March 2015 - cmucl-imp - mailman3.common-lisp.net

[cmucl-imp] define-compiler-macro and funcall forms.
by Mark Cox 26 Mar '15

26 Mar '15

G'day, The compiler macro functions created by CMUCL using define-compiler-macro do not correctly handle funcall forms in cases where the compiler macro function returns the input form. This is demonstrated with the following example: (defun square (x) (expt x 2)) (define-compiler-macro square (&whole form arg) (declare (ignore arg)) form) (funcall (compiler-macro-function 'square) '(square x) nil) => (SQUARE X) (funcall (compiler-macro-function 'square) '(funcall #'square x) nil) => (#'SQUARE X) The cause of this error is due to a bug in the body argument returned by lisp::parse-defmacro. (nth-value 0 (lisp::parse-defmacro '(&whole form arg) 'my-form '(form) 'square 'define-compiler-macro)) => (let* ((my-form (if (progn (not (and (listp my-form) (eq 'funcall (car my-form))))) my-form (progn (setf my-form (cdr my-form)))))) (unless (lisp::list-length-bounded-p (the list (cdr my-form)) 1 1) (lisp::do-arg-count-error 'define-compiler-macro 'square (cdr my-form) '(&whole form arg) 1 1)) (let* ((form my-form) (arg (car (cdr my-form)))) form)) The body above is evaluated in a lexical environment where MY-FORM is bound to '(funcall #'square x). A new binding of MY-FORM is introduced by the first LET* in the body above such that MY-FORM is (cdr '(#'square x)). This value is then bound to the &WHOLE symbol FORM specified in the input lambda list to PARSE-DEFMACRO. Thanks Mark [1]. http://www.lispworks.com/documentation/HyperSpec/Body/m_define.htm

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[cmucl-imp] Error coercing functions at compile time.
by Mark Cox 20 Mar '15

20 Mar '15

G'day, Compiling the following example produces an error. ;; /tmp/cmucl.lisp ;; $ cmucl -noinit -eval '(compile-file "/tmp/cmucl.lisp") (defun my-funcall (a) (print a)) (my-funcall (coerce '(lambda () (print "hello'")) 'function)) ;; Output ; Python version 1.1, VM version Intel x86/sse2 on 2015-03-21 08:58:17. ; Compiling: /private/tmp/cmucl.lisp 2015-03-21 08:58:11 ; Converted MY-FUNCALL. ; Compiling DEFUN MY-FUNCALL: ; Byte Compiling Top-Level Form: ; ; ; File: /private/tmp/cmucl.lisp ; In: MY-FUNCALL (COERCE '(LAMBDA # #) 'FUNCTION) ; (COERCE '(LAMBDA # #) 'FUNCTION) ; --> VALUES PROG1 LET ; ==> ; '#<Interpreted Function (LAMBDA # #) {480513E9}> ; Error: Cannot dump objects of type EVAL:INTERPRETED-FUNCTION into fasl files. ; ; (MY-FUNCALL (COERCE '# 'FUNCTION)) ; Note: Deleting unreachable code. ; ; Compilation unit finished. ; 1 error ; 1 note ; /tmp/cmucl.sse2f written. ; Compilation finished in 0:00:00. CMU Common Lisp snapshot-2014-12 (20F Unicode), running on me.local With core: /home/me/local/lib/cmucl/lib/lisp-sse2.core Dumped on: Sat, 2015-01-03 21:50:20+10:00 on me.local See <http://www.cmucl.org/> for support information. Loaded subsystems: Unicode 1.29 with Unicode version 6.2.0 Python 1.1, target Intel x86/sse2 CLOS based on Gerd's PCL 2010/03/19 15:19:03 * Thanks Mark

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[cmucl-imp] Lexical environment and compiler macro functions.
by Mark Cox 15 Mar '15

15 Mar '15

G'day, CMUCL does not shadow the compiler macro function present in the global environment when introducing a function with the same name in the current lexical environment. This is demonstrated with the following example: (defun square (x) (expt x 2)) (define-compiler-macro square (&whole form arg) (declare (ignore arg)) form) (defun test () (flet ((square (arg) (declare (ignore arg)) (write "SQUARE!"))) (macrolet ((my-square (arg &environment env) (if (compiler-macro-function 'square env) `(function square) nil))) (my-square 1)))) (test) => #<Function (FLET SQUARE TEST) {48704B89}> Thanks Mark

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