xspice, implement "CALLBACK"

Allow to register a callback function in the cfunc.mod files,
  which will be invoked in MIFdestroy.
Usefull to "free" memory which has been allocated locally in a cfunc.mod file.

src/include/ngspice/mifcmdat.h

@@ -366,6 +366,7 @@ struct Mif_Private {
     Mif_Param_Data_t       **param;       /* Information about each parameter     */
     int                    num_inst_var;  /* Number of instance variables         */
     Mif_Inst_Var_Data_t    **inst_var;    /* Information about each inst variable */
+    Mif_Callback_t         *callback;     /* Callback function */
 
 };
 

src/include/ngspice/mifdefs.h

@@ -79,6 +79,7 @@ struct MIFinstance {
     Mif_Boolean_t       event_driven;     /* true if this inst is event-driven or hybrid type */
 
     int                 inst_index;       /* Index into inst_table in evt struct in ckt */
+    Mif_Callback_t      callback;         /* instance callback function */
 
 };
 

src/include/ngspice/miftypes.h

@@ -172,6 +172,15 @@ typedef enum {
 } Mif_Cntl_Src_Type_t;
 
 
+/*
+ * The "reason" for a callback invocation
+ */
+
+typedef enum {
+    MIF_CB_DESTROY = 1,   /* MIFdestroy has been invoked, its time to clean up */
+}  Mif_Callback_Reason_t;
+
+
 /* ***************************************************************************** */
 
 
@@ -218,5 +227,7 @@ typedef struct Mif_Private Mif_Private_t;
 typedef struct MIFinstance MIFinstance;
 typedef struct MIFmodel MIFmodel;
 
+typedef void (* Mif_Callback_t)(Mif_Private_t *, Mif_Callback_Reason_t);
+
 
 #endif

src/xspice/cmpp/mod_lex.l

@@ -91,6 +91,7 @@ Z	[0-9A-Za-z_]
 
 ARGS			{return TOK_ARGS;}
 INIT			{return TOK_INIT;}
+CALLBACK		{return TOK_CALLBACK;}
 ANALYSIS		{return TOK_ANALYSIS;}
 NEW_TIMEPOINT		{return TOK_NEW_TIMEPOINT;}
 CALL_TYPE		{return TOK_CALL_TYPE;}

src/xspice/cmpp/mod_yacc.y

@@ -336,6 +336,7 @@ static void append (char *str)
 
 %token TOK_ARGS
 %token TOK_INIT
+%token TOK_CALLBACK
 %token TOK_ANALYSIS
 %token TOK_NEW_TIMEPOINT
 %token TOK_TIME
@@ -426,6 +427,8 @@ c_char			: TOK_IDENTIFIER {fputs (mod_yytext, mod_yyout);}
 
 macro			: TOK_INIT
 			   {fprintf (mod_yyout, "mif_private->circuit.init");}
+			| TOK_CALLBACK
+			   {fprintf (mod_yyout, "*(mif_private->callback)");}
 			| TOK_ARGS
 			   {fprintf (mod_yyout, "Mif_Private_t *mif_private");}
 			| TOK_ANALYSIS

src/xspice/evt/evtload.c

@@ -225,6 +225,7 @@ int EVTload(
     cm_data.param = inst->param;
     cm_data.num_inst_var = inst->num_inst_var;
     cm_data.inst_var = inst->inst_var;
+    cm_data.callback = &(inst->callback);
 
 
     /* ******************* */

src/xspice/mif/mif_inp2.c

@@ -652,6 +652,7 @@ static void  MIFinit_inst(
     fast->analog = MIF_FALSE;
     fast->event_driven = MIF_FALSE;
     fast->inst_index = 0;
+    fast->callback = NULL;
 }
 
 

src/xspice/mif/mifdelete.c

@@ -89,6 +89,21 @@ MIFdelete(
     model = (MIFmodel *) inModel;
     fast  = (MIFinstance **) inst;
 
+    if ((*fast)->callback) {
+        Mif_Private_t       cm_data;
+
+        /* Prepare the structure to be passed to the code model */
+        cm_data.num_conn = (*fast)->num_conn;
+        cm_data.conn = (*fast)->conn;
+        cm_data.num_param = (*fast)->num_param;
+        cm_data.param = (*fast)->param;
+        cm_data.num_inst_var = (*fast)->num_inst_var;
+        cm_data.inst_var = (*fast)->inst_var;
+        cm_data.callback = &((*fast)->callback);
+
+        (*fast)->callback(&cm_data, MIF_CB_DESTROY);
+    }
+
     /*******************************************/
     /* Cut the instance out of the linked list */
     /*******************************************/

src/xspice/mif/mifload.c

@@ -437,6 +437,7 @@ MIFload(
             cm_data.param = here->param;
             cm_data.num_inst_var = here->num_inst_var;
             cm_data.inst_var = here->inst_var;
+            cm_data.callback = &(here->callback);
 
             /* Initialize the auto_partial flag to false */
             g_mif_info.auto_partial.local = MIF_FALSE;