z3/src/ast/char_decl_plugin.cpp

/*++
Copyright (c) 2011 Microsoft Corporation

Module Name:

    char_decl_plugin.cpp

Abstract:

    char_plugin for unicode support

Author:

    Nikolaj Bjorner (nbjorner) 2021-01-26


--*/
#include "util/gparams.h"
#include "ast/bv_decl_plugin.h"
#include "ast/char_decl_plugin.h"
#include "ast/arith_decl_plugin.h"
#include "ast/ast_pp.h"

char_decl_plugin::char_decl_plugin(): 
    m_charc_sym("Char") {
}

char_decl_plugin::~char_decl_plugin() {
    m_manager->dec_ref(m_char);
}

func_decl* char_decl_plugin::mk_func_decl(decl_kind k, unsigned num_parameters, parameter const* parameters,
                        unsigned arity, sort* const* domain, sort* range) {
    ast_manager& m = *m_manager;
    std::stringstream msg;
    switch (k) {
    case OP_CHAR_LE:
        if (arity != 2)
            msg << "incorrect number of arguments passed. Expected 2, received " << arity;
        else if(domain[0] != m_char)
            msg << "incorrect first argument type " << mk_pp(domain[0], *m_manager);
        else if (domain[1] != m_char)
            msg << "incorrect second argument type " << mk_pp(domain[1], *m_manager);     
        else             
            return m.mk_func_decl(symbol("char.<="), arity, domain, m.mk_bool_sort(), func_decl_info(m_family_id, k, 0, nullptr));
        m.raise_exception(msg.str());

    case OP_CHAR_CONST:
        if (num_parameters != 1)
            msg << "incorrect number of parameters passed. Expected 1, received " << num_parameters;
        else if (arity != 0)
            msg << "incorrect number of arguments passed. Expected 0, received " << arity;
        else if (!parameters[0].is_int())
            msg << "integer parameter expected";
        else if (parameters[0].get_int() < 0)
            msg << "non-negative parameter expected";
        else if (parameters[0].get_int() > static_cast<int>(max_char()))
            msg << "parameter expected within character range";
        else
            return m.mk_const_decl(m_charc_sym, m_char, func_decl_info(m_family_id, OP_CHAR_CONST, num_parameters, parameters));
        m.raise_exception(msg.str());
    case OP_CHAR_TO_INT:
        if (num_parameters != 0)
            msg << "incorrect number of parameters passed. Expected 0, received " << num_parameters;
        else if (arity != 1)
            msg << "incorrect number of arguments passed. Expected one character, received " << arity;
        else {
            arith_util a(m);
            return m.mk_func_decl(symbol("char.to_int"), arity, domain, a.mk_int(), func_decl_info(m_family_id, k, 0, nullptr));
        }
        m.raise_exception(msg.str());
    case OP_CHAR_TO_BV:
        if (num_parameters != 0)
            msg << "incorrect number of parameters passed. Expected 0, received " << num_parameters;
        else if (arity != 1)
            msg << "incorrect number of arguments passed. Expected one character, received " << arity;
        else if (m_char != domain[0])
            msg << "expected character sort argument";
        else {
            bv_util b(m);
            unsigned sz = num_bits();
            return m.mk_func_decl(symbol("char.to_bv"), arity, domain, b.mk_sort(sz), func_decl_info(m_family_id, k, 0, nullptr));
        }
        m.raise_exception(msg.str());
    case OP_CHAR_FROM_BV: {
        bv_util b(m);
        if (num_parameters != 0)
            msg << "incorrect number of parameters passed. Expected 0, received " << num_parameters;
        else if (arity != 1)
            msg << "incorrect number of arguments passed. Expected one character, received " << arity;
        else if (!b.is_bv_sort(domain[0]) || b.get_bv_size(domain[0]) != num_bits())
            msg << "expected bit-vector sort argument with " << num_bits();
        else {
            return m.mk_func_decl(symbol("char.from_bv"), arity, domain, m_char, func_decl_info(m_family_id, k, 0, nullptr));
        }
        m.raise_exception(msg.str());
    }
    case OP_CHAR_IS_DIGIT:
        if (num_parameters != 0)
            msg << "incorrect number of parameters passed. Expected 0, received " << num_parameters;
        else if (arity != 1)
            msg << "incorrect number of arguments passed. Expected one character, received " << arity;
        else {
            return m.mk_func_decl(symbol("char.is_digit"), arity, domain, m.mk_bool_sort(), func_decl_info(m_family_id, k, 0, nullptr));
        }
        m.raise_exception(msg.str());
        
