kenmirrors/asterisk
1
0
Fork 0
mirror of https://github.com/asterisk/asterisk.git synced 2025-09-06 12:36:58 +00:00
Code Issues Packages Projects Releases Wiki Activity

switch to 'new' expression parser, remove support for old parser

Browse Source 
provide parser files in source tree, so flex/bison are not need to build
update Makefile to use simpler techniques to build parser
update README to remove references to old vs. new parsers
remove version comparison tool used for flex/bison programs


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6420 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Kevin P. Fleming
2005-08-26 19:21:57 +00:00
parent 7fa558c71e
commit 66e69e0143
7 changed files with 4772 additions and 639 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
.cvsignore
View File

@@ -1,12 +1,6 @@
asterisk asterisk
defaults.h defaults.h
ast_expr.c
ast_expr.h
ast_expr.output
ast_expr2.c
ast_expr2.h
ast_expr2.output ast_expr2.output
ast_expr2f.c
.version .version
.depend .depend
.applied .applied

72
Makefile
View File

@@ -204,11 +204,6 @@ GREP=/usr/xpg4/bin/grep
M4=/usr/local/bin/m4 M4=/usr/local/bin/m4
endif endif
# if doing a recursive make, don't double-up CFLAGS
ifeq ($(MAKECMDGOALS),ast_expr.a)
CFLAGS=
endif
INCLUDE=-Iinclude -I../include INCLUDE=-Iinclude -I../include
CFLAGS+=-pipe -Wall -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations $(DEBUG) $(INCLUDE) -D_REENTRANT -D_GNU_SOURCE #-DMAKE_VALGRIND_HAPPY CFLAGS+=-pipe -Wall -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations $(DEBUG) $(INCLUDE) -D_REENTRANT -D_GNU_SOURCE #-DMAKE_VALGRIND_HAPPY
CFLAGS+=$(OPTIMIZE) CFLAGS+=$(OPTIMIZE)
@@ -296,7 +291,7 @@ OBJS=io.o sched.o logger.o frame.o loader.o config.o channel.o \
dsp.o chanvars.o indications.o autoservice.o db.o privacy.o \ dsp.o chanvars.o indications.o autoservice.o db.o privacy.o \
astmm.o enum.o srv.o dns.o aescrypt.o aestab.o aeskey.o \ astmm.o enum.o srv.o dns.o aescrypt.o aestab.o aeskey.o \
utils.o config_old.o plc.o jitterbuf.o dnsmgr.o devicestate.o \ utils.o config_old.o plc.o jitterbuf.o dnsmgr.o devicestate.o \
netsock.o slinfactory.o netsock.o slinfactory.o ast_expr2.o ast_expr2f.o
ifeq (${OSARCH},Darwin) ifeq (${OSARCH},Darwin)
OBJS+=poll.o dlfcn.o OBJS+=poll.o dlfcn.o
ASTLINK=-Wl,-dynamic ASTLINK=-Wl,-dynamic
@@ -357,59 +352,13 @@ ifneq ($(wildcard .tags-depend),)
include .tags-depend include .tags-depend
endif endif
.PHONY: ast_expr ast_expr2.c: FORCE
bison -d --name-prefix=ast_yy ast_expr2.y -o ast_expr2.c
build_tools/vercomp: build_tools/vercomp.c ast_expr2f.c: FORCE
$(HOST_CC) -o $@ $<
ast_expr: build_tools/vercomp
$(MAKE) ast_expr.a
ifeq ($(MAKECMDGOALS),ast_expr.a)
FLEXVER_GT_2_5_31=$(shell build_tools/vercomp flex \>= 2.5.31)
BISONVER_GE_1_85=$(shell build_tools/vercomp bison \>= 1.85 )
endif
ifeq ($(FLEXVER_GT_2_5_31),true)
FLEXOBJS=ast_expr2.o ast_expr2f.o
else
FLEXOBJS=ast_expr.o
endif
ast_expr.o:: ast_expr.c
@echo "================================================================================="
@echo "NOTE: Using older version of expression parser. To use the newer version,"
@echo "NOTE: upgrade to flex 2.5.31 or higher, which can be found at"
