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2462470b9e
* lisp/emacs-lisp/cl-macs.el (dolist, dotimes): Use the same strategy for lexical scoping as in subr.el's dolist and dotimes. * lisp/emacs-lisp/bytecomp.el (byte-compile-unfold-bcf): Silence compiler warning. * lisp/thingatpt.el (forward-whitespace): Trivial coding style fix. * lisp/subr.el (with-output-to-temp-buffer): Provide an edebug spec. * lisp/international/ccl.el (ccl-compile): Trivial simplification. * lisp/help-fns.el (help-do-arg-highlight): Silence compiler warning. * lisp/emacs-lisp/testcover.el (testcover-end): Remove spurious `printflag' argument. * lisp/emacs-lisp/byte-run.el (make-obsolete, make-obsolete-variable): Purecopy the whole obsolescence data.
706 lines
30 KiB
EmacsLisp
706 lines
30 KiB
EmacsLisp
;;; cconv.el --- Closure conversion for statically scoped Emacs lisp. -*- lexical-binding: t; coding: utf-8 -*-
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;; Copyright (C) 2011 Free Software Foundation, Inc.
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;; Author: Igor Kuzmin <kzuminig@iro.umontreal.ca>
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;; Maintainer: FSF
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;; Keywords: lisp
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;; Package: emacs
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software: you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation, either version 3 of the License, or
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;; (at your option) any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
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;;; Commentary:
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;; This takes a piece of Elisp code, and eliminates all free variables from
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;; lambda expressions. The user entry points are cconv-closure-convert and
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;; cconv-closure-convert-toplevel(for toplevel forms).
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;; All macros should be expanded beforehand.
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;;
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;; Here is a brief explanation how this code works.
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;; Firstly, we analyse the tree by calling cconv-analyse-form.
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;; This function finds all mutated variables, all functions that are suitable
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;; for lambda lifting and all variables captured by closure. It passes the tree
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;; once, returning a list of three lists.
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;;
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;; Then we calculate the intersection of first and third lists returned by
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;; cconv-analyse form to find all mutated variables that are captured by
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;; closure.
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;; Armed with this data, we call cconv-closure-convert-rec, that rewrites the
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;; tree recursivly, lifting lambdas where possible, building closures where it
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;; is needed and eliminating mutable variables used in closure.
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;;
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;; We do following replacements :
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;; (lambda (v1 ...) ... fv1 fv2 ...) => (lambda (v1 ... fv1 fv2 ) ... fv1 fv2 .)
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;; if the function is suitable for lambda lifting (if all calls are known)
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;;
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;; (lambda (v0 ...) ... fv0 .. fv1 ...) =>
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;; (internal-make-closure (v0 ...) (fv1 ...)
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;; ... (internal-get-closed-var 0) ... (internal-get-closed-var 1) ...)
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;;
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;; If the function has no free variables, we don't do anything.
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;;
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;; If a variable is mutated (updated by setq), and it is used in a closure
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;; we wrap its definition with list: (list val) and we also replace
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;; var => (car var) wherever this variable is used, and also
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;; (setq var value) => (setcar var value) where it is updated.
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;;
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;; If defun argument is closure mutable, we letbind it and wrap it's
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;; definition with list.
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;; (defun foo (... mutable-arg ...) ...) =>
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;; (defun foo (... m-arg ...) (let ((m-arg (list m-arg))) ...))
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;;
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;;; Code:
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;; TODO: (not just for cconv but also for the lexbind changes in general)
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;; - let (e)debug find the value of lexical variables from the stack.
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;; - make eval-region do the eval-sexp-add-defvars danse.
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;; - byte-optimize-form should be applied before cconv.
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;; OTOH, the warnings emitted by cconv-analyze need to come before optimize
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;; since afterwards they can because obnoxious (warnings about an "unused
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;; variable" should not be emitted when the variable use has simply been
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;; optimized away).
