Code

frontend: Improved parser error reporting.
[sysdb.git] / src / frontend / grammar.y
index 551d1714d7a12cf86b64aea6834b4e4dd782dd89..ab9345e22c80272b6cbd4b84b0fd7ce4472fda87 100644 (file)
 #include "frontend/grammar.h"
 
 #include "core/store.h"
+#include "core/store-private.h"
+#include "core/time.h"
 
 #include "utils/error.h"
 #include "utils/llist.h"
 
+#include <assert.h>
+
 #include <stdio.h>
+#include <string.h>
+
+/*
+ * private helper functions
+ */
+
+static sdb_store_matcher_t *
+name_iter_matcher(int m_type, int type, const char *cmp,
+               sdb_store_expr_t *expr);
+
+/*
+ * public API
+ */
 
 int
 sdb_fe_yylex(YYSTYPE *yylval, YYLTYPE *yylloc, sdb_fe_yyscan_t yyscanner);
@@ -46,6 +63,8 @@ sdb_fe_yyget_extra(sdb_fe_yyscan_t scanner);
 
 void
 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
+void
+sdb_fe_yyerrorf(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *fmt, ...);
 
 /* quick access to the current parse tree */
 #define pt sdb_fe_yyget_extra(scanner)->parsetree
@@ -53,6 +72,15 @@ sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
 /* quick access to the parser mode */
 #define parser_mode sdb_fe_yyget_extra(scanner)->mode
 
+/* quick access to the parser's error buffer */
+#define errbuf sdb_fe_yyget_extra(scanner)->errbuf
+
+#define MODE_TO_STRING(m) \
+       (((m) == SDB_PARSE_DEFAULT) ? "statement" \
+               : ((m) == SDB_PARSE_COND) ? "condition" \
+               : ((m) == SDB_PARSE_EXPR) ? "expression" \
+               : "UNKNOWN")
+
 %}
 
 %pure-parser
@@ -61,37 +89,107 @@ sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
 %locations
 %error-verbose
 %expect 0
-%name-prefix="sdb_fe_yy"
+%name-prefix "sdb_fe_yy"
 
 %union {
+       const char *sstr; /* static string */
        char *str;
+       int integer;
+
+       sdb_data_t data;
+       sdb_time_t datetime;
 
        sdb_llist_t     *list;
        sdb_conn_node_t *node;
+
+       sdb_store_matcher_t *m;
+       sdb_store_expr_t *expr;
 }
 
 %start statements
 
 %token SCANNER_ERROR
 
-%token <str> IDENTIFIER
-%token <node> LIST
+%token AND OR IS NOT MATCHING FILTER
+%token CMP_EQUAL CMP_NEQUAL CMP_REGEX CMP_NREGEX
+%token CMP_LT CMP_LE CMP_GE CMP_GT ALL ANY IN
+%token CONCAT
+
+%token HOST_T HOSTS_T SERVICE_T SERVICES_T METRIC_T METRICS_T
+%token ATTRIBUTE_T ATTRIBUTES_T
+%token NAME_T LAST_UPDATE_T AGE_T INTERVAL_T BACKEND_T
+
+%token START END
+
+/* NULL token */
+%token NULL_T
+
+%token FETCH LIST LOOKUP TIMESERIES
+
+%token <str> IDENTIFIER STRING
+
+%token <data> INTEGER FLOAT
+
+%token <datetime> DATE TIME
+
+/* Precedence (lowest first): */
+%left OR
+%left AND
+%right NOT
+%left CMP_EQUAL CMP_NEQUAL
+%left CMP_LT CMP_LE CMP_GE CMP_GT
+%nonassoc CMP_REGEX CMP_NREGEX
+%nonassoc IN
+%left CONCAT
+%nonassoc IS
+%left '+' '-'
+%left '*' '/' '%'
+%left '[' ']'
+%left '(' ')'
+%left '.'
 
