Compiling flex / bison program error

Question

I got the following flex and bison code which I want to compile and run:

unari.lex:

%{
    #include "unari.tab.h"
    using namespace std;
%}
%option noyywrap

%%

a        {yylval=1;  return TOK_A;}
\n       return '\n';
\+       return '+';
.        /*ignore all rest*/

%%

unari.y:

%{
    #include <iostream>
    using namespace std;
    void yyerror(const char *errorinfo);
    int yylex();
%}

%left TOK_A 
%left '+'

%%
line: exp '\n'       {cout<<$1<<endl; return 0;}
      ;
exp: exp exp     {$$=$1+$2;}
      | exp '+' exp    {$$=$1+$3;}
      | TOK_A         {$$=yylval;}
      ;
%%
void yyerror(const char *errorinfo)  { 
      cout<<"problem"<<endl;
}


int main()  {
    while(yyparse()==0);
    return 0;
}

makefile:

calc: lex.yy.o unari.tab.o
    g++ unari.tab.o lex.yy.o -o calc.exe

unari.tab.o: unari.tab.c
    g++ -c unari.tab.c

lex.yy.o: lex.yy.c
    g++ -c lex.yy.c

lex.yy.c: unari.lex unari.tab.h
    flex unari.lex

unari.tab.c unari.tab.h: unari.y
    bison -d unari.y

clean:
    rm *.h *.c *.o  *.exe

The problem is, I get the following error when compiling on windows:

makefile1:: *** multiple target patterns. Stop.

Does anyone recognizes the problem? I'm breaking my head over this for more than 3 hours already, tried searching the web and found nothing useful....

The Flex tag is for the ADobe/Apache UI Framework. The Flex-lexer tag is used for the lexical analyzer. — JeffryHouser
This may be your issue: 'unari.tab.c unari.tab.h: unari.y'. Usually there is only one word left of the ':' — Charlie Burns
What's makefile1? Or did you type the error message incorrectly? Normally it would start makefile:[linenumber]: where [linenumber] is the number of the erroneous line (which would be useful to know). multiple target patterns is only produced (as far as I know) if you have a static rule with more than one target pattern. Static rules have two :'s, and I don't see any such rule in your makefile. — rici

Charlie Burns Charlie Burns · Accepted Answer · 2013-11-13T00:04:08

Instead of

unari.tab.c unari.tab.h: unari.y
    bison -d unari.y

try

unari.tab.h: unari.y
    bison -d unari.y

unari.tab.c: unari.y
    bison unari.y

There may be other ways to do it, but I'm pretty sure that will work for you.

Odd. I copied your files, and once I got all the spaces/tab issues worked out in the Makefile it seem to work fine.

[Charlies-MacBook-Pro:~/junk] crb% make clean
rm *.h *.c *.o  *.exe
[Charlies-MacBook-Pro:~/junk] crb% make
bison -d unari.y
unari.y: conflicts: 2 shift/reduce
flex unari.lex
g++ -c lex.yy.c
g++ -c unari.tab.c
g++ unari.tab.o lex.yy.o -o calc.exe


[Charlies-MacBook-Pro:~/junk] crb% which make
/usr/bin/make
[Charlies-MacBook-Pro:~/junk] crb% make --version
GNU Make 3.81

Could be issues with make on windows, and I don't have a windows machine. Maybe try googling 'multiple target patterns. Stop.'

Compiling flex / bison program error

2 Answers