1. 25 Jan, 2015 1 commit
  2. 16 Dec, 2014 1 commit
    • Robbert Krebbers's avatar
      Allow frozen pointer annotations to be refined. · 26917d00
      Robbert Krebbers authored
      The refinement relation on addresses allows union references to be refined:
      
        (β2 → β1) → RUnion i s β1 ⊆ RUnion i s β2
      
      The result is that frozen values are below their unfrozen variant, which made
      it possible to prove that constant propagation (see constant_propagation.v) can
      be performed on the level of the memory model.
      26917d00
  3. 30 Sep, 2014 1 commit
  4. 24 Sep, 2014 1 commit
  5. 06 Sep, 2014 1 commit
  6. 03 Sep, 2014 1 commit
  7. 06 Aug, 2014 1 commit
  8. 10 Jul, 2014 1 commit
  9. 25 Jun, 2014 1 commit
    • Robbert Krebbers's avatar
      Fix bugs in pointer operations · baaee9e0
      Robbert Krebbers authored
      * Equality comparison of NULL and non NULL pointers should be defined
      * Pointer comparisons, casts, and truth should only be defined for pointers
        that are alive
      * Treat dead pointers as indeterminate values in refinements. The proofs that
        all operations preserve refinement indicate that dead pointers can be indeed
        by replaced by anything without affecting the program's behavior.
      baaee9e0
  10. 23 Jun, 2014 1 commit
  11. 16 Jun, 2014 1 commit
    • Robbert Krebbers's avatar
      Changes in preparation of the C type system and C front-end language · 3503a91f
      Robbert Krebbers authored
      Major changes:
      * Make void a base type, and include a proper void base value. This is necessary
        because expressions (free, functions without return value) can yield a void.
        We now also allow void casts conforming to the C standard.
      * Various missing lemmas about typing, weakening, decidability, ...
      * The operations "free" and "alloc" now operate on l-values instead of r-values.
        This removes some duplication.
      * Improve notations of expressions and statements. Change the presence of the
        operators conforming to the C standard.
      
      Small changes:
      * Use the classes "Typed" and "TypeCheck" for validity of indexes in memory.
        This gives more uniform notations.
      * New tactic "typed_inversion" performs inversion on an inductive predicate
        of type "Typed" and folds the premises.
      * Remove a horrible hack in the definitions of the classes "FMap", "MBind",
        "OMap", "Alter" that was used to let "simpl" behave better. Instead, we have
        defined a tactic "csimpl" that folds the results after performing an
        ordinary "simpl".
      * Fast operation to remove duplicates from lists using hashsets.
      * Make various type constructors (mainly finite map implementations) universe
        polymorphic by packing them into an inductive. This way, the whole C syntax
        can live in type, avoiding the need for (slow) universe checks.
      3503a91f
  12. 06 Jun, 2014 1 commit
    • Robbert Krebbers's avatar
      Miscellaneous changes to the memory · ab930b45
      Robbert Krebbers authored
      * Remove generic path_typed instance for lists. For the zippers in the
        operational semantics, it goes the other way around.
      * Remove constructor lemmas for values/memory_trees and use a generic tactic
        instead. This tactic uses the standard constructor tactic, but folds the
        type classes afterward.
      ab930b45
  13. 05 Jun, 2014 1 commit
    • Robbert Krebbers's avatar
      Preparation to port the master branch · d60affc0
      Robbert Krebbers authored
      Major changes:
      * A data structure to collect locked addresses in memory.
      * Operations to lock and unlock addresses.
      * Remove [ctree_Forall] and express it using [Forall] and [ctree_flatten]. This
        saves a lot of lines of code.
      * Add a [void] value. This value cannot be typed, but will be used as a dummy
        return value for functions with return type [void].
      
      Minor changes:
      * Various deciders in preparation of the executable semantics.
      * Improve naming and notations.
      * Remove obsolete stuff.
      d60affc0
  14. 24 May, 2014 1 commit
  15. 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
  16. 04 May, 2014 1 commit
  17. 02 May, 2014 2 commits
  18. 09 Sep, 2013 1 commit
  19. 15 Aug, 2013 1 commit
  20. 24 Jun, 2013 1 commit
  21. 17 Jun, 2013 1 commit
  22. 15 May, 2013 1 commit
  23. 12 May, 2013 1 commit
  24. 11 May, 2013 1 commit
  25. 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
  26. 25 Mar, 2013 1 commit
  27. 14 Mar, 2013 1 commit
  28. 24 Feb, 2013 1 commit
  29. 22 Feb, 2013 1 commit
  30. 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
  31. 01 Feb, 2013 1 commit
  32. 09 Jan, 2013 1 commit
  33. 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
  34. 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
  35. 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
  36. 29 Aug, 2012 1 commit
  37. 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
  38. 11 Jun, 2012 1 commit