initial files to support theory-solver based synthesis

src/sat/smt/CMakeLists.txt

@@ -44,6 +44,7 @@ z3_add_component(sat_smt
     q_solver.cpp
     recfun_solver.cpp
     sat_th.cpp
+    synth_solver.cpp
     tseitin_theory_checker.cpp
     user_solver.cpp
   COMPONENT_DEPENDENCIES

src/sat/smt/euf_solver.cpp

@@ -28,6 +28,7 @@ Author:
 #include "sat/smt/fpa_solver.h"
 #include "sat/smt/dt_solver.h"
 #include "sat/smt/recfun_solver.h"
+#include "sat/smt/synth_solver.h"
 
 namespace euf {
 
@@ -130,6 +131,7 @@ namespace euf {
         arith_util arith(m);
         datatype_util dt(m);
         recfun::util rf(m);
+        
         if (pb.get_family_id() == fid)
             ext = alloc(pb::solver, *this, fid);
         else if (bvu.get_family_id() == fid)
@@ -144,6 +146,8 @@ namespace euf {
             ext = alloc(dt::solver, *this, fid);
         else if (rf.get_family_id() == fid)
             ext = alloc(recfun::solver, *this);
+        else if (m.mk_family_id("synth") == fid)
+            ext = alloc(synth::solver, *this);
         
         if (ext) 
             add_solver(ext);        

src/sat/smt/synth_solver.cpp

@@ -0,0 +1,90 @@
+/*++
+Copyright (c) 2020 Microsoft Corporation
+
+Module Name:
+
+    synth_solver.h
+
+Author:
+
+    Petra Hozzova 2023-08-08
+    Nikolaj Bjorner (nbjorner) 2020-08-17
+
+--*/
+
+
+#include "sat/smt/synth_solver.h"
+#include "sat/smt/euf_solver.h"
+
+namespace synth {
+
+    solver::solver(euf::solver& ctx):
+        th_euf_solver(ctx, symbol("synth"), ctx.get_manager().mk_family_id("synth")) {}
+        
+    solver::~solver() {}
+
+
+    // recognize synthesis objective as part of search objective.
+    // register it for calls to check.
+    void solver::asserted(sat::literal lit) {
+
+    }
+
+    // block current model using realizer by E-graph (and arithmetic)
+    // 
+    sat::check_result solver::check() {
+
+        return sat::check_result::CR_DONE;
+    }
+
+    // nothing particular to do
+    void solver::push_core() {
+
+    }
+
+    // nothing particular to do
+    void solver::pop_core(unsigned n) {
+    }
+
+    // nothing particular to do
+    bool solver::unit_propagate() {
+        return false;
+    }
+
+    // retrieve explanation for assertions made by synth solver. It only asserts unit literals so nothing to retrieve
+    void solver::get_antecedents(sat::literal l, sat::ext_justification_idx idx, sat::literal_vector & r, bool probing) {
+    }
+
+    // where we collect statistics (number of invocations?)
+    void solver::collect_statistics(statistics& st) const {}
+
+    // recognize synthesis objectives here.
+    sat::literal solver::internalize(expr* e, bool sign, bool root) {
+        NOT_IMPLEMENTED_YET();
+        return sat::null_literal;
+    }
+
+    // recognize synthesis objectives here and above
+    void solver::internalize(expr* e) {}
+
+    // display current state (eg. current set of realizers)
+    std::ostream& solver::display(std::ostream& out) const {
+        return out;
+    }
+
+    // justified by "synth".
+    std::ostream& solver::display_justification(std::ostream& out, sat::ext_justification_idx idx) const {
+        return out << "synth";
+    }
+    
+    std::ostream& solver::display_constraint(std::ostream& out, sat::ext_constraint_idx idx) const {
+        return out << "synth";
+    }
+
+    // create a clone of the solver.
+    euf::th_solver* solver::clone(euf::solver& ctx) {
+        NOT_IMPLEMENTED_YET();
+        return nullptr;
+    }
+
+}

src/sat/smt/synth_solver.h

@@ -0,0 +1,47 @@
+/*++
+Copyright (c) 2020 Microsoft Corporation
+
+Module Name:
+
+    synth_solver.h
+
+Author:
+
+    Petra Hozzova 2023-08-08
+    Nikolaj Bjorner (nbjorner) 2020-08-17
+
+--*/
+
+#pragma once
+
+#include "sat/smt/sat_th.h"
+#include "solver/solver.h"
+
+
+namespace synth {
+
+    class solver : public euf::th_euf_solver {
+
+    public:
+        solver(euf::solver& ctx);
+        
+        ~solver() override;
+
+        
+        void asserted(sat::literal lit) override;
+
+        sat::check_result check() override;
+        void push_core() override;
+        void pop_core(unsigned n) override;
+        bool unit_propagate() override;
+        void get_antecedents(sat::literal l, sat::ext_justification_idx idx, sat::literal_vector & r, bool probing) override;
+        void collect_statistics(statistics& st) const override;
+        sat::literal internalize(expr* e, bool sign, bool root) override;
+        void internalize(expr* e) override;
+        std::ostream& display(std::ostream& out) const override;
+        std::ostream& display_justification(std::ostream& out, sat::ext_justification_idx idx) const override;
+        std::ostream& display_constraint(std::ostream& out, sat::ext_constraint_idx idx) const override;
+        euf::th_solver* clone(euf::solver& ctx) override;
+
+    };
+};