[Chicken-janitors] #113: Crunch egg: bug in define-crunch-primitives / define-crunch-callback

[Chicken Trac]

#113: Crunch egg: bug in define-crunch-primitives / define-crunch-callback
------------------------+---------------------------------------------------
 Reporter:  jeronimo    |       Owner:       
     Type:  defect      |      Status:  new  
 Priority:  minor       |   Milestone:       
Component:  extensions  |     Version:  4.2.x
 Keywords:  crunch      |  
------------------------+---------------------------------------------------
 In line 78 of crunch.scm , pair? is called with two arguments:

 {{{
     (and (pair? (car p) (c (r '+>) (cadr p)))))))
 }}}

 The version of Crunch is svn trunk (but that line is the same in version
 0.7.2). I tested it with Chicken from git, commit
 43a11082ddc109bfe1b4fdb400b6079ca64d024a

 The following is a report of my attempt to debug the problem; since I'm
 new to Chicken Scheme, I may have made several silly mistakes along the
 way...

 The following code (crunch-bug.scm) does not compile (I suppose I
 undertood how to use define-crunch-primitives and define-crunch-callback):

 {{{
 (cond-expand
  (crunched (import crunch))
  (else
   (define-syntax crunch
     (syntax-rules ()
       ((_ body ...) (begin (display "Crunch not working") body ...) ) ) )
 ) )

 (define-crunch-primitives
   ((foo int) -> void))

 (define-crunch-callback
   (foo (int i)) void
   (display (format "Here's your int: ~a ~%" i)))

 (crunch
   (define work
    (lambda (max)
      (do ((k 0 (+ k 1)))
          ((>= k max))
        (foo k))))    )

 (work 10)
 }}}

 I tried fixing line 78 of crunch.scm, changing it to:

 {{{
     (and (pair? (car p) (c (r '+>) (cadr p)))))))
 }}}

 But then the code and declarations for the function (foo in the example
 above) are not generated properly in the C++ file:

 {{{
 $ csc -c++ -D crunched crunch-bug.scm

 Warning: reference to variable `unquote' possibly unintended crunch-
 bug.cpp: In function ‘type37 f36(type35)’:
 crunch-bug.cpp:58: error: ‘crunch_callback14’ was not declared in this
 scope crunch-bug.cpp: In function ‘void C_toplevel(long int, long int,
 long int)’:
 }}}

 That function is used in line 58 of the C++ file (I know line numbers in
 generated C++ could perhaps vary from my setup to others, but this is just
 to show the relative order of lines):
 {{{
 type55 t56 = crunch_callback14(t54);
 }}}

 but is only declared in line 76:
 {{{
 C_externexport  void  crunch_callback14(int t0);
 }}}

 And defined in line 135:
 {{{
 void  crunch_callback14(int t0){
 ...
 }
 }}}

 OK, so I manually added a declaration at the top of the file:
 {{{
 C_externexport  void  crunch_callback14(int t0);
 }}}

 and got this error:

 {{{
 crunch-bug.cpp: In function ‘type37 f36(type35)’:
 crunch-bug.cpp:62: error: conversion from ‘void’ to non-scalar type
 ‘type55’ requested
 }}}

 OK. It won't return anything, so I changed the function call from

 {{{
 type55 t56 = crunch_callback14(t54);
 }}}

 to:

 {{{
 crunch_callback14(t54);
 }}}

 (And verified that t56 is *not* referenced at all in the C++ code).

 And, HEY, it compiles!!!

 But the generated binary doesn't work:

 {{{
 $ g++ crunch-bug.o -lchicken
 $ ./crunch-bug
 Error: unbound variable: r

         Call history:

         r                       <--
 }}}

 I suppose this is the r here, in line 60 of crunch.scm:

 {{{
 (define-syntax (define-crunch-primitives x r c)
 }}}

 But I wasn't able to debug further.

-- 
Ticket URL: <http://www.irp.oist.jp/trac/chicken/ticket/113>
Chicken Scheme <http://www.call-with-current-continuation.org/>
Chicken Scheme is a compiler for the Scheme programming language.