[Araq]

Shrug, you left out:

- Conservative GC marking of the stack.

- No stack overflow check in release mode.

Compiling to C is not tricky, it is horrible and we don't do it for the fun of it! That said, clang has lots of options to tame C's undefined behaviour. Guess what, you can enable these too for C code generated by Nim.

[pcwalton]

> That said, clang has lots of options to tame C's undefined behaviour. Guess what, you can enable these too for C code generated by Nim.

They aren't really designed for performance though. For example, `-fsanitize-undefined-trap-on-error -fsanitize=null` emits explicit comparisons against null for every pointer load instead of catching SEGV like (for example) Java or Go do.

From what you're saying it sounds like maximum performance plus memory safety isn't a design goal for Nim. That's totally reasonable. It does mean that Nim and Rust have very different aims, however, and comparisons between the two need to take this into account.

[strcat]

> - No stack overflow check in release mode.

-fstack-check in GCC guarantees that the guard page will be hit (as long as there is one), assuming no undefined behaviour like buffer overflows. It has a negligible cost and should really be enabled by default. It only has to add a one byte write per uninitialized page on the stack, and a less efficient dynamic alloca due to probes.