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Diffstat (limited to 'grammar/grammar.y')
| -rw-r--r-- | grammar/grammar.y | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/grammar/grammar.y b/grammar/grammar.y new file mode 100644 index 00000000..402b1a57 --- /dev/null +++ b/grammar/grammar.y @@ -0,0 +1,186 @@ + /* Bison file for rsyslog config format v2 (RainerScript). + * Please note: this file introduces the new config format, but maintains + * backward compatibility. In order to do so, the grammar is not 100% clean, + * but IMHO still sufficiently easy both to understand for programmers + * maitaining the code as well as users writing the config file. Users are, + * of course, encouraged to use new constructs only. But it needs to be noted + * that some of the legacy constructs (specifically the in-front-of-action + * PRI filter) are very hard to beat in ease of use, at least for simpler + * cases. So while we hope that cfsysline support can be dropped some time in + * the future, we will probably keep these useful constructs. + * + * Copyright 2011 Rainer Gerhards and Adiscon GmbH. + * + * This file is part of the rsyslog runtime library. + * + * The rsyslog runtime library is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * The rsyslog runtime library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with the rsyslog runtime library. If not, see <http://www.gnu.org/licenses/>. + * + * A copy of the GPL can be found in the file "COPYING" in this distribution. + * A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution. + */ +%{ +#include <stdio.h> +#include <libestr.h> +#include "rainerscript.h" +#include "parserif.h" +#define YYDEBUG 1 +extern int yylineno; + +/* keep compile rule cleam of errors */ +extern int yylex(void); +extern int yyerror(char*); +%} + +%union { + char *s; + long long n; + es_str_t *estr; + enum cnfobjType objType; + struct cnfobj *obj; + struct nvlst *nvlst; + struct cnfactlst *actlst; + struct cnfexpr *expr; + struct cnfrule *rule; + struct cnffunc *func; + struct cnffparamlst *fparams; +} + +%token <estr> NAME +%token <estr> VALUE +%token <estr> FUNC +%token <objType> BEGINOBJ +%token ENDOBJ +%token <s> CFSYSLINE +%token BEGIN_ACTION +%token STOP +%token <s> LEGACY_ACTION +%token <s> PRIFILT +%token <s> PROPFILT +%token <s> BSD_TAG_SELECTOR +%token <s> BSD_HOST_SELECTOR +%token IF +%token THEN +%token OR +%token AND +%token NOT +%token <s> VAR +%token <estr> STRING +%token <n> NUMBER +%token CMP_EQ +%token CMP_NE +%token CMP_LE +%token CMP_GE +%token CMP_LT +%token CMP_GT +%token CMP_CONTAINS +%token CMP_CONTAINSI +%token CMP_STARTSWITH +%token CMP_STARTSWITHI + +%type <nvlst> nv nvlst +%type <obj> obj +%type <actlst> actlst +%type <actlst> act +%type <s> cfsysline +%type <actlst> block +%type <expr> expr +%type <rule> rule +%type <rule> scriptfilt +%type <fparams> fparams + +%left AND OR +%left CMP_EQ CMP_NE CMP_LE CMP_GE CMP_LT CMP_GT CMP_CONTAINS CMP_CONTAINSI CMP_STARTSWITH CMP_STARTSWITHI +%left '+' '-' +%left '*' '/' '%' +%nonassoc UMINUS NOT + +%expect 3 +/* these shift/reduce conflicts are created by the CFSYSLINE construct, which we + * unfortunately can not avoid. The problem is that CFSYSLINE can occur both in + * global context as well as within an action. It's not permitted somewhere else, + * but this is suficient for conflicts. The "dangling else" built-in resolution + * works well to solve this issue, so we accept it (it's a wonder that our + * old style grammar doesn't work at all, so we better do not complain...). + * Use "bison -v rscript.y" if more conflicts arise and check rscript.out for + * were exactly these conflicts exits. + */ +%% +/* note: we use left recursion below, because that saves stack space AND + * offers the right sequence so that we can submit the top-layer objects + * one by one. + */ +conf: /* empty (to end recursion) */ + | conf obj { cnfDoObj($2); } + | conf rule { cnfDoRule($2); } + | conf cfsysline { cnfDoCfsysline($2); } + | conf BSD_TAG_SELECTOR { cnfDoBSDTag($2); } + | conf BSD_HOST_SELECTOR { cnfDoBSDHost($2); } +obj: BEGINOBJ nvlst ENDOBJ { $$ = cnfobjNew($1, $2); } + | BEGIN_ACTION nvlst ENDOBJ { $$ = cnfobjNew(CNFOBJ_ACTION, $2); } +cfsysline: CFSYSLINE { $$ = $1; } +nvlst: { $$ = NULL; } + | nvlst nv { $2->next = $1; $$ = $2; } +nv: NAME '=' VALUE { $$ = nvlstNew($1, $3); } +rule: PRIFILT actlst { $$ = cnfruleNew(CNFFILT_PRI, $2); $$->filt.s = $1; } + | PROPFILT actlst { $$ = cnfruleNew(CNFFILT_PROP, $2); $$->filt.s = $1; } + | scriptfilt { $$ = $1; } + +scriptfilt: IF expr THEN actlst { $$ = cnfruleNew(CNFFILT_SCRIPT, $4); + $$->filt.expr = $2; } +block: actlst { $$ = $1; } + | block actlst { $2->next = $1; $$ = $2; } + /* v7: | actlst + v7: | block rule */ /* v7 extensions require new rule engine capabilities! */ +actlst: act { $$=$1; } + | actlst '&' act { $3->next = $1; $$ = $3; } + | actlst cfsysline { $$ = cnfactlstAddSysline($1, $2); } + | '{' block '}' { $$ = $2; } +act: BEGIN_ACTION nvlst ENDOBJ { $$ = cnfactlstNew(CNFACT_V2, $2, NULL); } + | LEGACY_ACTION { $$ = cnfactlstNew(CNFACT_LEGACY, NULL, $1); } +expr: expr AND expr { $$ = cnfexprNew(AND, $1, $3); } + | expr OR expr { $$ = cnfexprNew(OR, $1, $3); } + | NOT expr { $$ = cnfexprNew(NOT, NULL, $2); } + | expr CMP_EQ expr { $$ = cnfexprNew(CMP_EQ, $1, $3); } + | expr CMP_NE expr { $$ = cnfexprNew(CMP_NE, $1, $3); } + | expr CMP_LE expr { $$ = cnfexprNew(CMP_LE, $1, $3); } + | expr CMP_GE expr { $$ = cnfexprNew(CMP_GE, $1, $3); } + | expr CMP_LT expr { $$ = cnfexprNew(CMP_LT, $1, $3); } + | expr CMP_GT expr { $$ = cnfexprNew(CMP_GT, $1, $3); } + | expr CMP_CONTAINS expr { $$ = cnfexprNew(CMP_CONTAINS, $1, $3); } + | expr CMP_CONTAINSI expr { $$ = cnfexprNew(CMP_CONTAINSI, $1, $3); } + | expr CMP_STARTSWITH expr { $$ = cnfexprNew(CMP_STARTSWITH, $1, $3); } + | expr CMP_STARTSWITHI expr { $$ = cnfexprNew(CMP_STARTSWITHI, $1, $3); } + | expr '+' expr { $$ = cnfexprNew('+', $1, $3); } + | expr '-' expr { $$ = cnfexprNew('-', $1, $3); } + | expr '*' expr { $$ = cnfexprNew('*', $1, $3); } + | expr '/' expr { $$ = cnfexprNew('/', $1, $3); } + | expr '%' expr { $$ = cnfexprNew('%', $1, $3); } + | '(' expr ')' { $$ = $2; } + | '-' expr %prec UMINUS { $$ = cnfexprNew('M', NULL, $2); } + | FUNC '(' ')' { $$ = (struct cnfexpr*) cnffuncNew($1, NULL); } + | FUNC '(' fparams ')' { $$ = (struct cnfexpr*) cnffuncNew($1, $3); } + | NUMBER { $$ = (struct cnfexpr*) cnfnumvalNew($1); } + | STRING { $$ = (struct cnfexpr*) cnfstringvalNew($1); } + | VAR { $$ = (struct cnfexpr*) cnfvarNew($1); } +fparams: expr { $$ = cnffparamlstNew($1, NULL); } + | expr ',' fparams { $$ = cnffparamlstNew($1, $3); } + +%% +/* +int yyerror(char *s) +{ + printf("parse failure on or before line %d: %s\n", yylineno, s); + return 0; +} +*/ |