src/parser/parser.c

   1 /*
   2  * SysDB - src/parser/parser.c
   3  * Copyright (C) 2013-2015 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 "parser/ast.h"
  31 #include "parser/parser.h"
  32 #include "parser/grammar.h"
  33
  34 #include "utils/llist.h"
  35 #include "utils/strbuf.h"
  36
  37 #include <assert.h>
  38 #include <string.h>
  39
  40 /*
  41  * private helper functions
  42  */
  43
  44 static int
  45 scanner_init(const char *input, int len,
  46                 sdb_parser_yyscan_t *scanner, sdb_parser_yyextra_t *extra,
  47                 sdb_strbuf_t *errbuf)
  48 {
  49         if (! input) {
  50                 sdb_strbuf_sprintf(errbuf, "Missing scanner input");
  51                 return -1;
  52         }
  53
  54         memset(extra, 0, sizeof(*extra));
  55         extra->parsetree = sdb_llist_create();
  56         extra->mode = SDB_PARSE_DEFAULT;
  57         extra->errbuf = errbuf;
  58
  59         if (! extra->parsetree) {
  60                 sdb_strbuf_sprintf(errbuf, "Failed to allocate parse-tree");
  61                 return -1;
  62         }
  63
  64         *scanner = sdb_parser_scanner_init(input, len, extra);
  65         if (! *scanner) {
  66                 sdb_llist_destroy(extra->parsetree);
  67                 return -1;
  68         }
  69         return 0;
  70 } /* scanner_init */
  71
  72 /*
  73  * public API
  74  */
  75
  76 sdb_llist_t *
  77 sdb_parser_parse(const char *query, int len, sdb_strbuf_t *errbuf)
  78 {
  79         sdb_parser_yyscan_t scanner;
  80         sdb_parser_yyextra_t yyextra;
  81         sdb_llist_iter_t *iter;
  82         int yyres;
  83
  84         if (scanner_init(query, len, &scanner, &yyextra, errbuf))
  85                 return NULL;
  86
  87         yyres = sdb_parser_yyparse(scanner);
  88         sdb_parser_scanner_destroy(scanner);
  89
  90         if (yyres) {
  91                 sdb_llist_destroy(yyextra.parsetree);
  92                 return NULL;
  93         }
  94
  95         iter = sdb_llist_get_iter(yyextra.parsetree);
  96         while (sdb_llist_iter_has_next(iter)) {
  97                 sdb_ast_node_t *node;
  98                 node = SDB_AST_NODE(sdb_llist_iter_get_next(iter));
  99                 if (sdb_parser_analyze(node, errbuf) < 0) {
 100                         sdb_llist_iter_destroy(iter);
 101                         sdb_llist_destroy(yyextra.parsetree);
 102                         return NULL;
 103                 }
 104         }
 105         sdb_llist_iter_destroy(iter);
 106         return yyextra.parsetree;
 107 } /* sdb_parser_parse */
 108
 109 sdb_ast_node_t *
 110 sdb_parser_parse_conditional(const char *cond, int len, sdb_strbuf_t *errbuf)
 111 {
 112         sdb_parser_yyscan_t scanner;
 113         sdb_parser_yyextra_t yyextra;
 114
 115         sdb_ast_node_t *node;
 116
 117         int yyres;
 118
 119         if (scanner_init(cond, len, &scanner, &yyextra, errbuf))
 120                 return NULL;
 121
 122         yyextra.mode = SDB_PARSE_COND;
 123
 124         yyres = sdb_parser_yyparse(scanner);
 125         sdb_parser_scanner_destroy(scanner);
 126
 127         if (yyres) {
 128                 sdb_llist_destroy(yyextra.parsetree);
 129                 return NULL;
 130         }
 131
 132         node = SDB_AST_NODE(sdb_llist_get(yyextra.parsetree, 0));
 133         if (! node) {
 134                 sdb_strbuf_sprintf(errbuf, "Empty conditional expression '%s'", cond);
 135                 sdb_llist_destroy(yyextra.parsetree);
 136                 return NULL;
 137         }
 138
 139         assert(SDB_AST_IS_LOGICAL(node));
 140         sdb_llist_destroy(yyextra.parsetree);
 141
 142         if (sdb_parser_analyze_conditional(node, errbuf)) {
 143                 sdb_object_deref(SDB_OBJ(node));
 144                 return NULL;
 145         }
 146         return node;
 147 } /* sdb_parser_parse_conditional */
 148
 149 sdb_ast_node_t *
 150 sdb_parser_parse_arith(const char *expr, int len, sdb_strbuf_t *errbuf)
 151 {
 152         sdb_parser_yyscan_t scanner;
 153         sdb_parser_yyextra_t yyextra;
 154
 155         sdb_ast_node_t *node;
 156
 157         int yyres;
 158
 159         if (scanner_init(expr, len, &scanner, &yyextra, errbuf))
 160                 return NULL;
 161
 162         yyextra.mode = SDB_PARSE_ARITH;
 163
 164         yyres = sdb_parser_yyparse(scanner);
 165         sdb_parser_scanner_destroy(scanner);
 166
 167         if (yyres) {
 168                 sdb_llist_destroy(yyextra.parsetree);
 169                 return NULL;
 170         }
 171
 172         node = SDB_AST_NODE(sdb_llist_get(yyextra.parsetree, 0));
 173         if (! node) {
 174                 sdb_strbuf_sprintf(errbuf, "Empty expression '%s'", expr);
 175                 sdb_llist_destroy(yyextra.parsetree);
 176                 return NULL;
 177         }
 178
 179         assert(SDB_AST_IS_ARITHMETIC(node));
 180         sdb_llist_destroy(yyextra.parsetree);
 181
 182         if (sdb_parser_analyze_arith(node, errbuf)) {
 183                 sdb_object_deref(SDB_OBJ(node));
 184                 return NULL;
 185         }
 186         return node;
 187 } /* sdb_parser_parse_arith */
 188
 189 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 190