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;; - turn defun and defmacro into macros (and remove special handling of
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;; `declare' afterwards).
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;; - let macros specify that some let-bindings come from the same source,
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;; so the unused warning takes all uses into account.
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;; - let interactive specs return a function to build the args (to stash into
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;; command-history).
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;; - canonize code in macro-expand so we don't have to handle (let (var) body)
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;; and other oddities.
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;; - new byte codes for unwind-protect, catch, and condition-case so that
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;; closures aren't needed at all.
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;; - inline source code of different binding mode by first compiling it.
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;; - a reference to a var that is known statically to always hold a constant
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;; should be turned into a byte-constant rather than a byte-stack-ref.
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;; Hmm... right, that's called constant propagation and could be done here,
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;; but when that constant is a function, we have to be careful to make sure
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;; the bytecomp only compiles it once.
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;; - Since we know here when a variable is not mutated, we could pass that
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;; info to the byte-compiler, e.g. by using a new `immutable-let'.
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;; - add tail-calls to bytecode.c and the byte compiler.
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;; - call known non-escaping functions with `goto' rather than `call'.
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;; - optimize mapcar to a while loop.
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;; (defmacro dlet (binders &rest body)
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;; ;; Works in both lexical and non-lexical mode.
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;; `(progn
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;; ,@(mapcar (lambda (binder)
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;; `(defvar ,(if (consp binder) (car binder) binder)))
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;; binders)
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;; (let ,binders ,@body)))
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;; (defmacro llet (binders &rest body)
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;; ;; Only works in lexical-binding mode.
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;; `(funcall
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;; (lambda ,(mapcar (lambda (binder) (if (consp binder) (car binder) binder))
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;; binders)
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;; ,@body)
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;; ,@(mapcar (lambda (binder) (if (consp binder) (cadr binder)))
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;; binders)))
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(eval-when-compile (require 'cl))
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(defconst cconv-liftwhen 6
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"Try to do lambda lifting if the number of arguments + free variables
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is less than this number.")
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;; List of all the variables that are both captured by a closure
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;; and mutated. Each entry in the list takes the form
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;; (BINDER . PARENTFORM) where BINDER is the (VAR VAL) that introduces the
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;; variable (or is just (VAR) for variables not introduced by let).
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(defvar cconv-captured+mutated)
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;; List of candidates for lambda lifting.
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;; Each candidate has the form (BINDER . PARENTFORM). A candidate
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;; is a variable that is only passed to `funcall' or `apply'.
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(defvar cconv-lambda-candidates)
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;; Alist associating to each function body the list of its free variables.
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(defvar cconv-freevars-alist)
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;;;###autoload
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(defun cconv-closure-convert (form)
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"Main entry point for closure conversion.
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-- FORM is a piece of Elisp code after macroexpansion.
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-- TOPLEVEL(optional) is a boolean variable, true if we are at the root of AST
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Returns a form where all lambdas don't have any free variables."
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;; (message "Entering cconv-closure-convert...")
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(let ((cconv-freevars-alist '())
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(cconv-lambda-candidates '())
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(cconv-captured+mutated '()))
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;; Analyse form - fill these variables with new information.
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(cconv-analyse-form form '())
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(setq cconv-freevars-alist (nreverse cconv-freevars-alist))
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(cconv-convert form nil nil))) ; Env initially empty.
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(defconst cconv--dummy-var (make-symbol "ignored"))
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(defun cconv--set-diff (s1 s2)
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"Return elements of set S1 that are not in set S2."
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(let ((res '()))
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(dolist (x s1)
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(unless (memq x s2) (push x res)))
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(nreverse res)))
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(defun cconv--set-diff-map (s m)
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"Return elements of set S that are not in Dom(M)."
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(let ((res '()))
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(dolist (x s)
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(unless (assq x m) (push x res)))
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(nreverse res)))
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(defun cconv--map-diff (m1 m2)
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"Return the submap of map M1 that has Dom(M2) removed."
