Function: byte-compile-file
byte-compile-file is an autoloaded, interactive and byte-compiled
function defined in bytecomp.el.gz.
Signature
(byte-compile-file FILENAME)
Documentation
Compile a file of Lisp code named FILENAME into a file of byte code.
The output file's name is generated by passing FILENAME to the
function byte-compile-dest-file(var)/byte-compile-dest-file(fun) (which see).
The value is non-nil if there were no errors, nil if errors.
See also emacs-lisp-byte-compile-and-load.
Probably introduced at or before Emacs version 15.
Key Bindings
Source Code
;; Defined in /usr/src/emacs/lisp/emacs-lisp/bytecomp.el.gz
;;;###autoload
(defun byte-compile-file (filename &optional load)
"Compile a file of Lisp code named FILENAME into a file of byte code.
The output file's name is generated by passing FILENAME to the
function `byte-compile-dest-file' (which see).
The value is non-nil if there were no errors, nil if errors.
See also `emacs-lisp-byte-compile-and-load'."
(declare (advertised-calling-convention (filename) "28.1"))
;; (interactive "fByte compile file: \nP")
(interactive
(let ((file buffer-file-name)
(file-dir nil))
(and file
(derived-mode-p 'emacs-lisp-mode)
(setq file-dir (file-name-directory file)))
(list (read-file-name (if current-prefix-arg
"Byte compile and load file: "
"Byte compile file: ")
file-dir buffer-file-name nil)
current-prefix-arg)))
;; Expand now so we get the current buffer's defaults
(setq filename (expand-file-name filename))
;; If we're compiling a file that's in a buffer and is modified, offer
;; to save it first.
(or noninteractive
(let ((b (get-file-buffer (expand-file-name filename))))
(if (and b (buffer-modified-p b)
(y-or-n-p (format "Save buffer %s first? " (buffer-name b))))
(with-current-buffer b (save-buffer)))))
;; Force logging of the file name for each file compiled.
(setq byte-compile-last-logged-file nil)
(let ((byte-compile-current-file filename)
(byte-compile-current-group nil)
(set-auto-coding-for-load t)
(byte-compile--seen-defvars nil)
(byte-compile--known-dynamic-vars
(byte-compile--load-dynvars (getenv "EMACS_DYNVARS_FILE")))
target-file input-buffer output-buffer
byte-compile-dest-file byte-compiler-error-flag)
(setq target-file (byte-compile-dest-file filename))
(setq byte-compile-dest-file target-file)
(with-current-buffer
;; It would be cleaner to use a temp buffer, but if there was
;; an error, we leave this buffer around for diagnostics.
;; Its name is documented in the lispref.
(setq input-buffer (get-buffer-create
(concat " *Compiler Input*"
(if (zerop byte-compile-level) ""
(format "-%s" byte-compile-level)))))
(erase-buffer)
(setq buffer-file-coding-system nil)
;; Always compile an Emacs Lisp file as multibyte
;; unless the file itself forces unibyte with -*-coding: raw-text;-*-
(set-buffer-multibyte t)
(insert-file-contents filename)
;; Mimic the way after-insert-file-set-coding can make the
;; buffer unibyte when visiting this file.
(when (or (eq last-coding-system-used 'no-conversion)
(eq (coding-system-type last-coding-system-used) 5))
;; For coding systems no-conversion and raw-text...,
;; edit the buffer as unibyte.
(set-buffer-multibyte nil))
;; Run hooks including the uncompression hook.
;; If they change the file name, then change it for the output also.
(let ((buffer-file-name filename)
(dmm (default-value 'major-mode))
;; Ignore unsafe local variables.
;; We only care about a few of them for our purposes.
(enable-local-variables :safe)
(enable-local-eval nil))
(unwind-protect
(progn
(setq-default major-mode 'emacs-lisp-mode)
;; Arg of t means don't alter enable-local-variables.
(delay-mode-hooks (normal-mode t)))
(setq-default major-mode dmm))
;; There may be a file local variable setting (bug#10419).
(setq buffer-read-only nil
filename buffer-file-name))
;; Don't inherit lexical-binding from caller (bug#12938).
(unless (local-variable-p 'lexical-binding)
(setq-local lexical-binding nil))
;; Set the default directory, in case an eval-when-compile uses it.
(setq default-directory (file-name-directory filename)))
;; Check if the file's local variables explicitly specify not to
;; compile this file.