 %type <list> statements
 %type <node> statement
+       fetch_statement
        list_statement
-       expression
+       lookup_statement
+       timeseries_statement
+       matching_clause
+       filter_clause
+       condition
+
+%type <m> matcher
+       compare_matcher
+
+%type <expr> expression
+
+%type <integer> object_type object_type_plural
+%type <integer> iterable
+%type <integer> field
+
+%type <sstr> cmp
+
+%type <data> data
+       interval interval_elem
+
+%type <datetime> datetime
+       start_clause end_clause
+
+%destructor { free($$); } <str>
+%destructor { sdb_object_deref(SDB_OBJ($$)); } <node> <m> <expr>
+%destructor { sdb_data_free_datum(&$$); } <data>
 
 %%
 
 statements:
        statements ';' statement
                {
-                       /* only accept this in default parse mode */
+                       /* only accepted in default parse mode */
                        if (parser_mode != SDB_PARSE_DEFAULT) {
-                               sdb_fe_yyerror(&yylloc, scanner,
+                               sdb_fe_yyerrorf(&yylloc, scanner,
                                                YY_("syntax error, unexpected statement, "
-                                                       "expecting expression"));
+                                                       "expecting %s"), MODE_TO_STRING(parser_mode));
+                               sdb_object_deref(SDB_OBJ($3));
                                YYABORT;
                        }
 
@@ -103,11 +201,29 @@ statements:
        |
        statement
                {
-                       /* only accept this in default parse mode */
+                       /* only accepted in default parse mode */
                        if (parser_mode != SDB_PARSE_DEFAULT) {
-                               sdb_fe_yyerror(&yylloc, scanner,
+                               sdb_fe_yyerrorf(&yylloc, scanner,
                                                YY_("syntax error, unexpected statement, "
-                                                       "expecting expression"));
+                                                       "expecting %s"), MODE_TO_STRING(parser_mode));
+                               sdb_object_deref(SDB_OBJ($1));
+                               YYABORT;
+                       }
+
+                       if ($1) {
+                               sdb_llist_append(pt, SDB_OBJ($1));
+                               sdb_object_deref(SDB_OBJ($1));
+                       }
+               }
+       |
+       condition
+               {
+                       /* only accepted in condition parse mode */
+                       if (! (parser_mode & SDB_PARSE_COND)) {
+                               sdb_fe_yyerrorf(&yylloc, scanner,
+                                               YY_("syntax error, unexpected condition, "
+                                                       "expecting %s"), MODE_TO_STRING(parser_mode));
+                               sdb_object_deref(SDB_OBJ($1));
                                YYABORT;
                        }
 
@@ -119,51 +235,418 @@ statements:
        |
        expression
                {
-                       /* only accept this in expression parse mode */
+                       /* only accepted in expression parse mode */
                        if (! (parser_mode & SDB_PARSE_EXPR)) {
-                               sdb_fe_yyerror(&yylloc, scanner,
+                               sdb_fe_yyerrorf(&yylloc, scanner,
                                                YY_("syntax error, unexpected expression, "
-                                                       "expecting statement"));
+                                                       "expecting %s"), MODE_TO_STRING(parser_mode));
+                               sdb_object_deref(SDB_OBJ($1));
                                YYABORT;
                        }
 
                        if ($1) {
-                               sdb_llist_append(pt, SDB_OBJ($1));
-                               sdb_object_deref(SDB_OBJ($1));
+                               sdb_conn_node_t *n;
+                               n = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
+                                                       conn_expr_t, conn_expr_destroy));
+                               n->cmd = CONNECTION_EXPR;
+                               CONN_EXPR(n)->expr = $1;
+
+                               sdb_llist_append(pt, SDB_OBJ(n));
+                               sdb_object_deref(SDB_OBJ(n));
                        }
                }
        ;
 
 statement:
+       fetch_statement
+       |
        list_statement
        |
+       lookup_statement
+       |
+       timeseries_statement
+       |
        /* empty */
                {
                        $$ = NULL;
                }
        ;
 
