source: mainline/uspace/app/sbi/src/symbol.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 Symbols. */

#include <stdlib.h>
#include <assert.h>
#include "list.h"
#include "mytypes.h"
#include "strtab.h"
#include "stree.h"

#include "symbol.h"

static stree_symbol_t *symbol_search_global(stree_program_t *prog,
    stree_ident_t *name);
static stree_symbol_t *symbol_find_epoint_rec(stree_program_t *prog,
    stree_ident_t *name, stree_csi_t *csi);
static stree_ident_t *symbol_get_ident(stree_symbol_t *symbol);

/** Lookup symbol in CSI using a type expression.
 *
 * XXX This should be removed in favor of full type expression evaluation
 * (run_texpr). This cannot work properly with generics.
 *
 * @param prog          Program
 * @param scope         CSI used as base for relative references
 * @param texpr         Type expression
 *
 * @return              Symbol referenced by type expression or @c NULL
 *                      if not found
 */
stree_symbol_t *symbol_xlookup_in_csi(stree_program_t *prog,
    stree_csi_t *scope, stree_texpr_t *texpr)
{
        stree_symbol_t *a, *b;
        stree_csi_t *a_csi;

        switch (texpr->tc) {
        case tc_tnameref:
                return symbol_lookup_in_csi(prog, scope, texpr->u.tnameref->name);
        case tc_taccess:
                a = symbol_xlookup_in_csi(prog, scope, texpr->u.taccess->arg);
                a_csi = symbol_to_csi(a);
                if (a_csi == NULL) {
                        printf("Error: Symbol is not CSI.\n");
                        exit(1);
                }
                b = symbol_search_csi(prog, a_csi, texpr->u.taccess->member_name);
                if (b == NULL) {
                        printf("Error: CSI '%s' not found\n", strtab_get_str(texpr->u.taccess->member_name->sid));
                        exit(1);
                }
                return b;
        case tc_tapply:
                return symbol_xlookup_in_csi(prog, scope,
                    texpr->u.tapply->gtype);
        default:
                assert(b_false);
        }
}

/** Lookup symbol reference in CSI.
 *
 * XXX These functions should take just an sid, not a full identifier.
 * Sometimes we search for a name which has no associated cspan.
 *
 * @param prog  Program to look in
 * @param scope CSI in @a prog which is the base for references
 * @param name  Identifier of the symbol
 *
 * @return      Symbol or @c NULL if symbol not found
 */
stree_symbol_t *symbol_lookup_in_csi(stree_program_t *prog, stree_csi_t *scope,
    stree_ident_t *name)
{
        stree_symbol_t *symbol;

        /* This CSI node should have been processed. */
        assert(scope == NULL || scope->ancr_state == ws_visited);

        symbol = NULL;
        while (scope != NULL && symbol == NULL) {
                symbol = symbol_search_csi(prog, scope, name);
                scope = csi_to_symbol(scope)->outer_csi;
        }

        if (symbol == NULL)
                symbol = symbol_search_global(prog, name);

        return symbol;
}

/** Look for symbol strictly in CSI.
 *
 * Look for symbol in definition of a CSI and its ancestors. (But not
 * in lexically enclosing CSI.)
 *
 * @param prog  Program to look in
 * @param scope CSI in which to look
 * @param name  Identifier of the symbol
 *
 * @return      Symbol or @c NULL if symbol not found.
 */
stree_symbol_t *symbol_search_csi(stree_program_t *prog,
    stree_csi_t *scope, stree_ident_t *name)
{
        stree_csi_t *base_csi;
        stree_symbol_t *symbol;

        /* Look in new members in this class. */
        symbol = symbol_search_csi_no_base(prog, scope, name);
        if (symbol != NULL)
                return symbol;

        /* Try inherited members. */
        base_csi = symbol_get_base_class(prog, scope);
        if (base_csi != NULL)
                return symbol_search_csi(prog, base_csi, name);

        /* No match */
        return NULL;
}

/** Look for symbol strictly in CSI.
 *
 * Look for symbol in definition of a CSI and its ancestors. (But not
 * in lexically enclosing CSI or in base CSI.)
 *
 * @param prog  Program to look in
 * @param scope CSI in which to look
 * @param name  Identifier of the symbol
 *
 * @return      Symbol or @c NULL if symbol not found.
 */
stree_symbol_t *symbol_search_csi_no_base(stree_program_t *prog,
    stree_csi_t *scope, stree_ident_t *name)
{
        list_node_t *node;
        stree_csimbr_t *csimbr;
        stree_ident_t *mbr_name;

