1. 13 Feb, 2016 1 commit
  2. 11 Feb, 2016 1 commit
  3. 16 Nov, 2015 1 commit
  4. 01 Feb, 2017 1 commit
    • Robbert Krebbers's avatar
      Port to Coq 8.5 beta 2. · 02f213ce
      Robbert Krebbers authored
      The port makes the following notable changes:
      
      * The carrier types of separation algebras and integer environments are no
        longer in Set. Now they have a type at a fixed type level above Set. This
        both works better in 8.5 and makes the formalization more general.
        I have tried putting them at polymorphic type levels, but that increased the
        compilation time by an order of magnitude.
      * I am using a custom f_equal tactic written in Ltac to circumvent bug #4069.
        That bug has been fixed, so this custom tactic can be removed when the next
        beta of 8.5 is out.
      02f213ce
  5. 08 Feb, 2015 1 commit
  6. 23 Dec, 2014 1 commit
    • Robbert Krebbers's avatar
      More lenient pointer equality. · 914f32ee
      Robbert Krebbers authored
      Pointer equality is now defined using absolute object offsets. The treatment
      is similar to CompCert:
      
      * Equality of pointers in the same object is defined provided the object has
        not been deallocated.
      * Equality of pointers in different objects is defined provided both pointers
        have not been deallocated and both are strict (i.e. not end-of-array).
      
      Thus, pointer equality is defined for all pointers that are not-end-of-array
      and have not been deallocated. The following examples have defined behavior:
      
        int x, y;
        printf("%d\n", &x == &y);
        int *p = malloc(sizeof(int)), *q = malloc(sizeof(int));
        printf("%d\n", p == q);
        struct S { int a; int b; } s, *r = &s;
        printf("%d\n", &s.a + 1 == &(r->b));
      
      The following not:
      
        int x, y;
        printf("%d\n", &x + 1 == &y);
      914f32ee
  7. 22 Aug, 2014 1 commit
    • Robbert Krebbers's avatar
      Modify typing judgments to depend on a description of the types of objects in · 7f9c5994
      Robbert Krebbers authored
      memory instead of the whole memory itself.
      
      This has the following advantages:
      * Avoid parametrization in {addresses,pointers,pointer_bits,bits}.v
      * Make {base_values,values}.v independent of the memory, this makes better
        parallelized compilation possible.
      * Allow small memories (e.g. singletons as used in separation logic) with
        addresses to objects in another part to be typed.
      * Some proofs become easier, because the memory environments are preserved
        under many operations (insert, force, lock, unlock).
      
      It also as the following disadvantages:
      * At all kinds of places we now have explicit casts from memories to memory
        environments. This is kind of ugly. Note, we cannot declare memenv_of as a
        Coercion because it is non-uniform.
      * It is a bit inefficient with respect to the interpreter, because memory
        environments are finite functions instead of proper functions, so calling
        memenv_of often (which we do) is not too good.
      7f9c5994
  8. 22 May, 2014 1 commit
    • Robbert Krebbers's avatar
      Various changes. · bb9d75d9
      Robbert Krebbers authored
      * Parametrize refinements with memories. This way, refinements imply typing,
        for example [w1 ⊑{Γ,f@m1↦m2} w2 : τ → (Γ,m1) ⊢ w1 : τ]. This relieves us from
        various hacks.
      * Use addresses instead of index/references pairs for lookup and alter
        operations on memories.
      * Prove various disjointness properties.
      bb9d75d9
  9. 02 May, 2014 2 commits
  10. 21 Aug, 2013 1 commit
  11. 24 Jun, 2013 1 commit
  12. 21 May, 2013 1 commit
  13. 07 May, 2013 1 commit
    • Robbert Krebbers's avatar
      Lots of refactoring. and new results on permutations and list containment. · 361308c7
      Robbert Krebbers authored
      The refactoring includes:
      * Use infix notations for the various list relations
      * More consistent naming
      * Put lemmas on one line whenever possible
      * Change proofs into one-liners when possible
      * Make better use of the "Implicit Types" command
      * Improve the order of the list module by placing all definitions at the start,
        then the proofs, and finally the tactics.
      
