Compilation fails

[174n]

I was trying to compile levenshtein.c and got this error:

clang -fPIC -Isqlite3 -o levenshtein.sqlext levenshtein.c -v
clang version 9.0.1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-pc-linux-gnu/9.2.0
Found candidate GCC installation: /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0
Found candidate GCC installation: /usr/lib64/gcc/x86_64-pc-linux-gnu/9.2.0
Selected GCC installation: /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
 "/usr/bin/clang-9" -cc1 -triple x86_64-pc-linux-gnu -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name levenshtein.c -mrelocation-model pic -pic-level 2 -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -v -resource-dir /usr/lib/clang/9.0.1 -I sqlite3 -internal-isystem /usr/local/include -internal-isystem /usr/lib/clang/9.0.1/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdebug-compilation-dir /home/ivan/playground/wordparts_parser/SQLiteFuzzySearch -ferror-limit 19 -fmessage-length 0 -stack-protector 2 -fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics -faddrsig -o /tmp/levenshtein-167578.o -x c levenshtein.c
clang -cc1 version 9.0.1 based upon LLVM 9.0.1 default target x86_64-pc-linux-gnu
ignoring nonexistent directory "sqlite3"
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/clang/9.0.1/include
 /usr/include
End of search list.
 "/usr/bin/ld" -pie --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o levenshtein.sqlext /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../lib64/Scrt1.o /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../lib64/crti.o /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/crtbeginS.o -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0 -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../lib64 -L/usr/bin/../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../.. -L/usr/bin/../lib -L/lib -L/usr/lib /tmp/levenshtein-167578.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/crtendS.o /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../lib64/crtn.o
/usr/bin/ld: /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../lib64/Scrt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
clang-9: error: linker command failed with exit code 1 (use -v to see invocation)

Arch Linux x86_64, Kernel: 5.5.2-arch1-1