        (void) prog;

        /* Look in new members in this class. */

        node = list_first(&scope->members);
        while (node != NULL) {
                csimbr = list_node_data(node, stree_csimbr_t *);
                mbr_name = stree_csimbr_get_name(csimbr);

                if (name->sid == mbr_name->sid) {
                        /* Match */
                        return csimbr_to_symbol(csimbr);
                }

                node = list_next(&scope->members, node);
        }
        /* No match */
        return NULL;
}

/** Look for symbol in global scope.
 *
 * @param prog  Program to look in
 * @param name  Identifier of the symbol
 *
 * @return      Symbol or @c NULL if symbol not found.
 */
static stree_symbol_t *symbol_search_global(stree_program_t *prog,
    stree_ident_t *name)
{
        list_node_t *node;
        stree_modm_t *modm;
        stree_symbol_t *symbol;
        stree_ident_t *mbr_name;

        node = list_first(&prog->module->members);
        while (node != NULL) {
                modm = list_node_data(node, stree_modm_t *);

                /* Make compiler happy. */
                mbr_name = NULL;

                switch (modm->mc) {
                case mc_csi:
                        mbr_name = modm->u.csi->name;
                        break;
                case mc_enum:
                        mbr_name = modm->u.enum_d->name;
                        break;
                }

                /* The Clang static analyzer is just too picky. */
                assert(mbr_name != NULL);

                if (name->sid == mbr_name->sid) {
                        /* Make compiler happy. */
                        symbol = NULL;

                        /* Match */
                        switch (modm->mc) {
                        case mc_csi:
                                symbol = csi_to_symbol(modm->u.csi);
                                break;
                        case mc_enum:
                                symbol = enum_to_symbol(modm->u.enum_d);
                                break;
                        }
                        return symbol;
                }
                node = list_next(&prog->module->members, node);
        }

        return NULL;
}

/** Get explicit base class for a CSI.
 *
 * Note that if there is no explicit base class (class is derived implicitly
 * from @c object, then @c NULL is returned.
 *
 * @param prog  Program to look in
 * @param csi   CSI
 *
 * @return      Base class (CSI) or @c NULL if no explicit base class.
 */
stree_csi_t *symbol_get_base_class(stree_program_t *prog, stree_csi_t *csi)
{
        list_node_t *pred_n;
        stree_texpr_t *pred;
        stree_symbol_t *pred_sym;
        stree_csi_t *pred_csi;
        stree_csi_t *outer_csi;

        outer_csi = csi_to_symbol(csi)->outer_csi;

        pred_n = list_first(&csi->inherit);
        if (pred_n == NULL)
                return NULL;

        pred = list_node_data(pred_n, stree_texpr_t *);
        pred_sym = symbol_xlookup_in_csi(prog, outer_csi, pred);
        pred_csi = symbol_to_csi(pred_sym);
        assert(pred_csi != NULL); /* XXX! */

        if (pred_csi->cc == csi_class)
                return pred_csi;

        return NULL;
}

/** Get type expression referencing base class for a CSI.
 *
 * Note that if there is no explicit base class (class is derived implicitly
 * from @c object, then @c NULL is returned.
 *
 * @param prog  Program to look in
 * @param csi   CSI
 *
 * @return      Type expression or @c NULL if no explicit base class.
 */
stree_texpr_t *symbol_get_base_class_ref(stree_program_t *prog,
    stree_csi_t *csi)
{
        list_node_t *pred_n;
        stree_texpr_t *pred;
        stree_symbol_t *pred_sym;
        stree_csi_t *pred_csi;
        stree_csi_t *outer_csi;

        outer_csi = csi_to_symbol(csi)->outer_csi;

        pred_n = list_first(&csi->inherit);
        if (pred_n == NULL)
                return NULL;

        pred = list_node_data(pred_n, stree_texpr_t *);
        pred_sym = symbol_xlookup_in_csi(prog, outer_csi, pred);
        pred_csi = symbol_to_csi(pred_sym);
        assert(pred_csi != NULL); /* XXX! */

        if (pred_csi->cc == csi_class)
                return pred;

        return NULL;
}

/** Find entry point.
 *
 * Perform a walk of all CSIs and look for a function with the name @a name.
 *
 * @param prog  Program to look in
 * @param name  Name of entry point
 *
 * @return      Symbol or @c NULL if symbol not found.
 */
stree_symbol_t *symbol_find_epoint(stree_program_t *prog, stree_ident_t *name)
{
        list_node_t *node;
        stree_modm_t *modm;
        stree_symbol_t *entry, *etmp;