(if (with-current-buffer input-buffer no-byte-compile)
(progn
;; (message "%s not compiled because of `no-byte-compile: %s'"
;; (byte-compile-abbreviate-file filename)
;; (with-current-buffer input-buffer no-byte-compile))
(when (and target-file (file-exists-p target-file))
(message "%s deleted because of `no-byte-compile: %s'"
(byte-compile-abbreviate-file target-file)
(buffer-local-value 'no-byte-compile input-buffer))
(condition-case nil (delete-file target-file) (error nil)))
;; We successfully didn't compile this file.
'no-byte-compile)
(when byte-compile-verbose
(message "Compiling %s..." filename))
;; It is important that input-buffer not be current at this call,
;; so that the value of point set in input-buffer
;; within byte-compile-from-buffer lingers in that buffer.
(setq output-buffer
(save-current-buffer
(let ((byte-compile-level (1+ byte-compile-level)))
(byte-compile-from-buffer input-buffer))))
(if byte-compiler-error-flag
nil
(when byte-compile-verbose
(message "Compiling %s...done" filename))
(kill-buffer input-buffer)
(with-current-buffer output-buffer
(when (and target-file
(or (not byte-native-compiling)
(and byte-native-compiling byte+native-compile)))
(goto-char (point-max))
(insert "\n") ; aaah, unix.
(cond
((and (file-writable-p target-file)
;; We attempt to create a temporary file in the
;; target directory, so the target directory must be
;; writable.
(file-writable-p
(file-name-directory
;; Need to expand in case TARGET-FILE doesn't
;; include a directory (Bug#45287).
(expand-file-name target-file))))
;; We must disable any code conversion here.
(let* ((coding-system-for-write 'no-conversion)
;; Write to a tempfile so that if another Emacs
;; process is trying to load target-file (eg in a
;; parallel bootstrap), it does not risk getting a
;; half-finished file. (Bug#4196)
(tempfile
(make-temp-file (when (file-writable-p target-file)
(expand-file-name target-file))))
(default-modes (default-file-modes))
(temp-modes (logand default-modes #o600))
(desired-modes (logand default-modes #o666))
(kill-emacs-hook
(cons (lambda () (ignore-errors
(delete-file tempfile)))
kill-emacs-hook)))
(unless (= temp-modes desired-modes)
(set-file-modes tempfile desired-modes 'nofollow))
(write-region (point-min) (point-max) tempfile nil 1)
;; This has the intentional side effect that any
;; hard-links to target-file continue to
;; point to the old file (this makes it possible
;; for installed files to share disk space with
;; the build tree, without causing problems when
;; emacs-lisp files in the build tree are
;; recompiled). Previously this was accomplished by
;; deleting target-file before writing it.
(if byte-native-compiling
;; Defer elc final renaming.
(setf byte-to-native-output-file
(cons tempfile target-file))
(rename-file tempfile target-file t)))
(or noninteractive
byte-native-compiling
(message "Wrote %s" target-file)))
((file-writable-p target-file)
;; In case the target directory isn't writable (see e.g. Bug#44631),
;; try writing to the output file directly. We must disable any
;; code conversion here.
(let ((coding-system-for-write 'no-conversion))
(with-file-modes (logand (default-file-modes) #o666)
(write-region (point-min) (point-max) target-file nil 1)))
(or noninteractive (message "Wrote %s" target-file)))
(t
;; This is just to give a better error message than write-region
(let ((exists (file-exists-p target-file)))
(signal (if exists 'file-error 'file-missing)
(list "Opening output file"
(if exists
"Cannot overwrite file"
"Directory not writable or nonexistent")
target-file))))))
(kill-buffer (current-buffer)))
(if (and byte-compile-generate-call-tree
(or (eq t byte-compile-generate-call-tree)
(y-or-n-p (format "Report call tree for %s? "
filename))))
(save-excursion
(display-call-tree filename)))
(let ((gen-dynvars (getenv "EMACS_GENERATE_DYNVARS")))
(when (and gen-dynvars (not (equal gen-dynvars ""))
byte-compile--seen-defvars)
(let ((dynvar-file (concat target-file ".dynvars")))
(message "Generating %s" dynvar-file)
(with-temp-buffer
(dolist (var (delete-dups byte-compile--seen-defvars))
(insert (format "%S\n" (cons var filename))))
(write-region (point-min) (point-max) dynvar-file)))))
(if load
(load target-file))
t))))