@echo "NOTE: http://sourceforge.net/project/showfiles.php?group_id=72099"
@echo "================================================================================="
ast_expr.o:: ast_expr.c
ifeq ($(BISONVER_GE_1_85),false)
.y.c:
@echo "================================================================================="
@echo "NOTE: You may have trouble if you do not have bison-1.85 or higher installed!"
@echo "NOTE: You can pick up a copy at: http://ftp.gnu.org or its mirrors"
@echo "NOTE: You have:"
@bison --version
@echo "================================================================================"
bison -v -d --name-prefix=ast_yy $< -o $@
else
.y.c:
bison -v -d --name-prefix=ast_yy $< -o $@
endif
ast_expr2f.c: ast_expr2.fl
flex ast_expr2.fl flex ast_expr2.fl
ast_expr.a: $(FLEXOBJS) testexpr2: ast_expr2f.c ast_expr2.c ast_expr2.h
@rm -f $@
ar r $@ $(FLEXOBJS)
ranlib $@
testexpr2 :
flex ast_expr2.fl
bison -v -d --name-prefix=ast_yy -o ast_expr2.c ast_expr2.y
gcc -g -c -DSTANDALONE ast_expr2f.c gcc -g -c -DSTANDALONE ast_expr2f.c
gcc -g -c -DSTANDALONE ast_expr2.c gcc -g -c -DSTANDALONE ast_expr2.c
gcc -g -o testexpr2 ast_expr2f.o ast_expr2.o gcc -g -o testexpr2 ast_expr2f.o ast_expr2.o
@@ -443,7 +392,6 @@ defaults.h: FORCE
fi fi
rm -f $@.tmp rm -f $@.tmp
include/asterisk/build.h: include/asterisk/build.h:
build_tools/make_build_h > $@.tmp build_tools/make_build_h > $@.tmp
if cmp -s $@.tmp $@ ; then echo ; else \ if cmp -s $@.tmp $@ ; then echo ; else \
@@ -471,8 +419,8 @@ stdtime/libtime.a: FORCE
exit 1; \ exit 1; \
fi fi
asterisk: editline/libedit.a db1-ast/libdb1.a stdtime/libtime.a $(OBJS) ast_expr asterisk: editline/libedit.a db1-ast/libdb1.a stdtime/libtime.a $(OBJS)
$(CC) $(DEBUG) -o asterisk $(ASTLINK) $(OBJS) ast_expr.a $(LIBEDIT) db1-ast/libdb1.a stdtime/libtime.a $(LIBS) $(CC) $(DEBUG) -o asterisk $(ASTLINK) $(OBJS) $(LIBEDIT) db1-ast/libdb1.a stdtime/libtime.a $(LIBS)
muted: muted.o muted: muted.o
$(CC) $(AUDIO_LIBS) -o muted muted.o $(CC) $(AUDIO_LIBS) -o muted muted.o
@@ -486,9 +434,6 @@ clean:
rm -f defaults.h rm -f defaults.h
rm -f include/asterisk/build.h rm -f include/asterisk/build.h
rm -f include/asterisk/version.h rm -f include/asterisk/version.h
rm -f ast_expr.c ast_expr.h ast_expr.output
rm -f ast_expr2.c ast_expr2f.c ast_expr2.h ast_expr2.output
rm -f ast_expr.a build_tools/vercomp
rm -f .version rm -f .version
rm -f .tags-depend .tags-sources tags TAGS rm -f .tags-depend .tags-sources tags TAGS
@if [ -f editline/Makefile ]; then $(MAKE) -C editline distclean ; fi @if [ -f editline/Makefile ]; then $(MAKE) -C editline distclean ; fi
@@ -814,8 +759,7 @@ depend: include/asterisk/build.h include/asterisk/version.h .depend defaults.h
for x in $(SUBDIRS); do $(MAKE) -C $$x depend || exit 1 ; done for x in $(SUBDIRS); do $(MAKE) -C $$x depend || exit 1 ; done
.depend: include/asterisk/version.h .depend: include/asterisk/version.h
build_tools/mkdep ${CFLAGS} $(filter-out ast_expr.c,$(wildcard *.c)) build_tools/mkdep ${CFLAGS} $(wildcard *.c)
build_tools/mkdep -a -d ${CFLAGS} ast_expr.c
.tags-depend: .tags-depend:
@echo -n ".tags-depend: " > $@ @echo -n ".tags-depend: " > $@

