SDL2 undefined reference to `SDL_Init' - c

So I am trying to make game in C using SDL2 (both i686-w64... and x86...)
This is code I have:
#include "include/SDL2/SDL.h"
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char* argv[])
{
if (SDL_Init(SDL_INIT_EVERYTHING) != 0) return -1;
}
and error:
PS C:\Users\Olex7\OneDrive\Pulpit\Game> make
gcc -c -g src/main.c -o src/main.o
gcc src/main.o -g -o build/game
src/main.o: In function `SDL_main':
C:\Users\Olex7\OneDrive\Pulpit\Game/src/main.c:7: undefined reference to `SDL_Init'
c:/mingw/bin/../lib/gcc/mingw32/6.3.0/../../../libmingw32.a(main.o):(.text.startup+0xa0): undefined reference to `WinMain#16'
collect2.exe: error: ld returned 1 exit status
make: *** [Makefile:7: build/game] Error 1

Related

Compiling a sample SDL2 program with gcc/cygwin on windows: undefined reference to WinMain

I browsed the whole internet and tried every solution for this, without result.
What I'm using:
Windows 10
Cygwin
gcc compiler
I'm trying to compile this simple code:
#include "SDL.h"
int main(int ac, char **av)
{
return 0;
}
This is what my makefile looks like:
hellosdl:
gcc hellosdl.c -L../SDL2-2.0.18/x86_64-w64-mingw32/lib -lSDL2main -lSDL2 -mwindows -I../SDL2-2.0.18/x86_64-w64-mingw32/include/SDL2
where -lSDL2main -lSDL2 -mwindows is the output of sdl2-config --libs, minus -lmingw32.
Output:
/usr/lib/gcc/x86_64-pc-cygwin/10/../../../../x86_64-pc-cygwin/bin/ld: /usr/lib/gcc/x86_64-pc-cygwin/10/../../../../lib/libcygwin.a(libcmain.o): in function `main':
/usr/src/debug/cygwin-3.2.0-1/winsup/cygwin/lib/libcmain.c:37: undefined reference to `WinMain'
collect2: error: ld returned 1 exit status
make: *** [Makefile:3: hellosdl] Error 1
What am I not understanding?

Using SDL(Simple DirectMedia Layer) Libraries in Ubuntu

i'm trying to include all SDL libraries that i have already installed and exist in '/usr/include/SDL' this directory contains all .h files
#include <SDL/SDL.h>
#include <stdio.h>
#include <stdlib.h>
int main ()
{
SDL_Surface *screen=NULL ;
SDL_Init (SDL_INIT_VIDEO);
if (SDL_Init(SDL_INIT_VIDEO !=0))
{
printf("erreur");
return 1 ;
}
screen=SDL_SetVideoMode (400,400,32,SDL_HWSURFACE | SDL_DOUBLEBUF);
if (screen== NULL)
{
printf("Unable to set video mode : %s \n",SDL_GetError() );
return 1;
}
SDL_Flip (screen);
SDL_Quit ();
return 0;
}
when i compile code above that exists in main.c in terminal using this command:
gcc main.c -o program -LSDL
i get this :
axemaster#ubuntu:~/Desktop/stackoverflow$ gcc main.c -o program -LSDL
/tmp/ccMx1per.o: In function `main':
main.c:(.text+0x16): undefined reference to `SDL_Init'
main.c:(.text+0x20): undefined reference to `SDL_Init'
main.c:(.text+0x53): undefined reference to `SDL_SetVideoMode'
main.c:(.text+0x63): undefined reference to `SDL_GetError'
main.c:(.text+0x88): undefined reference to `SDL_Flip'
main.c:(.text+0x8d): undefined reference to `SDL_Quit'
collect2: error: ld returned 1 exit status
How can i solve this ?

gcc - undefined reference to `libusb_init'

I'm trying to compile a piece of code which uses libusb:
#include <stdio.h>
#include <libusb-1.0/libusb.h>
#include <assert.h>
int main(void) {
libusb_context *context = NULL;
int rc = 0;
rc = libusb_init(&context);
assert(rc == 0);
libusb_exit(context);
return 0;
}
Upon compiling with gcc -lusb -lusb-1.0 sample.c -o sample the following errors emerge:
/tmp/ccr65JBT.o: In function `main':
sample.c:(.text+0x2e): undefined reference to `libusb_init'
sample.c:(.text+0x62): undefined reference to `libusb_exit'
collect2: error: ld returned 1 exit status
To make sure libusb is availible on my system:
raven#enforcer:~/sample$ pkg-config --libs libusb-1.0
-lusb-1.0
raven#enforcer:~/sample$ pkg-config --libs libusb
-lusb
I'm running Ubuntu 18.04 with gcc 7.3.0-16ubuntu3, how to fix?
Got it working by appending the flags after the .c: gcc sample.c -o sample -lusb -lusb-1.0
Autotools: sample_LDADD instead of sample_LDFLAGS
Thanks to Felix Palmen.