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(let ((res '()))
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(dolist (x m1)
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(unless (assq (car x) m2) (push x res)))
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(nreverse res)))
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(defun cconv--map-diff-elem (m x)
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"Return the map M minus any mapping for X."
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;; Here we assume that X appears at most once in M.
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(let* ((b (assq x m))
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(res (if b (remq b m) m)))
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(assert (null (assq x res))) ;; Check the assumption was warranted.
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res))
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(defun cconv--map-diff-set (m s)
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"Return the map M minus any mapping for elements of S."
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;; Here we assume that X appears at most once in M.
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(let ((res '()))
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(dolist (b m)
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(unless (memq (car b) s) (push b res)))
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(nreverse res)))
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(defun cconv--convert-function (args body env parentform)
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(assert (equal body (caar cconv-freevars-alist)))
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(let* ((fvs (cdr (pop cconv-freevars-alist)))
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(body-new '())
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(letbind '())
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(envector ())
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(i 0)
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(new-env ()))
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;; Build the "formal and actual envs" for the closure-converted function.
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(dolist (fv fvs)
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(let ((exp (or (cdr (assq fv env)) fv)))
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(pcase exp
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;; If `fv' is a variable that's wrapped in a cons-cell,
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;; we want to put the cons-cell itself in the closure,
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;; rather than just a copy of its current content.
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(`(car ,iexp . ,_)
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(push iexp envector)
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(push `(,fv . (car (internal-get-closed-var ,i))) new-env))
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(_
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(push exp envector)
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(push `(,fv . (internal-get-closed-var ,i)) new-env))))
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(setq i (1+ i)))
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(setq envector (nreverse envector))
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(setq new-env (nreverse new-env))
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(dolist (arg args)
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(if (not (member (cons (list arg) parentform) cconv-captured+mutated))
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(if (assq arg new-env) (push `(,arg) new-env))
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(push `(,arg . (car ,arg)) new-env)
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(push `(,arg (list ,arg)) letbind)))
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(setq body-new (mapcar (lambda (form)
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(cconv-convert form new-env nil))
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body))
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(when letbind
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(let ((special-forms '()))
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;; Keep special forms at the beginning of the body.
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(while (or (stringp (car body-new)) ;docstring.
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(memq (car-safe (car body-new)) '(interactive declare)))
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(push (pop body-new) special-forms))
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(setq body-new
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`(,@(nreverse special-forms) (let ,letbind . ,body-new)))))
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(cond
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((null envector) ;if no freevars - do nothing
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`(function (lambda ,args . ,body-new)))
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(t
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`(internal-make-closure
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,args ,envector . ,body-new)))))
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(defun cconv-convert (form env extend)
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;; This function actually rewrites the tree.
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"Return FORM with all its lambdas changed so they are closed.
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ENV is a lexical environment mapping variables to the expression
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used to get its value. This is used for variables that are copied into
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closures, moved into cons cells, ...
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ENV is a list where each entry takes the shape either:
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(VAR . (car EXP)): VAR has been moved into the car of a cons-cell, and EXP
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is an expression that evaluates to this cons-cell.
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(VAR . (internal-get-closed-var N)): VAR has been copied into the closure
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environment's Nth slot.
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(VAR . (apply-partially F ARG1 ARG2 ..)): VAR has been λ-lifted and takes
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additional arguments ARGs.
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EXTEND is a list of variables which might need to be accessed even from places
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where they are shadowed, because some part of ENV causes them to be used at
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places where they originally did not directly appear."
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(assert (not (delq nil (mapcar (lambda (mapping)
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(if (eq (cadr mapping) 'apply-partially)
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(cconv--set-diff (cdr (cddr mapping))
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extend)))
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env))))
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;; What's the difference between fvrs and envs?
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;; Suppose that we have the code
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;; (lambda (..) fvr (let ((fvr 1)) (+ fvr 1)))
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;; only the first occurrence of fvr should be replaced by
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;; (aref env ...).
