;; For normal function calls, We can just mapcar the optimizer the cdr. But ;; we need to have special knowledge of the syntax of the special forms @@ -388,8 +386,7 @@ ;; the important aspect is that they are subrs that don't evaluate all of ;; their args.) ;; - (let ((for-effect for-effect-arg) - (fn (car-safe form)) + (let ((fn (car-safe form)) tmp) (cond ((not (consp form)) (if (not (and for-effect @@ -482,8 +479,8 @@ (byte-optimize-form (nth 2 form) for-effect) (byte-optimize-body (nthcdr 3 form) for-effect))))) - ((memq fn '(and or)) ; remember, and/or are control structures. - ;; take forms off the back until we can't any more. + ((memq fn '(and or)) ; Remember, and/or are control structures. + ;; Take forms off the back until we can't any more. ;; In the future it could conceivably be a problem that the ;; subexpressions of these forms are optimized in the reverse ;; order, but it's ok for now. @@ -498,7 +495,8 @@ (byte-compile-log " all subforms of %s called for effect; deleted" form)) (and backwards - (cons fn (nreverse (mapcar 'byte-optimize-form backwards))))) + (cons fn (nreverse (mapcar 'byte-optimize-form + backwards))))) (cons fn (mapcar 'byte-optimize-form (cdr form))))) ((eq fn 'interactive) @@ -537,8 +535,8 @@ ;; However, don't actually bother calling `ignore'. `(prog1 nil . ,(mapcar 'byte-optimize-form (cdr form)))) - ((eq fn 'internal-make-closure) - form) + ;; Neeeded as long as we run byte-optimize-form after cconv. + ((eq fn 'internal-make-closure) form) ((not (symbolp fn)) (debug) @@ -589,19 +587,18 @@ (setq list (cdr list))) constant)) -(defun byte-optimize-form (form &optional for-effect-arg) +(defun byte-optimize-form (form &optional for-effect) "The source-level pass of the optimizer." ;; ;; First, optimize all sub-forms of this one. - (setq form (byte-optimize-form-code-walker form for-effect-arg)) + (setq form (byte-optimize-form-code-walker form for-effect)) ;; ;; after optimizing all subforms, optimize this form until it doesn't ;; optimize any further. This means that some forms will be passed through ;; the optimizer many times, but that's necessary to make the for-effect ;; processing do as much as possible. ;; - (let ((for-effect for-effect-arg) - opt new) + (let (opt new) (if (and (consp form) (symbolp (car form)) (or (and for-effect @@ -618,7 +615,7 @@ (defun byte-optimize-body (forms all-for-effect) - ;; optimize the cdr of a progn or implicit progn; all forms is a list of + ;; Optimize the cdr of a progn or implicit progn; all forms is a list of ;; forms, all but the last of which are optimized with the assumption that ;; they are being called for effect. the last is for-effect as well if ;; all-for-effect is true. returns a new list of forms. |