diff options
Diffstat (limited to 'lisp/emacs-lisp/bytecomp.el')
| -rw-r--r-- | lisp/emacs-lisp/bytecomp.el | 376 |
1 files changed, 309 insertions, 67 deletions
diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el index 5df1205869c..384a357ee51 100644 --- a/lisp/emacs-lisp/bytecomp.el +++ b/lisp/emacs-lisp/bytecomp.el @@ -295,7 +295,8 @@ The information is logged to `byte-compile-log-buffer'." '(redefine callargs free-vars unresolved obsolete noruntime interactive-only make-local mapcar constants suspicious lexical lexical-dynamic - docstrings docstrings-non-ascii-quotes not-unused) + docstrings docstrings-non-ascii-quotes not-unused + empty-body) "The list of warning types used when `byte-compile-warnings' is t.") (defcustom byte-compile-warnings t "List of warnings that the byte-compiler should issue (t for almost all). @@ -316,7 +317,9 @@ Elements of the list may be: lexical-dynamic lexically bound variable declared dynamic elsewhere make-local calls to `make-variable-buffer-local' that may be incorrect. - mapcar mapcar called for effect. + ignored-return-value + function called without using the return value where this + is likely to be a mistake not-unused warning about using variables with symbol names starting with _. constants let-binding of, or assignment to, constants/nonvariables. docstrings docstrings that are too wide (longer than @@ -326,9 +329,12 @@ Elements of the list may be: docstrings-non-ascii-quotes docstrings that have non-ASCII quotes. This depends on the `docstrings' warning type. suspicious constructs that usually don't do what the coder wanted. + empty-body body argument to a special form or macro is empty. + mutate-constant + code that mutates program constants such as quoted lists If the list begins with `not', then the remaining elements specify warnings to -suppress. For example, (not mapcar) will suppress warnings about mapcar. +suppress. For example, (not free-vars) will suppress the `free-vars' warning. The t value means \"all non experimental warning types\", and excludes the types in `byte-compile--emacs-build-warning-types'. @@ -493,6 +499,42 @@ Return the compile-time value of FORM." (cdr form))) (funcall non-toplevel-case form))) + +(defvar bytecomp--copy-tree-seen) + +(defun bytecomp--copy-tree-1 (tree) + ;; TREE must be a cons. + (or (gethash tree bytecomp--copy-tree-seen) + (let* ((next (cdr tree)) + (result (cons nil next)) + (copy result)) + (while (progn + (puthash tree copy bytecomp--copy-tree-seen) + (let ((a (car tree))) + (setcar copy (if (consp a) + (bytecomp--copy-tree-1 a) + a))) + (and (consp next) + (let ((tail (gethash next bytecomp--copy-tree-seen))) + (if tail + (progn (setcdr copy tail) + nil) + (setq tree next) + (setq next (cdr next)) + (let ((prev copy)) + (setq copy (cons nil next)) + (setcdr prev copy) + t)))))) + result))) + +(defun bytecomp--copy-tree (tree) + "Make a copy of TREE, preserving any circular structure therein. +Only conses are traversed and duplicated, not arrays or any other structure." + (if (consp tree) + (let ((bytecomp--copy-tree-seen (make-hash-table :test #'eq))) + (bytecomp--copy-tree-1 tree)) + tree)) + (defconst byte-compile-initial-macro-environment `( ;; (byte-compiler-options . (lambda (&rest forms) @@ -528,11 +570,12 @@ Return the compile-time value of FORM." ;; or byte-compile-file-form. (let* ((print-symbols-bare