2347
ast_expr2.c Executable file
View File

File diff suppressed because it is too large Load Diff

109
ast_expr2.h Executable file
View File

@@ -0,0 +1,109 @@
/* A Bison parser, made by GNU Bison 1.875d. */
/* Skeleton parser for Yacc-like parsing with Bison,
Copyright (C) 1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* As a special exception, when this file is copied by Bison into a
Bison output file, you may use that output file without restriction.
This special exception was added by the Free Software Foundation
in version 1.24 of Bison. */
/* Tokens. */
#ifndef YYTOKENTYPE
# define YYTOKENTYPE
/* Put the tokens into the symbol table, so that GDB and other debuggers
know about them. */
enum yytokentype {
TOK_COLONCOLON = 258,
TOK_COND = 259,
TOK_OR = 260,
TOK_AND = 261,
TOK_NE = 262,
TOK_LE = 263,
TOK_GE = 264,
TOK_LT = 265,
TOK_GT = 266,
TOK_EQ = 267,
TOK_MINUS = 268,
TOK_PLUS = 269,
TOK_MOD = 270,
TOK_DIV = 271,
TOK_MULT = 272,
TOK_COMPL = 273,
TOK_EQTILDE = 274,
TOK_COLON = 275,
TOK_LP = 276,
TOK_RP = 277,
TOKEN = 278
};
#endif
#define TOK_COLONCOLON 258
#define TOK_COND 259
#define TOK_OR 260
#define TOK_AND 261
#define TOK_NE 262
#define TOK_LE 263
#define TOK_GE 264
#define TOK_LT 265
#define TOK_GT 266
#define TOK_EQ 267
#define TOK_MINUS 268
#define TOK_PLUS 269
#define TOK_MOD 270
#define TOK_DIV 271
#define TOK_MULT 272
#define TOK_COMPL 273
#define TOK_EQTILDE 274
#define TOK_COLON 275
#define TOK_LP 276
#define TOK_RP 277
#define TOKEN 278
#if ! defined (YYSTYPE) && ! defined (YYSTYPE_IS_DECLARED)
#line 137 "ast_expr2.y"
typedef union YYSTYPE {
struct val *val;
} YYSTYPE;
/* Line 1285 of yacc.c. */
#line 87 "ast_expr2.h"
# define yystype YYSTYPE /* obsolescent; will be withdrawn */
# define YYSTYPE_IS_DECLARED 1
# define YYSTYPE_IS_TRIVIAL 1
#endif
#if ! defined (YYLTYPE) && ! defined (YYLTYPE_IS_DECLARED)
typedef struct YYLTYPE
{
int first_line;
int first_column;
int last_line;
int last_column;
} YYLTYPE;
# define yyltype YYLTYPE /* obsolescent; will be withdrawn */
# define YYLTYPE_IS_DECLARED 1
# define YYLTYPE_IS_TRIVIAL 1
#endif

