Frama-C-discuss mailing list archives

This page gathers the archives of the old Frama-C-discuss archives, that was hosted by Inria's gforge before its demise at the end of 2020. To search for mails newer than September 2020, please visit the page of the new mailing list on Renater.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Frama-c-discuss] Use of ACSL types for WP

  • Subject: [Frama-c-discuss] Use of ACSL types for WP
  • From: mww at amazon.com (Whalen, Mike)
  • Date: Sun, 17 May 2020 04:38:43 +0000
I have a general question about representation types in frama-c.  I have a circular buffer of integers that is designed to represent a fifo queue.  I’d like to map it to a \list<int> and show that manipulations on the circular buffer preserve the abstract behavior of the list.  I notice that ACSL has a \list type that would seem to meet my needs.  However, I am not seeing how to create an abstract representation of the buffer.

My initial thought would be to put a ghost field of type \list<int> in the structure that defines a circular buffer.  However, it appears that ghost fields of any kind are not supported, unless I am misunderstanding the syntax in the ACSL manual:


// ghost field format matches the format

// in ACSL ANSI/ISO C Specification Language Version 1.14 document

// p. 99

typedef struct _foo {

    int field1;

    //@ ghost int bar;

    int field2;

} foo;

This does not compile using frama-c -wp test_ghost_field.c.

Next I thought I would just create ghost vars in the functions that modify the circular buffer and sync up that way, but it appears that \lists are not supported as ghost vars:

#include <stdio.h>

int main() {
    int x = 1;
    //@ ghost y = 2;
    //@ ghost y = y + 1;

    //@ ghost \list<int> z = [| |];
}

Frama-c will not compile this using: frama-c -wp test_ghost_list.c.

So…how *does* one create a type abstraction in frama-c/wp?  If there aren’t some good ways of abstracting types, I would expect reasoning to become complex, but perhaps I am approaching this the wrong way.  Any guidance or pointers is appreciated.

Thanks much,

Mike
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20200517/ec9d5298/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: test_ghost_field.c
Type: application/octet-stream
Size: 333 bytes
Desc: test_ghost_field.c
URL: <http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20200517/ec9d5298/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: test_ghost_list.c
Type: application/octet-stream
Size: 214 bytes
Desc: test_ghost_list.c
URL: <http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20200517/ec9d5298/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: circ_buffer.c
Type: application/octet-stream
Size: 2168 bytes
Desc: circ_buffer.c
URL: <http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20200517/ec9d5298/attachment-0002.obj>