+/*
+ * FETCH <type> <hostname> [FILTER <condition>];
+ *
+ * Retrieve detailed information about a single host.
+ */
+fetch_statement:
+       FETCH object_type STRING filter_clause
+               {
+                       $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
+                                               conn_fetch_t, conn_fetch_destroy));
+                       CONN_FETCH($$)->type = $2;
+                       CONN_FETCH($$)->host = $3;
+                       CONN_FETCH($$)->name = NULL;
+                       CONN_FETCH($$)->filter = CONN_MATCHER($4);
+                       $$->cmd = CONNECTION_FETCH;
+               }
+       |
+       FETCH object_type STRING '.' STRING filter_clause
+               {
+                       $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
+                                               conn_fetch_t, conn_fetch_destroy));
+                       CONN_FETCH($$)->type = $2;
+                       CONN_FETCH($$)->host = $3;
+                       CONN_FETCH($$)->name = $5;
+                       CONN_FETCH($$)->filter = CONN_MATCHER($6);
+                       $$->cmd = CONNECTION_FETCH;
+               }
+       ;
+
+/*
+ * LIST <type> [FILTER <condition>];
+ *
+ * Returns a list of all hosts in the store.
+ */
 list_statement:
-       LIST
+       LIST object_type_plural filter_clause
                {
-                       $$ = SDB_CONN_NODE(sdb_object_create_T(/* name = */ NULL,
-                                               sdb_conn_node_t));
+                       $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
+                                               conn_list_t, conn_list_destroy));
+                       CONN_LIST($$)->type = $2;
+                       CONN_LIST($$)->filter = CONN_MATCHER($3);
                        $$->cmd = CONNECTION_LIST;
                }
        ;
 
