Yes, the compiler will open the binary and only emit modified/new code and possibly change some values in a global offset table. As noted in the article, the s

Yes, the compiler will open the binary and only emit modified/new code and possibly change some values in a global offset table. As noted in the article, the same strategy will be used for hot code swapping, which is one of the benefits of doing this. This is indeed faster than generating new object files and relinking the whole executable. The video linked in the article shows a simple example with the current ELF incremental linker, where compiling the example program takes 1.5 ms while changing a string literal and updating the executable takes about 0.5 ms