source: mainline/uspace/app/sbi/src/p_expr.c

/*
 * Copyright (c) 2010 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @file Parse arithmetic expressions. */

#include <assert.h>
#include <stdlib.h>
#include "bigint.h"
#include "cspan.h"
#include "debug.h"
#include "lex.h"
#include "list.h"
#include "mytypes.h"
#include "p_type.h"
#include "parse.h"
#include "stree.h"

#include "p_expr.h"

static stree_expr_t *parse_assign(parse_t *parse);
static stree_expr_t *parse_disjunctive(parse_t *parse);
static stree_expr_t *parse_conjunctive(parse_t *parse);
static stree_expr_t *parse_comparative(parse_t *parse);
static stree_expr_t *parse_additive(parse_t *parse);
static stree_expr_t *parse_multip(parse_t *parse);
static stree_expr_t *parse_prefix(parse_t *parse);
static stree_expr_t *parse_prefix_new(parse_t *parse);
static stree_expr_t *parse_postfix(parse_t *parse);
static stree_expr_t *parse_pf_access(parse_t *parse, stree_expr_t *a);
static stree_expr_t *parse_pf_call(parse_t *parse, stree_expr_t *a);
static stree_expr_t *parse_pf_index(parse_t *parse, stree_expr_t *a);
static stree_expr_t *parse_pf_as(parse_t *parse, stree_expr_t *a);
static stree_expr_t *parse_paren(parse_t *parse);
static stree_expr_t *parse_primitive(parse_t *parse);
static stree_expr_t *parse_nameref(parse_t *parse);
static stree_expr_t *parse_lit_bool(parse_t *parse);
static stree_expr_t *parse_lit_char(parse_t *parse);
static stree_expr_t *parse_lit_int(parse_t *parse);
static stree_expr_t *parse_lit_ref(parse_t *parse);
static stree_expr_t *parse_lit_string(parse_t *parse);
static stree_expr_t *parse_self_ref(parse_t *parse);

static stree_expr_t *parse_recovery_expr(parse_t *parse);

/** Parse expression.
 *
 * Input is read from the input object associated with @a parse. If any
 * error occurs, parse->error will @c b_true when this function
 * returns. parse->error_bailout will be @c b_true if the error has not
 * been recovered yet. Similar holds for other parsing functions in this
 * module.
 *
 * @param parse         Parser object.
 */
stree_expr_t *parse_expr(parse_t *parse)
{
#ifdef DEBUG_PARSE_TRACE
        printf("Parse expression.\n");
#endif
        if (parse_is_error(parse))
                return parse_recovery_expr(parse);

        return parse_assign(parse);
}

/** Parse assignment expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_assign(parse_t *parse)
{
        stree_expr_t *a, *b, *tmp;
        stree_assign_t *assign;

        a = parse_disjunctive(parse);

        switch (lcur_lc(parse)) {
        case lc_assign:
                assign = stree_assign_new(ac_set);
                break;
        case lc_increase:
                assign = stree_assign_new(ac_increase);
                break;
        default:
                return a;
        }

        lskip(parse);
        b = parse_disjunctive(parse);

        assign->dest = a;
        assign->src = b;

        tmp = stree_expr_new(ec_assign);
        tmp->u.assign = assign;
        tmp->cspan = cspan_merge(a->cspan, b->cspan);

        assign->expr = tmp;

        return tmp;
}

/** Parse disjunctive expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_disjunctive(parse_t *parse)
{
        stree_expr_t *a, *b, *tmp;
        stree_binop_t *binop;
        cspan_t *cs;

        a = parse_conjunctive(parse);
        cs = a->cspan;

        while (lcur_lc(parse) == lc_or) {
                if (parse_is_error(parse))
                        break;

                lskip(parse);
                b = parse_conjunctive(parse);

                binop = stree_binop_new(bo_or);
                binop->arg1 = a;
                binop->arg2 = b;

                tmp = stree_expr_new(ec_binop);
                tmp->u.binop = binop;
                tmp->cspan = cspan_merge(cs, b->cspan);
                binop->expr = tmp;

