runtime: code generation confusion

[acln0]

I am hacking on the runtime. In the process, I wanted to add a constant such that it ends up in the (apparently machine-generated) defs_linux_$GOARCH.go files. I'm confused about whether or not I should be editing these files by hand. There appears to be a code generation step described in defs_linux.go, but I couldn't get it to work. A go tool cgo -cdefs does not appear to exist anymore. go tool cgo -godefs does seem to exist, but that one chokes (among other things), on this line, which cannot possibly be right.

If I fix that, I get a missing definition error for C.MAP_PRIVATE, which appears to be in linux/mman.h these days rather than asm/mman.h? (at least on my system, which is Debian GNU/Linux bullseye/sid, according to lsb_release)

Do these comments need an update? Am I doing something wrong or missing a detail? When 77f9b27 was written, was the code generation tool actually invoked?

Thanks.

[acln0]

/cc @tklauser

[bcmills]

This discussion is probably better suited to the golang-dev list.

[ianlancetaylor]

The code generation steps in the runtime package have been broken since the runtime was converted from C to Go. Since the files rarely change, nobody has cared enough to fix this.

This is a dup of #23341. See the discussion there.