CODEWITHSUNDEEP
c++windowsgccmakefileflex-lexer
Sathvik Chinnu
Sathvik Chinnu

Reputation: 575

mingw32/bin/ld.exe: cannot find -lfl collect2.exe: error: ld returned 1 exit status

I am trying to execute FLEX program from the Github on windows and I have installed Flex and MingW Compiler.

I have added below paths to Environmental variables

  1. C:\MinGW\bin
  2. C:\MinGW\msys\1.0\bin

After that, I trying to execute make command and I got the below output

g++ -g -Wall -ansi -pedantic -std=gnu++0x bison.o lex.o main.o -o mini_lang -lfl
c:/mingw/bin/../lib/gcc/mingw32/6.3.0/../../../../mingw32/bin/ld.exe: cannot find -lfl
collect2.exe: error: ld returned 1 exit status
make: *** [mini_lang] Error 1

Below is Makefile

OBJ = bison.o lex.o main.o
CC = g++
CFLAGS = -g -Wall -ansi -pedantic -std=gnu++0x

mini_lang:$(OBJ)
    $(CC) $(CFLAGS) $(OBJ) -o mini_lang -lfl

lex.o: lex.c
    $(CC) $(CFLAGS) -c lex.c -o lex.o

lex.c: lex_final.l
    flex lex_final.l
    cp lex.yy.c lex.c

bison.o: bison.c
    $(CC) $(CFLAGS) -c bison.c -o bison.o

bison.c: grammar.y
    bison -d -v grammar.y
    cp grammar.tab.c bison.c
    cmp -s grammar.tab.h tok.h || cp grammar.tab.h tok.h

main.o: main.cc
    $(CC) $(CFLAGS) -c main.cc -o main.o

lex.o yac.o main.o: headers.h
lex.o main.o: tok.h


clean:
    rm -f *.o *~ lex.c lex.yy.c bison.c tok.h grammar.tab.c grammar.tab.h grammar.output mini_lang

Please, can anyone help me to fix this error?

Upvotes: 1

Views: 14453

Answers (3)

ankolodz
ankolodz

Reputation: 19

If you use the MinGW compiler, open InstallationManager and install this package:

mingw32-pthreads-w32

Upvotes: 1

rici
rici

Reputation: 241671

My advice is to find a different tutorial.

Either the flex distribution you installed does not include libfl or you did not add the path to libfl to the correct environment variable. You might try adding the path explicitly to the minilang rule, using a -L option before -lfl: ... -L /path/to/directory-containinglibfl -lfl.

However, there is absolutely no need for -lfl, so the better solution is to just remove it from the minilang action, and add

%option noyywrap

to your flex input file. (That will prevent it from producing a scanner which calls yywrap, so you will not require the yywrap which is in libfl.)

Upvotes: 1

valiano
valiano

Reputation: 18541

I'm using MingW+MSYS2, and for me the Flex library is located at c:\msys32\usr\lib\libfl.a.

Try searching for libfl.a in your MinGW folder tree, and use the -L compiler/linker flag, followed by the folder path where the library is located, to instruct the compiler/linker to look for libfl.a in that location.

For example:

g++ -g -Wall -ansi -pedantic -std=gnu++0x bison.o lex.o main.o -o mini_lang -lfl -Lc:\msys32\usr\lib

Upvotes: 0

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