compiling with libssl does not work

I have a very simple code:
#include <openssl/sha.h>
int main() {
SHA_CTX sha1;
SHA_Init(&sha1);
}
I have installed both libssl-dev and libcrypto++-dev:
However I have a build failure using the following command:
$ gcc -lcrypto -lssl main.c
/tmp/ccfnCAxT.o: In function `main':
main.c:(.text+0x1f): undefined reference to `SHA1_Init'
collect2: error: ld returned 1 exit status
$
$ gcc -lssl main.c
/tmp/ccfnCAxT.o: In function `main':
main.c:(.text+0x1f): undefined reference to `SHA1_Init'
collect2: error: ld returned 1 exit status
Platform: Ubuntu 16.04
-lssl is not needed, -lcrypto is enough, and it must be at the end:
gcc -o main main.c -lcrypto
(or whatever you want your program to be called goes after -o)

compilation error on Executing embedded lua in C file

I am using Cygwin environment with Lua Interpreter package included while cygwin installation.
So I am able to compile and run sample lua progs.
But when i try to execute a sample c file which has lua calls , i am always getting this following error.
$ cc -o ../samples/ctest -Wall ../samples/ctest.c
/tmp/ccOYgLj4.o:ctest.c:(.text+0x2b): undefined reference to `_luaL_newstate'
/tmp/ccOYgLj4.o:ctest.c:(.text+0x3d): undefined reference to `_luaL_openlibs'
/tmp/ccOYgLj4.o:ctest.c:(.text+0x59): undefined reference to `_luaL_loadfile'
/tmp/ccOYgLj4.o:ctest.c:(.text+0x82): undefined reference to `_lua_pcall'
/tmp/ccOYgLj4.o:ctest.c:(.text+0xb8): undefined reference to `_lua_getfield'
/tmp/ccOYgLj4.o:ctest.c:(.text+0xd5): undefined reference to `_lua_call'
/tmp/ccOYgLj4.o:ctest.c:(.text+0xf0): undefined reference to `_lua_close'
collect2: ld returned 1 exit status
My sample ctest.c file contents:
#include <stdio.h>
#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"
/* lua interpreter */
lua_State* l;
int main () {
int dofile;
/* initialize lua */
l = lua_open();
/* load lua libraries */
luaL_openlibs(l);
/* run the hello.lua script */
dofile = luaL_dofile(l, "hello.lua");
if (dofile == 0) {
/* call foo */
lua_getglobal(l,"foo");
lua_call(l,0,0);
}
else {
printf("Error, unable to run hello.lua\n");
}
/* cleanup Lua */
lua_close(l);
return 0;
}
hello.lua file contents:
print("from c hurray")
on searching the net everywhere they say some linker error and have to include -llua51. So i tried the following .
$ cc -o ../samples/ctest -Wall -llua5.1 ../samples/ctest.c
/tmp/cc3v5Nim.o:ctest.c:(.text+0x2b): undefined reference to `_luaL_newstate'
/tmp/cc3v5Nim.o:ctest.c:(.text+0x3d): undefined reference to `_luaL_openlibs'
/tmp/cc3v5Nim.o:ctest.c:(.text+0x59): undefined reference to `_luaL_loadfile'
/tmp/cc3v5Nim.o:ctest.c:(.text+0x82): undefined reference to `_lua_pcall'
/tmp/cc3v5Nim.o:ctest.c:(.text+0xb8): undefined reference to `_lua_getfield'
/tmp/cc3v5Nim.o:ctest.c:(.text+0xd5): undefined reference to `_lua_call'
/tmp/cc3v5Nim.o:ctest.c:(.text+0xf0): undefined reference to `_lua_close'
collect2: ld returned 1 exit status
Vedhashree#Vedhashree-PC /cygdrive/c/cygwin/bin
$ ls /usr/lib/liblua*.a
/usr/lib/liblua.a /usr/lib/liblua5.1.a
/usr/lib/liblua.dll.a /usr/lib/liblua5.1.dll.a
Can you help me fix this issue and make my first embedded lua c program work?
Update:
$ cc -o ctesing -Wall ctesting.c -llua5.1
/usr/lib/gcc/i686-pc-cygwin/4.3.4/../../../../i686-pc-cygwin/bin/ld: cannot find
-llua5.1
collect2: ld returned 1 exit status
-----------------------------------------------------------------
cc -o ../samples/ctest -Wall ../samples/ctest.c -llua
/usr/lib/gcc/i686-pc-cygwin/4.3.4/../../../../i686-pc-cygwin/bin/ld: cannot find
-llua51
collect2: ld returned 1 exit status
-----------------------------------------------------------------
cc -o ../samples/ctest -Wall ../samples/ctest.c -llua51
/usr/lib/gcc/i686-pc-cygwin/4.3.4/../../../../i686-pc-cygwin/bin/ld: cannot find
-llua
collect2: ld returned 1 exit status
-----------------------------------------------------------------
Still I get only these errors :(
Place -llua5.1 after ../samples/ctest.c. Objects should be linked in reverse order of dependency.
cc -o ../samples/ctest -Wall ../samples/ctest.c -llua5.1
UPDATE: Your update describes a different problem. In this case the linker cannot find a liblua5.1.a file in its search path. Make sure that you have such a library on your system and try adding its path using the -L option.

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