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
  41 int
  42 sdb_fe_yylex(YYSTYPE *yylval, YYLTYPE *yylloc, sdb_fe_yyscan_t yyscanner);
  43
  44 sdb_fe_yyextra_t *
  45 sdb_fe_yyget_extra(sdb_fe_yyscan_t scanner);
  46
  47 void
  48 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
  49
  50 /* quick access to the current parse tree */
  51 #define pt sdb_fe_yyget_extra(scanner)->parsetree
  52
  53 /* quick access to the parser mode */
  54 #define parser_mode sdb_fe_yyget_extra(scanner)->mode
  55
  56 %}
  57
  58 %pure-parser
  59 %lex-param {sdb_fe_yyscan_t scanner}
  60 %parse-param {sdb_fe_yyscan_t scanner}
  61 %locations
  62 %error-verbose
  63 %expect 0
  64 %name-prefix="sdb_fe_yy"
  65
  66 %union {
  67         char *str;
  68
  69         sdb_llist_t     *list;
  70         sdb_conn_node_t *node;
  71 }
  72
  73 %start statements
  74
  75 %token SCANNER_ERROR
  76
  77 %token <str> IDENTIFIER
  78 %token <node> LIST
  79
  80 %type <list> statements
  81 %type <node> statement
  82         list_statement
  83         expression
  84
  85 %%
  86
  87 statements:
  88         statements ';' statement
  89                 {
  90                         /* only accept this in default parse mode */
  91                         if (parser_mode != SDB_PARSE_DEFAULT) {
  92                                 sdb_fe_yyerror(&yylloc, scanner,
  93                                                 YY_("syntax error, unexpected statement, "
  94                                                         "expecting expression"));
  95                                 YYABORT;
  96                         }
  97
  98                         if ($3) {
  99                                 sdb_llist_append(pt, SDB_OBJ($3));
 100                                 sdb_object_deref(SDB_OBJ($3));
 101                         }
 102                 }
 103         |
 104         statement
 105                 {
 106                         /* only accept this in default parse mode */
 107                         if (parser_mode != SDB_PARSE_DEFAULT) {
 108                                 sdb_fe_yyerror(&yylloc, scanner,
 109                                                 YY_("syntax error, unexpected statement, "
 110                                                         "expecting expression"));
 111                                 YYABORT;
 112                         }
 113
 114                         if ($1) {
 115                                 sdb_llist_append(pt, SDB_OBJ($1));
 116                                 sdb_object_deref(SDB_OBJ($1));
 117                         }
 118                 }
 119         |
 120         expression
 121                 {
 122                         /* only accept this in expression parse mode */
 123                         if (! (parser_mode & SDB_PARSE_EXPR)) {
 124                                 sdb_fe_yyerror(&yylloc, scanner,
 125                                                 YY_("syntax error, unexpected expression, "
 126                                                         "expecting statement"));
 127                                 YYABORT;
 128                         }
 129
 130                         if ($1) {
 131                                 sdb_llist_append(pt, SDB_OBJ($1));
 132                                 sdb_object_deref(SDB_OBJ($1));
 133                         }
 134                 }
 135         ;
 136
 137 statement:
 138         list_statement
 139         |
 140         /* empty */
 141                 {
 142                         $$ = NULL;
 143                 }
 144         ;
 145
 146 list_statement:
 147         LIST
 148                 {
 149                         $$ = SDB_CONN_NODE(sdb_object_create_T(/* name = */ NULL,
 150                                                 sdb_conn_node_t));
 151                         $$->cmd = CONNECTION_LIST;
 152                 }
 153         ;
 154
 155 expression:
 156         IDENTIFIER
 157                 {
 158                         $$ = SDB_CONN_NODE(sdb_object_create_T(/* name = */ NULL,
 159                                                 conn_node_matcher_t));
 160                         $$->cmd = CONNECTION_EXPR;
 161                         /* XXX: this is just a placeholder for now */
 162                         CONN_MATCHER($$)->matcher = sdb_store_host_matcher($1,
 163                                         /* name_re = */ NULL, /* service = */ NULL,
 164                                         /* attr = */ NULL);
 165                         free($1);
 166                         $1 = NULL;
 167                 }
 168         ;
 169
 170 %%
 171
 172 void
 173 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg)
 174 {
 175         sdb_log(SDB_LOG_ERR, "frontend: parse error: %s", msg);
 176 } /* sdb_fe_yyerror */
 177
 178 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 179