        entry = NULL;

        node = list_first(&prog->module->members);
        while (node != NULL) {
                modm = list_node_data(node, stree_modm_t *);
                if (modm->mc == mc_csi) {
                        etmp = symbol_find_epoint_rec(prog, name, modm->u.csi);
                        if (etmp != NULL) {
                                if (entry != NULL) {
                                        printf("Error: Duplicate entry point.\n");
                                        exit(1);
                                }
                                entry = etmp;
                        }
                }
                node = list_next(&prog->module->members, node);
        }

        return entry;
}

/** Find entry point under CSI.
 *
 * Internal part of symbol_find_epoint() that recursively walks CSIs.
 *
 * @param prog  Program to look in
 * @param name  Name of entry point
 *
 * @return      Symbol or @c NULL if symbol not found.
 */
static stree_symbol_t *symbol_find_epoint_rec(stree_program_t *prog,
    stree_ident_t *name, stree_csi_t *csi)
{
        list_node_t *node;
        stree_csimbr_t *csimbr;
        stree_symbol_t *entry, *etmp;
        stree_symbol_t *fun_sym;

        entry = NULL;

        node = list_first(&csi->members);
        while (node != NULL) {
                csimbr = list_node_data(node, stree_csimbr_t *);

                switch (csimbr->cc) {
                case csimbr_csi:
                        etmp = symbol_find_epoint_rec(prog, name, csimbr->u.csi);
                        if (etmp != NULL) {
                                if (entry != NULL) {
                                        printf("Error: Duplicate entry point.\n");
                                        exit(1);
                                }
                                entry = etmp;
                        }
                        break;
                case csimbr_fun:
                        fun_sym = fun_to_symbol(csimbr->u.fun);

                        if (csimbr->u.fun->name->sid == name->sid &&
                            stree_symbol_has_attr(fun_sym, sac_static)) {
                                if (entry != NULL) {
                                        printf("Error: Duplicate entry point.\n");
                                        exit(1);
                                }
                                entry = fun_sym;
                        }
                default:
                        break;
                }

                node = list_next(&csi->members, node);
        }

        return entry;
}

/*
 * The notion of symbol is designed as a common base class for several
 * types of declarations with global and CSI scope. Here we simulate
 * conversion from this base class (symbol) to derived classes (CSI,
 * fun, ..) and vice versa.
 */

/** Convert symbol to delegate (base to derived).
 *
 * @param symbol        Symbol
 * @return              Delegate or @c NULL if symbol is not a delegate
 */
stree_deleg_t *symbol_to_deleg(stree_symbol_t *symbol)
{
        if (symbol->sc != sc_deleg)
                return NULL;

        return symbol->u.deleg;
}

/** Convert delegate to symbol (derived to base).
 *
 * @param deleg         Delegate
 * @return              Symbol
 */
stree_symbol_t *deleg_to_symbol(stree_deleg_t *deleg)
{
        assert(deleg->symbol);
        return deleg->symbol;
}

/** Convert symbol to enum (base to derived).
 *
 * @param symbol        Symbol
 * @return              Enum or @c NULL if symbol is not a enum
 */
stree_enum_t *symbol_to_enum(stree_symbol_t *symbol)
{
        if (symbol->sc != sc_enum)
                return NULL;

        return symbol->u.enum_d;
}

/** Convert enum to symbol (derived to base).
 *
 * @param deleg         Enum
 * @return              Symbol
 */
stree_symbol_t *enum_to_symbol(stree_enum_t *enum_d)
{
        assert(enum_d->symbol);
        return enum_d->symbol;
}

/** Convert symbol to CSI (base to derived).
 *
 * @param symbol        Symbol
 * @return              CSI or @c NULL if symbol is not a CSI
 */
stree_csi_t *symbol_to_csi(stree_symbol_t *symbol)
{
        if (symbol->sc != sc_csi)
                return NULL;

        return symbol->u.csi;
}

/** Convert CSI to symbol (derived to base).
 *
 * @param csi           CSI
 * @return              Symbol
 */
stree_symbol_t *csi_to_symbol(stree_csi_t *csi)
{
        assert(csi->symbol);
        return csi->symbol;
}

/** Convert symbol to constructor (base to derived).
 *
 * @param symbol        Symbol
 * @return              Constructor or @c NULL if symbol is not a constructor
 */
stree_ctor_t *symbol_to_ctor(stree_symbol_t *symbol)
{
        if (symbol->sc != sc_ctor)
                return NULL;

        return symbol->u.ctor;
}

/** Convert constructor to symbol (derived to base).
 *
 * @param ctor          Constructor
 * @return              Symbol
 */
stree_symbol_t *ctor_to_symbol(stree_ctor_t *ctor)
{
        assert(ctor->symbol);
        return ctor->symbol;
}