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;; So initially envs and fvrs are the same thing, but when we descend to
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;; the 'let, we delete fvr from fvrs. Why we don't delete fvr from envs?
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;; Because in envs the order of variables is important. We use this list
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;; to find the number of a specific variable in the environment vector,
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;; so we never touch it(unless we enter to the other closure).
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;;(if (listp form) (print (car form)) form)
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(pcase form
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(`(,(and letsym (or `let* `let)) ,binders . ,body)
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; let and let* special forms
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(let ((binders-new '())
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(new-env env)
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(new-extend extend))
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(dolist (binder binders)
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(let* ((value nil)
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(var (if (not (consp binder))
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(prog1 binder (setq binder (list binder)))
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(setq value (cadr binder))
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(car binder)))
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(new-val
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(cond
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;; Check if var is a candidate for lambda lifting.
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((and (member (cons binder form) cconv-lambda-candidates)
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(progn
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(assert (and (eq (car value) 'function)
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(eq (car (cadr value)) 'lambda)))
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(assert (equal (cddr (cadr value))
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(caar cconv-freevars-alist)))
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;; Peek at the freevars to decide whether to λ-lift.
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(let* ((fvs (cdr (car cconv-freevars-alist)))
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(fun (cadr value))
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(funargs (cadr fun))
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(funcvars (append fvs funargs)))
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; lambda lifting condition
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(and fvs (>= cconv-liftwhen (length funcvars))))))
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; Lift.
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(let* ((fvs (cdr (pop cconv-freevars-alist)))
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(fun (cadr value))
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(funargs (cadr fun))
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(funcvars (append fvs funargs))
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(funcbody (cddr fun))
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(funcbody-env ()))
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(push `(,var . (apply-partially ,var . ,fvs)) new-env)
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(dolist (fv fvs)
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(pushnew fv new-extend)
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(if (and (eq 'car (car-safe (cdr (assq fv env))))
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(not (memq fv funargs)))
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(push `(,fv . (car ,fv)) funcbody-env)))
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`(function (lambda ,funcvars .
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,(mapcar (lambda (form)
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(cconv-convert
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form funcbody-env nil))
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funcbody)))))
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;; Check if it needs to be turned into a "ref-cell".
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((member (cons binder form) cconv-captured+mutated)
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;; Declared variable is mutated and captured.
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(push `(,var . (car ,var)) new-env)
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`(list ,(cconv-convert value env extend)))
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;; Normal default case.
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(t
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(if (assq var new-env) (push `(,var) new-env))
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(cconv-convert value env extend)))))
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;; The piece of code below letbinds free variables of a λ-lifted
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;; function if they are redefined in this let, example:
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;; (let* ((fun (lambda (x) (+ x y))) (y 1)) (funcall fun 1))
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;; Here we can not pass y as parameter because it is redefined.
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;; So we add a (closed-y y) declaration. We do that even if the
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;; function is not used inside this let(*). The reason why we
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;; ignore this case is that we can't "look forward" to see if the
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;; function is called there or not. To treat this case better we'd
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;; need to traverse the tree one more time to collect this data, and
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;; I think that it's not worth it.
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(when (memq var new-extend)
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(let ((closedsym
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(make-symbol (concat "closed-" (symbol-name var)))))
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(setq new-env
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(mapcar (lambda (mapping)
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(if (not (eq (cadr mapping) 'apply-partially))
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mapping
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(assert (eq (car mapping) (nth 2 mapping)))
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(list* (car mapping)
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'apply-partially
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(car mapping)
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(mapcar (lambda (arg)
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(if (eq var arg)
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closedsym arg))
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(nthcdr 3 mapping)))))
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new-env))
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(setq new-extend (remq var new-extend))
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(push closedsym new-extend)
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(push `(,closedsym ,var) binders-new)))
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;; We push the element after redefined free variables are
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;; processed. This is important to avoid the bug when free
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;; variable and the function have the same name.
