Hi,
I am using flex and bizon to write HTTP parser.
I am passing well flex and bison tools but can't compile their output.
Flex file (http_parser.lpp)
%{
#include <iostream>
#include 'http_parser.tab.hpp'
#define ECHO yyerror('Parse error.')
%}
%x REQUEST
%x AFTER_METHOD
%x RESP_VERSION
%x AFTER_RESP_VERSION
%x RESP_CODE
%x AFTER_RESP_CODE
%x RESP_MSG
%x AFTER_RESP_MSG
%x REQ_HOST
%x REQ_AFTER_HOST
%x REQ_PORT_DELIMITER
%x REQ_PORT
%x REQ_PATH
%x AFTER_REQ_PATH
%x REQ_BEFORE_VERSION
%x REQ_VERSION
%x AFTER_REQ_VERSION
%x HEADER_NAME
%x HEADER_DELIMITER
%x HEADER_VALUE
%x AFTER_HEADER_VALUE
WS [x20t]+
CRLF (rn r n)
TOKEN [^x80-xFFx7Fx00-x1Fx20x22rnt]+
LETTER [a-zA-Z]
HEADER_NAME [-_a-zA-Z]+
DIGIT [0-9]
PROTOCOL (http:// ftp://)
HOST [^x2Fx3Ax80-xFFx7Fx00-x1Fx20x22rnt]+
PORT {DIGIT}+
METHOD {LETTER}+
%%
{METHOD}/{WS} {
BEGIN AFTER_METHOD;
std::cout << 'REQUESTn';
std::cout << 'METHOD=' << YYText() << 'n';
return T_REQ_METHOD;
}
<AFTER_METHOD>{WS} {
BEGIN REQUEST;
}
'HTTP/' {
BEGIN RESP_VERSION;
std::cout << 'RESPONSEn';
}
<RESP_VERSION>{DIGIT}+.{DIGIT}+/{WS} {
BEGIN AFTER_RESP_VERSION;
std::cout << 'RESP_VERSION=' << YYText() << 'n';
return T_RESP_VERSION;
}
<AFTER_RESP_VERSION>{WS} {
BEGIN RESP_CODE;
}
<RESP_CODE>{DIGIT}+/{WS} {
BEGIN AFTER_RESP_CODE;
std::cout << 'RESP_CODE=' << YYText() << 'n';
return T_RESP_CODE;
}
<AFTER_RESP_CODE>{WS} {
BEGIN RESP_MSG;
}
<RESP_MSG>{TOKEN}/{CRLF} {
BEGIN AFTER_RESP_MSG;
std::cout << 'RESP_MSG=' << YYText() << 'n';
return T_RESP_MSG;
}
<AFTER_RESP_MSG>{CRLF} {
BEGIN HEADER_NAME;
}
<REQUEST>'/' {
BEGIN REQ_PATH;
std::cout << 'REQ_RELATIVE_1n';
}
<REQUEST>'/'{WS} {
BEGIN REQ_BEFORE_VERSION;
std::cout << 'REQ_RELATIVE_2n';
}
<REQUEST>{PROTOCOL} {
BEGIN REQ_HOST;
std::cout << 'REQ_ABSOLUTE_1n';
std::cout << 'PROTOCOL=' << YYText() << 'n';
return T_REQ_PROTOCOL;
}
<REQ_HOST>{HOST}/: {
BEGIN REQ_PORT_DELIMITER;
std::cout << 'REQ_HOST_1=' << YYText() << 'n';
return T_REQ_HOST;
}
<REQ_HOST>{HOST}// {
BEGIN REQ_PATH;
std::cout << 'REQ_HOST_2=' << YYText() << 'n';
return T_REQ_HOST;
}
<REQ_HOST>{HOST}/{WS} {
BEGIN REQ_AFTER_HOST;
std::cout << 'REQ_HOST_3=' << YYText() << 'n';
return T_REQ_HOST;
}
<REQ_AFTER_HOST>{WS} {
BEGIN REQ_BEFORE_VERSION;
}
<REQ_PORT_DELIMITER>':' {
BEGIN REQ_PORT;
}
<REQ_PORT>{PORT}// {
BEGIN REQ_PATH;
std::cout << 'REQ_PORT_1=' << YYText() << 'n';
return T_REQ_PORT;
}
<REQ_PORT>{PORT}/{WS} {
BEGIN REQ_BEFORE_VERSION;
std::cout << 'REQ_PORT_2=' << YYText() << 'n';
return T_REQ_PORT;
}
REQ_PATH>{TOKEN}/{WS} {
BEGIN AFTER_REQ_PATH;
std::cout << 'REQ_PATH=' << YYText() << 'n';
return T_REQ_PATH;
}
<AFTER_REQ_PATH>{WS} {
BEGIN REQ_BEFORE_VERSION;
}
<REQ_BEFORE_VERSION>'HTTP/' {
BEGIN REQ_VERSION;
}
<REQ_VERSION>{DIGIT}+.{DIGIT}+/{CRLF} {
BEGIN AFTER_REQ_VERSION;
std::cout << 'REQ_VERSION=' << YYText() << 'n';
return T_REQ_VERSION;
}
<AFTER_REQ_VERSION>{CRLF} {
BEGIN HEADER_NAME;
}
<HEADER_NAME>{HEADER_NAME}+/:{WS} {