/** Convert symbol to function (base to derived).
 *
 * @param symbol        Symbol
 * @return              Function or @c NULL if symbol is not a function
 */
stree_fun_t *symbol_to_fun(stree_symbol_t *symbol)
{
        if (symbol->sc != sc_fun)
                return NULL;

        return symbol->u.fun;
}

/** Convert function to symbol (derived to base).
 *
 * @param fun           Function
 * @return              Symbol
 */
stree_symbol_t *fun_to_symbol(stree_fun_t *fun)
{
        assert(fun->symbol);
        return fun->symbol;
}

/** Convert symbol to member variable (base to derived).
 *
 * @param symbol        Symbol
 * @return              Variable or @c NULL if symbol is not a member variable
 */
stree_var_t *symbol_to_var(stree_symbol_t *symbol)
{
        if (symbol->sc != sc_var)
                return NULL;

        return symbol->u.var;
}

/** Convert variable to symbol (derived to base).
 *
 * @param fun           Variable
 * @return              Symbol
 */
stree_symbol_t *var_to_symbol(stree_var_t *var)
{
        assert(var->symbol);
        return var->symbol;
}

/** Convert symbol to property (base to derived).
 *
 * @param symbol        Symbol
 * @return              Property or @c NULL if symbol is not a property
 */
stree_prop_t *symbol_to_prop(stree_symbol_t *symbol)
{
        if (symbol->sc != sc_prop)
                return NULL;

        return symbol->u.prop;
}

/** Get symbol from CSI member.
 *
 * A symbol corresponds to any CSI member. Return it.
 *
 * @param csimbr        CSI member
 * @return              Symbol
 */
stree_symbol_t *csimbr_to_symbol(stree_csimbr_t *csimbr)
{
        stree_symbol_t *symbol;

        /* Keep compiler happy. */
        symbol = NULL;

        /* Match */
        switch (csimbr->cc) {
        case csimbr_csi:
                symbol = csi_to_symbol(csimbr->u.csi);
                break;
        case csimbr_ctor:
                symbol = ctor_to_symbol(csimbr->u.ctor);
                break;
        case csimbr_deleg:
                symbol = deleg_to_symbol(csimbr->u.deleg);
                break;
        case csimbr_enum:
                symbol = enum_to_symbol(csimbr->u.enum_d);
                break;
        case csimbr_fun:
                symbol = fun_to_symbol(csimbr->u.fun);
                break;
        case csimbr_var:
                symbol = var_to_symbol(csimbr->u.var);
                break;
        case csimbr_prop:
                symbol = prop_to_symbol(csimbr->u.prop);
                break;
        }

        return symbol;
}

/** Convert property to symbol (derived to base).
 *
 * @param fun           Property
 * @return              Symbol
 */
stree_symbol_t *prop_to_symbol(stree_prop_t *prop)
{
        assert(prop->symbol);
        return prop->symbol;
}

/** Print fully qualified name of symbol.
 *
 * @param symbol        Symbol
 */
void symbol_print_fqn(stree_symbol_t *symbol)
{
        stree_ident_t *name;
        stree_symbol_t *outer_sym;

        if (symbol->outer_csi != NULL) {
                outer_sym = csi_to_symbol(symbol->outer_csi);
                symbol_print_fqn(outer_sym);
                printf(".");
        }

        name = symbol_get_ident(symbol);
        printf("%s", strtab_get_str(name->sid));
}

/** Return symbol identifier.
 *
 * @param symbol        Symbol
 * @return              Symbol identifier
 */
static stree_ident_t *symbol_get_ident(stree_symbol_t *symbol)
{
        stree_ident_t *ident;

        /* Make compiler happy. */
        ident = NULL;

        switch (symbol->sc) {
        case sc_csi:
                ident = symbol->u.csi->name;
                break;
        case sc_ctor:
                ident = symbol->u.ctor->name;
                break;
        case sc_deleg:
                ident = symbol->u.deleg->name;
                break;
        case sc_enum:
                ident = symbol->u.enum_d->name;
                break;
        case sc_fun:
                ident = symbol->u.fun->name;
                break;
        case sc_var:
                ident = symbol->u.var->name;
                break;
        case sc_prop:
                ident = symbol->u.prop->name;
                break;
        }

        return ident;
}