__strcpy_sse2_unaligned with -fno-builtin

Question

I was debugging my program, then the last line happened, how can I fix it? I used the -fno-builtin to have a look at the strcpy() but it shows that the

Answer 1

__strcpy_sse2_unaligned is the implementation of strcpy which is used on your machine. glibc automatically chooses an optimized implementation based on CPU characteristics, using an IFUNC resolver.

This does not have to do anything with GCC and GCC built-ins. GCC emits a call to strcpy. It is just that glibc happens to call the function which it __strcpy_sse2_unaligned.