2163
ast_expr2f.c Executable file
View File

File diff suppressed because it is too large Load Diff

350
build_tools/vercomp.c
View File

@@ -1,350 +0,0 @@
/*
* Asterisk -- A telephony toolkit for Linux.
*
* A simple program version comparison tool.
*
* Copyright (C) 2005, Steven Michael Murphy (murf at e-tools dot com).
*
* This program is free software, distributed under the terms of
* the GNU General Public License
*/
/* vercomp.c
args: <program> <comparison> <version>
where:
program = path to program (bison or flex)
comparison = ">", "<", "<=", ">=", "=" -- depending on shell, you may have to use backslash escapes
version = a version compare against, say 1.875, or 2.5.4, or whatever.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
char *program_version[5];
char *arg_version[5];
void get_program_version_string(char *command, char *output)
{
char cbuf[8000];
char pbuf[8000];
char zbuf[8000];
char *res;
FILE *p1;
zbuf[0] = 0;
sprintf( cbuf, "%s --version", command );
p1 = popen(cbuf, "r");
if( !p1 )
{
fprintf(stderr,"vercomp: Could not execute the command: %s\n", command);
exit(125);
}
/* the first line is the magic one */
res = fgets(zbuf, 8000, p1);
/* clear the trailing blank */
if( zbuf[strlen(zbuf)-1] == '\n' )
zbuf[strlen(zbuf)-1] = 0;
/* the rest is cruft, just empty the input stream */
while( res )
{
res = fgets(pbuf, 8000, p1);
}
/* close the stream. Hopefully, we have what we need */
pclose(p1);
/* all we want is the last "word"-- so find the last blank, and grab everything after that */
res = strrchr(zbuf,' ');
if( !res )
{
fprintf(stderr,"Something is wrong with the version string: %s\n", zbuf);
exit(124);
}
strcpy(output,res+1);
}
void extract_version(char *ver_string, char **where)
{
int i=0;
char *p=ver_string;
while( p && *p )
{
where[i++] = p;
p = strchr(p,'.');
if( p )
{
*p= 0;
p++;
}
}
}
void compare_versions(char *compare_func)
{
int i;
for(i=0;i<5;i++)
{
/* start out at the beginning, then go to the end */
if( program_version[i] && arg_version[i] && *program_version[i] && *arg_version[i] )
{
if( strlen(program_version[i]) == strspn(program_version[i],"0123456789")
&& strlen(arg_version[i]) == strspn(arg_version[i],"0123456789") )
{
/* just pure numbers -- do a numeric compare */
int pv = atoi(program_version[i]);
int av = atoi(arg_version[i]);
if( pv < av )
{
if( !strcmp(compare_func,"=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, "<") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, ">=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, "<=") )
{
printf("true\n");
exit(0);
}
}
else if( pv > av )
{
if( !strcmp(compare_func,"=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, "<") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">=") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, "<=") )
{
printf("false\n");
exit(0);
}
}
}
else
{
/* other junk thrown in -- do string compare */
int res = strcmp(program_version[i], arg_version[i]);
if( res < 0 ) /* prog is less than arg */
{
if( !strcmp(compare_func,"=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, "<") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, ">=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, "<=") )
{
printf("true\n");
exit(0);
}
}
else if( res > 0 ) /* prog is greater than arg */
{
if( !strcmp(compare_func,"=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, "<") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">=") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, "<=") )
{
printf("false\n");
exit(0);
}
}
}
}
else if( program_version[i] && *program_version[i] )
{
if( !strcmp(compare_func,"=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, "<") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">=") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, "<=") )
{
printf("false\n");
exit(0);
}
}
else if( arg_version[i] && *arg_version[i] )
{
if( !strcmp(compare_func,"=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, "<") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, ">=") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, "<=") )
{
printf("true\n");
exit(0);
}
}
else
break;
}
if( !strcmp(compare_func,"=") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, ">") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, "<") )
{
printf("false\n");
exit(0);
}
else if( !strcmp(compare_func, ">=") )
{
printf("true\n");
exit(0);
}
else if( !strcmp(compare_func, "<=") )
{
printf("true\n");
exit(0);
}
}
void usage(void)
{
printf("Usage: <program-path> <comparison> <version>\n\
\n\
where:\n\
\n\
program-path = path to program (bison or flex)\n\
comparison = '>', '<', '<=', '>=', '=' -- depending on shell, you may have to use backslash escapes\n\
version = a version compare against, say 1.875, or 2.5.4, or whatever.\n\n");
}
int main(int argc, char **argv)
{
char program_version_string[8000];
/* before starting, check args and make sure all is OK */
if( argc < 4 || argc > 4 )
{
usage();
exit(-256);
}
if ( strcmp(argv[2],"=") && strcmp(argv[2],">") && strcmp(argv[2],"<") && strcmp(argv[2],">=") && strcmp(argv[2],"<=") )
{
fprintf(stderr,"vercomp: ILLEGAL input Comparison value: %s\n\n", argv[2]);
usage();
exit(-256);
}
/* first, extract a version from the command line arg */
extract_version(argv[3], arg_version);
/* next, extract a version from the command line */
get_program_version_string(argv[1], program_version_string);
extract_version(program_version_string, program_version);
/* next compare and return result */
compare_versions(argv[2]);
/* the above func shouldn't return */
}

