1. 25 Feb, 2015 1 commit
  2. 16 Feb, 2015 1 commit
  3. 08 Feb, 2015 2 commits
    • Robbert Krebbers's avatar
      Update copyright headers. · 5a73c4ed
      Robbert Krebbers authored
      5a73c4ed
    • Robbert Krebbers's avatar
      Support function pointers and use a state monad in the frontend. · b2109c25
      Robbert Krebbers authored
      Important changes in the core semantics:
      * Types extended with function types. Since function types are a special kind
        of pointer types, types now have an additional mutual part called "ptr_type".
      * Pointers extended with function pointers. Theses are just names that refer
        to an actual function in the function environment.
      * Typing environments extended to assign argument and return types to function
        names. Before we used a separate environment for these, but since the
        argument and return types are already needed to type function pointers, this
        environment would appear in pretty much every typing judgment.
      
      As a side-effect, the frontend has been rewritten entirely. The important
      changes are:
      
      * Type checking of expressions is more involved: there is a special kind of
        expression type corresponding to a function designator.
      * To handle things like block scoped extern function, more state-fullness was
        needed. To prepare for future extensions, the entire frontend now uses a
        state monad.
      b2109c25
  4. 29 Jan, 2015 2 commits
  5. 25 Jan, 2015 1 commit
  6. 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
  7. 30 Sep, 2014 1 commit
  8. 24 Sep, 2014 1 commit
  9. 06 Sep, 2014 1 commit
  10. 03 Sep, 2014 1 commit
  11. 06 Aug, 2014 1 commit
  12. 10 Jul, 2014 1 commit
  13. 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
  14. 23 Jun, 2014 1 commit
  15. 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
  16. 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
  17. 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
  18. 24 May, 2014 1 commit
  19. 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
  20. 04 May, 2014 1 commit
  21. 02 May, 2014 2 commits
  22. 09 Sep, 2013 1 commit
  23. 15 Aug, 2013 1 commit
  24. 24 Jun, 2013 1 commit
  25. 17 Jun, 2013 1 commit
  26. 15 May, 2013 1 commit
  27. 12 May, 2013 1 commit
  28. 11 May, 2013 1 commit
  29. 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
  30. 25 Mar, 2013 1 commit
  31. 14 Mar, 2013 1 commit
  32. 24 Feb, 2013 1 commit
  33. 22 Feb, 2013 1 commit
  34. 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
  35. 01 Feb, 2013 1 commit
  36. 09 Jan, 2013 1 commit
  37. 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