/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * rpc_parse.c, Parser for the RPC protocol compiler
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "rpc/types.h"
#include "rpc_scan.h"
#include "rpc_parse.h"
#include "rpc_util.h"

#define ARGNAME "arg"

extern char *make_argname(char *, char *);

static void isdefined(definition *);
static void def_struct(definition *);
static void def_program(definition *);
static void def_enum(definition *);
static void def_const(definition *);
static void def_union(definition *);
static void def_typedef(definition *);
static void get_declaration(declaration *, defkind);
static void get_prog_declaration(declaration *, defkind, int);
static void get_type(char **, char **, defkind);
static void unsigned_dec(char **);

/*
 * return the next definition you see
 */
definition *
get_definition(void)
{
        definition *defp;
        token tok;

        defp = calloc(1, sizeof (definition));
        get_token(&tok);
        switch (tok.kind) {
        case TOK_STRUCT:
                def_struct(defp);
                break;
        case TOK_UNION:
                def_union(defp);
                break;
        case TOK_TYPEDEF:
                def_typedef(defp);
                break;
        case TOK_ENUM:
                def_enum(defp);
                break;
        case TOK_PROGRAM:
                def_program(defp);
                break;
        case TOK_CONST:
                def_const(defp);
                break;
        case TOK_EOF:
                return (NULL);
        default:
                error("definition keyword expected");
        }
        scan(TOK_SEMICOLON, &tok);
        isdefined(defp);
        return (defp);
}

static void
isdefined(definition *defp)
{
        STOREVAL(&defined, defp);
}

/*
 * We treat s == NULL the same as *s == '\0'
 */
static int
streqn(const char *s1, const char *s2)
{
        if (s1 == NULL)
                s1 = "";
        if (s2 == NULL)
                s2 = "";
        if (s1 == s2)
                return (1);

        return (strcmp(s1, s2) == 0);
}

static int
cmptype(definition *defp, char *type)
{
        /* We only want typedef definitions */
        if (streq(defp->def_name, type) && defp->def_kind == DEF_TYPEDEF)
                return (1);
        return (0);
}

static int
check_self_reference(const char *name, const declaration *decp, int first)
{
        /*
         * Now check for the following special case if first is true:
         *
         * struct foo {
         *      ...
         *      foo *next;
         * };
         *
         *
         * In the above cases foo has not yet been entered in the type list,
         * defined. So there is no typedef entry. The prefix in that case
         * could be empty.
         */
        if (decp->rel == REL_POINTER &&
            (streqn(decp->prefix, "struct") ||
            (first && streqn(decp->prefix, ""))) &&
            streqn(name, decp->type))
                return (1);
        return (0);
}

static int
is_self_reference(definition *defp, declaration *decp)
{
        declaration current;
        definition *dp;

        if (check_self_reference(defp->def_name, decp, 1))
                return (1);

        /*
         * Check for valid declaration:
         * Only prefixes allowed are none and struct.
         * Only relations allowed are pointer or alias.
         */
        if (!streqn(decp->prefix, "struct") && !streqn(decp->prefix, ""))
                return (0);
        if (decp->rel != REL_POINTER && decp->rel != REL_ALIAS)
                return (0);

        current.rel = decp->rel;
        current.prefix = decp->prefix;
        current.type = decp->type;
        current.name = decp->name;
        decp = &current;
        while (!check_self_reference(defp->def_name, decp, 0)) {
                dp = FINDVAL(defined, decp->type, cmptype);

                /*
                 * Check if we found a definition.
                 */
                if (dp == NULL)
                        return (0);

                /*
                 * Check for valid prefix. We eventually need to see one
                 * and only one struct.
                 */
                if (streqn(decp->prefix, "")) {
                        /*
                         * If the current declaration prefix in empty
                         * then the definition found must have an empty
                         * prefix or a struct prefix
                         */
                        if (!streqn(dp->def.ty.old_prefix, "") &&
                            !streqn(dp->def.ty.old_prefix, "struct"))
                                return (0);
                } else if (streqn(decp->prefix, "struct") &&
                    !streqn(dp->def.ty.old_prefix, ""))
                        /*
                         * if the current prefix is struct tne new prefix
                         * must be empty
                         */
                        return (0);
                else if (!streqn(decp->prefix, "struct"))
                        /* Should never get here */
                        return (0);