350
doc/README.variables
View File

@@ -13,15 +13,6 @@ Asterisk has user-defined variables and standard variables set
by various modules in Asterisk. These standard variables are by various modules in Asterisk. These standard variables are
listed at the end of this document. listed at the end of this document.
NOTE: During the Asterisk build process, the versions of bison and
flex available on your system are probed. If you have versions of
flex greater than or equal to 2.5.31, it will use flex to build a
"pure" (re-entrant) tokenizer for expressions. If you use bison version
greater than 1.85, it will use a bison grammar to generate a pure (re-entrant)
parser for $[] expressions.
Notes specific to the flex parser are marked with "**" at the beginning
of the line.
___________________________ ___________________________
PARAMETER QUOTING: PARAMETER QUOTING:
--------------------------- ---------------------------
@@ -131,13 +122,6 @@ considered as an expression and it is evaluated. Evaluation works similar to
(but is done on a later stage than) variable substitution: the expression (but is done on a later stage than) variable substitution: the expression
(including the square brackets) is replaced by the result of the expression (including the square brackets) is replaced by the result of the expression
evaluation. evaluation.
Note: The arguments and operands of the expression MUST BE separated
by at least one space.
** Using the Flex generated tokenizer, this is no longer the case. Spaces
** are only required where they would seperate tokens that would normally
** be merged into a single token. Using the new tokenizer, spaces can be
** used freely.
For example, after the sequence: For example, after the sequence:
@@ -146,26 +130,9 @@ exten => 1,2,Set(koko=$[2 * ${lala}])
the value of variable koko is "6". the value of variable koko is "6".
** Using the new Flex generated tokenizer, the expressions above are still
** legal, but so are the following:
** exten => 1,1,Set(lala=$[1+2])
** exten => 1,2,Set(koko=$[2* ${lala}])
And, further:
exten => 1,1,Set(lala=$[1+2]);
will not work as you might have expected. Since all the chars in the single
token "1+2" are not numbers, it will be evaluated as the string "1+2". Again,
please do not forget, that this is a very simple parsing engine, and it
uses a space (at least one), to separate "tokens".
** Please note that spaces are not required to separate tokens if you have
** Flex version 2.5.31 or higher on your system.
and, further: and, further:
exten => 1,1,Set,"lala=$[ 1 + 2 ]"; exten => 1,1,Set,(lala=$[ 1 + 2 ]);
will parse as intended. Extra spaces are ignored. will parse as intended. Extra spaces are ignored.
@@ -227,17 +194,17 @@ with equal precedence are grouped within { } symbols.
Return the results of multiplication, integer division, or Return the results of multiplication, integer division, or
remainder of integer-valued arguments. remainder of integer-valued arguments.
** - expr1 - expr1
** Return the result of subtracting expr1 from 0. Return the result of subtracting expr1 from 0.
** This, the unary minus operator, is right associative, and This, the unary minus operator, is right associative, and
** has the same precedence as the ! operator. has the same precedence as the ! operator.
**
** ! expr1 ! expr1
** Return the result of a logical complement of expr1. Return the result of a logical complement of expr1.
** In other words, if expr1 is null, 0, an empty string, In other words, if expr1 is null, 0, an empty string,
** or the string "0", return a 1. Otherwise, return a "0". (only with flex >= 2.5.31) or the string "0", return a 1. Otherwise, return a 0.
** It has the same precedence as the unary minus operator, and It has the same precedence as the unary minus operator, and
** is also right associative. is also right associative.
expr1 : expr2 expr1 : expr2
The `:' operator matches expr1 against expr2, which must be a The `:' operator matches expr1 against expr2, which must be a
@@ -256,43 +223,36 @@ with equal precedence are grouped within { } symbols.
before the regex match is made, beginning and ending double quote before the regex match is made, beginning and ending double quote
characters are stripped from both the pattern and the string. characters are stripped from both the pattern and the string.
** expr1 =~ expr2 expr1 =~ expr2
** Exactly the same as the ':' operator, except that the match is Exactly the same as the ':' operator, except that the match is
** not anchored to the beginning of the string. Pardon any similarity not anchored to the beginning of the string. Pardon any similarity
** to seemingly similar operators in other programming languages! to seemingly similar operators in other programming languages!
** (only if flex >= 2.5.31). The ":" and "=~" operators share the The ":" and "=~" operators share the same precedence.
** same precedence.
** expr1 ? expr2 :: expr3 expr1 ? expr2 :: expr3
** Traditional Conditional operator. If expr1 is a number that evaluates Traditional Conditional operator. If expr1 is a number
** to 0 (false), expr3 is result of the this expression evaluation. that evaluates to 0 (false), expr3 is result of the this
** Otherwise, expr2 is the result. expression evaluation. Otherwise, expr2 is the result.
** If expr1 is a string, and evaluates to an empty string, or the two If expr1 is a string, and evaluates to an empty string,
** characters (""), then expr3 is the result. Otherwise, expr2 is the result. or the two characters (""), then expr3 is the
** In Asterisk, all 3 exprs will be "evaluated"; if expr1 is "true", result. Otherwise, expr2 is the result. In Asterisk, all
** expr2 will be the result of the "evaluation" of this expression. 3 exprs will be "evaluated"; if expr1 is "true", expr2
** expr3 will be the result otherwise. This operator has the lowest will be the result of the "evaluation" of this
** precedence. expression. expr3 will be the result otherwise. This
operator has the lowest precedence.
