added Z3_global_param_reset_all API

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/api/api_config_params.cpp

@@ -43,6 +43,13 @@ extern "C" {
         }
     }
 
+    void Z3_API Z3_global_param_reset_all() {
+        memory::initialize(UINT_MAX);
+        LOG_Z3_global_param_reset_all();
+        gparams::reset();
+        env_params::updt_params();
+    }
+
     std::string g_Z3_global_param_get_buffer;
     
     Z3_bool_opt Z3_API Z3_global_param_get(Z3_string param_id, Z3_string_ptr param_value) {

src/api/c++/z3++.h

@@ -67,6 +67,7 @@ namespace z3 {
     inline void set_param(char const * param, char const * value) { Z3_global_param_set(param, value); }
     inline void set_param(char const * param, bool value) { Z3_global_param_set(param, value ? "true" : "false"); }
     inline void set_param(char const * param, int value) { std::ostringstream oss; oss << value; Z3_global_param_set(param, oss.str().c_str()); }
+    inline void reset_params() { Z3_global_param_reset_all(); }
 
     /**
        \brief Exception used to sign API usage errors.

src/api/python/z3.py

@@ -219,6 +219,11 @@ def set_param(*args, **kws):
             Z3_global_param_set(str(prev), _to_param_value(a))
             prev = None
 
+def reset_params():
+    """Reset all global (or module) parameters.
+    """
+    Z3_global_param_reset_all()
+
 def set_option(*args, **kws):
     """Alias for 'set_param' for backward compatibility.
     """

src/api/z3_api.h

@@ -1260,6 +1260,17 @@ extern "C" {
        def_API('Z3_global_param_set', VOID, (_in(STRING), _in(STRING)))
     */
     void Z3_API Z3_global_param_set(__in Z3_string param_id, __in Z3_string param_value);
+
+
+    /**
+       \brief Restore the value of all global (and module) parameters.
+       This command will not affect already created objects (such as tactics and solvers).
+
+       \sa Z3_global_param_set
+
+       def_API('Z3_global_param_reset_all', VOID, ())
+    */
+    void Z3_API Z3_global_param_reset_all();
     
     /**
        \brief Get a global (or module) parameter.

src/util/gparams.cpp

@@ -60,20 +60,22 @@ public:
     }
 
     ~imp() {
-        {
-            dictionary<param_descrs*>::iterator it  = m_module_param_descrs.begin();
-            dictionary<param_descrs*>::iterator end = m_module_param_descrs.end();
-            for (; it != end; ++it) {
-                dealloc(it->m_value);
-            }
+        reset();
+        dictionary<param_descrs*>::iterator it  = m_module_param_descrs.begin();
+        dictionary<param_descrs*>::iterator end = m_module_param_descrs.end();
+        for (; it != end; ++it) {
+            dealloc(it->m_value);
         }
-        {
-            dictionary<params_ref*>::iterator it  = m_module_params.begin();
-            dictionary<params_ref*>::iterator end = m_module_params.end();
-            for (; it != end; ++it) {
-                dealloc(it->m_value);
-            }
+    }
+
+    void reset() {
+        m_params.reset();
+        dictionary<params_ref*>::iterator it  = m_module_params.begin();
+        dictionary<params_ref*>::iterator end = m_module_params.end();
+        for (; it != end; ++it) {
+            dealloc(it->m_value);
         }
+        m_module_params.reset();
     }
 
     // -----------------------------------------------
@@ -448,6 +450,11 @@ public:
 
 gparams::imp * gparams::g_imp = 0;
 
+void gparams::reset() {
+    SASSERT(g_imp != 0);
+    g_imp->reset();
+}
+
 void gparams::set(char const * name, char const * value) {
     TRACE("gparams", tout << "setting [" << name << "] <- '" << value << "'\n";);
     SASSERT(g_imp != 0);

src/util/gparams.h

@@ -27,6 +27,11 @@ class gparams {
 public:
     typedef default_exception exception;
 
+    /**
+       \brief Reset all global and module parameters.
+    */
+    static void reset();
+
     /**
        \brief Set a global parameter \c name with \c value.