    default:
        UNREACHABLE();
    }    
    return nullptr;
}

void char_decl_plugin::set_manager(ast_manager * m, family_id id) {
    decl_plugin::set_manager(m, id);
    m_char = m->mk_sort(symbol("Unicode"), sort_info(m_family_id, CHAR_SORT, 0, nullptr));
    m->inc_ref(m_char);
}

void char_decl_plugin::get_op_names(svector<builtin_name>& op_names, symbol const& logic) {
    op_names.push_back(builtin_name("char.<=", OP_CHAR_LE));
    op_names.push_back(builtin_name("Char", OP_CHAR_CONST));
    op_names.push_back(builtin_name("char.to_int", OP_CHAR_TO_INT));
    op_names.push_back(builtin_name("char.is_digit", OP_CHAR_IS_DIGIT));
    op_names.push_back(builtin_name("char.to_bv", OP_CHAR_TO_BV));
    op_names.push_back(builtin_name("char.from_bv", OP_CHAR_FROM_BV));
}

void char_decl_plugin::get_sort_names(svector<builtin_name>& sort_names, symbol const& logic) {
    sort_names.push_back(builtin_name("Unicode", CHAR_SORT));
}

bool char_decl_plugin::is_value(app* e) const {
    return is_app_of(e, m_family_id, OP_CHAR_CONST);
}

bool char_decl_plugin::is_unique_value(app* e) const {
    return is_value(e);
}

bool char_decl_plugin::are_equal(app* a, app* b) const {
    return a == b;
}

bool char_decl_plugin::are_distinct(app* a, app* b) const {
    return 
        a != b && 
        is_app_of(a, m_family_id, OP_CHAR_CONST) && 
        is_app_of(b, m_family_id, OP_CHAR_CONST); 
}

app* char_decl_plugin::mk_char(unsigned u) {
    SASSERT(u <= max_char());
    parameter param(u);
    func_decl* f = m_manager->mk_const_decl(m_charc_sym, m_char, func_decl_info(m_family_id, OP_CHAR_CONST, 1, &param));
    return m_manager->mk_const(f);
}

expr* char_decl_plugin::get_some_value(sort* s) {
    return mk_char('A');
}

app* char_decl_plugin::mk_le(expr* a, expr* b) {
    expr_ref _ch1(a, *m_manager), _ch2(b, *m_manager);
    unsigned v1 = 0, v2 = 0;
    if (a == b)
        return m_manager->mk_true();
    bv_util bv(*m_manager);
    if (bv.is_bv(a)) 
        return bv.mk_ule(a, b);
    arith_util arith(*m_manager);
    if (arith.is_int_real(a))
        return arith.mk_le(a, b);
    if (a->get_sort() != char_sort()) 
        throw default_exception("range comparison is only supported for bit-vectors, int, real and characters");
    bool c1 = is_const_char(a, v1);
    bool c2 = is_const_char(b, v2);
    if (c1 && c2)
        return m_manager->mk_bool_val(v1 <= v2);
    if (c1 && v1 == 0)
        return m_manager->mk_true();
    if (c2 && v2 == max_char())
        return m_manager->mk_true();
    expr* es[2] = { a, b };
    return m_manager->mk_app(m_family_id, OP_CHAR_LE, 2, es);    
}