t) ; Possibly redundant binding. (expanded - (byte-run-strip-symbol-positions - (macroexpand--all-toplevel - form - macroexpand-all-environment)))) - (eval expanded lexical-binding) + (macroexpand--all-toplevel + form + macroexpand-all-environment))) + (eval (byte-run-strip-symbol-positions + (bytecomp--copy-tree expanded)) + lexical-binding) expanded))))) (with-suppressed-warnings . ,(lambda (warnings &rest body) @@ -541,15 +584,19 @@ Return the compile-time value of FORM." ;; Later `internal--with-suppressed-warnings' binds it again, this ;; time in order to affect warnings emitted during the ;; compilation itself. - (let ((byte-compile--suppressed-warnings - (append warnings byte-compile--suppressed-warnings))) - ;; This function doesn't exist, but is just a placeholder - ;; symbol to hook up with the - ;; `byte-hunk-handler'/`byte-defop-compiler-1' machinery. - `(internal--with-suppressed-warnings - ',warnings - ,(macroexpand-all `(progn ,@body) - macroexpand-all-environment)))))) + (if body + (let ((byte-compile--suppressed-warnings + (append warnings byte-compile--suppressed-warnings))) + ;; This function doesn't exist, but is just a placeholder + ;; symbol to hook up with the + ;; `byte-hunk-handler'/`byte-defop-compiler-1' machinery. + `(internal--with-suppressed-warnings + ',warnings + ,(macroexpand-all `(progn ,@body) + macroexpand-all-environment))) + (macroexp-warn-and-return + (format-message "`with-suppressed-warnings' with empty body") + nil '(empty-body with-suppressed-warnings) t warnings))))) "The default macro-environment passed to macroexpand by the compiler. Placing a macro here will cause a macro to have different semantics when expanded by the compiler as when expanded by the interpreter.") @@ -1569,24 +1616,23 @@ extra args." "`%s' called with %d args to fill %d format field(s)" (car form) nargs nfields))))) -(dolist (elt '(format message error)) +(dolist (elt '(format message format-message error)) (put elt 'byte-compile-format-like t)) -(defun byte-compile--suspicious-defcustom-choice (type) - "Say whether defcustom TYPE looks odd." - ;; Check whether there's anything like (choice (const :tag "foo" ;; 'bar)). +(defun byte-compile--defcustom-type-quoted (type) + "Whether defcustom TYPE contains an accidentally quoted value." + ;; Detect mistakes such as (const 'abc). ;; We don't actually follow the syntax for defcustom types, but this ;; should be good enough. - (catch 'found - (if (and (consp type) - (proper-list-p type)) - (if (memq (car type) '(const other)) - (when (assq 'quote type) - (throw 'found t)) - (when (memq t (mapcar #'byte-compile--suspicious-defcustom-choice - type)) - (throw 'found t))) - nil))) + (and (consp type) + (proper-list-p type) + (if (memq (car type) '(const other)) + (assq 'quote type) + (let ((elts (cdr type))) + (while (and elts (not (byte-compile--defcustom-type-quoted + (car elts)))) + (setq elts (cdr elts))) + elts)))) ;; Warn if a custom definition fails to specify :group, or :type. (defun byte-compile-nogroup-warn (form) @@ -1600,10 +1646,10 @@ extra args." (byte-compile-warn-x (cadr name) "defcustom for `%s' fails to specify type" (cadr name))) - ((byte-compile--suspicious-defcustom-choice type) + ((byte-compile--defcustom-type-quoted type) (byte-compile-warn-x (cadr name) - "defcustom for `%s' has syntactically