langref: clarify the lifetime of locals in inline functions, inline for, and blocks

[jeffective]

Inline functions

Please clarify in the language reference if this is illegal:

pub fn inline returnsLocal() *i32 {
    var local: i32 = 0;
    return &local;
}

Inline for

Please clarify in the language reference if this is illegal:

const std = @import("std");

pub fn main() void {
    var bufs: [4]*const [4]u8 = undefined;
    inline for (0..4) |i| {
        const buf: [4]u8 = @splat(@intCast(i));
        bufs[i] = &buf;
    }
    for (bufs) |buf| {
        std.debug.print("{x}\n", .{buf});
    }
}

00000000
01010101
02020202
03030303

Blocks

Please clarify in the language reference if this is illegal:

const std = @import("std");

pub fn main() void {
    var x: *const i32 = &0;
    {
        var y: i32 = 1;
        x = &y;
    }
    std.debug.print("x = {}\n", .{x.*});
}

x = 1

Related community thread: https://ziggit.dev/t/exploiting-inline-for-to-avoid-stack-curruption/8697/5