X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/284f1fa2ace3e276052ff1bd7d66442500e693da..9e91c8e7b5fcdeb6389ac7ccbcd9c77348c4493a:/src/c-types-parse.lisp diff --git a/src/c-types-parse.lisp b/src/c-types-parse.lisp index b9a53db..6a622b7 100644 --- a/src/c-types-parse.lisp +++ b/src/c-types-parse.lisp @@ -302,7 +302,7 @@ ;;; `parse-declarator' will be of this form. (export 'parse-declarator) -(defun parse-declarator (scanner base-type &key kernel abstractp) +(defun parse-declarator (scanner base-type &key kernel abstractp keywordp) "Parse a C declarator, returning a pair (C-TYPE . NAME). The SCANNER is a token scanner to read from. The BASE-TYPE is the type @@ -315,10 +315,23 @@ defaults to matching a simple identifier `:id'. This might, e.g., be (? :id) to parse an `abstract declarator' which has optional names. + If KEYWORDP is true, then a keyword argument list is permitted in + function declarations. + There's an annoying ambiguity in the syntax, if an empty KERNEL is permitted. In this case, you must ensure that ABSTRACTP is true so that the appropriate heuristic can be applied. As a convenience, if ABSTRACTP is true then `(? :id)' is used as the default KERNEL." + + ;; This is a bit confusing. This is a strangely-shaped operator grammer, + ;; which wouldn't be so bad, but the `values' being operated on are pairs + ;; of the form (FUNC . NAME). The NAME is whatever the KERNEL parser + ;; produces as its result, and will be passed out unchanged. The FUNC is a + ;; type-constructor function which will be eventually be applied to the + ;; input BASE-TYPE, but we can't calculate the actual result as we go along + ;; because of the rather annoying inside-out nature of the declarator + ;; syntax. + (with-parser-context (token-scanner-context :scanner scanner) (let ((kernel-parser (cond (kernel kernel) (abstractp (parser () (? :id))) @@ -338,12 +351,18 @@ 'qualifier))))))) (mapcar #'ds-label quals)))) + (disallow-keyword-functions (type) + (when (typep type 'c-keyword-function-type) + (error "Functions with keyword arguments are only ~ + allowed at top-level."))) + (star () ;; Prefix: `*' qualifiers (parse (seq (#\* (quals (qualifiers))) (preop "*" (state 9) (cons (lambda (type) + (disallow-keyword-functions type) (funcall (car state) (make-pointer-type type quals))) (cdr state)))))) @@ -383,26 +402,64 @@ (parse (seq ((name (funcall kernel-parser))) (cons #'identity name)))) + (arg-decl (abstractp) + (parse (seq ((base-type (parse-c-type scanner)) + (dtor (parse-declarator scanner base-type + :abstractp abstractp))) + dtor))) + + (argument () + ;; argument ::= type abstract-declspec + + (parse (seq ((dtor (arg-decl t))) + (make-argument (cdr dtor) (car dtor))))) + + (kw-argument () + ;; kw-argument ::= type declspec [= c-fragment] + + (parse (seq ((dtor (arg-decl nil)) + (dflt (? (when (eq (token-type scanner) #\=) + (parse-delimited-fragment + scanner #\= '(#\, #\)) + :keep-end t))))) + (make-argument (cdr dtor) (car dtor) dflt)))) + (argument-list () - ;; [argument [`,' argument]* [`,' `...']] | `...' + ;; argument-list ::= + ;; [argument [`,' argument]* [`,' argument-tail]] + ;; | argument-tail + ;; + ;; argument-tail ::= `...' | keyword-tail + ;; + ;; keyword-tail ::= `?' [kw-argument [`,' kw-argument]*] + ;; + ;; kw-argument ::= argument [= c-fragment] ;; ;; The possibility of a trailing `,' `...' means that we ;; can't use the standard `list' parser. Note that, unlike ;; `real' C, we allow an ellipsis even if there are no ;; explicit arguments. - (let ((args nil)) + (let ((args nil) + (keys nil) + (keysp nil)) (loop (when (eq (token-type scanner) :ellipsis) (push :ellipsis args) (scanner-step scanner) (return)) + (when (and keywordp (eq (token-type scanner) #\?)) + (setf keysp t) + (scanner-step scanner) + (multiple-value-bind (arg winp consumedp) + (parse (list (:min 0) (kw-argument) #\,)) + (declare (ignore consumedp)) + (unless winp + (return-from argument-list (values arg nil t))) + (setf keys arg) + (return))) (multiple-value-bind (arg winp consumedp) - (parse (seq ((base-type (parse-c-type scanner)) - (dtor (parse-declarator scanner - base-type - :abstractp t))) - (make-argument (cdr dtor) (car dtor)))) + (argument) (unless winp (if (or consumedp args) (return-from argument-list (values arg nil t)) @@ -411,16 +468,26 @@ (unless (eq (token-type scanner) #\,) (return)) (scanner-step scanner)) - (values (nreverse args) t args))) + (values (let ((rargs (nreverse args)) + (rkeys (nreverse keys))) + (if keysp + (lambda (ret) + (make-keyword-function-type + ret rargs rkeys)) + (lambda (ret) + (make-function-type ret rargs)))) + t + (or args keysp)))) (postfix-lparen () ;; Postfix: `(' argument-list `)' - (parse (seq (#\( (args (argument-list)) #\)) + (parse (seq (#\( (make (argument-list)) #\)) (postop "()" (state 10) (cons (lambda (type) + (disallow-keyword-functions type) (funcall (car state) - (make-function-type type args))) + (funcall make type))) (cdr state)))))) (dimension () @@ -436,6 +503,7 @@ (parse (seq ((dims (list (:min 1) (dimension)))) (postop "[]" (state 10) (cons (lambda (type) + (disallow-keyword-functions type) (funcall (car state) (make-array-type type dims))) (cdr state)))))))