                /*
                 * Check for valid relation. We need to see one and
                 * only one REL_POINTER. The only valid relation types
                 * are REL_POINTER and REL_ALIAS.
                 */
                if (decp->rel == REL_POINTER && dp->def.ty.rel != REL_ALIAS)
                        return (0);
                if (decp->rel == REL_ALIAS &&
                    (dp->def.ty.rel != REL_ALIAS &&
                    dp->def.ty.rel != REL_POINTER))
                        return (0);
                if (decp->rel != REL_ALIAS && decp->rel != REL_POINTER)
                        /* Should never get here */
                        return (0);

                /* Set up the current declaration */
                if (streqn(decp->prefix, ""))
                        decp->prefix = dp->def.ty.old_prefix;
                decp->type = dp->def.ty.old_type;
                if (decp->rel == REL_ALIAS)
                        decp->rel = dp->def.ty.rel;
        }

        /* We have a self reference type */
        return (1);
}

static void
def_struct(definition *defp)
{
        token tok;
        declaration dec;
        decl_list *decls;
        decl_list **tailp, *endp;

        defp->def_kind = DEF_STRUCT;

        scan(TOK_IDENT, &tok);
        defp->def_name = tok.str;
        scan(TOK_LBRACE, &tok);
        tailp = &defp->def.st.decls;
        defp->def.st.tail = NULL;
        do {
                get_declaration(&dec, DEF_STRUCT);
                decls = calloc(1, sizeof (decl_list));
                decls->decl = dec;
                /*
                 * Keep a referenct to the last declaration to check for
                 * tail recurrsion.
                 */
                endp = *tailp = decls;
                tailp = &decls->next;
                scan(TOK_SEMICOLON, &tok);
                peek(&tok);
        } while (tok.kind != TOK_RBRACE);
        *tailp = NULL;
        /*
         * Check for tail recurse. If the last declaration refers to this
         * structure then mark this stucture to convert the tail recursion
         * to itteration.
         */
        defp->def.st.self_pointer = is_self_reference(defp, &endp->decl);
        get_token(&tok);
        defp->def.st.tail = endp;
}

static void
def_program(definition *defp)
{
        token tok;
        declaration dec;
        decl_list *decls;
        decl_list **tailp;
        version_list *vlist;
        version_list **vtailp;
        proc_list *plist;
        proc_list **ptailp;
        int num_args;
        bool_t isvoid = FALSE;  /* whether first argument is void */
        defp->def_kind = DEF_PROGRAM;
        scan(TOK_IDENT, &tok);
        defp->def_name = tok.str;
        scan(TOK_LBRACE, &tok);
        vtailp = &defp->def.pr.versions;
        tailp = &defp->def.st.decls;
        scan(TOK_VERSION, &tok);
        do {
                scan(TOK_IDENT, &tok);
                vlist = calloc(1, sizeof (version_list));
                vlist->vers_name = tok.str;
                scan(TOK_LBRACE, &tok);
                ptailp = &vlist->procs;
                do {
                        /* get result type */
                        plist = calloc(1, sizeof (proc_list));
                        get_type(&plist->res_prefix, &plist->res_type,
                            DEF_RESULT);
                        if (streq(plist->res_type, "opaque")) {
                                error("illegal result type");
                        }
                        scan(TOK_IDENT, &tok);
                        plist->proc_name = tok.str;
                        scan(TOK_LPAREN, &tok);
                        /* get args - first one */
                        num_args = 1;
                        isvoid = FALSE;
                        /*
                         * type of DEF_PROGRAM in the first
                         * get_prog_declaration and DEF_STURCT in the next
                         * allows void as argument if it is the only argument
                         */
                        get_prog_declaration(&dec, DEF_PROGRAM, num_args);
                        if (streq(dec.type, "void"))
                                isvoid = TRUE;
                        decls = calloc(1, sizeof (decl_list));
                        plist->args.decls = decls;
                        decls->decl = dec;
                        tailp = &decls->next;
                        /* get args */
                        while (peekscan(TOK_COMMA, &tok)) {
                                num_args++;
                                get_prog_declaration(&dec, DEF_STRUCT,
                                    num_args);
                                decls = calloc(1, sizeof (decl_list));
                                decls->decl = dec;
                                *tailp = decls;
                                if (streq(dec.type, "void"))
                                        isvoid = TRUE;
                                tailp = &decls->next;
                        }
                        /* multiple arguments are only allowed in newstyle */
                        if (!newstyle && num_args > 1) {
                                error("only one argument is allowed");
                        }
                        if (isvoid && num_args > 1) {
                                error("illegal use of void "
                                    "in program definition");
                        }
                        *tailp = NULL;
                        scan(TOK_RPAREN, &tok);
                        scan(TOK_EQUAL, &tok);
                        scan_num(&tok);
                        scan(TOK_SEMICOLON, &tok);
                        plist->proc_num = tok.str;
                        plist->arg_num = num_args;
                        *ptailp = plist;
                        ptailp = &plist->next;
                        peek(&tok);
                } while (tok.kind != TOK_RBRACE);
                *ptailp = NULL;
                *vtailp = vlist;
                vtailp = &vlist->next;
                scan(TOK_RBRACE, &tok);
                scan(TOK_EQUAL, &tok);
                scan_num(&tok);
                vlist->vers_num = tok.str;
                /* make the argument structure name for each arg */
                for (plist = vlist->procs; plist != NULL; plist = plist->next) {
                        plist->args.argname = make_argname(plist->proc_name,
                            vlist->vers_num);
                        /* free the memory ?? */
                }
                scan(TOK_SEMICOLON, &tok);
                scan2(TOK_VERSION, TOK_RBRACE, &tok);
        } while (tok.kind == TOK_VERSION);
        scan(TOK_EQUAL, &tok);
        scan_num(&tok);
        defp->def.pr.prog_num = tok.str;
        *vtailp = NULL;
}

