记录编译报错信息
1. symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1
Undefined symbols for architecture x86_64:
"_InitContract", referenced from:
_contract in test-c1cdd7.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
解决：
1 . 在.c文件头引用对应.h头文件
2. gcc *.c -o output