This question is a follow up to the following question.
I have a predicate (I use the name "heavier" in this case) over two integers that I need to evaluate using a custom algorithm. I have written the following piece of code to do it. But I see that the parameters that get passed into the function CMTh_reduce_app() are not actual integers, but consts of type integer. What I need is 2 integers, so that I can evaluate the predicate and return the result (The operations done in the function CMTh_reduce_app() right now are meaningless).
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<stdarg.h>
#include<memory.h>
#include<z3.h>
#include "z3++.h"
#include<iostream>
using namespace z3;
using namespace std;
struct _CMTheoryData {
Z3_func_decl heavier;
};
typedef struct _CMTheoryData CMTheoryData;
Z3_context ctx;
//Exit function
void exitf(const char* message)
{
fprintf(stderr,"BUG: %s.\n", message);
exit(1);
}
//Check and print model if available
void check(Z3_context ctx)
{
Z3_model m = 0;
Z3_lbool result = Z3_check_and_get_model(ctx, &m);
switch (result) {
case Z3_L_FALSE:
printf("unsat\n");
break;
case Z3_L_UNDEF:
printf("unknown\n");
printf("potential model:\n%s\n", Z3_model_to_string(ctx, m));
break;
case Z3_L_TRUE:
printf("sat\n%s\n", Z3_model_to_string(ctx, m));
break;
}
if (m) {
Z3_del_model(ctx, m);
}
}
//Create logical context. Enable model generation, and set error handler
void error_handler(Z3_error_code e)
{
printf("Error code: %d\n", e);
exitf("incorrect use of Z3");
}
Z3_context mk_context_custom(Z3_config cfg, Z3_error_handler err)
{
Z3_context ctx;
Z3_set_param_value(cfg, "MODEL", "true");
ctx = Z3_mk_context(cfg);
#ifdef TRACING
Z3_trace_to_stderr(ctx);
#endif
Z3_set_error_handler(ctx, err);
return ctx;
}
Z3_context mk_context()
{
Z3_config cfg;
Z3_context ctx;
cfg = Z3_mk_config();
ctx = mk_context_custom(cfg, error_handler);
Z3_del_config(cfg);
return ctx;
}
//Shortcut for binary fn application
Z3_ast mk_binary_app(Z3_context ctx, Z3_func_decl f, Z3_ast x, Z3_ast y)
{
Z3_ast args[2] = {x, y};
return Z3_mk_app(ctx, f, 2, args);
}
//Shortcut to create an int
Z3_ast mk_int(Z3_context ctx, int v)
{
Z3_sort ty = Z3_mk_int_sort(ctx);
return Z3_mk_int(ctx, v, ty);
}
Z3_ast mk_var(Z3_context ctx, const char * name, Z3_sort ty)
{
Z3_symbol s = Z3_mk_string_symbol(ctx, name);
return Z3_mk_const(ctx, s, ty);
}
Z3_ast mk_int_var(Z3_context ctx, const char * name)
{
Z3_sort ty = Z3_mk_int_sort(ctx);
return mk_var(ctx, name, ty);
}
//Callback when final check is to be carried out
Z3_bool CMTh_final_check(Z3_theory t) {
printf("Final check\n");
return Z3_TRUE;
}
//Callback when theory is to be deleted
void CMTh_delete(Z3_theory t) {
CMTheoryData * td = (CMTheoryData *)Z3_theory_get_ext_data(t);
printf("Delete\n");
free(td);
}
//Callback to reduce a function application(definition of custom functions, predicates)
Z3_bool CMTh_reduce_app(Z3_theory t, Z3_func_decl d, unsigned n, Z3_ast const args[], Z3_ast * result) {
CMTheoryData * td = (CMTheoryData*)Z3_theory_get_ext_data(t);
cout<<Z3_ast_to_string(ctx, args[0])<<' '<<Z3_ast_to_string(ctx,args[1])<<endl;
if (d == td->heavier) {
cout<<"Reducing the fn \'heavier\'"<<endl;
if(Z3_is_eq_ast(ctx,mk_int(ctx, 1),args[0])||Z3_is_eq_ast(ctx,mk_int(ctx,2),args[0]))
{
*result = Z3_mk_true(Z3_theory_get_context(t));
return Z3_TRUE;;
}
else
{
*result = Z3_mk_false(Z3_theory_get_context(t));
return Z3_TRUE;;
}
}
return Z3_FALSE; // failed to simplify
}
Z3_theory mk_cm_theory(Z3_context ctx) {
Z3_sort heavier_domain[2];
Z3_symbol heavier_name = Z3_mk_string_symbol(ctx, "heavier");
Z3_sort B = Z3_mk_bool_sort(ctx);
CMTheoryData * td = (CMTheoryData*)malloc(sizeof(CMTheoryData));
Z3_theory Th = Z3_mk_theory(ctx, "cm_th", td);
heavier_domain[0] = Z3_mk_int_sort(ctx);
heavier_domain[1] = Z3_mk_int_sort(ctx);
td->heavier = Z3_theory_mk_func_decl(ctx, Th, heavier_name, 2, heavier_domain, B); //context, theory, name_of_fn, number of arguments, argument type list, return type
Z3_set_delete_callback(Th, CMTh_delete);
Z3_set_reduce_app_callback(Th, CMTh_reduce_app);
Z3_set_final_check_callback(Th, CMTh_final_check);
return Th;
}
main()
{
Z3_ast a_ast, b_ast, c_ast, f1, f3, r;
Z3_sort i;
Z3_pattern p;
Z3_app bound[2];
Z3_theory Th;
CMTheoryData * td;
printf("\nCustom theory example\n");
ctx = mk_context();
Th = mk_cm_theory(ctx);
td = (CMTheoryData*)Z3_theory_get_ext_data(Th);
a_ast = mk_int_var(ctx, "a");
b_ast = mk_int_var(ctx, "b");
bound[0] = (Z3_app)a_ast;
f1=mk_binary_app(ctx, td->heavier, a_ast, b_ast);
r= Z3_mk_exists_const(ctx, 0, 1, bound, 0, 0,f1);
printf("assert axiom:\n%s\n", Z3_ast_to_string(ctx, r));
Z3_assert_cnstr(ctx, r);
check(ctx);
}
I know the user theory plugin is not supported anymore, but I really need to get this working, so if I could get any information, it would be really helpful. I tried looking at the source code, but I didn't know where to get started with building new theories into it. So, I'd appreciate some help with the theory plugin.
