From 9cf17ef1360b4565137b464c1d513b8707983389 Mon Sep 17 00:00:00 2001 From: Alan Mackenzie Date: Sat, 20 Jan 2007 19:29:30 +0000 Subject: [PATCH] Reformulate c-in-knr-argdecl to do much more rigorous analysis of putative K&R regions. --- lisp/progmodes/cc-engine.el | 140 ++++++++++++++++++++++-------------- 1 file changed, 88 insertions(+), 52 deletions(-) diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el index 9e004edf41d..569d1b4479f 100644 --- a/lisp/progmodes/cc-engine.el +++ b/lisp/progmodes/cc-engine.el @@ -6221,65 +6221,101 @@ comment at the start of cc-engine.el for more info." ;; `c-recognize-knr-p' is not checked. If LIM is non-nil, it's a ;; position that bounds the backward search for the argument list. ;; - ;; Note: A declaration level context is assumed; the test can return - ;; false positives for statements. + ;; Point must be within a possible K&R region, e.g. just before a top-level + ;; "{". It must be outside of parens and brackets. The test can return + ;; false positives otherwise. ;; ;; This function might do hidden buffer changes. (save-excursion (save-restriction + ;; If we're in a macro, our search range is restricted to it. Narrow to + ;; the searchable range. + (let* ((macro-start (c-query-macro-start)) + (lim (max (or lim (point-min)) (or macro-start (point-min)))) + before-lparen after-rparen) + (narrow-to-region lim (c-point 'eol)) + + ;; Search backwards for the defun's argument list. We give up if we + ;; encounter a "}" (end of a previous defun) or BOB. + ;; + ;; The criterion for a paren structure being the arg list is: + ;; o - there is non-WS stuff after it but before any "{"; AND + ;; o - the token after it isn't a ";" AND + ;; o - it is preceded by either an identifier (the function name) or + ;; a macro expansion like "DEFUN (...)"; AND + ;; o - its content is a non-empty comma-separated list of identifiers + ;; (an empty arg list won't have a knr region). + ;; + ;; The following snippet illustrates these rules: + ;; int foo (bar, baz, yuk) + ;; int bar [] ; + ;; int (*baz) (my_type) ; + ;; int (*) (void) (*yuk) (void) ; + ;; { + + (catch 'knr + (while t ; go round one paren/bracket construct each time round. + (or (c-syntactic-skip-backward "^)]}") + (throw 'knr nil)) ; no more bpb pairs left. + (cond ((eq (char-before) ?\)) + (setq after-rparen (point))) + ((eq (char-before) ?\}) + (throw 'knr nil)) + (t (setq after-rparen nil))) ; "]" + + (if after-rparen + ;; We're inside a paren. Could it be our argument list....? + (if + (and + (progn + (goto-char after-rparen) + (unless (c-go-list-backward) (throw 'knr nil)) ; + ;; FIXME!!! What about macros between the parens? 2007/01/20 + (setq before-lparen (point))) - ;; Go back to the closest preceding normal parenthesis sexp. We - ;; take that as the argument list in the function header. Then - ;; check that it's followed by some symbol before the next ';' - ;; or '{'. If it does, it's the header of the K&R argdecl we're - ;; in. - (if lim (narrow-to-region lim (c-point 'eol))) - (let ((outside-macro (not (c-query-macro-start))) - paren-end) - - (catch 'done - (while (if (and (setq paren-end (c-down-list-backward (point))) - (eq (char-after paren-end) ?\))) - (progn - (goto-char (1+ paren-end)) - (if outside-macro - (c-beginning-of-macro))) - (throw 'done nil)))) - - (and (progn - (c-forward-syntactic-ws) - (looking-at "\\w\\|\\s_")) - - (save-excursion - ;; The function header in a K&R declaration should only - ;; contain identifiers separated by comma. It should - ;; also contain at least one identifier since there - ;; wouldn't be anything to declare in the K&R region - ;; otherwise. - (when (c-go-up-list-backward paren-end) - (forward-char) - (catch 'knr-ok - (while t - (c-forward-syntactic-ws) - (if (or (looking-at c-known-type-key) - (looking-at c-keywords-regexp)) - (throw 'knr-ok nil)) - (c-forward-token-2) - (if (eq (char-after) ?,) - (forward-char) - (throw 'knr-ok (and (eq (char-after) ?\)) - (= (point) paren-end)))))))) + ;; It can't be the arg list if next token is ; or { + (progn (goto-char after-rparen) + (c-forward-syntactic-ws) + (not (memq (char-after) '(?\; ?\{)))) - (save-excursion - ;; If it's a K&R declaration then we're now at the - ;; beginning of the function arglist. Check that there - ;; isn't a '=' before it in this statement since that - ;; means it some kind of initialization instead. - (c-syntactic-skip-backward "^;=}{") - (not (eq (char-before) ?=))) - - (point)))))) + ;; Is the thing preceding the list an identifier (the + ;; function name), or a macro expansion? + (progn + (goto-char before-lparen) + (eq (c-backward-token-2) 0) + (or (c-on-identifier) + (and (eq (char-after) ?\)) + (c-go-up-list-backward) + (eq (c-backward-token-2) 0) + (c-on-identifier)))) + + ;; Have we got a non-empty list of comma-separated + ;; identifiers? + (progn + (goto-char before-lparen) + (c-forward-token-2) ; to first token inside parens + (and + (c-on-identifier) + (c-forward-token-2) + (catch 'id-list + (while (eq (char-after) ?\,) + (c-forward-token-2) + (unless (c-on-identifier) (throw 'id-list nil)) + (c-forward-token-2)) + (eq (char-after) ?\)))))) + + ;; ...Yes. We've identified the function's argument list. + (throw 'knr + (progn (goto-char after-rparen) + (c-forward-syntactic-ws) + (point))) + + ;; ...No. The current parens aren't the function's arg list. + (goto-char before-lparen)) + + (or (c-go-list-backward) ; backwards over [ .... ] + (throw 'knr nil))))))))) (defun c-skip-conditional () ;; skip forward over conditional at point, including any predicate -- 2.39.2