+/*
+ * LOOKUP <type> MATCHING <condition> [FILTER <condition>];
+ *
+ * Returns detailed information about <type> matching condition.
+ */
+lookup_statement:
+       LOOKUP HOSTS_T matching_clause filter_clause
+               {
+                       /* TODO: support other types as well */
+
+                       $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
+                                               conn_lookup_t, conn_lookup_destroy));
+                       CONN_LOOKUP($$)->type = SDB_HOST;
+                       CONN_LOOKUP($$)->matcher = CONN_MATCHER($3);
+                       CONN_LOOKUP($$)->filter = CONN_MATCHER($4);
+                       $$->cmd = CONNECTION_LOOKUP;
+               }
+       ;
+
+matching_clause:
+       MATCHING condition { $$ = $2; }
+       |
+       /* empty */ { $$ = NULL; }
+
+filter_clause:
+       FILTER condition { $$ = $2; }
+       |
+       /* empty */ { $$ = NULL; }
+
+/*
+ * TIMESERIES <host>.<metric> [START <datetime>] [END <datetime>];
+ *
+ * Returns a time-series for the specified host's metric.
+ */
+timeseries_statement:
+       TIMESERIES STRING '.' STRING start_clause end_clause
+               {
+                       $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
+                                               conn_ts_t, conn_ts_destroy));
+                       CONN_TS($$)->hostname = $2;
+                       CONN_TS($$)->metric = $4;
+                       CONN_TS($$)->opts.start = $5;
+                       CONN_TS($$)->opts.end = $6;
+                       $$->cmd = CONNECTION_TIMESERIES;
+               }
+       ;
+
+start_clause:
+       START datetime { $$ = $2; }
+       |
+       /* empty */ { $$ = sdb_gettime() - SDB_INTERVAL_HOUR; }
+
+end_clause:
+       END datetime { $$ = $2; }
+       |
+       /* empty */ { $$ = sdb_gettime(); }
+
+/*
+ * Basic expressions.
+ */
+
+condition:
+       matcher
+               {
+                       if (! $1) {
+                               /* TODO: improve error reporting */
+                               sdb_fe_yyerror(&yylloc, scanner,
+                                               YY_("syntax error, invalid condition"));
+                               YYABORT;
+                       }
+
+                       $$ = SDB_CONN_NODE(sdb_object_create_dT(/* name = */ NULL,
+                                               conn_matcher_t, conn_matcher_destroy));
+                       $$->cmd = CONNECTION_MATCHER;
+                       CONN_MATCHER($$)->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
+               {
+                       $$ = $1;
+               }
+       ;
+
+compare_matcher:
+       expression cmp expression
+               {
+                       sdb_store_matcher_op_cb cb = sdb_store_parse_matcher_op($2);
+                       assert(cb); /* else, the grammar accepts invalid 'cmp' */
+                       $$ = cb($1, $3);
+                       sdb_object_deref(SDB_OBJ($1));
+                       sdb_object_deref(SDB_OBJ($3));
+               }
+       |
+       ANY iterable cmp expression
+               {
+                       $$ = name_iter_matcher(MATCHER_ANY, $2, $3, $4);
+                       sdb_object_deref(SDB_OBJ($4));
+               }
+       |
+       ALL iterable cmp expression
+               {
+                       $$ = name_iter_matcher(MATCHER_ALL, $2, $3, $4);
+                       sdb_object_deref(SDB_OBJ($4));
+               }
+       |
+       expression IS NULL_T
+               {
+                       $$ = sdb_store_isnull_matcher($1);
+                       sdb_object_deref(SDB_OBJ($1));
+               }
+       |
+       expression IS NOT NULL_T
+               {
+                       $$ = sdb_store_isnnull_matcher($1);
+                       sdb_object_deref(SDB_OBJ($1));
+               }
+       |
+       expression IN expression
+               {
+                       $$ = sdb_store_in_matcher($1, $3);
+                       sdb_object_deref(SDB_OBJ($1));
+                       sdb_object_deref(SDB_OBJ($3));
+               }
+       ;
+
 expression:
-       IDENTIFIER
+       '(' expression ')'
+               {
+                       $$ = $2;
+               }
+       |
+       expression '+' expression
+               {
+                       $$ = sdb_store_expr_create(SDB_DATA_ADD, $1, $3);
+                       sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
+                       sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
+               }
+       |
+       expression '-' expression
+               {
+                       $$ = sdb_store_expr_create(SDB_DATA_SUB, $1, $3);
+                       sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
+                       sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
+               }
+       |
+       expression '*' expression
+               {
+                       $$ = sdb_store_expr_create(SDB_DATA_MUL, $1, $3);
+                       sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
+                       sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
+               }
+       |
+       expression '/' expression
+               {
+                       $$ = sdb_store_expr_create(SDB_DATA_DIV, $1, $3);
+                       sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
+                       sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
+               }
+       |
+       expression '%' expression
+               {
+                       $$ = sdb_store_expr_create(SDB_DATA_MOD, $1, $3);
+                       sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
+                       sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
+               }
+       |
+       expression CONCAT expression
+               {
+                       $$ = sdb_store_expr_create(SDB_DATA_CONCAT, $1, $3);
+                       sdb_object_deref(SDB_OBJ($1)); $1 = NULL;
+                       sdb_object_deref(SDB_OBJ($3)); $3 = NULL;
+               }
+       |
+       HOST_T
+               {
+                       /* TODO: this only works as long as queries
+                        * are limited to hosts */
+                       $$ = sdb_store_expr_fieldvalue(SDB_FIELD_NAME);
+               }
+       |
+       field
+               {
+                       $$ = sdb_store_expr_fieldvalue($1);
+               }
+       |
+       ATTRIBUTE_T '[' STRING ']'
+               {
+                       $$ = sdb_store_expr_attrvalue($3);
+                       free($3); $3 = NULL;
+               }
+       |
+       data
+               {
+                       $$ = sdb_store_expr_constvalue(&$1);
+                       sdb_data_free_datum(&$1);
+               }
+       ;
+
+object_type:
+       HOST_T { $$ = SDB_HOST; }
+       |
+       SERVICE_T { $$ = SDB_SERVICE; }
+       |
+       METRIC_T { $$ = SDB_METRIC; }
+       ;
+
+object_type_plural:
+       HOSTS_T { $$ = SDB_HOST; }
+       |
+       SERVICES_T { $$ = SDB_SERVICE; }
+       |
+       METRICS_T { $$ = SDB_METRIC; }
+       ;
+
+iterable:
+       SERVICE_T { $$ = SDB_SERVICE; }
+       |
+       METRIC_T { $$ = SDB_METRIC; }
+       |
+       ATTRIBUTE_T { $$ = SDB_ATTRIBUTE; }
+       ;
+
+field:
+       NAME_T { $$ = SDB_FIELD_NAME; }
+       |
+       LAST_UPDATE_T { $$ = SDB_FIELD_LAST_UPDATE; }
+       |
+       AGE_T { $$ = SDB_FIELD_AGE; }
+       |
+       INTERVAL_T { $$ = SDB_FIELD_INTERVAL; }
+       |
+       BACKEND_T { $$ = SDB_FIELD_BACKEND; }
+       ;
+
+cmp:
+       CMP_EQUAL { $$ = "="; }
+       |
+       CMP_NEQUAL { $$ = "!="; }
+       |
+       CMP_REGEX { $$ = "=~"; }
+       |
+       CMP_NREGEX { $$ = "!~"; }
+       |
+       CMP_LT { $$ = "<"; }
+       |
+       CMP_LE { $$ = "<="; }
+       |
+       CMP_GE { $$ = ">="; }
+       |
+       CMP_GT { $$ = ">"; }
+       ;
+
+data:
+       STRING { $$.type = SDB_TYPE_STRING; $$.data.string = $1; }
+       |
+       INTEGER { $$ = $1; }
+       |
+       FLOAT { $$ = $1; }
+       |
+       datetime { $$.type = SDB_TYPE_DATETIME; $$.data.datetime = $1; }
+       |
+       interval { $$ = $1; }
+       ;
+
+datetime:
+       DATE TIME { $$ = $1 + $2; }
+       |
+       DATE { $$ = $1; }
+       |
+       TIME { $$ = $1; }
+       ;
+
+interval:
+       interval interval_elem
                {
-                       $$ = SDB_CONN_NODE(sdb_object_create_T(/* name = */ NULL,
-                                               conn_node_matcher_t));
-                       $$->cmd = CONNECTION_EXPR;
-                       /* XXX: this is just a placeholder for now */
-                       CONN_MATCHER($$)->matcher = sdb_store_host_matcher($1,
-                                       /* name_re = */ NULL, /* service = */ NULL,
-                                       /* attr = */ NULL);
-                       free($1);
-                       $1 = NULL;
+                       $$.data.datetime = $1.data.datetime + $2.data.datetime;
+               }
+       |
+       interval_elem { $$ = $1; }
+       ;
+
+interval_elem:
+       INTEGER IDENTIFIER
+               {
+                       sdb_time_t unit = 1;
+
+                       unit = sdb_strpunit($2);
+                       if (! unit) {
+                               sdb_fe_yyerrorf(&yylloc, scanner,
+                                               YY_("invalid time unit %s"), $2);
+                               free($2); $2 = NULL;
+                               YYABORT;
+                       }
+                       free($2); $2 = NULL;
+
+                       $$.type = SDB_TYPE_DATETIME;
+                       $$.data.datetime = (sdb_time_t)$1.data.integer * unit;
+
+                       if ($1.data.integer < 0) {
+                               sdb_fe_yyerror(&yylloc, scanner,
+                                               YY_("syntax error, negative intervals not supported"));
+                               YYABORT;
+                       }
                }
        ;
 