static void
def_enum(definition *defp)
{
        token tok;
        enumval_list *elist;
        enumval_list **tailp;

        defp->def_kind = DEF_ENUM;
        scan(TOK_IDENT, &tok);
        defp->def_name = tok.str;
        scan(TOK_LBRACE, &tok);
        tailp = &defp->def.en.vals;
        do {
                scan(TOK_IDENT, &tok);
                elist = calloc(1, sizeof (enumval_list));
                elist->name = tok.str;
                elist->assignment = NULL;
                scan3(TOK_COMMA, TOK_RBRACE, TOK_EQUAL, &tok);
                if (tok.kind == TOK_EQUAL) {
                        scan_num(&tok);
                        elist->assignment = tok.str;
                        scan2(TOK_COMMA, TOK_RBRACE, &tok);
                }
                *tailp = elist;
                tailp = &elist->next;
        } while (tok.kind != TOK_RBRACE);
        *tailp = NULL;
}

static void
def_const(definition *defp)
{
        token tok;

        defp->def_kind = DEF_CONST;
        scan(TOK_IDENT, &tok);
        defp->def_name = tok.str;
        scan(TOK_EQUAL, &tok);
        scan2(TOK_IDENT, TOK_STRCONST, &tok);
        defp->def.co = tok.str;
}

static void
def_union(definition *defp)
{
        token tok;
        declaration dec;
        case_list *cases;
        case_list **tailp;
        int flag;

        defp->def_kind = DEF_UNION;
        scan(TOK_IDENT, &tok);
        defp->def_name = tok.str;
        scan(TOK_SWITCH, &tok);
        scan(TOK_LPAREN, &tok);
        get_declaration(&dec, DEF_UNION);
        defp->def.un.enum_decl = dec;
        tailp = &defp->def.un.cases;
        scan(TOK_RPAREN, &tok);
        scan(TOK_LBRACE, &tok);
        scan(TOK_CASE, &tok);
        while (tok.kind == TOK_CASE) {
                scan2(TOK_IDENT, TOK_CHARCONST, &tok);
                cases = calloc(1, sizeof (case_list));
                cases->case_name = tok.str;
                scan(TOK_COLON, &tok);
                /* now peek at next token */
                flag = 0;
                if (peekscan(TOK_CASE, &tok)) {
                        do {
                                scan2(TOK_IDENT, TOK_CHARCONST, &tok);
                                cases->contflag = 1;
                                /* continued case statement */
                                *tailp = cases;
                                tailp = &cases->next;
                                cases = calloc(1, sizeof (case_list));
                                cases->case_name = tok.str;
                                scan(TOK_COLON, &tok);
                        } while (peekscan(TOK_CASE, &tok));
                } else if (flag) {
                        *tailp = cases;
                        tailp = &cases->next;
                        cases = calloc(1, sizeof (case_list));
                }

