CODEWITHSUNDEEP
cgcclex
Meepo
Meepo

Reputation: 1371

error: unknown type name ‘bool’

I downloaded the source code and wanted to compile the file of scanner. It produces this error:

[meepo@localhost cs143-pp1]$ gcc -o lex.yy.o lex.yy.c -ll
In file included from scanner.l:15:0:
scanner.h:59:5: error: unknown type name ‘bool’
In file included from scanner.l:16:0:
utility.h:64:38: error: unknown type name ‘bool’
utility.h:74:1: error: unknown type name ‘bool’
In file included from scanner.l:17:0:
errors.h:16:18: fatal error: string: No such file or directory
compilation terminated.

And I tried to use different complier to compile it, but it appeared different errors.

[meepo@localhost cs143-pp1]$ g++ -o scan lex.yy.c -ll
/usr/bin/ld: cannot find -ll
collect2: ld returned 1 exit status

My os is 3.0-ARCH, I don't know why this happened. How do I fix the error?

Upvotes: 135

Views: 324691

Answers (5)

Rockrid3r
Rockrid3r

Reputation: 191

In my case the #include <stdbool.h> was not enough. The solution was to set Intelli Sense Mode to gcc-x64 in the C/C++ Extension Settings.

Upvotes: 0

Thomas
Thomas

Reputation: 899

C99 does, if you have 

#include <stdbool.h>

If the compiler does not support C99, you can define it yourself:

// file : myboolean.h
#ifndef MYBOOLEAN_H
#define MYBOOLEAN_H

#define false 0
#define true 1
typedef int bool; // or #define bool int

#endif

(but note that this definition changes ABI for bool type so linking against external libraries which were compiled with properly defined bool may cause hard-to-diagnose runtime errors).

Upvotes: 70

user978122
user978122

Reputation: 5761

C90 does not support the boolean data type.

C99 does include it with this include:

#include <stdbool.h>

Upvotes: 245

M.Hefny
M.Hefny

Reputation: 2745

Just add the following:

#define __USE_C99_MATH

#include <stdbool.h>

Upvotes: 6

Roland Illig
Roland Illig

Reputation: 41617

Somewhere in your code there is a line #include <string>. This by itself tells you that the program is written in C++. So using g++ is better than gcc.

For the missing library: you should look around in the file system if you can find a file called libl.so. Use the locate command, try /usr/lib, /usr/local/lib, /opt/flex/lib, or use the brute-force find / | grep /libl.

Once you have found the file, you have to add the directory to the compiler command line, for example:

g++ -o scan lex.yy.c -L/opt/flex/lib -ll

Upvotes: 5

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