                a = tmp;
                cs = tmp->cspan;
        }

        return a;
}

/** Parse conjunctive expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_conjunctive(parse_t *parse)
{
        stree_expr_t *a, *b, *tmp;
        stree_binop_t *binop;
        cspan_t *cs;

        a = parse_comparative(parse);
        cs = a->cspan;

        while (lcur_lc(parse) == lc_and) {
                if (parse_is_error(parse))
                        break;

                lskip(parse);
                b = parse_comparative(parse);

                binop = stree_binop_new(bo_and);
                binop->arg1 = a;
                binop->arg2 = b;

                tmp = stree_expr_new(ec_binop);
                tmp->u.binop = binop;
                tmp->cspan = cspan_merge(cs, b->cspan);
                binop->expr = tmp;

                a = tmp;
                cs = tmp->cspan;
        }

        return a;
}

/** Parse comparative expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_comparative(parse_t *parse)
{
        stree_expr_t *a, *b, *tmp;
        stree_binop_t *binop;
        binop_class_t bc;
        cspan_t *cs;

        a = parse_additive(parse);
        cs = a->cspan;

        while (lcur_lc(parse) == lc_equal || lcur_lc(parse) == lc_notequal ||
            lcur_lc(parse) == lc_lt || lcur_lc(parse) == lc_gt ||
            lcur_lc(parse) == lc_lt_equal || lcur_lc(parse) == lc_gt_equal) {

                if (parse_is_error(parse))
                        break;

                switch (lcur_lc(parse)) {
                case lc_equal:
                        bc = bo_equal;
                        break;
                case lc_notequal:
                        bc = bo_notequal;
                        break;
                case lc_lt:
                        bc = bo_lt;
                        break;
                case lc_gt:
                        bc = bo_gt;
                        break;
                case lc_lt_equal:
                        bc = bo_lt_equal;
                        break;
                case lc_gt_equal:
                        bc = bo_gt_equal;
                        break;
                default:
                        assert(b_false);
                }

                lskip(parse);
                b = parse_additive(parse);

                binop = stree_binop_new(bc);
                binop->arg1 = a;
                binop->arg2 = b;

                tmp = stree_expr_new(ec_binop);
                tmp->u.binop = binop;
                tmp->cspan = cspan_merge(cs, b->cspan);
                binop->expr = tmp;

                a = tmp;
                cs = tmp->cspan;
        }

        return a;
}

/** Parse additive expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_additive(parse_t *parse)
{
        stree_expr_t *a, *b, *tmp;
        stree_binop_t *binop;
        binop_class_t bc;
        cspan_t *cs;

        a = parse_multip(parse);
        cs = a->cspan;

        while (lcur_lc(parse) == lc_plus || lcur_lc(parse) == lc_minus) {
                if (parse_is_error(parse))
                        break;

                switch (lcur_lc(parse)) {
                case lc_plus:
                        bc = bo_plus;
                        break;
                case lc_minus:
                        bc = bo_minus;
                        break;
                default:
                        assert(b_false);
                }

                lskip(parse);
                b = parse_multip(parse);

                binop = stree_binop_new(bc);
                binop->arg1 = a;
                binop->arg2 = b;

                tmp = stree_expr_new(ec_binop);
                tmp->u.binop = binop;
                tmp->cspan = cspan_merge(cs, b->cspan);
                binop->expr = tmp;

                a = tmp;
                cs = tmp->cspan;
        }

        return a;
}

/** Parse multiplicative expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_multip(parse_t *parse)
{
        stree_expr_t *a, *b, *tmp;
        stree_binop_t *binop;
        binop_class_t bc;
        cspan_t *cs;

        a = parse_prefix(parse);
        cs = a->cspan;

        while (lcur_lc(parse) == lc_mult) {
                if (parse_is_error(parse))
                        break;

                switch (lcur_lc(parse)) {
                case lc_mult:
                        bc = bo_mult;
                        break;
                default:
                        assert(b_false);
                }

                lskip(parse);
                b = parse_prefix(parse);