                get_declaration(&dec, DEF_UNION);
                cases->case_decl = dec;
                cases->contflag = 0; /* no continued case statement */
                *tailp = cases;
                tailp = &cases->next;
                scan(TOK_SEMICOLON, &tok);

                scan3(TOK_CASE, TOK_DEFAULT, TOK_RBRACE, &tok);
        }
        *tailp = NULL;
        if (tok.kind == TOK_DEFAULT) {
                scan(TOK_COLON, &tok);
                get_declaration(&dec, DEF_UNION);
                defp->def.un.default_decl = calloc(1, sizeof (declaration));
                *defp->def.un.default_decl = dec;
                scan(TOK_SEMICOLON, &tok);
                scan(TOK_RBRACE, &tok);
        } else {
                defp->def.un.default_decl = NULL;
        }
}

static char *reserved_words[] = {
        "array",
        "bytes",
        "destroy",
        "free",
        "getpos",
        "inline",
        "pointer",
        "reference",
        "setpos",
        "sizeof",
        "union",
        "vector",
        NULL
};

static char *reserved_types[] = {
        "opaque",
        "string",
        NULL
};

/*
 * check that the given name is not one that would eventually result in
 * xdr routines that would conflict with internal XDR routines.
 */
static void
check_type_name(char *name, int new_type)
{
        int i;
        char tmp[100];

        for (i = 0; reserved_words[i] != NULL; i++) {
                if (strcmp(name, reserved_words[i]) == 0) {
                        (void) snprintf(tmp, sizeof (tmp),
                            "illegal (reserved) name :\'%s\' "
                            "in type definition",
                            name);
                        error(tmp);
                }
        }
        if (new_type) {
                for (i = 0; reserved_types[i] != NULL; i++) {
                        if (strcmp(name, reserved_types[i]) == 0) {
                                (void) snprintf(tmp, sizeof (tmp),
                                    "illegal (reserved) name :\'%s\' "
                                    "in type definition",
                                    name);
                                error(tmp);
                        }
                }
        }
}

static void
def_typedef(definition *defp)
{
        declaration dec;

        defp->def_kind = DEF_TYPEDEF;
        get_declaration(&dec, DEF_TYPEDEF);
        defp->def_name = dec.name;
        check_type_name(dec.name, 1);
        defp->def.ty.old_prefix = dec.prefix;
        defp->def.ty.old_type = dec.type;
        defp->def.ty.rel = dec.rel;
        defp->def.ty.array_max = dec.array_max;
}

static void
get_declaration(declaration *dec, defkind dkind)
{
        token tok;

        get_type(&dec->prefix, &dec->type, dkind);
        dec->rel = REL_ALIAS;
        if (streq(dec->type, "void"))
                return;

        check_type_name(dec->type, 0);
        scan2(TOK_STAR, TOK_IDENT, &tok);
        if (tok.kind == TOK_STAR) {
                dec->rel = REL_POINTER;
                scan(TOK_IDENT, &tok);
        }
        dec->name = tok.str;
        if (peekscan(TOK_LBRACKET, &tok)) {
                if (dec->rel == REL_POINTER)
                        error("no array-of-pointer declarations "
                            "-- use typedef");
                dec->rel = REL_VECTOR;
                scan_num(&tok);
                dec->array_max = tok.str;
                scan(TOK_RBRACKET, &tok);
        } else if (peekscan(TOK_LANGLE, &tok)) {
                if (dec->rel == REL_POINTER)
                        error("no array-of-pointer declarations "
                            "-- use typedef");
                dec->rel = REL_ARRAY;
                if (peekscan(TOK_RANGLE, &tok)) {
                        dec->array_max = "~0";  /* unspecified size, use max */
                } else {
                        scan_num(&tok);
                        dec->array_max = tok.str;
                        scan(TOK_RANGLE, &tok);
                }
        }
        if (streq(dec->type, "opaque")) {
                if (dec->rel != REL_ARRAY && dec->rel != REL_VECTOR) {
                        error("array declaration expected");
                }
        } else if (streq(dec->type, "string")) {
                if (dec->rel != REL_ARRAY) {
                        error("variable-length array declaration expected");
                }
        }
}

static void
get_prog_declaration(declaration *dec, defkind dkind, int num)
{
        token tok;
        char name[sizeof (ARGNAME) + 10];

