MacOS ld: symbols not found (x86_64) - c++

Question

I have the following error:
Undefined symbols for architecture x86_64:
"_inflateEnd", referenced from:
uWS::Hub::~Hub() in main.o
"_inflateInit2_", referenced from:
uWS::Hub::Hub(int, bool, unsigned int) in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I have checked all the similar questions and their solutions but nothing worked for me.
I am trying to test uWebSockets (https://github.com/uNetworking/uWebSockets) and have the following file structure:
my_app (which has main.cpp)
ext/uWebSockets (which is a clone of the repository above)
So, I am doing the following:
~/ext/uWebSockets$ make
make `(uname -s)`
c++ -std=c++11 -O3 -I src -shared -fPIC src/Extensions.cpp src/Group.cpp src/Networking.cpp src/Hub.cpp src/Node.cpp src/WebSocket.cpp src/HTTPSocket.cpp src/Socket.cpp src/Epoll.cpp -stdlib=libc++ -mmacosx-version-min=10.7 -undefined dynamic_lookup -L/usr/local/opt/openssl/lib -I/usr/local/opt/openssl/include -o libuWS.dylib
and obtain libuWS.dylib in /ext/uWebSockets
Then, I do the following:
~/my_app$ g++ -c main.cpp -o main.o -I../ext/uWebSockets/src -I/usr/local/opt/openssl/include -std=c++11
So now I have main.o in /my_app. But when I'm trying to:
~/my_app$ g++ -o start main.o -L../ext/uWebSockets -luWS
I receive the aforementioned error:
Undefined symbols for architecture x86_64:
"_inflateEnd", referenced from:
uWS::Hub::~Hub() in main.o
"_inflateInit2_", referenced from:
uWS::Hub::Hub(int, bool, unsigned int) in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Here is the same command with -v:
~/my_app$ g++ -o start main.o -L../ext/uWebSockets -luWS -v
Apple LLVM version 9.0.0 (clang-900.0.39.2)
Target: x86_64-apple-darwin17.3.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
"/Library/Developer/CommandLineTools/usr/bin/ld" -demangle -lto_library /Library/Developer/CommandLineTools/usr/lib/libLTO.dylib -dynamic -arch x86_64 -macosx_version_min 10.13.0 -o start -L../ext/uWebSockets main.o -luWS -lc++ -lSystem /Library/Developer/CommandLineTools/usr/lib/clang/9.0.0/lib/darwin/libclang_rt.osx.a
Undefined symbols for architecture x86_64:
"_inflateEnd", referenced from:
uWS::Hub::~Hub() in main.o
"_inflateInit2_", referenced from:
uWS::Hub::Hub(int, bool, unsigned int) in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
How can I link them correctly?
main.cpp:
#include <iostream>
#include "uWS.h"
int main() {
uWS::Hub h;
h.onError([](void *user) {
std::cout << "WebSocket: Error has occured" << std::endl;
});
h.onConnection([](uWS::WebSocket<uWS::CLIENT> *ws, uWS::HttpRequest req) {
std::cout << "Client established a remote connection over non-SSL" << std::endl;
});
h.onDisconnection([](uWS::WebSocket<uWS::CLIENT> *ws, int code, char *message, size_t length) {
std::cout << "Client got disconnected with data: " << ws->getUserData() << ", code: " << code << ", message: <" << std::string(message, length) << ">" << std::endl;
});
// url, user, headers, timeout, group client
h.connect("wss://www.test.com/", (void *) 0, {}, 5000);
h.run();
std::cout << "Falling through testConnections" << std::endl;
return 0;
}

Answer 1

Finally, I was able to fix it. The problem was in zlib, which I didn't include.
So the correct way of running this is g++ -o start main.o -luWS -lz