src/frontend/parser.c

   1 /*
   2  * SysDB - src/frontend/parser.c
   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 #include "sysdb.h"
  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/llist.h"
  37 #include "utils/strbuf.h"
  38
  39 #include <assert.h>
  40 #include <string.h>
  41
  42 /*
  43  * private helper functions
  44  */
  45
  46 static int
  47 scanner_init(const char *input, int len,
  48                 sdb_fe_yyscan_t *scanner, sdb_fe_yyextra_t *extra,
  49                 sdb_strbuf_t *errbuf)
  50 {
  51         if (! input) {
  52                 sdb_strbuf_sprintf(errbuf, "Missing scanner input");
  53                 return -1;
  54         }
  55
  56         memset(extra, 0, sizeof(*extra));
  57         extra->parsetree = sdb_llist_create();
  58         extra->mode = SDB_PARSE_DEFAULT;
  59         extra->errbuf = errbuf;
  60
  61         if (! extra->parsetree) {
  62                 sdb_strbuf_sprintf(errbuf, "Failed to allocate parse-tree");
  63                 return -1;
  64         }
  65
  66         *scanner = sdb_fe_scanner_init(input, len, extra);
  67         if (! scanner) {
  68                 sdb_llist_destroy(extra->parsetree);
  69                 return -1;
  70         }
  71         return 0;
  72 } /* scanner_init */
  73
  74 /*
  75  * public API
  76  */
  77
  78 sdb_llist_t *
  79 sdb_fe_parse(const char *query, int len, sdb_strbuf_t *errbuf)
  80 {
  81         sdb_fe_yyscan_t scanner;
  82         sdb_fe_yyextra_t yyextra;
  83         sdb_llist_iter_t *iter;
  84         int yyres;
  85
  86         if (scanner_init(query, len, &scanner, &yyextra, errbuf))
  87                 return NULL;
  88
  89         yyres = sdb_fe_yyparse(scanner);
  90         sdb_fe_scanner_destroy(scanner);
  91
  92         if (yyres) {
  93                 sdb_llist_destroy(yyextra.parsetree);
  94                 return NULL;
  95         }
  96
  97         iter = sdb_llist_get_iter(yyextra.parsetree);
  98         while (sdb_llist_iter_has_next(iter)) {
  99                 sdb_conn_node_t *node;
 100                 node = SDB_CONN_NODE(sdb_llist_iter_get_next(iter));
 101                 if (sdb_fe_analyze(node)) {
 102                         /* TODO: pass on errbuf to the analyzer */
 103                         sdb_strbuf_sprintf(errbuf, "Failed to verify "
 104                                         "query '%s'", query);
 105                         sdb_llist_iter_destroy(iter);
 106                         sdb_llist_destroy(yyextra.parsetree);
 107                         return NULL;
 108                 }
 109         }
 110         sdb_llist_iter_destroy(iter);
 111         return yyextra.parsetree;
 112 } /* sdb_fe_parse */
 113
 114 sdb_store_matcher_t *
 115 sdb_fe_parse_matcher(const char *cond, int len, sdb_strbuf_t *errbuf)
 116 {
 117         sdb_fe_yyscan_t scanner;
 118         sdb_fe_yyextra_t yyextra;
 119
 120         sdb_conn_node_t *node;
 121         sdb_store_matcher_t *m;
 122
 123         int yyres;
 124
 125         if (scanner_init(cond, len, &scanner, &yyextra, errbuf))
 126                 return NULL;
 127
 128         yyextra.mode = SDB_PARSE_COND;
 129
 130         yyres = sdb_fe_yyparse(scanner);
 131         sdb_fe_scanner_destroy(scanner);
 132
 133         if (yyres) {
 134                 sdb_llist_destroy(yyextra.parsetree);
 135                 return NULL;
 136         }
 137
 138         node = SDB_CONN_NODE(sdb_llist_get(yyextra.parsetree, 0));
 139         if (! node) {
 140                 sdb_strbuf_sprintf(errbuf, "Empty matcher expression '%s'", cond);
 141                 sdb_llist_destroy(yyextra.parsetree);
 142                 return NULL;
 143         }
 144
 145         assert(node->cmd == CONNECTION_MATCHER);
 146         m = CONN_MATCHER(node)->matcher;
 147         CONN_MATCHER(node)->matcher = NULL;
 148
 149         sdb_llist_destroy(yyextra.parsetree);
 150         sdb_object_deref(SDB_OBJ(node));
 151         return m;
 152 } /* sdb_fe_parse_matcher */
 153
 154 sdb_store_expr_t *
 155 sdb_fe_parse_expr(const char *expr, int len, sdb_strbuf_t *errbuf)
 156 {
 157         sdb_fe_yyscan_t scanner;
 158         sdb_fe_yyextra_t yyextra;
 159
 160         sdb_conn_node_t *node;
 161         sdb_store_expr_t *e;
 162
 163         int yyres;
 164
 165         if (scanner_init(expr, len, &scanner, &yyextra, errbuf))
 166                 return NULL;
 167
 168         yyextra.mode = SDB_PARSE_EXPR;
 169
 170         yyres = sdb_fe_yyparse(scanner);
 171         sdb_fe_scanner_destroy(scanner);
 172
 173         if (yyres) {
 174                 sdb_llist_destroy(yyextra.parsetree);
 175                 return NULL;
 176         }
 177
 178         node = SDB_CONN_NODE(sdb_llist_get(yyextra.parsetree, 0));
 179         if (! node) {
 180                 sdb_strbuf_sprintf(errbuf, "Empty expression '%s'", expr);
 181                 sdb_llist_destroy(yyextra.parsetree);
 182                 return NULL;
 183         }
 184
 185         assert(node->cmd == CONNECTION_EXPR);
 186         e = CONN_EXPR(node)->expr;
 187         CONN_EXPR(node)->expr = NULL;
 188
 189         sdb_llist_destroy(yyextra.parsetree);
 190         sdb_object_deref(SDB_OBJ(node));
 191         return e;
 192 } /* sdb_fe_parse_expr */
 193
 194 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 195