merge unstable into opt

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/api/api_context.cpp

@@ -129,6 +129,7 @@ namespace api {
             for (unsigned i = 0; i < m_replay_stack.size(); ++i) {
                 dealloc(m_replay_stack[i]);
             }
+            m_ast_trail.reset();
         }
         reset_parser();
         dealloc(m_solver);
@@ -343,24 +344,21 @@ namespace api {
     
     void context::push() {
         get_smt_kernel().push();
-        if (!m_user_ref_count) {
-            m_ast_lim.push_back(m_ast_trail.size());
-            m_replay_stack.push_back(0);
-        }
+        m_ast_lim.push_back(m_ast_trail.size());
+        m_replay_stack.push_back(0);        
     }
     
     void context::pop(unsigned num_scopes) {
         for (unsigned i = 0; i < num_scopes; ++i) {
-            if (!m_user_ref_count) {
-                unsigned sz = m_ast_lim.back();
-                m_ast_lim.pop_back();
-                dealloc(m_replay_stack.back());
-                m_replay_stack.pop_back();
-                while (m_ast_trail.size() > sz) {
-                    m_ast_trail.pop_back();
-                }
+            unsigned sz = m_ast_lim.back();
+            m_ast_lim.pop_back();
+            dealloc(m_replay_stack.back());
+            m_replay_stack.pop_back();
+            while (m_ast_trail.size() > sz) {
+                m_ast_trail.pop_back();
             }
         }
+        SASSERT(num_scopes <= get_smt_kernel().get_scope_level());
         get_smt_kernel().pop(num_scopes);
     }
 

src/api/api_interp.cpp

@@ -38,6 +38,7 @@ Revision History:
 #include"iz3hash.h"
 #include"iz3pp.h"
 #include"iz3checker.h"
+#include"scoped_proof.h"
 
 using namespace stl_ext;
 
@@ -290,6 +291,99 @@ extern "C" {
     opts->map[name] = value;
   }
 
+  Z3_ast_vector Z3_API Z3_get_interpolant(__in Z3_context c, __in Z3_ast pf, __in Z3_ast pat, __in Z3_params p){
+    Z3_TRY;
+    LOG_Z3_get_interpolant(c, pf, pat, p);
+    RESET_ERROR_CODE();
+
+    Z3_ast_vector_ref * v = alloc(Z3_ast_vector_ref, mk_c(c)->m());
+    mk_c(c)->save_object(v);
+
+    ast *_pf = to_ast(pf);
+    ast *_pat = to_ast(pat);
+    
+    ptr_vector<ast> interp;
+    ptr_vector<ast> cnsts; // to throw away
+    
+    ast_manager &_m = mk_c(c)->m();
+
+    iz3interpolate(_m,
+		   _pf,
+		   cnsts,
+		   _pat,
+		   interp,
+		   (interpolation_options_struct *) 0 // ignore params for now
+		   );
+    
+    // copy result back
+    for(unsigned i = 0; i < interp.size(); i++){
+      v->m_ast_vector.push_back(interp[i]);
+      _m.dec_ref(interp[i]);
+    }
+    RETURN_Z3(of_ast_vector(v));
+    Z3_CATCH_RETURN(0);
+  }
+
+  Z3_lbool Z3_API Z3_compute_interpolant(__in Z3_context c, __in Z3_ast pat, __in Z3_params p, __out Z3_ast_vector *out_interp, __out Z3_model *model){
+    Z3_TRY;
+    LOG_Z3_compute_interpolant(c, pat, p, out_interp, model);
+    RESET_ERROR_CODE();
+
+
+    // params_ref &_p = to_params(p)->m_params;
+    params_ref _p;
+    _p.set_bool("proof", true); // this is currently useless
+
+    scoped_proof_mode spm(mk_c(c)->m(),PGM_FINE);
+    scoped_ptr<solver_factory> sf = mk_smt_solver_factory();
+    scoped_ptr<solver> m_solver((*sf)(mk_c(c)->m(), _p, true, true, true, ::symbol::null));
+    m_solver.get()->updt_params(_p); // why do we have to do this?
+
+    ast *_pat = to_ast(pat);
+    
+    ptr_vector<ast> interp;
+    ptr_vector<ast> cnsts; // to throw away
+    
+    ast_manager &_m = mk_c(c)->m();
+
+    model_ref m;
+    lbool _status = iz3interpolate(_m,
+				   *(m_solver.get()),
+				   _pat,
+				   cnsts,
+				   interp,
+				   m,
+				   0 // ignore params for now
+				   );
+    
+    Z3_lbool status = of_lbool(_status);
+    
+    Z3_ast_vector_ref *v = 0;
+    *model = 0;
+
+    if(_status == l_false){
+      // copy result back
+      v = alloc(Z3_ast_vector_ref, mk_c(c)->m());
+      mk_c(c)->save_object(v);
+      for(unsigned i = 0; i < interp.size(); i++){
+	v->m_ast_vector.push_back(interp[i]);
+	_m.dec_ref(interp[i]);
+      }
+    }
+    else {
+      model_ref _m;
+      m_solver.get()->get_model(_m);
+      Z3_model_ref *crap = alloc(Z3_model_ref);
+      crap->m_model = _m.get();
+      mk_c(c)->save_object(crap);
+      *model = of_model(crap);
+    }
+
+    *out_interp = of_ast_vector(v);
+    
+    return status;
+    Z3_CATCH_RETURN(Z3_L_UNDEF);
+  }
 
