src/frontend/grammar.y

   1 /*
   2  * SysDB - src/frontend/grammar.y
   3  * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 %{
  29
  30 #include "frontend/connection-private.h"
  31 #include "frontend/parser.h"
  32 #include "frontend/grammar.h"
  33
  34 #include "core/store.h"
  35
  36 #include "utils/error.h"
  37 #include "utils/llist.h"
  38
  39 #include <stdio.h>
  40 #include <string.h>
  41
  42 int
  43 sdb_fe_yylex(YYSTYPE *yylval, YYLTYPE *yylloc, sdb_fe_yyscan_t yyscanner);
  44
  45 sdb_fe_yyextra_t *
  46 sdb_fe_yyget_extra(sdb_fe_yyscan_t scanner);
  47
  48 void
  49 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
  50
  51 /* quick access to the current parse tree */
  52 #define pt sdb_fe_yyget_extra(scanner)->parsetree
  53
  54 /* quick access to the parser mode */
  55 #define parser_mode sdb_fe_yyget_extra(scanner)->mode
  56
  57 %}
  58
  59 %pure-parser
  60 %lex-param {sdb_fe_yyscan_t scanner}
  61 %parse-param {sdb_fe_yyscan_t scanner}
  62 %locations
  63 %error-verbose
  64 %expect 0
  65 %name-prefix="sdb_fe_yy"
  66
  67 %union {
  68         char *str;
  69
  70         sdb_llist_t     *list;
  71         sdb_conn_node_t *node;
  72 }
  73
  74 %start statements
  75
  76 %token SCANNER_ERROR
  77
  78 %token <str> IDENTIFIER STRING
  79 %token <node> FETCH LIST
  80
  81 %type <list> statements
  82 %type <node> statement
  83         fetch_statement
  84         list_statement
  85         expression
  86
  87 %%
  88
  89 statements:
  90         statements ';' statement
  91                 {
  92                         /* only accept this in default parse mode */
  93                         if (parser_mode != SDB_PARSE_DEFAULT) {
  94                                 sdb_fe_yyerror(&yylloc, scanner,
  95                                                 YY_("syntax error, unexpected statement, "
  96                                                         "expecting expression"));
  97                                 YYABORT;
  98                         }
  99
 100                         if ($3) {
 101                                 sdb_llist_append(pt, SDB_OBJ($3));
 102                                 sdb_object_deref(SDB_OBJ($3));
 103                         }
 104                 }
 105         |
 106         statement
 107                 {
 108                         /* only accept this in default parse mode */
 109                         if (parser_mode != SDB_PARSE_DEFAULT) {
 110                                 sdb_fe_yyerror(&yylloc, scanner,
 111                                                 YY_("syntax error, unexpected statement, "
 112                                                         "expecting expression"));
 113                                 YYABORT;
 114                         }
 115
 116                         if ($1) {
 117                                 sdb_llist_append(pt, SDB_OBJ($1));
 118                                 sdb_object_deref(SDB_OBJ($1));
 119                         }
 120                 }
 121         |
 122         expression
 123                 {
 124                         /* only accept this in expression parse mode */
 125                         if (! (parser_mode & SDB_PARSE_EXPR)) {
 126                                 sdb_fe_yyerror(&yylloc, scanner,
 127                                                 YY_("syntax error, unexpected expression, "
 128                                                         "expecting statement"));
 129                                 YYABORT;
 130                         }
 131
 132                         if ($1) {
 133                                 sdb_llist_append(pt, SDB_OBJ($1));
 134                                 sdb_object_deref(SDB_OBJ($1));
 135                         }
 136                 }
 137         ;
 138
 139 statement:
 140         fetch_statement
 141         |
 142         list_statement
 143         |
 144         /* empty */
 145                 {
 146                         $$ = NULL;
 147                 }
 148         ;
 149
 150 /*
 151  * FETCH <hostname>;
 152  *
 153  * Retrieve detailed information about a single host.
 154  */
 155 fetch_statement:
 156         FETCH STRING
 157                 {
 158                         $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
 159                                                 conn_fetch_t, conn_fetch_destroy));
 160                         CONN_FETCH($$)->name = strdup($2);
 161                         $$->cmd = CONNECTION_FETCH;
 162                         free($2);
 163                         $2 = NULL;
 164                 }
 165         ;
 166
 167 /*
 168  * LIST;
 169  *
 170  * Returns a list of all hosts in the store.
 171  */
 172 list_statement:
 173         LIST
 174                 {
 175                         $$ = SDB_CONN_NODE(sdb_object_create_T(/* name = */ NULL,
 176                                                 sdb_conn_node_t));
 177                         $$->cmd = CONNECTION_LIST;
 178                 }
 179         ;
 180
 181 expression:
 182         STRING
 183                 {
 184                         $$ = SDB_CONN_NODE(sdb_object_create_T(/* name = */ NULL,
 185                                                 conn_node_matcher_t));
 186                         $$->cmd = CONNECTION_EXPR;
 187                         /* XXX: this is just a placeholder for now */
 188                         CONN_MATCHER($$)->matcher = sdb_store_host_matcher($1,
 189                                         /* name_re = */ NULL, /* service = */ NULL,
 190                                         /* attr = */ NULL);
 191                         free($1);
 192                         $1 = NULL;
 193                 }
 194         ;
 195
 196 %%
 197
 198 void
 199 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg)
 200 {
 201         sdb_log(SDB_LOG_ERR, "frontend: parse error: %s", msg);
 202 } /* sdb_fe_yyerror */
 203
 204 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 205