Multiple lexers with flex++
I am trying to link various Flex++ Lexers in the same executable. However, I get compile errors as a result because of symbol redefinition. I tried to set different prefixes but it was no use: These are my options:
Lexer1:
%option c++
%option noyywrap
%option yyclass="SendmailScanner"
%option prefix="zz"
Lexer2:
%option c++
%option noyywrap
%option yyclass="SSHDFailureScanner"
%option prefix="xx"
According to the manual, I should only unset the variable yyFlexLexer and change it into zzFlexLexer (in the source file that uses that lexer) or xxFlexerLexer. Unfortunately, I got the following errors:
/usr/include/FlexLexer.h:103: error: redefinition of ‘class zzFlexLexer’
/usr/include/FlexLexer.h:103: error: previous definition of ‘class zzFlexLexer’
This error also appears even whe开发者_开发问答n I have only one Lexer... I do not know what to do.
Thank you in advance,
Though I didn't test thoroughly, the redefinition error didn't occur when I
tested with simple files.
My flex
's version is 2.5.35.
For your information, my test files are configured like the following:
Lexer1.h:
struct SendmailScanner : yyFlexLexer {
int yylex();
};
Lexer2.h:
struct SSHDFailureScanner : yyFlexLexer {
int yylex();
};
Lexer1.l:
%{
#include "Lexer1.h"
%}
%option c++
%option noyywrap
%option yyclass="SendmailScanner"
%option prefix="zz"
%%
...
Lexer2.l:
%{
#include "Lexer2.h"
%}
%option c++
%option noyywrap
%option yyclass="SSHDFailureScanner"
%option prefix="xx"
%%
...
The above files don't include #undef yyFlexLexer
and #define yyFlexLexer ...
directives.
Probably those directives aren't needed when flex-generated files are compiled.
Hope this helps
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