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(push (list var new-val) binders-new)
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(when (eq letsym 'let*)
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(setq env new-env)
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(setq extend new-extend))
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)) ; end of dolist over binders
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`(,letsym ,(nreverse binders-new)
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. ,(mapcar (lambda (form)
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(cconv-convert
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form new-env new-extend))
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body))))
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;end of let let* forms
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; first element is lambda expression
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(`(,(and `(lambda . ,_) fun) . ,args)
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;; FIXME: it's silly to create a closure just to call it.
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;; Running byte-optimize-form earlier will resolve this.
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`(funcall
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,(cconv-convert `(function ,fun) env extend)
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,@(mapcar (lambda (form)
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(cconv-convert form env extend))
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args)))
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(`(cond . ,cond-forms) ; cond special form
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`(cond . ,(mapcar (lambda (branch)
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(mapcar (lambda (form)
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(cconv-convert form env extend))
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branch))
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cond-forms)))
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(`(function (lambda ,args . ,body) . ,_)
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(cconv--convert-function args body env form))
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(`(internal-make-closure . ,_)
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(byte-compile-report-error
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"Internal error in compiler: cconv called twice?"))
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(`(quote . ,_) form)
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(`(function . ,_) form)
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;defconst, defvar
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(`(,(and sym (or `defconst `defvar)) ,definedsymbol . ,forms)
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`(,sym ,definedsymbol
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. ,(mapcar (lambda (form) (cconv-convert form env extend))
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forms)))
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;defun, defmacro
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(`(,(and sym (or `defun `defmacro))
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,func ,args . ,body)
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(assert (equal body (caar cconv-freevars-alist)))
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(assert (null (cdar cconv-freevars-alist)))
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(let ((new (cconv--convert-function args body env form)))
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(pcase new
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(`(function (lambda ,newargs . ,new-body))
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(assert (equal args newargs))
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`(,sym ,func ,args . ,new-body))
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(t (byte-compile-report-error
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(format "Internal error in cconv of (%s %s ...)" sym func))))))
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;condition-case
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(`(condition-case ,var ,protected-form . ,handlers)
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(let ((newform (cconv--convert-function
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() (list protected-form) env form)))
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`(condition-case :fun-body ,newform
|
|
,@(mapcar (lambda (handler)
|
|
(list (car handler)
|
|
(cconv--convert-function
|
|
(list (or var cconv--dummy-var))
|
|
(cdr handler) env form)))
|
|
handlers))))
|
|
|
|
(`(,(and head (or `catch `unwind-protect)) ,form . ,body)
|
|
`(,head ,(cconv-convert form env extend)
|
|
:fun-body ,(cconv--convert-function () body env form)))
|
|
|
|
(`(track-mouse . ,body)
|
|
`(track-mouse
|
|
:fun-body ,(cconv--convert-function () body env form)))
|
|
|
|
(`(setq . ,forms) ; setq special form
|
|
(let ((prognlist ()))
|
|
(while forms
|
|
(let* ((sym (pop forms))
|
|
(sym-new (or (cdr (assq sym env)) sym))
|
|
(value (cconv-convert (pop forms) env extend)))
|
|
(push (pcase sym-new
|
|
((pred symbolp) `(setq ,sym-new ,value))
|
|
(`(car ,iexp) `(setcar ,iexp ,value))
|
|
;; This "should never happen", but for variables which are
|
|
;; mutated+captured+unused, we may end up trying to `setq'
|
|
;; on a closed-over variable, so just drop the setq.
|
|
(_ ;; (byte-compile-report-error
|
|
;; (format "Internal error in cconv of (setq %s ..)"