        if (dkind == DEF_PROGRAM) {
                peek(&tok);
                if (tok.kind == TOK_RPAREN) { /* no arguments */
                        dec->rel = REL_ALIAS;
                        dec->type = "void";
                        dec->prefix = NULL;
                        dec->name = NULL;
                        return;
                }
        }
        get_type(&dec->prefix, &dec->type, dkind);
        dec->rel = REL_ALIAS;
        if (peekscan(TOK_IDENT, &tok)) /* optional name of argument */
                dec->name = strdup(tok.str);
        else {
                /* default name of argument */
                (void) snprintf(name, sizeof (name), "%s%d", ARGNAME, num);
                dec->name = strdup(name);
        }
        if (dec->name == NULL)
                error("internal error -- out of memory");

        if (streq(dec->type, "void"))
                return;

        if (streq(dec->type, "opaque"))
                error("opaque -- illegal argument type");
        if (peekscan(TOK_STAR, &tok)) {
                if (streq(dec->type, "string")) {
                        error("pointer to string not allowed "
                            "in program arguments\n");
                }
                dec->rel = REL_POINTER;
                if (peekscan(TOK_IDENT, &tok))
                        /* optional name of argument */
                        dec->name = strdup(tok.str);
        }
        if (peekscan(TOK_LANGLE, &tok)) {
                if (!streq(dec->type, "string")) {
                        error("arrays cannot be declared as arguments "
                            "to procedures -- use typedef");
                }
                dec->rel = REL_ARRAY;
                if (peekscan(TOK_RANGLE, &tok)) {
                        dec->array_max = "~0";
                        /* unspecified size, use max */
                } else {
                        scan_num(&tok);
                        dec->array_max = tok.str;
                        scan(TOK_RANGLE, &tok);
                }
        }
        if (streq(dec->type, "string")) {
                if (dec->rel != REL_ARRAY) {
                        /*
                         * .x specifies just string as
                         * type of argument
                         * - make it string<>
                         */
                        dec->rel = REL_ARRAY;
                        dec->array_max = "~0"; /* unspecified size, use max */
                }
        }
}

static void
get_type(char **prefixp, char **typep, defkind dkind)
{
        token tok;

        *prefixp = NULL;
        get_token(&tok);
        switch (tok.kind) {
        case TOK_IDENT:
                *typep = tok.str;
                break;
        case TOK_STRUCT:
        case TOK_ENUM:
        case TOK_UNION:
                *prefixp = tok.str;
                scan(TOK_IDENT, &tok);
                *typep = tok.str;
                break;
        case TOK_UNSIGNED:
                unsigned_dec(typep);
                break;
        case TOK_SHORT:
                *typep = "short";
                (void) peekscan(TOK_INT, &tok);
                break;
        case TOK_LONG:
                *typep = "long";
                (void) peekscan(TOK_INT, &tok);
                break;
        case TOK_HYPER:
                *typep = "longlong_t";
                (void) peekscan(TOK_INT, &tok);
                break;

        case TOK_VOID:
                if (dkind != DEF_UNION && dkind != DEF_PROGRAM &&
                    dkind != DEF_RESULT) {
                        error("voids allowed only inside union and "
                            "program definitions with one argument");
                }
                *typep = tok.str;
                break;
        case TOK_ONEWAY:
                if (dkind != DEF_RESULT) {
                        error("oneways allowed only inside result definitions");
                }
                *typep = tok.str;
                break;
        case TOK_STRING:
        case TOK_OPAQUE:
        case TOK_CHAR:
        case TOK_INT:
        case TOK_FLOAT:
        case TOK_DOUBLE:
        case TOK_BOOL:
        case TOK_QUAD:
                *typep = tok.str;
                break;
        default:
                error("expected type specifier");
        }
}

static void
unsigned_dec(char **typep)
{
        token tok;

        peek(&tok);
        switch (tok.kind) {
        case TOK_CHAR:
                get_token(&tok);
                *typep = "u_char";
                break;
        case TOK_SHORT:
                get_token(&tok);
                *typep = "u_short";
                (void) peekscan(TOK_INT, &tok);
                break;
        case TOK_LONG:
                get_token(&tok);
                *typep = "u_long";
                (void) peekscan(TOK_INT, &tok);
                break;
        case TOK_HYPER:
                get_token(&tok);
                *typep = "u_longlong_t";
                (void) peekscan(TOK_INT, &tok);
                break;
        case TOK_INT:
                get_token(&tok);
                *typep = "u_int";
                break;
        default:
                *typep = "u_int";
                break;
        }
}