 
 };
@@ -317,7 +411,7 @@ static void get_file_params(const char *filename, hash_map<std::string,std::stri
       for(unsigned i = 0; i < tokens.size(); i++){
 	std::string &tok = tokens[i];
 	size_t eqpos = tok.find('=');
-	if(eqpos < tok.size()){
+	if(eqpos != std::string::npos){
 	  std::string left = tok.substr(0,eqpos);
 	  std::string right = tok.substr(eqpos+1,tok.size()-eqpos-1);
 	  params[left] = right;

src/api/api_solver.cpp

@@ -40,6 +40,7 @@ extern "C" {
         params_ref p = s->m_params;
         mk_c(c)->params().get_solver_params(mk_c(c)->m(), p, proofs_enabled, models_enabled, unsat_core_enabled);
         s->m_solver = (*(s->m_solver_factory))(mk_c(c)->m(), p, proofs_enabled, models_enabled, unsat_core_enabled, s->m_logic);
+        s->m_solver->updt_params(p);
     }
 
     static void init_solver(Z3_context c, Z3_solver s) {

src/api/api_solver_old.cpp

@@ -40,7 +40,7 @@ extern "C" {
         LOG_Z3_pop(c, num_scopes);
         RESET_ERROR_CODE();
         CHECK_SEARCHING(c);
-        if (num_scopes > mk_c(c)->get_smt_kernel().get_scope_level()) {
+        if (num_scopes > mk_c(c)->get_num_scopes()) {
             SET_ERROR_CODE(Z3_IOB);
             return;
         }

src/api/dotnet/Context.cs

@@ -3565,7 +3565,7 @@ namespace Microsoft.Z3
         /// </summary>
         /// <remarks>
         /// The list of all configuration parameters can be obtained using the Z3 executable:
-        /// <c>z3.exe -ini?</c>
+        /// <c>z3.exe -p</c>
         /// Only a few configuration parameters are mutable once the context is created.
         /// An exception is thrown when trying to modify an immutable parameter.
         /// </remarks>
@@ -3691,7 +3691,7 @@ namespace Microsoft.Z3
         internal Optimize.DecRefQueue Optimize_DRQ { get { Contract.Ensures(Contract.Result<Optimize.DecRefQueue>() != null); return m_Optimize_DRQ; } }
 