                binop = stree_binop_new(bc);
                binop->arg1 = a;
                binop->arg2 = b;

                tmp = stree_expr_new(ec_binop);
                tmp->u.binop = binop;
                tmp->cspan = cspan_merge(cs, b->cspan);
                binop->expr = tmp;

                a = tmp;
                cs = tmp->cspan;
        }

        return a;
}

/** Parse prefix expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_prefix(parse_t *parse)
{
        stree_expr_t *a;
        stree_expr_t *tmp;
        stree_unop_t *unop;
        unop_class_t uc;
        cspan_t *cs0;

        switch (lcur_lc(parse)) {
        case lc_plus:
        case lc_minus:
        case lc_not:
                if (parse_is_error(parse))
                        return parse_recovery_expr(parse);

                switch (lcur_lc(parse)) {
                case lc_plus:
                        uc = uo_plus;
                        break;
                case lc_minus:
                        uc = uo_minus;
                        break;
                case lc_not:
                        uc = uo_not;
                        break;
                default:
                        assert(b_false);
                }

                cs0 = lcur_span(parse);
                lskip(parse);
                a = parse_postfix(parse);

                unop = stree_unop_new(uc);
                unop->arg = a;

                tmp = stree_expr_new(ec_unop);
                tmp->u.unop = unop;
                tmp->cspan = cspan_merge(cs0, a->cspan);
                unop->expr = tmp;
                a = tmp;
                break;
        case lc_new:
                a = parse_prefix_new(parse);
                break;
        default:
                a = parse_postfix(parse);
                break;
        }

        return a;
}

/** Parse @c new operator.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_prefix_new(parse_t *parse)
{
        stree_texpr_t *texpr;
        stree_new_t *new_op;
        stree_expr_t *expr;
        stree_expr_t *arg;
        cspan_t *cs0, *cs1;

        cs0 = lcur_span(parse);
        lmatch(parse, lc_new);
        texpr = parse_texpr(parse);

        /* XXX Take span from texpr */
        cs1 = lprev_span(parse);

        new_op = stree_new_new();
        new_op->texpr = texpr;
        expr = stree_expr_new(ec_new);
        expr->u.new_op = new_op;

        list_init(&new_op->ctor_args);

        /* Parenthesized arguments should be present except for arrays. */
        if (texpr->tc != tc_tindex) {
                lmatch(parse, lc_lparen);

                /* Parse constructor arguments */

                if (lcur_lc(parse) != lc_rparen) {
                        while (!parse_is_error(parse)) {
                                arg = parse_expr(parse);
                                list_append(&new_op->ctor_args, arg);

                                if (lcur_lc(parse) == lc_rparen)
                                        break;
                                lmatch(parse, lc_comma);
                        }
                }

                lmatch(parse, lc_rparen);
                cs1 = cspan_merge(cs0, lprev_span(parse));
        }

        expr->cspan = cspan_merge(cs0, cs1);
        new_op->expr = expr;

        return expr;
}

/** Parse postfix expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_postfix(parse_t *parse)
{
        stree_expr_t *a;
        stree_expr_t *tmp;

        a = parse_paren(parse);

        while (lcur_lc(parse) == lc_period || lcur_lc(parse) == lc_lparen ||
            lcur_lc(parse) == lc_lsbr || lcur_lc(parse) == lc_as) {

                if (parse_is_error(parse))
                        break;

                switch (lcur_lc(parse)) {
                case lc_period:
                        tmp = parse_pf_access(parse, a);
                        break;
                case lc_lparen:
                        tmp = parse_pf_call(parse, a);
                        break;
                case lc_lsbr:
                        tmp = parse_pf_index(parse, a);
                        break;
                case lc_as:
                        tmp = parse_pf_as(parse, a);
                        break;
                default:
                        assert(b_false);
                }

                a = tmp;
        }

        return a;
}

/** Parse member access expression
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_pf_access(parse_t *parse, stree_expr_t *a)
{
        stree_ident_t *ident;
        stree_expr_t *expr;
        stree_access_t *access;
        cspan_t *cs1;

        lmatch(parse, lc_period);
        ident = parse_ident(parse);

