[db48x]

More specifically, a proc macro is a Rust function that is compiled and run inside the compiler at build time. With IDEs, LSP and other protocols for having your editor query the compiler (or language runtime, like SLIME/SWANK), the compiler now runs whenever you open your editor.

It’s just not a new problem. Bash does auto–completion on Makefiles, which requires running make and asking it what the make targets are. IDEs can and will run ./configure for you, so that it can find the right include paths. Etc, etc.

Personally, I thought everyone already knew about this. I knew that proc macros would be a risk when I first heard about rls, years ago.

Certainly editors need to confirm with the user that they are ok with starting the compiler when they load a new project, but also we need to use fine–grained security systems like SELinux that can and do prevent programs from accessing things that they’re not supposed to access.