odd type `%s'" + "defcustom for `%s' may have accidentally quoted value in type `%s'" (cadr name) type))))) (if (and (memq (car form) '(custom-declare-face custom-declare-variable)) byte-compile-current-group) @@ -1766,10 +1812,16 @@ It is too wide if it has any lines longer than the largest of kind name col)) ;; There's a "naked" ' character before a symbol/list, so it ;; should probably be quoted with \=. - (when (string-match-p "\\( [\"#]\\|[ \t]\\|^\\)'[a-z(]" docs) + (when (string-match-p (rx (| (in " \t") bol) + (? (in "\"#")) + "'" + (in "A-Za-z" "(")) + docs) (byte-compile-warn-x - name "%s%sdocstring has wrong usage of unescaped single quotes (use \\= or different quoting)" - kind name)) + name + (concat "%s%sdocstring has wrong usage of unescaped single quotes" + " (use \\=%c or different quoting such as %c...%c)") + kind name ?' ?` ?')) ;; There's a "Unicode quote" in the string -- it should probably ;; be an ASCII one instead. (when (byte-compile-warning-enabled-p 'docstrings-non-ascii-quotes) @@ -3405,7 +3457,7 @@ lambda-expression." (let* ((fn (car form)) (handler (get fn 'byte-compile)) (interactive-only - (or (get fn 'interactive-only) + (or (function-get fn 'interactive-only) (memq fn byte-compile-interactive-only-functions)))) (when (memq fn '(set symbol-value run-hooks ;; add-to-list add-hook remove-hook run-hook-with-args @@ -3432,15 +3484,54 @@ lambda-expression." (format "; %s" (substitute-command-keys interactive-only))) - ((and (symbolp 'interactive-only) + ((and (symbolp interactive-only) (not (eq interactive-only t))) (format-message "; use `%s' instead." interactive-only)) (t ".")))) + (let ((mutargs (function-get (car form) 'mutates-arguments))) + (when mutargs + (dolist (idx (if (eq mutargs 'all-but-last) + (number-sequence 1 (- (length form) 2)) + mutargs)) + (let ((arg (nth idx form))) + (when (and (or (and (eq (car-safe arg) 'quote) + (consp (nth 1 arg))) + (arrayp arg)) + (byte-compile-warning-enabled-p + 'mutate-constant (car form))) + (byte-compile-warn-x form "`%s' on constant %s (arg %d)" + (car form) + (if (consp arg) "list" (type-of arg)) + idx)))))) + (if (eq (car-safe (symbol-function (car form))) 'macro) (byte-compile-report-error - (format "`%s' defined after use in %S (missing `require' of a library file?)" + (format-message "`%s' defined after use in %S (missing `require' of a library file?)" (car form) form))) + + (when byte-compile--for-effect + (let ((sef (function-get (car form) 'side-effect-free))) + (cond + ((and sef (or (eq sef 'error-free) + byte-compile-delete-errors)) + ;; This transform is normally done in the Lisp optimiser, + ;; so maybe we don't need to bother about it here? + (setq form (cons 'progn (cdr form))) + (setq handler #'byte-compile-progn)) + ((and (or sef (function-get (car form) 'important-return-value)) + ;; Don't warn for arguments to `ignore'. + (not (eq byte-compile--for-effect 'for-effect-no-warn)) + (byte-compile-warning-enabled-p + 'ignored-return-value (car form))) + (byte-compile-warn-x + (car form) + "value from call to `%s' is unused%s" + (car form) + (cond ((eq (car form) 'mapcar) + "; use `mapc' or `dolist' instead") + (t ""))))))) + (if (and handler ;; Make sure that function exists. (and (functionp handler) @@ -3464,6 +3555,66 @@ lambda-expression." (byte-compile-discard)) (pop byte-compile-form-stack))) +(let ((important-return-value-fns + '( + ;; These functions are side-effect-free except for the + ;; behaviour of functions passed as argument. + mapcar mapcan mapconcat + assoc assoc-string plist-get plist-member + + ;; It's safe to ignore the value of `sort' and `nreverse' + ;; when used on arrays, but most calls pass lists. + nreverse sort + + match-data + + ;; Warning about these functions causes some false positives that are + ;; laborious to eliminate; see bug#61730. + ;;delq delete + ;;nconc plist-put + ))) + (dolist (fn important-return-value-fns) + (put fn 'important-return-value t))) + +(let ((mutating-fns + ;; FIXME: Should there be a function declaration for this? + ;; + ;; (FUNC . ARGS) means that FUNC mutates arguments whose indices are + ;; in the list ARGS, starting at 1, or all but the last argument if + ;; ARGS is `all-but-last'. + '( + (setcar 1) (setcdr 1) (aset 1) + (nreverse 1) + (nconc . all-but-last) + (nbutlast 1) (ntake 2) + (sort 1) + (delq 2) (delete 2) + (delete-dups 1) (delete-consecutive-dups 1) + (plist-put 1) + (assoc-delete-all 2) (assq-delete-all 2) (rassq-delete-all 2) + (fillarray 1) + (store-substring 1) + (clear-string 1) + + (add-text-properties 4) (put-text-property 5) (set-text-properties 4) + (remove-text-properties 4) (remove-list-of-text-properties 4) + (alter-text-property 5) + (add-face-text-property 5) (add-display-text-property 5) + + (cl-delete 2) (cl-delete-if 2) (cl-delete-if-not 2) + (cl-delete-duplicates 1) + (cl-nsubst 3) (cl-nsubst-if 3) (cl-nsubst-if-not 3) + (cl-nsubstitute 3) (cl-nsubstitute-if 3) (cl-nsubstitute-if-not 3) + (cl-nsublis 2) + (cl-nunion 1 2) (cl-nintersection 1 2) (cl-nset-difference 1 2) + (cl-nset-exclusive-or 1 2) + (cl-nreconc 1) + (cl-sort 1) (cl-stable-sort 1) (cl-merge 2 3) + ))) + (dolist (entry mutating-fns) + (put (car entry) 'mutates-arguments (cdr entry)))) + + (defun byte-compile-normal-call (form) (when (and (symbolp (car form)) (byte-compile-warning-enabled-p 'callargs (car form))) @@ -3474,11 +3625,7 @@ lambda-expression." (byte-compile-callargs-warn form)) (if byte-compile-generate-call-tree (byte-compile-annotate-call-tree form)) - (when (and byte-compile--for-effect (eq (car form) 'mapcar) - (byte-compile-warning-enabled-p 'mapcar 'mapcar)) - (byte-compile-warn-x - (car form) - "`mapcar' called for effect; use `mapc' or `dolist' instead")) + (byte-compile-push-constant (car form)) (mapc 'byte-compile-form (cdr form)) ; wasteful, but faster. (byte-compile-out 'byte-call (length (cdr form)))) @@ -3736,7 +3883,7 @@ If it is nil, then the handler is \"byte-compile-SYMBOL.\"" '((0 . byte-compile-no-args) (1 . byte-compile-one-arg) (2 . byte-compile-two-args) - (2-and . byte-compile-and-folded) + (2-cmp . byte-compile-cmp) (3 . byte-compile-three-args) (0-1 . byte-compile-zero-or-one-arg) (1-2 . byte-compile-one-or-two-args) @@ -3815,11 +3962,11 @@ If it is nil, then the handler is \"byte-compile-SYMBOL.\"" (byte-defop-compiler cons 2) (byte-defop-compiler aref 2) (byte-defop-compiler set 2) -(byte-defop-compiler (= byte-eqlsign) 2-and) -(byte-defop-compiler (< byte-lss) 2-and) -(byte-defop-compiler (> byte-gtr) 2-and) -(byte-defop-compiler (<= byte-leq) 2-and) -(byte-defop-compiler (>= byte-geq) 2-and) +(byte-defop-compiler (= byte-eqlsign) 2-cmp) +(byte-defop-compiler (< byte-lss) 2-cmp) +(byte-defop-compiler (> byte-gtr) 2-cmp) +(byte-defop-compiler (<= byte-leq) 2-cmp) +(byte-defop-compiler (>= byte-geq) 2-cmp) (byte-defop-compiler get 2) (byte-defop-compiler nth 2) (byte-defop-compiler substring 1-3) @@ -3883,18 +4030,20 @@ If it is nil, then the handler is \"byte-compile-SYMBOL.