xcode is the devil

output.txt

bash-4.4$ gcc -Xlinker -v
@(#)PROGRAM:ld  PROJECT:ld64-409.12
BUILD 17:47:51 Sep 25 2018
configured to support archs: armv6 armv7 armv7s arm64 i386 x86_64 x86_64h armv6m armv7k armv7m armv7em arm64e arm64_32
Library search paths:
        /usr/lib
        /usr/local/lib
Framework search paths:
        /Library/Frameworks/
        /System/Library/Frameworks/
Undefined symbols for architecture x86_64:
  "_main", referenced from:
     implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
bash-4.4$ type -a clang
clang is /usr/bin/clang
bash-4.4$