BEGIN HEADER_DELIMITER;
std::cout << 'HEADER_NAME=' << YYText() << 'n';
return T_HEADER_NAME;
}
<HEADER_DELIMITER>:{WS} {
BEGIN HEADER_VALUE;
}
<HEADER_VALUE>[^rn]*/{CRLF} {
BEGIN AFTER_HEADER_VALUE;
std::cout << 'HEADER_VALUE=' << YYText() << 'n';
return T_HEADER_VALUE;
}
<AFTER_HEADER_VALUE>{CRLF} {
BEGIN HEADER_NAME;
}
<AFTER_HEADER_VALUE>{CRLF}{CRLF} { ; }
%%
Bizon file (http_parser.ypp)
%{
#include <iostream>
extern 'C'
{
void yyerror(char *);
int yyparse(void);
int yylex(void);
int yywrap();
}
%}
%token T_REQ_METHOD
%token T_REQ_PROTOCOL
%token T_REQ_HOST
%token T_REQ_PORT
%token T_REQ_PATH
%token T_REQ_VERSION
%token T_RESP_VERSION
%token T_RESP_CODE
%token T_RESP_MSG
%token T_HEADER_NAME
%token T_HEADER_VALUE
%%
program:
request
response
;
request:
/* Absolute requests */
T_REQ_METHOD T_REQ_PROTOCOL T_REQ_HOST T_REQ_PORT T_REQ_PATH
T_REQ_VERSION headers {
std::cout << 'ABS => T_REQ_METHOD T_REQ_PROTOCOL T_REQ_HOST
T_REQ_PORT T_REQ_PATH T_REQ_VERSION headersn';
}
T_REQ_METHOD T_REQ_PROTOCOL T_REQ_HOST T_REQ_PATH T_REQ_VERSION
headers {
std::cout << 'ABS => T_REQ_METHOD T_REQ_PROTOCOL T_REQ_HOST
T_REQ_PATH T_REQ_VERSION headersn';
}
T_REQ_METHOD T_REQ_PROTOCOL T_REQ_HOST T_REQ_VERSION headers {
std::cout << 'ABS => T_REQ_METHOD T_REQ_PROTOCOL T_REQ_HOST
T_REQ_VERSION headersn';
}
/* Relative requests */
T_REQ_METHOD T_REQ_PATH T_REQ_VERSION headers {
std::cout << 'REL => T_REQ_METHOD T_REQ_PATH T_REQ_VERSION
headersn';
}
T_REQ_METHOD T_REQ_VERSION headers {
std::cout << 'REL => T_REQ_METHOD T_REQ_VERSION headersn';
}
;
response:
T_RESP_VERSION T_RESP_CODE T_RESP_MSG headers {
std::cout << 'T_RESP_VERSION T_RESP_CODE T_RESP_MSG headersn';
}
;
headers:
headers header
;
header:
T_HEADER_NAME T_HEADER_VALUE {
std::cout << 'T_HEADER_NAME T_HEADER_VALUEn';
}
;
%%
int yywrap(void) {
return 1;
}
void yyerror(char * msg)
{
std::cout << 'ERROR: ' << msg << std::endl;
}
int main( void )
{
FlexLexer* lexer = new yyFlexLexer;
while(lexer->yylex() != 0)
;
return 0;
}
Compile
1. flex --c++ http_parser.lpp
OK
2. bison -d http_parser.ypp
OK
3. Files list
http_parser.lpp
http_parser.tab.cpp
http_parser.tab.hpp
http_parser.ypp
lex.yy.cc
4. g++ -c lex.yy.cc http_parser.tab.cpp
http_parser.lpp: In member function `virtual int yyFlexLexer::yylex()':
http_parser.lpp:222: error: `yyerror' undeclared (first use this
function)
http_parser.lpp:222: error: (Each undeclared identifier is reported
only once
for each function it appears in.)
lex.yy.cc:1174: error: `yywrap' undeclared (first use this function)
http_parser.ypp: In function `int main()':
http_parser.ypp:90: error: `FlexLexer' undeclared (first use this
function)
http_parser.ypp:90: error: (Each undeclared identifier is reported only
once
for each function it appears in.)
http_parser.ypp:90: error: `lexer' undeclared (first use this function)
http_parser.ypp:90: error: parse error before `;' token
What i am doing wrong ???
Thanks a lot.