\"" (byte-compile-form (nth 2 form)) (byte-compile-out (get (car form) 'byte-opcode) 0))) -(defun byte-compile-and-folded (form) - "Compile calls to functions like `<='. -These implicitly `and' together a bunch of two-arg bytecodes." - (let ((l (length form))) - (cond - ((< l 3) (byte-compile-form `(progn ,(nth 1 form) t))) - ((= l 3) (byte-compile-two-args form)) - ;; Don't use `cl-every' here (see comment where we require cl-lib). - ((not (memq nil (mapcar #'macroexp-copyable-p (nthcdr 2 form)))) - (byte-compile-form `(and (,(car form) ,(nth 1 form) ,(nth 2 form)) - (,(car form) ,@(nthcdr 2 form))))) - (t (byte-compile-normal-call form))))) +(defun byte-compile-cmp (form) + "Compile calls to numeric comparisons such as `<', `=' etc." + ;; Lisp-level transforms should already have reduced valid calls to 2 args. + (if (not (= (length form) 3)) + (byte-compile-subr-wrong-args form "1 or more") + (byte-compile-two-args + (if (macroexp-const-p (nth 1 form)) + ;; First argument is constant: flip it so that the constant + ;; is last, which may allow more lapcode optimisations. + (let* ((op (car form)) + (flipped-op (cdr (assq op '((< . >) (<= . >=) + (> . <) (>= . <=) (= . =)))))) + (list flipped-op (nth 2 form) (nth 1 form))) + form)))) (defun byte-compile-three-args (form) (if (not (= (length form) 4)) @@ -4049,9 +4198,15 @@ This function is never called when `lexical-binding' is nil." (byte-compile-constant 1) (byte-compile-out (get '* 'byte-opcode) 0)) (3 - (byte-compile-form (nth 1 form)) - (byte-compile-form (nth 2 form)) - (byte-compile-out (get (car form) 'byte-opcode) 0)) + (let ((arg1 (nth 1 form)) + (arg2 (nth 2 form))) + (when (and (memq (car form) '(+ *)) + (macroexp-const-p arg1)) + ;; Put constant argument last for better LAP optimisation. + (cl-rotatef arg1 arg2)) + (byte-compile-form arg1) + (byte-compile-form arg2) + (byte-compile-out (get (car form) 'byte-opcode) 0))) (_ ;; >2 args: compile as a single function call. (byte-compile-normal-call form)))) @@ -4310,7 +4465,8 @@ This function is never called when `lexical-binding' is nil." (defun byte-compile-ignore (form) (dolist (arg (cdr form)) - (byte-compile-form arg t)) + ;; Compile each argument for-effect but suppress unused-value warnings. + (byte-compile-form arg 'for-effect-no-warn)) (byte-compile-form nil)) ;; Return the list of items in CONDITION-PARAM that match PRED-LIST. @@ -4571,6 +4727,7 @@ Return (TAIL VAR TEST CASES), where: (if switch-prefix (progn (byte-compile-cond-jump-table (cdr switch-prefix) donetag) + (setq clause nil) (setq clauses (car switch-prefix))) (setq clause (car clauses)) (cond ((or (eq (car clause) t) @@ -4835,6 +4992,11 @@ binding slots have been popped." (dolist (clause (reverse clauses)) (let ((condition (nth 1 clause))) + (when (and (eq (car-safe condition) 'quote) + (cdr condition) (null (cddr condition))) + (byte-compile-warn-x + condition "`condition-case' condition should not be quoted: %S" + condition)) (unless (consp condition) (setq condition (list condition))) (dolist (c condition) (unless (and c (symbolp c)) @@ -5055,7 +5217,10 @@ binding slots have been popped." (defun byte-compile-suppressed-warnings (form) (let ((byte-compile--suppressed-warnings (append (cadadr form) byte-compile--suppressed-warnings))) - (byte-compile-form (macroexp-progn (cddr form))))) + ;; Propagate the for-effect mode explicitly so that warnings about + ;; ignored return values can be detected and suppressed correctly. + (byte-compile-form (macroexp-progn (cddr form)) byte-compile--for-effect) + (setq byte-compile--for-effect nil))) ;; Warn about misuses of make-variable-buffer-local. (byte-defop-compiler-1 make-variable-buffer-local @@ -5487,6 +5652,83 @@ and corresponding effects." (eval form) form))) +;; Check for (in)comparable constant values in calls to `eq', `memq' etc. + +(defun bytecomp--dodgy-eq-arg-p (x number-ok) + "Whether X is a bad argument to `eq' (or `eql' if NUMBER-OK is non-nil)." + (pcase x + ((or `(quote ,(pred consp)) `(function (lambda . ,_))) t) + ((or (pred consp) (pred symbolp)) nil) + ((pred integerp) + (not (or (<= -536870912 x 536870911) number-ok))) + ((pred floatp) (not number-ok)) + (_ t))) + +(defun bytecomp--value-type-description (x) + (cond + ((proper-list-p x) "list") + ((recordp x) "record") + (t (symbol-name (type-of x))))) + +(defun bytecomp--arg-type-description (x) + (pcase x + (`(function (lambda . ,_)) "function") + (`(quote . ,val) (bytecomp--value-type-description val)) + (_ (bytecomp--value-type-description x)))) + +(defun bytecomp--warn-dodgy-eq-arg (form type parenthesis) + (macroexp-warn-and-return + (format-message "`%s' called with literal %s that may never match (%s)" + (car form) type parenthesis) + form (list 'suspicious (car form)) t)) + +(defun bytecomp--check-eq-args (form &optional a b &rest _ignore) + (let* ((number-ok (eq (car form) 'eql)) + (bad-arg (cond ((bytecomp--dodgy-eq-arg-p a number-ok) 1) + ((bytecomp--dodgy-eq-arg-p b number-ok) 2)))) + (if bad-arg + (bytecomp--warn-dodgy-eq-arg + form + (bytecomp--arg-type-description (nth bad-arg form)) + (format "arg %d" bad-arg)) + form))) + +(put 'eq 'compiler-macro #'bytecomp--check-eq-args) +(put 'eql 'compiler-macro #'bytecomp--check-eq-args) + +(defun bytecomp--check-memq-args (form &optional elem list &rest _ignore) + (let* ((fn (car form)) + (number-ok (eq fn 'memql))) + (cond + ((bytecomp--dodgy-eq-arg-p elem number-ok) + (bytecomp--warn-dodgy-eq-arg + form (bytecomp--arg-type-description elem) "arg 1")) + ((and (consp list) (eq (car list) 'quote) + (proper-list-p (cadr list))) + (named-let loop ((elts (cadr list)) (i 1)) + (if elts + (let* ((elt (car elts)) + (x (cond ((eq fn 'assq) (car-safe elt)) + ((eq fn 'rassq) (cdr-safe elt)) + (t elt)))) + (if (or (symbolp x) + (and (integerp x) + (or (<= -536870912 x 536870911) number-ok)) + (and (floatp x) number-ok)) + (loop (cdr elts) (1+ i)) + (bytecomp--warn-dodgy-eq-arg + form (bytecomp--value-type-description x) + (format "element %d of arg 2" i)))) + form))) + (t form)))) + +(put 'memq 'compiler-macro #'bytecomp--check-memq-args) +(put 'memql 'compiler-macro #'bytecomp--check-memq-args) +(put 'assq 'compiler-macro #'bytecomp--check-memq-args) +(put 'rassq 'compiler-macro #'bytecomp--check-memq-args) +(put 'remq 'compiler-macro #'bytecomp--check-memq-args) +(put 'delq 'compiler-macro #'bytecomp--check-memq-args) + (provide 'byte-compile) (provide 'bytecomp) |