Hi, i stumbled over strange error messages and some unexpected behavior in the ffi implementation.
The following code raises a very misleading error message: (define _tm (_array _byte 1024 1024 1200 2)) (malloc _tm) -> malloc: expects argument of type <non-void-C-type>; given #<ctype> One dimensional arrays fail eariler and with a slightly better error: (_array _byte 2147483649) -> make-array-type: expects type <pointer-sized nonnegative exact integer> as 2nd argument, given: 2147483649; other arguments were: #<ctype:uint8>Searching in foreign.c for the cause i found out, that the current implementation
fails badly with types > 2GB size (not only arrays) because it uses int as result for ctype_sizeof.As a consequence it should even fail at the 2GB mark on 64bit (gcc-)systems where
int is usually fixed to 32bit for compatibility reasons.The problem seems to be limited to the foreign.c as libc, libffi and rackets gc2 functions use size_t for all size arguments. I tried to fix it and attached a patch vs git head. But it may be that the use of size_t leads to strange overflow behavior whenever size is multiplied by a potentially negative value to get an offset that is stored in a intptr_t. As far as i can see these overflow cases are not handled in the current
implementation so it may be ok to continue to ignore them.As a side question: What is the sense of foreign.rktc if it is never used to generate
the c file from it? Tobias -- --------------------------------------------------------- Tobias Hammer DLR / Institute of Robotics and Mechatronics Tel.: 08153/28-1487 Mail: tobias.ham...@dlr.de
ffi-2gb.patch
Description: Binary data
ffi-2gb-limit-demo.rkt
Description: Binary data
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