      Besides, there is some new machinery for proofs by reflection on lists. It is
      used for a decision procedure for permutations and list containment.
      361308c7
  14. 14 Mar, 2013 1 commit
  15. 19 Feb, 2013 1 commit
    • Robbert Krebbers's avatar
      Support sequence point, add permissions, and update prelude. · 415a4f1c
      Robbert Krebbers authored
      Both the operational and axiomatic semantics are extended with sequence points
      and a permission system based on fractional permissions. In order to achieve
      this, the memory model has been completely revised, and is now built on top
      of an abstract interface for permissions.
      
      Apart from these changed, the library on lists and sets has been heavily
      extended, and minor changed have been made to other parts of the prelude.
      415a4f1c
  16. 01 Feb, 2013 1 commit
  17. 09 Jan, 2013 1 commit
  18. 05 Jan, 2013 1 commit
    • Robbert Krebbers's avatar
      Various small changes. · 507a150a
      Robbert Krebbers authored
      * Define the standard strict order on pre orders.
      * Prove that this strict order is well founded for finite sets and finite maps.
        We also provide some utilities to compute with well founded recursion.
      * Improve the "simplify_option_equality" tactic to handle more cases.
      * Axiomatize finiteness of finite maps by translation to lists, instead of by
        them having a finite domain.
      * Prove many additional properties of finite maps.
      * Add many functions and theorems on lists, including: permutations, resize,
        filter, ...
      507a150a
  19. 12 Nov, 2012 1 commit
    • Robbert Krebbers's avatar
      Many relatively small changes. · 50dfc148
      Robbert Krebbers authored
      Most interestingly:
      * Use [lia] instead of [omega] everywhere
      * More many generic lemmas on the memory to the theory on finite maps.
      * Many additional list lemmas.
      * A new interface for a monad for collections, which is now also used by the
        collection tactics.
      * Provide an additional finite collection implementation using unordered lists
        without duplicates removed. This implementation forms a monad (just the list
        monad in disguise).
      50dfc148
  20. 19 Oct, 2012 1 commit
    • Robbert Krebbers's avatar
      Add non-deterministic expressions with side-effects. · e82cda6c
      Robbert Krebbers authored
      The following things have been changed in this revision:
      
      * We now give a small step semantics for expressions. The denotational semantics
        only works for side-effect free expressions.
      * Dynamically allocated memory through alloc and free is now supported.
      * The following expressions are added: assignment, function call, unary
        operators, conditional, alloc, and free.
      * Some customary induction schemes for expressions are proven.
      * The axiomatic semantics (and its interpretation) have been changed in order
        to deal with non-deterministic expressions.
      * We have added inversion schemes based on small inversions for the operational
        semantics. Inversions using these schemes are much faster.
      * We improved the statement preservation proof of the operational semantics.
      * We now use a variant of SsReflect's [by] and [done], instead of Coq's [now]
        and [easy]. The [done] tactic is much faster as it does not perform
        inversions.
      * Add theory, definitions and notations on vectors.
      * Separate theory on contexts.
      * Change [Arguments] declarations to ensure better unfolding.
      e82cda6c
  21. 29 Aug, 2012 1 commit
  22. 21 Aug, 2012 1 commit
    • Robbert Krebbers's avatar
      Major revision of the whole development. · 18669b92
      Robbert Krebbers authored
      The main changes are:
      
      * Function calls in the operational semantics
      * Mutually recursive function calls in the axiomatic semantics
      * A general definition of the interpretation of the axiomatic semantics  so as
        to improve reusability (useful for function calls, and also for expressions
        in future versions)
      * Type classes for stack independent, memory independent, and memory extensible
        assertions, and a lot of instances to automatically derive these properties.
      * Many additional lemmas on the memory and more robust tactics to simplify
        goals involving is_free and mem_disjoint
      * Proof of preservation of statements in the smallstep semantics
      
      * Some new tactics: feed, feed destruct, feed inversion, etc...
      * More robust tactic scripts using bullets and structured scripts
      * Truncate most lines at 80 characters
      18669b92
  23. 11 Jun, 2012 1 commit