@@ -173,7 +656,45 @@ void
 sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg)
 {
        sdb_log(SDB_LOG_ERR, "frontend: parse error: %s", msg);
+       sdb_strbuf_sprintf(errbuf, "%s", msg);
 } /* sdb_fe_yyerror */
 
+void
+sdb_fe_yyerrorf(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *fmt, ...)
+{
+       va_list ap, aq;
+       va_start(ap, fmt);
+       va_copy(aq, ap);
+       sdb_vlog(SDB_LOG_ERR, fmt, ap);
+       sdb_strbuf_vsprintf(errbuf, "%s", aq);
+       va_end(ap);
+} /* sdb_fe_yyerrorf */
+
+static sdb_store_matcher_t *
+name_iter_matcher(int m_type, int type, const char *cmp,
+               sdb_store_expr_t *expr)
+{
+       sdb_store_matcher_op_cb cb = sdb_store_parse_matcher_op(cmp);
+       sdb_store_expr_t *e;
+       sdb_store_matcher_t *m, *tmp = NULL;
+       assert(cb);
+
+       /* TODO: this only works as long as queries
+        * are limited to hosts */
+       if (type == SDB_HOST) {
+               return NULL;
+       }
+
+       e = sdb_store_expr_fieldvalue(SDB_FIELD_NAME);
+       m = cb(e, expr);
+       if (m_type == MATCHER_ANY)
+               tmp = sdb_store_any_matcher(type, m);
+       else if (m_type == MATCHER_ALL)
+               tmp = sdb_store_all_matcher(type, m);
+       sdb_object_deref(SDB_OBJ(m));
+       sdb_object_deref(SDB_OBJ(e));
+       return tmp;
+} /* name_iter_matcher */
+
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */