Fails to build on 32-bit architecture

[jbeich]

Build Environment

• OS: FreeBSD 11.4/12.2/13.0 i386
• Compiler: Clang 10
• Rust version: 1.49.0 packaged downstream

Dependencies

I've used downstream package which builds fine at least on amd64.

The build output

From error log:

error: literal out of range for usize
   --> termwiz/src/cell.rs:371:17
    |
371 |                 0x7f000000_00000000
    |                 ^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[deny(overflowing_literals)]` on by default
    = note: the literal `0x7f000000_00000000` (decimal `9151314442816847872`) does not fit into the type `usize` and will become `0usize`

$ rustc --print cfg
debug_assertions
target_arch="x86"
target_endian="little"
target_env=""
target_family="unix"
target_os="freebsd"
target_pointer_width="32"
target_vendor="unknown"
unix

[wez]

Thanks for adding the wezterm port!

re: 32-bit: supporting it hasn't been an active goal thus far, but I don't believe that there have been any deliberate choices that prevent it from working (except perhaps on Windows where the PTY stuff requires additional binaries to work).

what's curious is that the line in that error message is in the target_pointer_width=64 case of some code that should in theory be doing the right thing for 32-bit systems:

            if cfg!(target_pointer_width = "64") {
                0x7f000000_00000000
            } else if cfg!(target_pointer_width = "32") {
                0x7f000000
            } else if cfg!(target_pointer_width = "16") {
                0x7f00
            } else {
                panic!("unsupported target");
            }

https://github.com/wez/wezterm/blob/main/termwiz/src/cell.rs#L370-L378

I won't have time to investigate this further for a few days.

[valpackett]

Oh.. well that's not correct!

if cfg!(..) will still compile all branches on all cfg's (it's just a plain if!), and only eliminate branches in the optimization phase (because the values are constants).

Use the cfg_if macro.

[jbeich]

Confirmed and applied the fix downstream.

[github-actions]

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