 
-        internal uint refCount = 0;
+        internal long refCount = 0;
 
         /// <summary>
         /// Finalizer.

src/api/dotnet/Z3Object.cs

@@ -19,6 +19,7 @@ Notes:
 
 using System;
 using System.Diagnostics.Contracts;
+using System.Threading;
 
 namespace Microsoft.Z3
 {
@@ -50,8 +51,7 @@ namespace Microsoft.Z3
 
             if (m_ctx != null)
             {
-                m_ctx.refCount--;
-                if (m_ctx.refCount == 0)
+                if (Interlocked.Decrement(ref m_ctx.refCount) == 0)
                     GC.ReRegisterForFinalize(m_ctx);
                 m_ctx = null;
             }
@@ -77,7 +77,7 @@ namespace Microsoft.Z3
         {
             Contract.Requires(ctx != null);
 
-            ctx.refCount++;
+            Interlocked.Increment(ref ctx.refCount);
             m_ctx = ctx;
         }
 
@@ -85,7 +85,7 @@ namespace Microsoft.Z3
         {
             Contract.Requires(ctx != null);
 
-            ctx.refCount++;
+            Interlocked.Increment(ref ctx.refCount);
             m_ctx = ctx;
             IncRef(obj);
             m_n_obj = obj;

src/api/python/z3.py

@@ -7117,7 +7117,7 @@ def substitute(t, *m):
     if isinstance(m, tuple):
         m1 = _get_args(m)
         if isinstance(m1, list):
-            m = _get_args(m1)
+            m = m1
     if __debug__:
         _z3_assert(is_expr(t), "Z3 expression expected")
         _z3_assert(all([isinstance(p, tuple) and is_expr(p[0]) and is_expr(p[1]) and p[0].sort().eq(p[1].sort()) for p in m]), "Z3 invalid substitution, expression pairs expected.")
@@ -7410,3 +7410,128 @@ def parse_smt2_file(f, sorts={}, decls={}, ctx=None):
     dsz, dnames, ddecls = _dict2darray(decls, ctx)
     return _to_expr_ref(Z3_parse_smtlib2_file(ctx.ref(), f, ssz, snames, ssorts, dsz, dnames, ddecls), ctx)
    
