ossp-pkg/l2/l2_spec_parse.y
%{
/*
** OSSP l2 - Flexible Logging
** Copyright (c) 2001-2005 Cable & Wireless <http://www.cw.com/>
** Copyright (c) 2001-2005 The OSSP Project <http://www.ossp.org/>
** Copyright (c) 2001-2005 Ralf S. Engelschall <rse@engelschall.com>
**
** This file is part of OSSP l2, a flexible logging library which
** can be found at http://www.ossp.org/pkg/lib/l2/.
**
** Permission to use, copy, modify, and distribute this software for
** any purpose with or without fee is hereby granted, provided that
** the above copyright notice and this permission notice appear in all
** copies.
**
** THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR
** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
** USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
** ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
** OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
** OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
**
** l2_spec_parse.y: GNU Bison (Yacc-style) parser specification
**
** ATTENTION: This requires GNU Bison 1.875 or newer!
*/
#include "l2.h" /* for l2_xxx() API */
#include "l2_spec.h" /* for l2_spec_ctx_t */
/* make sure yyparse() accepts a context pointer and
passes through its inlined scanner context to yylex() */
#define CTX ((l2_spec_ctx_t *)ctx)
#define YYPARSE_PARAM ctx
#define YYLEX_PARAM CTX->yyscan
/* provide an explicit prototype for the yylex() function but use
"void *" instead of correct type because at this point in the
generation process we have the types still not available */
extern int yylex(/*YYSTYPE*/ void *lvalp,
/*YYLTYPE*/ void *llocp, l2_spec_ctx_t *ctx);
/* generate verbose error messages and remember them inside the context */
#undef yyerror
#define yyerror(msg) \
l2_spec_error(CTX, L2_ERR_SYN, &yylloc, msg)
/* scanner state transition */
extern void l2_spec_scan_push(l2_spec_ctx_t *, const char *state);
extern void l2_spec_scan_pop(l2_spec_ctx_t *);
%}
/* parser options */
%error-verbose
%pure_parser
%locations
%defines
/* the YYSTYPE: parser token value */
%union {
char *cpValue;
l2_channel_t *chChannel;
unsigned int nLevels;
}
/* assign YYSTYPE elements to parser rules */
%type <chChannel> stream
%type <chChannel> streams
%type <chChannel> channel
%type <chChannel> channel_cons
%type <nLevels> channel_level
%type <nLevels> channel_level_mask
/* list of scanner tokens */
%token <cpValue> T_ID
%token <cpValue> T_PARAM
%token <cpValue> T_STRING
%token T_OP_ARROW
/* operator association */
%right T_OP_ARROW
/* grammar start rule
(technically redundant but explicit to be sure) */
%start tree
%%
/* channel tree */
tree
: stream {
CTX->ch = $1;
}
;
/* stream of channels */
stream
: /* empty */ {
l2_channel_t *ch;
if ((CTX->rv = l2_channel_create(&ch, CTX->env, "null")) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "failed to create channel 'null'");
YYERROR;
}
$$ = ch;
}
| channel {
$$ = $1;
}
| channel T_OP_ARROW stream {
$$ = $1;
if ((CTX->rv = l2_channel_link($1, L2_LINK_CHILD, $3, NULL)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "unable to link parent with child");
YYERROR;
}
}
| channel T_OP_ARROW '{' streams '}' {
$$ = $1;
if ((CTX->rv = l2_channel_link($1, L2_LINK_CHILD, $4, NULL)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "unable to link parent with child list");
YYERROR;
}
}
;
/* list of sibling streams */
streams
: stream {
$$ = $1;
}
| stream ';' streams {
$$ = $1;
if ((CTX->rv = l2_channel_link($1, L2_LINK_SIBLING, $3, NULL)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "unable to link childs together");
YYERROR;
}
}
;
/* channel */
channel
: channel_level '/' channel_level ':' channel_cons {
$$ = $5;
if ((CTX->rv = l2_channel_levels($5, $1, $3)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "failed to set channel write and flush levels");
YYERROR;
}
}
| channel_level ':' channel_cons {
$$ = $3;
if ((CTX->rv = l2_channel_levels($3, $1, L2_LEVEL_NONE)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "failed to set channel write levels");
YYERROR;
}
}
| channel_cons {
$$ = $1;
}
;
/* channel level */
channel_level
: T_ID {
unsigned int levelmask;
if ((CTX->rv = l2_util_s2l($1, strlen($1), ',', &levelmask)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "invalid level '%s'", $1);
free($1);
YYERROR;
}
free($1);
$$ = L2_LEVEL_UPTO(levelmask);
}
| '(' channel_level_mask ')' {
$$ = $2;
}
;
/* channel level mask */
channel_level_mask
: T_ID {
unsigned int levelmask;
if ((CTX->rv = l2_util_s2l($1, strlen($1), ',', &levelmask)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "invalid level '%s'", $1);
free($1);
YYERROR;
}
free($1);
$$ = levelmask;
}
| T_ID '|' channel_level_mask {
unsigned int levelmask;
if ((CTX->rv = l2_util_s2l($1, strlen($1), ',', &levelmask)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "invalid level '%s'", $1);
free($1);
YYERROR;
}
free($1);
$$ = levelmask | $3;
}
;
/* channel constructor */
channel_cons
: T_ID {
l2_channel_t *ch;
if ((CTX->rv = l2_channel_create(&ch, CTX->env, $1)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "failed to create channel '%s'", $1);
free($1);
YYERROR;
}
free($1);
$$ = ch;
/* provide channel to channel_param rule below because it does
not know where on the token stack our $$ is because it is a
sub-rule of the recursive channel_param_list rule and hence
cannot use "$<chChannel>-n". */
CTX->chTmp = ch;
}
channel_params {
$$ = $<chChannel>2; /* pass-through result */
CTX->chTmp = NULL;
}
;
/* channel parameters */
channel_params
: /* empty */
| '(' ')'
| '(' channel_param_list ')'
;
/* channel parameter list */
channel_param_list
: channel_param
| channel_param ',' channel_param_list
;
/* channel parameter */
channel_param
: T_ID '=' { l2_spec_scan_push(CTX, "SS_PARAM"); } T_PARAM { l2_spec_scan_pop(CTX); } {
if ((CTX->rv = l2_channel_configure(CTX->chTmp, "%s=\"%s\"", $1, $4)) != L2_OK) {
l2_spec_error(CTX, CTX->rv, &yylloc, "failed to configure channel with '%s=\"%s\"'", $1, $4);
free($1);
free($4);
YYERROR;
}
free($1);
free($4);
}
;
%%