|
|
;; sym-new))
|
|
value))
|
|
prognlist)))
|
|
(if (cdr prognlist)
|
|
`(progn . ,(nreverse prognlist))
|
|
(car prognlist))))
|
|
|
|
(`(,(and (or `funcall `apply) callsym) ,fun . ,args)
|
|
;; These are not special forms but we treat them separately for the needs
|
|
;; of lambda lifting.
|
|
(let ((mapping (cdr (assq fun env))))
|
|
(pcase mapping
|
|
(`(apply-partially ,_ . ,(and fvs `(,_ . ,_)))
|
|
(assert (eq (cadr mapping) fun))
|
|
`(,callsym ,fun
|
|
,@(mapcar (lambda (fv)
|
|
(let ((exp (or (cdr (assq fv env)) fv)))
|
|
(pcase exp
|
|
(`(car ,iexp . ,_) iexp)
|
|
(_ exp))))
|
|
fvs)
|
|
,@(mapcar (lambda (arg)
|
|
(cconv-convert arg env extend))
|
|
args)))
|
|
(_ `(,callsym ,@(mapcar (lambda (arg)
|
|
(cconv-convert arg env extend))
|
|
(cons fun args)))))))
|
|
|
|
(`(interactive . ,forms)
|
|
`(interactive . ,(mapcar (lambda (form)
|
|
(cconv-convert form nil nil))
|
|
forms)))
|
|
|
|
(`(declare . ,_) form) ;The args don't contain code.
|
|
|
|
(`(,func . ,forms)
|
|
;; First element is function or whatever function-like forms are: or, and,
|
|
;; if, progn, prog1, prog2, while, until
|
|
`(,func . ,(mapcar (lambda (form)
|
|
(cconv-convert form env extend))
|
|
forms)))
|
|
|
|
(_ (or (cdr (assq form env)) form))))
|
|
|
|
(unless (fboundp 'byte-compile-not-lexical-var-p)
|
|
;; Only used to test the code in non-lexbind Emacs.
|
|
(defalias 'byte-compile-not-lexical-var-p 'boundp))
|
|
|
|
(defun cconv--analyse-use (vardata form varkind)
|
|
"Analyse the use of a variable.
|
|
VARDATA should be (BINDER READ MUTATED CAPTURED CALLED).
|
|
VARKIND is the name of the kind of variable.
|
|
FORM is the parent form that binds this var."
|
|
;; use = `(,binder ,read ,mutated ,captured ,called)
|
|
(pcase vardata
|
|
(`(,_ nil nil nil nil) nil)
|
|
(`((,(and (pred (lambda (var) (eq ?_ (aref (symbol-name var) 0)))) var) . ,_)
|
|
,_ ,_ ,_ ,_)
|
|
(byte-compile-log-warning
|
|
(format "%s `%S' not left unused" varkind var))))
|
|
(pcase vardata
|
|
(`((,var . ,_) nil ,_ ,_ nil)
|
|
;; FIXME: This gives warnings in the wrong order, with imprecise line
|
|
;; numbers and without function name info.
|
|
(unless (or ;; Uninterned symbols typically come from macro-expansion, so
|
|
;; it is often non-trivial for the programmer to avoid such
|
|
;; unused vars.
|
|
(not (intern-soft var))
|
|
(eq ?_ (aref (symbol-name var) 0))
|
|
;; As a special exception, ignore "ignore".
|
|
(eq var 'ignored))
|
|
(byte-compile-log-warning (format "Unused lexical %s `%S'"
|
|
varkind var))))
|
|
;; If it's unused, there's no point converting it into a cons-cell, even if
|
|
;; it's captured and mutated.
|
|
(`(,binder ,_ t t ,_)
|
|
(push (cons binder form) cconv-captured+mutated))
|
|
(`(,(and binder `(,_ (function (lambda . ,_)))) nil nil nil t)
|
|
(push (cons binder form) cconv-lambda-candidates))))
|
|
|
|
(defun cconv--analyse-function (args body env parentform)
|
|
(let* ((newvars nil)
|
|
(freevars (list body))
|
|
;; We analyze the body within a new environment where all uses are
|
|
;; nil, so we can distinguish uses within that function from uses
|
|
;; outside of it.
