parser: Don't leak memory when building nested matchers.

[sysdb.git] / src / frontend / grammar.y

diff --git a/src/frontend/grammar.y b/src/frontend/grammar.y
index 50bb00e7f632fa35abb283ca7025b0c02a80a908..450a20f34218ef1df4db9e713bb3b0247cddc0bb 100644 (file)
--- a/src/frontend/grammar.y
+++ b/src/frontend/grammar.y
@@ -32,6 +32,7 @@
 #include "frontend/grammar.h"
 
 #include "core/store.h"
+#include "core/store-private.h"
 
 #include "utils/error.h"
 #include "utils/llist.h"
@@ -69,17 +70,30 @@ sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
 
        sdb_llist_t     *list;
        sdb_conn_node_t *node;
+
+       sdb_store_matcher_t *m;
 }
 
 %start statements
 
 %token SCANNER_ERROR
 
-%token WHERE
+%token AND OR NOT WHERE
+
+%token CMP_EQUAL CMP_NEQUAL CMP_REGEX CMP_NREGEX
 
 %token <str> IDENTIFIER STRING
 %token <node> FETCH LIST LOOKUP
 
+/* Precedence (lowest first): */
+%left OR
+%left AND
+%left NOT
+%left CMP_EQUAL CMP_NEQUAL
+%left CMP_REGEX CMP_NREGEX
+%left '(' ')'
+%left '.'
+
 %type <list> statements
 %type <node> statement
        fetch_statement
@@ -87,6 +101,9 @@ sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
        lookup_statement
        expression
 
+%type <m> matcher
+       compare_matcher
+
 %%
 
 statements:
@@ -97,6 +114,7 @@ statements:
                                sdb_fe_yyerror(&yylloc, scanner,
                                                YY_("syntax error, unexpected statement, "
                                                        "expecting expression"));
+                               sdb_object_deref(SDB_OBJ($3));
                                YYABORT;
                        }
 
@@ -113,6 +131,7 @@ statements:
                                sdb_fe_yyerror(&yylloc, scanner,
                                                YY_("syntax error, unexpected statement, "
                                                        "expecting expression"));
+                               sdb_object_deref(SDB_OBJ($1));
                                YYABORT;
                        }
 
@@ -129,6 +148,7 @@ statements:
                                sdb_fe_yyerror(&yylloc, scanner,
                                                YY_("syntax error, unexpected expression, "
                                                        "expecting statement"));
+                               sdb_object_deref(SDB_OBJ($1));
                                YYABORT;
                        }
 
@@ -164,8 +184,7 @@ fetch_statement:
                                                conn_fetch_t, conn_fetch_destroy));
                        CONN_FETCH($$)->name = strdup($2);
                        $$->cmd = CONNECTION_FETCH;
-                       free($2);
-                       $2 = NULL;
+                       free($2); $2 = NULL;
                }
        ;
 
@@ -197,6 +216,8 @@ lookup_statement:
                                snprintf(errmsg, sizeof(errmsg),
                                                YY_("unknown table %s"), $2);
                                sdb_fe_yyerror(&yylloc, scanner, errmsg);
+                               free($2); $2 = NULL;
+                               sdb_object_deref(SDB_OBJ($4));
                                YYABORT;
                        }
 
@@ -204,28 +225,104 @@ lookup_statement:
                                                conn_lookup_t, conn_lookup_destroy));
                        CONN_LOOKUP($$)->matcher = CONN_MATCHER($4);
                        $$->cmd = CONNECTION_LOOKUP;
-                       free($2);
-                       $2 = NULL;
+                       free($2); $2 = NULL;
                }
        ;
 
 expression:
-       STRING
+       matcher
                {
-                       $$ = SDB_CONN_NODE(sdb_object_create_T(/* name = */ NULL,
-                                               conn_node_matcher_t));
+                       if (! $1) {
+                               /* TODO: improve error reporting */
+                               sdb_fe_yyerror(&yylloc, scanner,
+                                               YY_("syntax error, invalid expression"));
+                               YYABORT;
+                       }
+
+                       $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
+                                               conn_node_matcher_t, conn_matcher_destroy));
                        $$->cmd = CONNECTION_EXPR;
-                       /* XXX: this is just a placeholder for now */
-                       CONN_MATCHER($$)->matcher = sdb_store_host_matcher($1,
-                                       /* name_re = */ NULL, /* service = */ NULL,
-                                       /* attr = */ NULL);
-                       free($1);
-                       $1 = NULL;
+                       CONN_MATCHER($$)->matcher = $1;
+               }
+       ;
+
+matcher:
+       '(' matcher ')'
+               {
+                       $$ = $2;
+               }
+       |
+       matcher AND matcher
+               {
+                       $$ = sdb_store_con_matcher($1, $3);
+                       sdb_object_deref(SDB_OBJ($1));
+                       sdb_object_deref(SDB_OBJ($3));
+               }
+       |
+       matcher OR matcher
+               {
+                       $$ = sdb_store_dis_matcher($1, $3);
+                       sdb_object_deref(SDB_OBJ($1));
+                       sdb_object_deref(SDB_OBJ($3));
+               }
+       |
+       NOT matcher
+               {
+                       $$ = sdb_store_inv_matcher($2);
+                       sdb_object_deref(SDB_OBJ($2));
+               }
+       |
+       compare_matcher
+               {
+                       $$ = $1;
+               }
+       ;
+
+/*
+ * <object_type>.<object_attr> <op> <value>
+ *
+ * Parse matchers comparing object attributes with a value.
+ */
+compare_matcher:
+       IDENTIFIER '.' IDENTIFIER CMP_EQUAL STRING
+               {
+                       $$ = sdb_store_matcher_parse_cmp($1, $3, "=", $5);
+                       /* TODO: simplify memory management in the parser */
+                       free($1); $1 = NULL;
+                       free($3); $3 = NULL;
+                       free($5); $5 = NULL;
+               }
+       |
+       IDENTIFIER '.' IDENTIFIER CMP_NEQUAL STRING
+               {
+                       $$ = sdb_store_matcher_parse_cmp($1, $3, "!=", $5);
+                       /* TODO: simplify memory management in the parser */
+                       free($1); $1 = NULL;
+                       free($3); $3 = NULL;
+                       free($5); $5 = NULL;
+               }
+       |
+       IDENTIFIER '.' IDENTIFIER CMP_REGEX STRING
+               {
+                       $$ = sdb_store_matcher_parse_cmp($1, $3, "=~", $5);
+                       free($1); $1 = NULL;
+                       free($3); $3 = NULL;
+                       free($5); $5 = NULL;
+               }
+       |
+       IDENTIFIER '.' IDENTIFIER CMP_NREGEX STRING
+               {
+                       $$ = sdb_store_matcher_parse_cmp($1, $3, "!~", $5);
+                       free($1); $1 = NULL;
+                       free($3); $3 = NULL;
+                       free($5); $5 = NULL;
                }
        ;
 
 %%
 
+/* XXX: on parse errors, allocated objects, strings, etc. need to be freed */
+
 void
 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg)
 {