examples/simple/example.c

/**************
 *
 * Author: Dan Liew
 *
 * Date: Oct, 2013
 *
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
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furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
********************************************************************/

/* This small program is a trivial example showing
 * how to use a few bits of the STP C-API
 *
 */
#include <stp/c_interface.h>
#include <stdio.h>
#include <stdlib.h>

void handleQuery(VC handle, Expr queryExpr);

// Error handler
void errorHandler(const char* err_msg)
{
    printf("Error: %s\n", err_msg);
    exit(1);
}

int main(int argc, char** argv)
{
    int width=8;

    VC handle = vc_createValidityChecker();

    // Register a callback for errors
    vc_registerErrorHandler(errorHandler);

    // Create variable "x"
    Expr x = vc_varExpr(handle, "x", vc_bvType(handle, width));

    // Create bitvector x + x
    Expr xPlusx = vc_bvPlusExpr(handle, width, x, x);

    // Create bitvector constant 2
    Expr two = vc_bvConstExprFromInt(handle, width, 2);

    // Create bitvector 2*x
    Expr xTimes2 = vc_bvMultExpr(handle, width, two, x);

    // Create bool expression x + x = 2*x
    Expr equality = vc_eqExpr(handle, xPlusx , xTimes2);

    vc_assertFormula(handle, vc_trueExpr(handle) );

    // We are asking STP: ∀ x. true → ( x + x = 2*x )
    // This should be VALID.
    printf("######First Query\n");
    handleQuery(handle, equality);

    // We are asking STP: ∀ x. true → ( x + x = 2 )
    // This should be INVALID.
    printf("######Second Query\n");
    // Create bool expression x + x = 2
    Expr badEquality = vc_eqExpr(handle, xPlusx , two);
    handleQuery(handle, badEquality);

    // Clean up
    vc_Destroy(handle);

    return 0;
}

void handleQuery(VC handle, Expr queryExpr)
{
    // Print the assertions
    printf("Assertions:\n");
    vc_printAsserts(handle, 0);

    int result = vc_query(handle, queryExpr);
    printf("Query:\n");
    vc_printQuery(handle);
    switch(result)
    {
        case 0: printf("Query is INVALID\n");

                // print counter example
                printf("Counter example:\n");
                vc_printCounterExample(handle);
                break;


        case 1: printf("Query is VALID\n");break;
        case 2: printf("Could not answer query\n");break;
        case 3: printf("Timeout.\n"); break;
        default: printf("Unhandled error\n");
    }
    printf("\n\n");
}