|
|
(envcopy
|
|
(mapcar (lambda (vdata) (list (car vdata) nil nil nil nil)) env))
|
|
(newenv envcopy))
|
|
;; Push it before recursing, so cconv-freevars-alist contains entries in
|
|
;; the order they'll be used by closure-convert-rec.
|
|
(push freevars cconv-freevars-alist)
|
|
(dolist (arg args)
|
|
(cond
|
|
((byte-compile-not-lexical-var-p arg)
|
|
(byte-compile-log-warning
|
|
(format "Argument %S is not a lexical variable" arg)))
|
|
((eq ?& (aref (symbol-name arg) 0)) nil) ;Ignore &rest, &optional, ...
|
|
(t (let ((varstruct (list arg nil nil nil nil)))
|
|
(push (cons (list arg) (cdr varstruct)) newvars)
|
|
(push varstruct newenv)))))
|
|
(dolist (form body) ;Analyse body forms.
|
|
(cconv-analyse-form form newenv))
|
|
;; Summarize resulting data about arguments.
|
|
(dolist (vardata newvars)
|
|
(cconv--analyse-use vardata parentform "argument"))
|
|
;; Transfer uses collected in `envcopy' (via `newenv') back to `env';
|
|
;; and compute free variables.
|
|
(while env
|
|
(assert (and envcopy (eq (caar env) (caar envcopy))))
|
|
(let ((free nil)
|
|
(x (cdr (car env)))
|
|
(y (cdr (car envcopy))))
|
|
(while x
|
|
(when (car y) (setcar x t) (setq free t))
|
|
(setq x (cdr x) y (cdr y)))
|
|
(when free
|
|
(push (caar env) (cdr freevars))
|
|
(setf (nth 3 (car env)) t))
|
|
(setq env (cdr env) envcopy (cdr envcopy))))))
|
|
|
|
(defun cconv-analyse-form (form env)
|
|
"Find mutated variables and variables captured by closure.
|
|
Analyse lambdas if they are suitable for lambda lifting.
|
|
- FORM is a piece of Elisp code after macroexpansion.
|
|
- ENV is an alist mapping each enclosing lexical variable to its info.
|
|
I.e. each element has the form (VAR . (READ MUTATED CAPTURED CALLED)).
|
|
This function does not return anything but instead fills the
|
|
`cconv-captured+mutated' and `cconv-lambda-candidates' variables
|
|
and updates the data stored in ENV."
|
|
(pcase form
|
|
; let special form
|
|
(`(,(and (or `let* `let) letsym) ,binders . ,body-forms)
|
|
|
|
(let ((orig-env env)
|
|
(newvars nil)
|
|
(var nil)
|
|
(value nil))
|
|
(dolist (binder binders)
|
|
(if (not (consp binder))
|
|
(progn
|
|
(setq var binder) ; treat the form (let (x) ...) well
|
|
(setq binder (list binder))
|
|
(setq value nil))
|
|
(setq var (car binder))
|
|
(setq value (cadr binder))
|
|
|
|
(cconv-analyse-form value (if (eq letsym 'let*) env orig-env)))
|
|
|
|
(unless (byte-compile-not-lexical-var-p var)
|
|
(let ((varstruct (list var nil nil nil nil)))
|
|
(push (cons binder (cdr varstruct)) newvars)
|
|
(push varstruct env))))
|
|
|
|
(dolist (form body-forms) ; Analyse body forms.
