Can't compile with editline on OpenBSD

I think that I must install the editline (libedit?) library but where can I get it for OpenBSD? The code compiles fine with PC-BSD, but with OpenBSD I get this error

implicit declaration of rl_bind_key

It is the editline library that is not found. I tried googling for where to find it for OpenBSD, but it was not found. Can you help me? The headers I use are

#define _XOPEN_SOURCE 500

#include <sys/stat.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/wait.h>
#include "openshell.h"
#include "errors.h"
#include <errno.h>
#include <locale.h>
#include <editline/readline.h>

Makefile

CC = gcc
GIT_VERSION := $(shell git describe --abbrev=4 --dirty --always --tags)
CFLAGS := $(CFLAGS) -pedantic -std=c99 -Wall -O3 -ledit -g -DVERSION=\"$(GIT_VERSION)\"

shell: main.o
    $(CC) -o shell main.o errors.c util.c pipeline.c -ledit

main.o: main.c errors.c util.c

.PHONY: clean
clean:
    rm -f *.o

This is the offending code

int exec_program(const char *name) {
    FILE *fp;
    int r = 0;
    char *input, shell_prompt[100];
    if (sourceCount >= MAX_SOURCE) {
        fprintf(stderr, "Too many source files\n");
        return 1;
    }
    fp = stdin;
    if (name) {
        fp = fopen(name, "r");

        if (fp == NULL) {
            perror(name);

            return 1;
        }
    }
    sourcefiles[sourceCount++] = fp;
    setlocale(LC_CTYPE, "");
    /*Configure readline to auto-complete paths when the tab key is hit.*/
    rl_bind_key('\t', rl_complete);
    stifle_history(7);
    for (; ;) {
        /* Create prompt string from user name and current working directory.*/
        snprintf(shell_prompt, sizeof(shell_prompt), "%s:%s $ ", getenv("USER"), getcwd(NULL, 1024));
        // Display prompt and read input (NB: input must be freed after use)...
        input = readline(shell_prompt);
        // Check for EOF.
        if (!input)
            break;
        add_history(input);
        r = command(input);
        free(input);
    }
    return r;
}

If I run locate editline then it finds and I change the Makefile and get a new error undefined reference to tgetnum that according to google seems like I must link with the ncurseslibrary. Now it compiles. The new Makefile is:

CC = gcc
GIT_VERSION := $(shell git describe --abbrev=4 --dirty --always --tags)
CFLAGS := $(CFLAGS) -L/usr/local/include/ -L/usr/include -pedantic -std=c99 -Wall -O3 -g -DVERSION=\"$(GIT_VERSION)\" -ledit -lncurses

LDIRS = -L/usr/local/lib -L/usr/lib
LIBS = -ledit lncurses -lcurses

shell: main.o
    $(CC) -o shell main.o errors.c util.c pipeline.c -ledit -lncurses -lcurses

main.o: main.c errors.c util.c

.PHONY: clean
clean:
    rm -f *.o

Check where editline/readline.h can be found (e.g. with locate).

If it is in /usr/local/include, you should probably add that to your CFLAGS in your Makefile;

CFLAGS := $(CFLAGS) -I/usr/local/include -pedantic -std=c99 -Wall -O3 -g -DVERSION=\"$(GIT_VERSION)\"
LDIRS = -L/usr/local/lib
LIBS = -ledit

SRCS= main.c errors.c util.c pipeline.c
OBJS= $(SRCS:.c=.o)

shell: $(OBJS)
    $(CC) $(LDIRS) -o shell $(OBJS) $(LIBS)