+def Interp(a,ctx=None):
+    """Create an interpolation operator.
+    
+    The argument is an interpolation pattern (see tree_interpolant). 
+
+    >>> x = Int('x')
+    >>> print Interp(x>0)
+    interp(x > 0)
+    """
+    ctx = _get_ctx(_ctx_from_ast_arg_list([a], ctx))
+    s = BoolSort(ctx)
+    a = s.cast(a)
+    return BoolRef(Z3_mk_interp(ctx.ref(), a.as_ast()), ctx)
+
+def tree_interpolant(pat,p=None,ctx=None):
+    """Compute interpolant for a tree of formulas.
+
+    The input is an interpolation pattern over a set of formulas C.
+    The pattern pat is a formula combining the formulas in C using
+    logical conjunction and the "interp" operator (see Interp). This
+    interp operator is logically the identity operator. It marks the
+    sub-formulas of the pattern for which interpolants should be
+    computed. The interpolant is a map sigma from marked subformulas
+    to formulas, such that, for each marked subformula phi of pat
+    (where phi sigma is phi with sigma(psi) substituted for each
+    subformula psi of phi such that psi in dom(sigma)):
+
+      1) phi sigma implies sigma(phi), and
+
+      2) sigma(phi) is in the common uninterpreted vocabulary between
+      the formulas of C occurring in phi and those not occurring in
+      phi
+
+      and moreover pat sigma implies false. In the simplest case
+      an interpolant for the pattern "(and (interp A) B)" maps A
+      to an interpolant for A /\ B. 
+
+      The return value is a vector of formulas representing sigma. This
+      vector contains sigma(phi) for each marked subformula of pat, in
+      pre-order traversal. This means that subformulas of phi occur before phi
+      in the vector. Also, subformulas that occur multiply in pat will
+      occur multiply in the result vector.
+
+    If pat is satisfiable, raises an object of class ModelRef
+    that represents a model of pat.
+
+    If parameters p are supplied, these are used in creating the
+    solver that determines satisfiability.
+
+    >>> x = Int('x')
+    >>> y = Int('y')
+    >>> print tree_interpolant(And(Interp(x < 0), Interp(y > 2), x == y))
+    [Not(x >= 0), Not(y <= 2)]
+
+    >>> g = And(Interp(x<0),x<2)
+    >>> try:
+    ...     print tree_interpolant(g).sexpr()
+    ... except ModelRef as m:
+    ...     print m.sexpr()
+    (define-fun x () Int
+      (- 1))
+    """
+    f = pat
+    ctx = _get_ctx(_ctx_from_ast_arg_list([f], ctx))
+    ptr = (AstVectorObj * 1)()
+    mptr = (Model * 1)()
+    if p == None:
+        p = ParamsRef(ctx)
+    res = Z3_compute_interpolant(ctx.ref(),f.as_ast(),p.params,ptr,mptr)
+    if res == Z3_L_FALSE:
+        return AstVector(ptr[0],ctx)
+    raise ModelRef(mptr[0], ctx)
+
+def binary_interpolant(a,b,p=None,ctx=None):
+    """Compute an interpolant for a binary conjunction.
+
+    If a & b is unsatisfiable, returns an interpolant for a & b.
+    This is a formula phi such that
+
+    1) a implies phi
+    2) b implies not phi
+    3) All the uninterpreted symbols of phi occur in both a and b.
+
+    If a & b is satisfiable, raises an object of class ModelRef
+    that represents a model of a &b.
+
+    If parameters p are supplied, these are used in creating the
+    solver that determines satisfiability.
+
+    x = Int('x')
+    print binary_interpolant(x<0,x>2)
+    Not(x >= 0)
+    """
+    f = And(Interp(a),b)
+    return tree_interpolant(f,p,ctx)[0]
+
+def sequence_interpolant(v,p=None,ctx=None):
+    """Compute interpolant for a sequence of formulas.
+
+    If len(v) == N, and if the conjunction of the formulas in v is
+    unsatisfiable, the interpolant is a sequence of formulas w
+    such that len(w) = N-1 and v[0] implies w[0] and for i in 0..N-1:
+
+    1) w[i] & v[i+1] implies w[i+1] (or false if i+1 = N)
+    2) All uninterpreted symbols in w[i] occur in both v[0]..v[i]
+    and v[i+1]..v[n]
+    
+    Requires len(v) >= 1. 
+
+    If a & b is satisfiable, raises an object of class ModelRef
+    that represents a model of a & b.
+
+    If parameters p are supplied, these are used in creating the
+    solver that determines satisfiability.
+
+    >>> x = Int('x')
+    >>> y = Int('y')
+    >>> print sequence_interpolant([x < 0, y == x , y > 2])
+    [Not(x >= 0), Not(y >= 0)]
+    """
+    f = v[0]
+    for i in range(1,len(v)):
+        f = And(Interp(f),v[i])
+    return tree_interpolant(f,p,ctx)
+

src/api/python/z3types.py

@@ -113,3 +113,4 @@ class FuncEntryObj(ctypes.c_void_p):
 class RCFNumObj(ctypes.c_void_p):
   def __init__(self, e): self._as_parameter_ = e
   def from_param(obj): return obj
+

src/api/z3_api.h

@@ -1392,6 +1392,16 @@ extern "C" {
        although some parameters can be changed using #Z3_update_param_value.
        All main interaction with Z3 happens in the context of a \c Z3_context.
 
+       In contrast to #Z3_mk_context_rc, the life time of Z3_ast objects
+       are determined by the scope level of #Z3_push and #Z3_pop.
+       In other words, a Z3_ast object remains valid until there is a 
+       call to Z3_pop that takes the current scope below the level where 
+       the object was created.
+
+       Note that all other reference counted objects, including Z3_model,
+       Z3_solver, Z3_func_interp have to be managed by the caller. 
+       Their reference counts are not handled by the context.       
+
        \conly \sa Z3_del_context
 
        \conly \deprecated Use #Z3_mk_context_rc
@@ -6841,6 +6851,13 @@ END_MLAPI_EXCLUDE
     /**
        \brief Create a new (incremental) solver.
 
+       The function #Z3_solver_get_model retrieves a model if the
+       assertions is satisfiable (i.e., the result is \c
+       Z3_L_TRUE) and model construction is enabled.
+       The function #Z3_solver_get_model can also be used even
+       if the result is \c Z3_L_UNDEF, but the returned model
+       is not guaranteed to satisfy quantified assertions.
+
        def_API('Z3_mk_simple_solver', SOLVER, (_in(CONTEXT),))
     */
     Z3_solver Z3_API Z3_mk_simple_solver(__in Z3_context c);
@@ -6978,8 +6995,11 @@ END_MLAPI_EXCLUDE
        \brief Check whether the assertions in a given solver are consistent or not.
 
        The function #Z3_solver_get_model retrieves a model if the
-       assertions are not unsatisfiable (i.e., the result is not \c
-       Z3_L_FALSE) and model construction is enabled.
+       assertions is satisfiable (i.e., the result is \c
+       Z3_L_TRUE) and model construction is enabled.
+       Note that if the call returns Z3_L_UNDEF, Z3 does not
+       ensure that calls to #Z3_solver_get_model succeed and any models
+       produced in this case are not guaranteed to satisfy the assertions.
 
        The function #Z3_solver_get_proof retrieves a proof if proof
        generation was enabled when the context was created, and the 
@@ -7290,7 +7310,7 @@ END_MLAPI_EXCLUDE
        \mlonly then a valid model is returned.  Otherwise, it is unsafe to use the returned model.\endmlonly
        \conly The caller is responsible for deleting the model using the function #Z3_del_model.
        
-       \conly \remark In constrast with the rest of the Z3 API, the reference counter of the
+       \conly \remark In contrast with the rest of the Z3 API, the reference counter of the
        \conly model is incremented. This is to guarantee backward compatibility. In previous
        \conly versions, models did not support reference counting.
        
@@ -7403,6 +7423,11 @@ END_MLAPI_EXCLUDE
        \brief Delete a model object.
        
        \sa Z3_check_and_get_model
+
+       \conly \remark The Z3_check_and_get_model automatically increments a reference count on the model.
+       \conly The expected usage is that models created by that method are deleted using Z3_del_model.
+       \conly This is for backwards compatibility and in contrast to the rest of the API where
+       \conly callers are responsible for managing reference counts.
     
        \deprecated Subsumed by Z3_solver API
        
@@ -7930,6 +7955,108 @@ END_MLAPI_EXCLUDE
 
   Z3_context Z3_API Z3_mk_interpolation_context(__in Z3_config cfg);
 