Parentheses are used for grouping in the usual manner. Parentheses are used for grouping in the usual manner.
Operator precedence is applied as one would expect in any of the C Operator precedence is applied as one would expect in any of the C
or C derived languages. or C derived languages.
The parser must be generated with bison (bison is REQUIRED - yacc cannot
produce pure parsers, which are reentrant) The same with flex, if flex
is at 2.5.31 or greater; Re-entrant scanners were not available before that
version.
Examples Examples
** "One Thousand Five Hundred" =~ "(T[^ ]+)" "One Thousand Five Hundred" =~ "(T[^ ]+)"
** returns: Thousand returns: Thousand
** "One Thousand Five Hundred" =~ "T[^ ]+" "One Thousand Five Hundred" =~ "T[^ ]+"
** returns: 8 returns: 8
"One Thousand Five Hundred" : "T[^ ]+" "One Thousand Five Hundred" : "T[^ ]+"
returns: 0 returns: 0
@@ -303,34 +263,37 @@ Examples
"3075551212":"...(...)" "3075551212":"...(...)"
returns: 555 returns: 555
** ! "One Thousand Five Hundred" =~ "T[^ ]+" ! "One Thousand Five Hundred" =~ "T[^ ]+"
** returns: 0 (because it applies to the string, which is non-null, which it turns to "0", returns: 0 (because it applies to the string, which is non-null,
and then looks for the pattern in the "0", and doesn't find it) which it turns to "0", and then looks for the pattern
in the "0", and doesn't find it)
** !( "One Thousand Five Hundred" : "T[^ ]+" ) !( "One Thousand Five Hundred" : "T[^ ]+" )
** returns: 1 (because the string doesn't start with a word starting with T, so the returns: 1 (because the string doesn't start with a word starting
match evals to 0, and the ! operator inverts it to 1 ). with T, so the match evals to 0, and the ! operator
inverts it to 1 ).
2 + 8 / 2 2 + 8 / 2
returns 6. (because of operator precedence; the division is done first, then the addition). returns 6. (because of operator precedence; the division is done first, then the addition).
** 2+8/2 2+8/2
** returns 6. Spaces aren't necessary. returns 6. Spaces aren't necessary.
**(2+8)/2 (2+8)/2
** returns 5, of course. returns 5, of course.
Of course, all of the above examples use constants, but would work the same if any of the Of course, all of the above examples use constants, but would work the
numeric or string constants were replaced with a variable reference ${CALLERIDNUM}, for same if any of the numeric or string constants were replaced with a
instance. variable reference ${CALLERIDNUM}, for instance.
__________________________ __________________________
NUMBERS VS STRINGS NUMBERS VS STRINGS
-------------------------- --------------------------
Tokens consisting only of numbers are converted to 64-bit numbers for most of the Tokens consisting only of numbers are converted to 64-bit numbers for
operators. This means that overflows can occur when the numbers get above 18 digits. most of the operators. This means that overflows can occur when the
Warnings will appear in the logs in this case. numbers get above 18 digits. Warnings will appear in the logs in this
case.
___________________________ ___________________________
CONDITIONALS CONDITIONALS
--------------------------- ---------------------------
@@ -349,7 +312,6 @@ above, eg :
exten => 1,2,gotoif($[${CALLERID} = 123456]?2|1:3|1) exten => 1,2,gotoif($[${CALLERID} = 123456]?2|1:3|1)
Example of use : Example of use :
exten => s,2,Set(vara=1) exten => s,2,Set(vara=1)
@@ -369,44 +331,18 @@ exten => s,6,GotoIf($[ "${CALLERIDNUM}" = "3071234567" & & "${CALLERIDNAME}" :
You may see an error in /var/log/asterisk/messages like this: You may see an error in /var/log/asterisk/messages like this:
May 3 15:58:53 WARNING[1234455344]: ast_yyerror(): syntax error: parse error; Input: Jul 15 21:27:49 WARNING[1251240752]: ast_yyerror(): syntax error: parse error, unexpected TOK_AND, expecting TOK_MINUS or TOK_LP or TOKEN; Input:
"3072312154" : "3071234567" & & "Steves Extension" : "Privacy Manager" "3072312154" = "3071234567" & & "Steves Extension" : "Privacy Manager"
^^^^^^^^^^^^^^^^^^^^^^^^^^^
^ ^
The first line shows the string passed to the expression parser. This The log line tells you that a syntax error was encountered. It now
string is the result of the variable replacements, etc. This way, you also tells you (in grand standard bison format) that it hit an "AND"
can see the actual string that went into the parser. (&) token unexpectedly, and that was hoping for for a MINUS (-), LP
(left parenthesis), or a plain token (a string or number).
The second line usually shows a string of '^' chars, that show what's
been legally parsed so far.
And the third line shows where the parser was (lookahead token lexing,
