Opened 11 years ago

Closed 11 years ago

Last modified 11 years ago

#1011 closed defect (invalid)

float and double foreign-lambdas return wrong values

Reported by: Shawn Rutledge Owned by:
Priority: major Milestone: someday
Component: unknown Version: 4.8.x
Keywords: Cc:
Estimated difficulty:


Sometimes I've had better luck with double, but now I wrote an egg just to demonstrate this, and it's failing pretty consistently for both float and double, at least for me, on 64-bit Arch Linux.

Version (stability/4.8.0) (rev 091c3d9)

#;1> (use getafloat)
; loading /usr/lib/chicken/6/ ...
; loading /usr/lib/chicken/6/ ...
#;2> (get-float)
get_float returning 1368477568.000000
#;3> (get-double)
get_float returning 1368477622.402598
#;4> (get-int)
#;5> (get-pair)
get_float returning 1368477696.000000
get_float returning 1368477696.000000
(38.0 . 38.0)

Attachments (1)

getafloat.tgz (808 bytes) - added by Shawn Rutledge 11 years ago.
egg to demonstrate the bug

Download all attachments as: .zip

Change History (3)

Changed 11 years ago by Shawn Rutledge

Attachment: getafloat.tgz added

egg to demonstrate the bug

comment:1 Changed 11 years ago by Shawn Rutledge

Resolution: invalid
Status: newclosed

The solution is to declare the C function prototypes, e.g. declare them in a header and include it in the scm, or declare them inline. Despite the fact that the foreign-lambda looks like it declares the signature, chicken still assumes the return value will be an int unless it has the C function prototype. (This is still a bit of an annoyance, IMO.)

(module getafloat *
   (import ...)
#include "impl.h"

See also

comment:2 Changed 11 years ago by Shawn Rutledge

Or rather the C compiler assumes int.

Note: See TracTickets for help on using tickets.