Android NDK compile error

[CRC32EX]

Steps to reproduce this issue

1. clone & build my project

git clone https://github.com/CRC32EX/AndroidWebServer
cd AndroidWebServer
ndk-build

2. Error

$ ndk-build
[arm64-v8a] Executable     : AndroidWebServer
./obj/local/arm64-v8a/objs/AndroidWebServer/__/main.o: In function `main':
C:\Users\user01\Desktop\AndroidTest/jni/../main.cpp:17: undefined reference to `mg_mgr_init(mg_mgr*)'
C:\Users\user01\Desktop\AndroidTest/jni/../main.cpp:20: undefined reference to `mg_http_listen(mg_mgr*, char const*, void (*)(mg_connection*, int, void*, void*), void*)'
C:\Users\user01\Desktop\AndroidTest/jni/../main.cpp:24: undefined reference to `mg_mgr_poll(mg_mgr*, int)'
./obj/local/arm64-v8a/objs/AndroidWebServer/__/main.o: In function `fn(mg_connection*, int, void*, void*)':
C:\Users\user01\Desktop\AndroidTest/jni/../main.cpp:7: undefined reference to `mg_http_match_uri(mg_http_message const*, char const*)'
C:\Users\user01\Desktop\AndroidTest/jni/../main.cpp:8: undefined reference to `mg_http_reply(mg_connection*, int, char const*, char const*, ...)'
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [C:/Android/ndk/21.1.6352462/build//../build/core/build-binary.mk:738: obj/local/arm64-v8a/AndroidWebServer] Error 1

Possible solution

• I can compile with C code only.
  But I want use mongoose with C++.

main.cpp -> main.c

Environment

• Windows 10 64bit 20H2
• mongoose 7.3
• Android NDK

$ ndk-build --version
GNU Make 4.2.1
Built for x86_64-w64-mingw32
Copyright (C) 1988-2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

[CRC32EX]

Solved.
Use extern "C".

main.cpp

extern "C" {
#include "mongoose.h"
}