etc), when the parse hit the rocks. A single '^' here. The error is
going to be somewhere between the last '^' on the second line, and the
'^' on the third line. That's right, in the example above, there are two
'&' chars, separated by a space, and this is a definite no-no!
** WITH FLEX >= 2.5.31, this has changed slightly. The line showing the
** part of the expression that was successfully parsed has been dropped,
** and the parse error is explained in a somewhat cryptic format in the log.
**
** The same line in extensions.conf as above, will now generate an error
** message in /var/log/asterisk/messages that looks like this:
**
** Jul 15 21:27:49 WARNING[1251240752]: ast_yyerror(): syntax error: parse error, unexpected TOK_AND, expecting TOK_MINUS or TOK_LP or TOKEN; Input:
** "3072312154" = "3071234567" & & "Steves Extension" : "Privacy Manager"
** ^
**
** The log line tells you that a syntax error was encountered. It now
** also tells you (in grand standard bison format) that it hit an "AND" (&)
** token unexpectedly, and that was hoping for for a MINUS (-), LP (left parenthesis),
** or a plain token (a string or number).
**
** As before, the next line shows the evaluated expression, and the line after
** that, the position of the parser in the expression when it became confused,
** marked with the "^" character.
The next line shows the evaluated expression, and the line after
that, the position of the parser in the expression when it became confused,
marked with the "^" character.
___________________________ ___________________________
NULL STRINGS NULL STRINGS
@@ -443,11 +379,12 @@ INCOMPATIBILITIES
The asterisk expression parser has undergone some evolution. It is hoped The asterisk expression parser has undergone some evolution. It is hoped
that the changes will be viewed as positive. that the changes will be viewed as positive.
The "original" expression parser had a simple, hand-written scanner, and The "original" expression parser had a simple, hand-written scanner,
a simple bison grammar. This was upgraded to a more involved bison grammar, and a simple bison grammar. This was upgraded to a more involved bison
and a hand-written scanner upgraded to allow extra spaces, and to generate grammar, and a hand-written scanner upgraded to allow extra spaces,
better error diagnostics. This upgrade required bison 1.85, and a [art of the user and to generate better error diagnostics. This upgrade required bison
community felt the pain of having to upgrade their bison version. 1.85, and part of the user community felt the pain of having to
upgrade their bison version.
The next upgrade included new bison and flex input files, and the makefile The next upgrade included new bison and flex input files, and the makefile
was upgraded to detect current version of both flex and bison, conditionally was upgraded to detect current version of both flex and bison, conditionally
@@ -499,98 +436,87 @@ of possible concern with "legacy" extension.conf files:
but they were not documented. The symbolic operators, <=, >=, and != but they were not documented. The symbolic operators, <=, >=, and !=
should be used instead. should be used instead.
**5. flex 2.5.31 or greater should be used. Bison-1.875 or greater. In 5. Added the unary '-' operator. So you can 3+ -4 and get -1.
** the case of flex, earlier versions do not generate 'pure', or
** reentrant C scanners. In the case of bison-1.875, earlier versions
** didn't support the location tracking mechanism.
** http://ftp.gnu.org/gnu/bison/bison-1.875.tar.bz2 6. Added the unary '!' operator, which is a logical complement.
** http://prdownloads.sourceforge.net/lex/flex-2.5.31.tar.bz2?download Basically, if the string or number is null, empty, or '0',
** or http://lex.sourceforge.net/ a '1' is returned. Otherwise a '0' is returned.
**6. Added the unary '-' operator. So you can 3+ -4 and get -1. 7. Added the '=~' operator, just in case someone is just looking for
match anywhere in the string. The only diff with the ':' is that
match doesn't have to be anchored to the beginning of the string.
**7. Added the unary '!' operator, which is a logical complement. 8. Added the conditional operator 'expr1 ? true_expr :: false_expr'
** Basically, if the string or number is null, empty, or '0', First, all 3 exprs are evaluated, and if expr1 is false, the 'false_expr'
** a '1' is returned. Otherwise a '0' is returned. is returned as the result. See above for details.
**8. Added the '=~' operator, just in case someone is just looking for 9. Unary operators '-' and '!' were made right associative.
** match anywhere in the string. The only diff with the ':' is that
** match doesn't have to be anchored to the beginning of the string.
**9. Added the conditional operator 'expr1 ? true_expr :: false_expr'
** First, all 3 exprs are evaluated, and if expr1 is false, the 'false_expr'
** is returned as the result. See above for details.
**10. Unary operators '-' and '!' were made right associative.
-------------------------------------------------------- --------------------------------------------------------
DEBUGGING HINTS FOR $[ ] EXPRESSIONS DEBUGGING HINTS FOR $[ ] EXPRESSIONS
-------------------------------------------------------- --------------------------------------------------------