|
|
(cconv-analyse-form form env))
|
|
|
|
(dolist (vardata newvars)
|
|
(cconv--analyse-use vardata form "variable"))))
|
|
|
|
; defun special form
|
|
(`(,(or `defun `defmacro) ,func ,vrs . ,body-forms)
|
|
(when env
|
|
(byte-compile-log-warning
|
|
(format "Function %S will ignore its context %S"
|
|
func (mapcar #'car env))
|
|
t :warning))
|
|
(cconv--analyse-function vrs body-forms nil form))
|
|
|
|
(`(function (lambda ,vrs . ,body-forms))
|
|
(cconv--analyse-function vrs body-forms env form))
|
|
|
|
(`(setq . ,forms)
|
|
;; If a local variable (member of env) is modified by setq then
|
|
;; it is a mutated variable.
|
|
(while forms
|
|
(let ((v (assq (car forms) env))) ; v = non nil if visible
|
|
(when v (setf (nth 2 v) t)))
|
|
(cconv-analyse-form (cadr forms) env)
|
|
(setq forms (cddr forms))))
|
|
|
|
(`((lambda . ,_) . ,_) ; first element is lambda expression
|
|
(dolist (exp `((function ,(car form)) . ,(cdr form)))
|
|
(cconv-analyse-form exp env)))
|
|
|
|
(`(cond . ,cond-forms) ; cond special form
|
|
(dolist (forms cond-forms)
|
|
(dolist (form forms) (cconv-analyse-form form env))))
|
|
|
|
(`(quote . ,_) nil) ; quote form
|
|
(`(function . ,_) nil) ; same as quote
|
|
|
|
(`(condition-case ,var ,protected-form . ,handlers)
|
|
;; FIXME: The bytecode for condition-case forces us to wrap the
|
|
;; form and handlers in closures (for handlers, it's understandable
|
|
;; but not for the protected form).
|
|
(cconv--analyse-function () (list protected-form) env form)
|
|
(dolist (handler handlers)
|
|
(cconv--analyse-function (if var (list var)) (cdr handler) env form)))
|
|
|
|
;; FIXME: The bytecode for catch forces us to wrap the body.
|
|
(`(,(or `catch `unwind-protect) ,form . ,body)
|
|
(cconv-analyse-form form env)
|
|
(cconv--analyse-function () body env form))
|
|
|
|
;; FIXME: The lack of bytecode for track-mouse forces us to wrap the body.
|
|
;; `track-mouse' really should be made into a macro.
|
|
(`(track-mouse . ,body)
|
|
(cconv--analyse-function () body env form))
|
|
|
|
(`(,(or `defconst `defvar) ,var ,value . ,_)
|
|
(push var byte-compile-bound-variables)
|
|
(cconv-analyse-form value env))
|
|
|
|
(`(,(or `funcall `apply) ,fun . ,args)
|
|
;; Here we ignore fun because funcall and apply are the only two
|
|
;; functions where we can pass a candidate for lambda lifting as
|
|
;; argument. So, if we see fun elsewhere, we'll delete it from
|
|
;; lambda candidate list.
|
|
(let ((fdata (and (symbolp fun) (assq fun env))))
|
|
(if fdata
|
|
(setf (nth 4 fdata) t)
|
|
(cconv-analyse-form fun env)))
|
|
(dolist (form args) (cconv-analyse-form form env)))
|
|
|
|
(`(interactive . ,forms)
|
|
;; These appear within the function body but they don't have access
|
|
;; to the function's arguments.
|
|
;; We could extend this to allow interactive specs to refer to
|
|
;; variables in the function's enclosing environment, but it doesn't
|
|
;; seem worth the trouble.
|
|
(dolist (form forms) (cconv-analyse-form form nil)))
|
|
|
|
(`(declare . ,_) nil) ;The args don't contain code.
|
|
|
|
(`(,_ . ,body-forms) ; First element is a function or whatever.
|
|
(dolist (form body-forms) (cconv-analyse-form form env)))
|
|
|
|
((pred symbolp)
|
|
(let ((dv (assq form env))) ; dv = declared and visible
|
|
(when dv
|
|
(setf (nth 1 dv) t))))))
|
|
|
|
(provide 'cconv)
|
|
;;; cconv.el ends here
|