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Cfa subproject in the Theta model checking framework
There is a newer version: 6.8.5
/*
 *  Copyright 2024 Budapest University of Technology and Economics
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package hu.bme.mit.theta.cfa.dsl;

import static com.google.common.base.Preconditions.checkNotNull;
import static hu.bme.mit.theta.core.stmt.Stmts.Assign;
import static hu.bme.mit.theta.core.stmt.Stmts.Assume;
import static hu.bme.mit.theta.core.stmt.Stmts.Havoc;
import static hu.bme.mit.theta.core.type.booltype.BoolExprs.Bool;

import hu.bme.mit.theta.cfa.dsl.gen.CfaDslBaseVisitor;
import hu.bme.mit.theta.cfa.dsl.gen.CfaDslParser.AssignStmtContext;
import hu.bme.mit.theta.cfa.dsl.gen.CfaDslParser.AssumeStmtContext;
import hu.bme.mit.theta.cfa.dsl.gen.CfaDslParser.HavocStmtContext;
import hu.bme.mit.theta.cfa.dsl.gen.CfaDslParser.StmtContext;
import hu.bme.mit.theta.common.dsl.Env;
import hu.bme.mit.theta.common.dsl.Scope;
import hu.bme.mit.theta.common.dsl.Symbol;
import hu.bme.mit.theta.core.decl.VarDecl;
import hu.bme.mit.theta.core.stmt.Stmt;
import hu.bme.mit.theta.core.type.Expr;
import hu.bme.mit.theta.core.type.Type;
import hu.bme.mit.theta.core.type.booltype.BoolType;
import hu.bme.mit.theta.core.utils.TypeUtils;

final class CfaStatement {

    private final Scope scope;
    private final StmtContext context;

    public CfaStatement(final Scope scope, final StmtContext context) {
        this.scope = checkNotNull(scope);
        this.context = checkNotNull(context);
    }

    public Stmt instantiate(final Env env) {
        final StmtCreatorVisitor visitor = new StmtCreatorVisitor(scope, env);
        final Stmt stmt = context.accept(visitor);
        if (stmt == null) {
            throw new AssertionError();
        } else {
            return stmt;
        }
    }

    private static final class StmtCreatorVisitor extends CfaDslBaseVisitor {

        private final Scope scope;
        private final Env env;

        public StmtCreatorVisitor(final Scope scope, final Env env) {
            this.scope = checkNotNull(scope);
            this.env = checkNotNull(env);
        }

        @Override
        public Stmt visitHavocStmt(final HavocStmtContext ctx) {
            final String lhsId = ctx.lhs.getText();
            final Symbol lhsSymbol = scope.resolve(lhsId).get();
            final VarDecl var = (VarDecl) env.eval(lhsSymbol);
            return Havoc(var);
        }

        @Override
        public Stmt visitAssumeStmt(final AssumeStmtContext ctx) {
            final CfaExpression expression = new CfaExpression(scope, ctx.cond);
            final Expr expr = TypeUtils.cast(expression.instantiate(env), Bool());
            return Assume(expr);
        }

        @Override
        public Stmt visitAssignStmt(final AssignStmtContext ctx) {
            final String lhsId = ctx.lhs.getText();
            final Symbol lhsSymbol = scope.resolve(lhsId).get();
            final VarDecl var = (VarDecl) env.eval(lhsSymbol);

            final CfaExpression expression = new CfaExpression(scope, ctx.value);
            final Expr expr = expression.instantiate(env);

            if (expr.getType().equals(var.getType())) {
                @SuppressWarnings("unchecked") final VarDecl tVar = (VarDecl) var;
                @SuppressWarnings("unchecked") final Expr tExpr = (Expr) expr;
                return Assign(tVar, tExpr);
            } else {
                throw new IllegalArgumentException(
                        "Type of " + var + " is incompatilbe with " + expr);
            }
        }

    }

}