** THE FOLLOWING UTILITIES ARE PROVIDED ONLY FOR SYSTEMS THAT There are two utilities you can build to help debug the $[ ] in
** HAVE FLEX-2.5.31 OR GREATER, AND USE THE UPGRADED LEXER!!! your extensions.conf file.
**
** There are two utilities you can build to help debug the $[ ] in The first, and most simplistic, is to issue the command:
** your extensions.conf file.
** make testexpr2
** The first, and most simplistic, is to issue the command:
** in the top level asterisk source directory. This will build a small
** make testexpr2 executable, that is able to take the first command line argument, and
** run it thru the expression parser. No variable substitutions will be
** in the top level asterisk source directory. This will build performed. It might be safest to wrap the expression in single
** a small executable, that is able to take the first command line quotes...
** argument, and run it thru the expression parser. No variable
** substitutions will be performed. It might be safest to wrap testexpr2 '2*2+2/2'
** the expression in single quotes...
** is an example.
** testexpr2 '2*2+2/2'
** And, in the utils directory, you can say:
** is an example.
** make check_expr
** And, in the utils directory, you can say:
** and a small program will be built, that will check the file mentioned
** make check_expr in the first command line argument, for any expressions that might be
** have problems when you move to flex-2.5.31. It was originally
** and a small program will be built, that will check the file designed to help spot possible incompatibilities when moving from the
** mentioned in the first command line argument, for any expressions pre-2.5.31 world to the upgraded version of the lexer.
** that might be have problems when you move to flex-2.5.31.
** It was originally designed to help spot possible incompatibilities But one more capability has been added to check_expr, that might make
** when moving from the pre-2.5.31 world to the upgraded version of it more generally useful. It now does a simple minded evaluation of
** the lexer. all variables, and then passes the $[] exprs to the parser. If there
** are any parse errors, they will be reported in the log file. You can
** But one more capability has been added to check_expr, that might use check_expr to do a quick sanity check of the expressions in your
** make it more generally useful. It now does a simple minded evaluation of extensions.conf file, to see if they pass a crude syntax check.
** all variables, and then passes the $[] exprs to the parser. If there are
** any parse errors, they will be reported in the log file. You can use The "simple-minded" variable substitution replaces ${varname} variable
** check_expr to do a quick sanity check of the expressions in your references with '555'. You can override the 555 for variable values,
** extensions.conf file, to see if they pass a crude syntax check. by entering in var=val arguments after the filename on the command
** line. So...
** The "simple-minded" variable substitution replaces ${varname} variable
** references with '555'. You can override the 555 for variable values, check_expr /etc/asterisk/extensions.conf CALLERIDNUM=3075551212 DIALSTATUS=TORTURE EXTEN=121
** by entering in var=val arguments after the filename on the command line.
** So... will substitute any ${CALLERIDNUM} variable references with
** 3075551212, any ${DIALSTATUS} variable references with 'TORTURE', and
** check_expr /etc/asterisk/extensions.conf CALLERIDNUM=3075551212 DIALSTATUS=TORTURE EXTEN=121 any ${EXTEN} references with '121'. If there is any fancy stuff
** going on in the reference, like ${EXTEN:2}, then the override will
** will substitute any ${CALLERIDNUM} variable references with 3075551212, any ${DIALSTATUS} not work. Everything in the ${...} has to match. So, to substitute
** variable references with 'TORTURE', and any ${EXTEN} references with '121'. #{EXTEN:2} references, you'd best say:
** If there is any fancy stuff going on in the reference, like ${EXTEN:2}, then the
** override will not work. Everything in the ${...} has to match. So, to substitute check_expr /etc/asterisk/extensions.conf CALLERIDNUM=3075551212 DIALSTATUS=TORTURE EXTEN:2=121
** #{EXTEN:2} references, you'd best say:
** on stdout, you will see something like:
** check_expr /etc/asterisk/extensions.conf CALLERIDNUM=3075551212 DIALSTATUS=TORTURE EXTEN:2=121
** OK -- $[ "${DIALSTATUS}" = "TORTURE" | "${DIALSTATUS}" = "DONTCALL" ] at line 416
** on stdout, you will see something like:
** In the expr2_log file that is generated, you will see:
** OK -- $[ "${DIALSTATUS}" = "TORTURE" | "${DIALSTATUS}" = "DONTCALL" ] at line 416
** line 416, evaluation of $[ "TORTURE" = "TORTURE" | "TORTURE" = "DONTCALL" ] result: 1
** In the expr2_log file that is generated, you will see:
** check_expr is a very simplistic algorithm, and it is far from being
** line 416, evaluation of $[ "TORTURE" = "TORTURE" | "TORTURE" = "DONTCALL" ] result: 1 guaranteed to work in all cases, but it is hoped that it will be
** useful.
** check_expr is a very simplistic algorithm, and it is far from being guaranteed
** to work in all cases, but it is hoped that it will be useful.
--------------------------------------------------------- ---------------------------------------------------------
Asterisk standard channel variables Asterisk standard channel variables