+  /** Compute an interpolant from a refutation. This takes a proof of
+      "false" from a set of formulas C, and an interpolation
+      pattern. The pattern pat is a formula combining the formulas in C
+      using logical conjunction and the "interp" operator (see
+      #Z3_mk_interp). This interp operator is logically the identity
+      operator. It marks the sub-formulas of the pattern for which interpolants should
+      be computed. The interpolant is a map sigma from marked subformulas to
+      formulas, such that, for each marked subformula phi of pat (where phi sigma
+      is phi with sigma(psi) substituted for each subformula psi of phi such that
+      psi in dom(sigma)):
+
+      1) phi sigma implies sigma(phi), and
+
+      2) sigma(phi) is in the common uninterpreted vocabulary between
+      the formulas of C occurring in phi and those not occurring in
+      phi
+
+      and moreover pat sigma implies false. In the simplest case
+      an interpolant for the pattern "(and (interp A) B)" maps A
+      to an interpolant for A /\ B. 
+
+      The return value is a vector of formulas representing sigma. The
+      vector contains sigma(phi) for each marked subformula of pat, in
+      pre-order traversal. This means that subformulas of phi occur before phi
+      in the vector. Also, subformulas that occur multiply in pat will
+      occur multiply in the result vector.
+
+      In particular, calling Z3_get_interpolant on a pattern of the
+      form (interp ... (interp (and (interp A_1) A_2)) ... A_N) will
+      result in a sequence interpolant for A_1, A_2,... A_N. 
+
+      Neglecting interp markers, the pattern must be a conjunction of
+      formulas in C, the set of premises of the proof. Otherwise an
+      error is flagged.
+
+      Any premises of the proof not present in the pattern are
+      treated as "background theory". Predicate and function symbols
+      occurring in the background theory are treated as interpreted and
+      thus always allowed in the interpolant.
+
+      Interpolant may not necessarily be computable from all
+      proofs. To be sure an interpolant can be computed, the proof
+      must be generated by an SMT solver for which interpoaltion is
+      supported, and the premises must be expressed using only
+      theories and operators for which interpolation is supported.
+
+      Currently, the only SMT solver that is supported is the legacy
+      SMT solver. Such a solver is available as the default solver in
+      #Z3_context objects produced by #Z3_mk_interpolation_context.
+      Currently, the theories supported are equality with
+      uninterpreted functions, linear integer arithmetic, and the
+      theory of arrays (in SMT-LIB terms, this is AUFLIA).
+      Quantifiers are allowed. Use of any other operators (including
+      "labels") may result in failure to compute an interpolant from a
+      proof.
+
+      Parameters:
+
+      \param c logical context.
+      \param pf a refutation from premises (assertions) C
+      \param pat an interpolation pattern over C
+      \param p parameters
+
+       def_API('Z3_get_interpolant', AST_VECTOR, (_in(CONTEXT), _in(AST), _in(AST), _in(PARAMS)))
+    */
+
+  Z3_ast_vector Z3_API Z3_get_interpolant(__in Z3_context c, __in Z3_ast pf, __in Z3_ast pat, __in Z3_params p);
+
+  /* Compute an interpolant for an unsatisfiable conjunction of formulas.
+
+     This takes as an argument an interpolation pattern as in
+     #Z3_get_interpolant. This is a conjunction, some subformulas of
+     which are marked with the "interp" operator (see #Z3_mk_interp).
+     
+     The conjunction is first checked for unsatisfiability. The result
+     of this check is returned in the out parameter "status". If the result
+     is unsat, an interpolant is computed from the refutation as in #Z3_get_interpolant
+     and returned as a vector of formulas. Otherwise the return value is
+     an empty formula. 
+
+     See #Z3_get_interpolant for a discussion of supported theories.
+
+     The advantage of this function over #Z3_get_interpolant is that
+     it is not necessary to create a suitable SMT solver and generate
+     a proof. The disadvantage is that it is not possible to use the
+     solver incrementally.
+
+     Parameters:
+     
+     \param c logical context.
+     \param pat an interpolation pattern
+     \param p parameters for solver creation
+     \param status returns the status of the sat check
+     \param model returns model if satisfiable
+
+     Return value: status of SAT check
+     
+     def_API('Z3_compute_interpolant', INT, (_in(CONTEXT), _in(AST), _in(PARAMS), _out(AST_VECTOR), _out(MODEL)))
+  */
+  
+  Z3_lbool Z3_API Z3_compute_interpolant(__in Z3_context c, __in Z3_ast pat, __in Z3_params p, __out Z3_ast_vector *interp, __out Z3_model *model);
+
 
 /** Constant reprepresenting a root of a formula tree for tree interpolation */
 #define IZ3_ROOT SHRT_MAX