        /* XXX Take span from ident */
        cs1 = lprev_span(parse);

        access = stree_access_new();
        access->arg = a;
        access->member_name = ident;

        expr = stree_expr_new(ec_access);
        expr->u.access = access;
        expr->cspan = cspan_merge(a->cspan, cs1);

        access->expr = expr;

        return expr;
}

/** Parse function call expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_pf_call(parse_t *parse, stree_expr_t *a)
{
        stree_expr_t *expr;
        stree_call_t *call;
        stree_expr_t *arg;
        cspan_t *cs1;

        lmatch(parse, lc_lparen);

        call = stree_call_new();
        call->fun = a;
        list_init(&call->args);

        /* Parse function arguments */

        if (lcur_lc(parse) != lc_rparen) {
                while (!parse_is_error(parse)) {
                        arg = parse_expr(parse);
                        list_append(&call->args, arg);

                        if (lcur_lc(parse) == lc_rparen)
                                break;
                        lmatch(parse, lc_comma);
                }
        }

        lmatch(parse, lc_rparen);
        cs1 = lprev_span(parse);

        expr = stree_expr_new(ec_call);
        expr->u.call = call;
        expr->cspan = cspan_merge(a->cspan, cs1);
        call->expr = expr;

        return expr;
}

/** Parse index expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_pf_index(parse_t *parse, stree_expr_t *a)
{
        stree_expr_t *expr;
        stree_index_t *index;
        stree_expr_t *arg;
        cspan_t *cs1;

        lmatch(parse, lc_lsbr);

        index = stree_index_new();
        index->base = a;
        list_init(&index->args);

        /* Parse indices */

        if (lcur_lc(parse) != lc_rsbr) {
                while (!parse_is_error(parse)) {
                        arg = parse_expr(parse);
                        list_append(&index->args, arg);

                        if (lcur_lc(parse) == lc_rsbr)
                                break;
                        lmatch(parse, lc_comma);
                }
        }

        lmatch(parse, lc_rsbr);
        cs1 = lprev_span(parse);

        expr = stree_expr_new(ec_index);
        expr->u.index = index;
        expr->cspan = cspan_merge(a->cspan, cs1);
        index->expr = expr;

        return expr;
}

/** Parse @c as operator.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_pf_as(parse_t *parse, stree_expr_t *a)
{
        stree_expr_t *expr;
        stree_texpr_t *texpr;
        stree_as_t *as_op;
        cspan_t *cs1;

        lmatch(parse, lc_as);
        texpr = parse_texpr(parse);

        /* XXX Take span from texpr */
        cs1 = lprev_span(parse);

        as_op = stree_as_new();
        as_op->arg = a;
        as_op->dtype = texpr;

        expr = stree_expr_new(ec_as);
        expr->u.as_op = as_op;
        expr->cspan = cspan_merge(a->cspan, cs1);

        as_op->expr = expr;

        return expr;
}

/** Parse possibly partenthesized expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_paren(parse_t *parse)
{
        stree_expr_t *expr;
        cspan_t *cs0, *cs1;

        if (lcur_lc(parse) == lc_lparen) {
                cs0 = lcur_span(parse);
                lskip(parse);
                expr = parse_expr(parse);
                lmatch(parse, lc_rparen);
                cs1 = lprev_span(parse);

                expr->cspan = cspan_merge(cs0, cs1);
        } else {
                expr = parse_primitive(parse);
        }

        return expr;
}

/** Parse primitive expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_primitive(parse_t *parse)
{
        stree_expr_t *expr;

        switch (lcur_lc(parse)) {
        case lc_ident:
                expr = parse_nameref(parse);
                break;
        case lc_false:
        case lc_true:
                expr = parse_lit_bool(parse);
                break;
        case lc_lit_char:
                expr = parse_lit_char(parse);
                break;
        case lc_lit_int:
                expr = parse_lit_int(parse);
                break;
        case lc_nil:
                expr = parse_lit_ref(parse);
                break;
        case lc_lit_string:
                expr = parse_lit_string(parse);
                break;
        case lc_self:
                expr = parse_self_ref(parse);
                break;
        default:
                lunexpected_error(parse);
                expr = parse_recovery_expr(parse);
        }

