Declare rustc_target's dependency on object/macho

[dtolnay]

Without this, cargo check fails in crates that depend on rustc_target.

`cargo check` diagnostics

    Checking rustc_target v0.0.0
error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:176:17
    |
176 |         object::macho::PLATFORM_MACOS => Some((13, 1)),
    |                 ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:177:17
    |
177 |         object::macho::PLATFORM_IOS
    |                 ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:178:19
    |
178 |         | object::macho::PLATFORM_IOSSIMULATOR
    |                   ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:179:19
    |
179 |         | object::macho::PLATFORM_TVOS
    |                   ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:180:19
    |
180 |         | object::macho::PLATFORM_TVOSSIMULATOR
    |                   ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:181:19
    |
181 |         | object::macho::PLATFORM_MACCATALYST => Some((16, 2)),
    |                   ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:182:17
    |
182 |         object::macho::PLATFORM_WATCHOS | object::macho::PLATFORM_WATCHOSSIMULATOR => Some((9, 1)),
    |                 ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:182:51
    |
182 |         object::macho::PLATFORM_WATCHOS | object::macho::PLATFORM_WATCHOSSIMULATOR => Some((9, 1)),
    |                                                   ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:189:33
    |
189 |         ("macos", _) => object::macho::PLATFORM_MACOS,
    |                                 ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:190:38
    |
190 |         ("ios", "macabi") => object::macho::PLATFORM_MACCATALYST,
    |                                      ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:191:35
    |
191 |         ("ios", "sim") => object::macho::PLATFORM_IOSSIMULATOR,
    |                                   ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:192:31
    |
192 |         ("ios", _) => object::macho::PLATFORM_IOS,
    |                               ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:193:39
    |
193 |         ("watchos", "sim") => object::macho::PLATFORM_WATCHOSSIMULATOR,
    |                                       ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:194:35
    |
194 |         ("watchos", _) => object::macho::PLATFORM_WATCHOS,
    |                                   ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:195:36
    |
195 |         ("tvos", "sim") => object::macho::PLATFORM_TVOSSIMULATOR,
    |                                    ^^^^^ could not find `macho` in `object`

error[E0433]: failed to resolve: could not find `macho` in `object`
   --> compiler/rustc_target/src/spec/apple_base.rs:196:32
    |
196 |         ("tvos", _) => object::macho::PLATFORM_TVOS,
    |                                ^^^^^ could not find `macho` in `object`

rustc_target unconditionally contains its spec module (i.e. there is no #[cfg] on the mod spec;). The spec/mod.rs also does not start with #![cfg].

rust/compiler/rustc_target/src/lib.rs

Line 37 in aa91057

pub mod spec;

Similarly, the spec module unconditionally contains apple_base.

rust/compiler/rustc_target/src/spec/mod.rs

Line 62 in aa91057

mod apple_base;

And, apple_base unconditionally refers to object::macho.

rust/compiler/rustc_target/src/spec/apple_base.rs

Line 176 in aa91057

object::macho::PLATFORM_MACOS => Some((13, 1)),

So I figure there is no way object::macho isn't needed by rustc.

object::macho only exists if the object crate's "macho" feature is enabled. https://github.com/gimli-rs/object/blob/0.32.0/src/lib.rs#L111-L112

[rustbot]

r? @b-naber

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[dtolnay]

Bisects to #114114.

[Noratrieb]

r? Nilstrieb
@bors r+ rollup

I don't think we really intend to support this, but this is a clear fix in any case, thanks!

[bors]

📌 Commit 0a82920 has been approved by Nilstrieb

It is now in the queue for this repository.