fixes

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

src/api/api_goal.cpp

@@ -178,4 +178,18 @@ extern "C" {
         Z3_CATCH_RETURN("");
     }
 
+    Z3_string Z3_API Z3_goal_to_dimacs_string(Z3_context c, Z3_goal g) {
+        Z3_TRY;
+        LOG_Z3_goal_to_dimacs_string(c, g);
+        RESET_ERROR_CODE();
+        std::ostringstream buffer;
+        to_goal_ref(g)->display_dimacs(buffer);
+        // Hack for removing the trailing '\n'
+        std::string result = buffer.str();
+        SASSERT(result.size() > 0);
+        result.resize(result.size()-1);
+        return mk_c(c)->mk_external_string(result);
+        Z3_CATCH_RETURN("");
+    }
+
 };

src/api/api_solver.cpp

@@ -139,6 +139,10 @@ extern "C" {
             SET_ERROR_CODE(Z3_PARSER_ERROR);
             return;
         }
+
+        bool initialized = to_solver(s)->m_solver.get() != 0;
+        if (!initialized)
+            init_solver(c, s);
         ptr_vector<expr>::const_iterator it  = ctx->begin_assertions();
         ptr_vector<expr>::const_iterator end = ctx->end_assertions();
         for (; it != end; ++it) {

src/api/dotnet/Goal.cs

@@ -208,6 +208,15 @@ namespace Microsoft.Z3
             return Native.Z3_goal_to_string(Context.nCtx, NativeObject);
         }
 
+        /// <summary>
+        /// Goal to DIMACS formatted string conversion.
+        /// </summary>
+        /// <returns>A string representation of the Goal.</returns>
+        public string ToDimacs()
+        {
+            return Native.Z3_goal_to_dimacs_string(Context.nCtx, NativeObject);
+        }
+
         /// <summary>
         /// Goal to BoolExpr conversion.
         /// </summary>

src/api/python/z3/z3.py

@@ -4971,6 +4971,10 @@ class Goal(Z3PPObject):
         """Return a textual representation of the s-expression representing the goal."""
         return Z3_goal_to_string(self.ctx.ref(), self.goal)
 
+    def dimacs(self):
+        """Return a textual representation of the goal in DIMACS format."""
+        return Z3_goal_to_dimacs_string(self.ctx.ref(), self.goal)
+
     def translate(self, target):
         """Copy goal `self` to context `target`.
 
@@ -6300,7 +6304,7 @@ class Solver(Z3PPObject):
 
     def from_file(self, filename):
         """Parse assertions from a file"""
-        Z3_solver_from_file(self.ctx.ref(), self.solver)
+        Z3_solver_from_file(self.ctx.ref(), self.solver, filename)
 
     def from_string(self, s):
         """Parse assertions from a string"""

src/api/z3_api.h

@@ -5568,6 +5568,13 @@ extern "C" {
     */
     Z3_string Z3_API Z3_goal_to_string(Z3_context c, Z3_goal g);
 
+    /**
+       \brief Convert a goal into a DIMACS formatted string.
+
+       def_API('Z3_goal_to_dimacs_string', STRING, (_in(CONTEXT), _in(GOAL)))
+    */
+    Z3_string Z3_API Z3_goal_to_dimacs_string(Z3_context c, Z3_goal g);
+
     /*@}*/
 
     /** @name Tactics and Probes */