        return expr;
}

/** Parse name reference.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_nameref(parse_t *parse)
{
        stree_nameref_t *nameref;
        stree_expr_t *expr;

        nameref = stree_nameref_new();
        nameref->name = parse_ident(parse);
        expr = stree_expr_new(ec_nameref);
        expr->u.nameref = nameref;
        expr->cspan = lprev_span(parse);
        nameref->expr = expr;

        return expr;
}

/** Parse boolean literal.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_lit_bool(parse_t *parse)
{
        stree_literal_t *literal;
        stree_expr_t *expr;
        bool_t value;

        switch (lcur_lc(parse)) {
        case lc_false:
                value = b_false;
                break;
        case lc_true:
                value = b_true;
                break;
        default:
                assert(b_false);
        }

        lskip(parse);

        literal = stree_literal_new(ltc_bool);
        literal->u.lit_bool.value = value;

        expr = stree_expr_new(ec_literal);
        expr->u.literal = literal;
        expr->cspan = lprev_span(parse);
        literal->expr = expr;

        return expr;
}

/** Parse character literal.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_lit_char(parse_t *parse)
{
        stree_literal_t *literal;
        stree_expr_t *expr;

        lcheck(parse, lc_lit_char);

        literal = stree_literal_new(ltc_char);
        bigint_clone(&lcur(parse)->u.lit_char.value,
            &literal->u.lit_char.value);

        lskip(parse);

        expr = stree_expr_new(ec_literal);
        expr->u.literal = literal;
        expr->cspan = lprev_span(parse);
        literal->expr = expr;

        return expr;
}

/** Parse integer literal.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_lit_int(parse_t *parse)
{
        stree_literal_t *literal;
        stree_expr_t *expr;

        lcheck(parse, lc_lit_int);

        literal = stree_literal_new(ltc_int);
        bigint_clone(&lcur(parse)->u.lit_int.value,
            &literal->u.lit_int.value);

        lskip(parse);

        expr = stree_expr_new(ec_literal);
        expr->u.literal = literal;
        expr->cspan = lprev_span(parse);
        literal->expr = expr;

        return expr;
}

/** Parse reference literal (@c nil).
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_lit_ref(parse_t *parse)
{
        stree_literal_t *literal;
        stree_expr_t *expr;

        lmatch(parse, lc_nil);

        literal = stree_literal_new(ltc_ref);

        expr = stree_expr_new(ec_literal);
        expr->u.literal = literal;
        expr->cspan = lprev_span(parse);
        literal->expr = expr;

        return expr;
}

/** Parse string literal.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_lit_string(parse_t *parse)
{
        stree_literal_t *literal;
        stree_expr_t *expr;

        lcheck(parse, lc_lit_string);

        literal = stree_literal_new(ltc_string);
        literal->u.lit_string.value = lcur(parse)->u.lit_string.value;

        lskip(parse);

        expr = stree_expr_new(ec_literal);
        expr->u.literal = literal;
        expr->cspan = lprev_span(parse);
        literal->expr = expr;

        return expr;
}

/** Parse @c self keyword.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_self_ref(parse_t *parse)
{
        stree_self_ref_t *self_ref;
        stree_expr_t *expr;

        lmatch(parse, lc_self);

        self_ref = stree_self_ref_new();

        expr = stree_expr_new(ec_self_ref);
        expr->u.self_ref = self_ref;
        expr->cspan = lprev_span(parse);
        self_ref->expr = expr;

        return expr;
}

/** Construct a special recovery expression.
 *
 * @param parse         Parser object.
 */
static stree_expr_t *parse_recovery_expr(parse_t *parse)
{
        stree_literal_t *literal;
        stree_expr_t *expr;

        (void) parse;

        literal = stree_literal_new(ltc_ref);

        expr = stree_expr_new(ec_literal);
        expr->u.literal = literal;
        literal->expr = expr;

        return expr;
}