Start using pattern types in libcore

[oli-obk]

cc #135996

[compiler-errors]

Well r=me when/if it does get unblocked.

[scottmcm]

Unsure: at least for the NonZeroBlahInner ones, it'd be nicer if these could just be type $name = pattern_type!($int is $low..=$high);, without the extra wrapper. Is that feasible, or are the trait implementations too far off?

(Relatedly, I'd love to be able to just derive traits on these again, particularly to not have to manually StructuralPartialEq.)

[oli-obk]

Yea... I wanna get there, but directly using pattern types is not a great experience at present

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[Veykril]

Re rust-analyzer blocker, as it turns out to implement pattern types (to a degree that would unblock this) it comes down to the same architecture changes required as for rust-lang/rust-analyzer#7434 (which I am currently looking into), so that will take a bit.

[rustbot]

Some changes occurred to the CTFE machinery

cc @rust-lang/wg-const-eval

Some changes occurred to the CTFE / Miri interpreter

cc @rust-lang/miri

[rustbot]

This PR changes rustc_public

cc @oli-obk, @celinval, @ouz-a

[bors]

☔ The latest upstream changes (presumably #144249) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #143897) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #144814) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #142771) made this pull request unmergeable. Please resolve the merge conflicts.

[rustbot]

This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[rustbot]

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo, @GuillaumeGomez

[rust-log-analyzer]

The job aarch64-gnu-llvm-20-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[BUILD] mini_core
error: cannot find macro `pattern_type` in this scope
##[error]   --> example/mini_core.rs:575:41
    |
575 | pub struct NonNull<T: PointeeSized>(pub pattern_type!(*const T is !null));
    |                                         ^^^^^^^^^^^^

error[E0635]: unknown feature `pattern_type`
##[error]  --> example/mini_core.rs:11:5
   |
---

error[E0374]: implementing `CoerceUnsized` requires a field to be coerced
##[error]   --> example/mini_core.rs:577:1
    |
577 | impl<T: PointeeSized, U: PointeeSized> CoerceUnsized<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: expected a single field to be coerced, none found

error[E0392]: type parameter `T` is never used
##[error]   --> example/mini_core.rs:575:20
    |
575 | pub struct NonNull<T: PointeeSized>(pub pattern_type!(*const T is !null));
    |                    ^ unused type parameter
    |
    = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`

error[E0308]: mismatched types
##[error]   --> example/mini_core.rs:602:43
    |
602 |             Box(Unique { pointer: NonNull(ptr as *const T), _marker: PhantomData }, Global)
    |                                   ------- ^^^^^^^^^^^^^^^ expected `()`, found `*const T`
    |                                   |
    |                                   arguments to this struct are incorrect
    |
    = note: expected unit type `()`
             found raw pointer `*const T`
note: tuple struct defined here
   --> example/mini_core.rs:575:12
    |
575 | pub struct NonNull<T: PointeeSized>(pub pattern_type!(*const T is !null));
    |            ^^^^^^^

error[E0605]: non-primitive cast: `()` as `*mut u8`
##[error]   --> example/mini_core.rs:611:24
    |
611 |             libc::free(self.0.pointer.0 as *mut u8);
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object

error: aborting due to 7 previous errors

Some errors have detailed explanations: E0308, E0374, E0392, E0605, E0635.
For more information about an error, try `rustc --explain E0308`.
"/checkout/obj/build/aarch64-unknown-linux-gnu/stage2-codegen/cg_clif/dist/rustc-clif" "-Csymbol-mangling-version=v0" "-Zrandomize-layout" "-Zunstable-options" "--check-cfg=cfg(bootstrap)" "-Zmacro-backtrace" "-Csplit-debuginfo=off" "-Clink-arg=-L/usr/lib/llvm-20/lib" "-Cllvm-args=-import-instr-limit=10" "-Clink-args=-Wl,-z,origin" "-Clink-args=-Wl,-rpath,$ORIGIN/../lib" "-Alinker-messages" "-L" "crate=/checkout/obj/build/aarch64-unknown-linux-gnu/stage2-codegen/cg_clif/build/example" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2-codegen/cg_clif/build/example" "-Cdebuginfo=2" "--target" "aarch64-unknown-linux-gnu" "-Cpanic=abort" "--check-cfg=cfg(jit)" "example/mini_core.rs" "--crate-type" "lib,dylib" exited with status ExitStatus(unix_wait_status(256))
Command `/checkout/obj/build/aarch64-unknown-linux-gnu/stage0/bin/cargo run --target aarch64-unknown-linux-gnu -Zbinary-dep-depinfo -j 4 -Zroot-dir=/checkout --locked --color always --release --manifest-path /checkout/compiler/rustc_codegen_cranelift/build_system/Cargo.toml -- test --download-dir /checkout/obj/build/cg_clif_download --out-dir /checkout/obj/build/aarch64-unknown-linux-gnu/stage2-codegen/cg_clif --no-unstable-features --use-backend cranelift --sysroot llvm --skip-test testsuite.extended_sysroot [workdir=/checkout/compiler/rustc_codegen_cranelift]` failed with exit code 1
Created at: src/bootstrap/src/core/build_steps/test.rs:3689:25
Executed at: src/bootstrap/src/core/build_steps/test.rs:3734:26

Command has failed. Rerun with -v to see more details.
Bootstrap failed while executing `--stage 2 test --skip tests --skip coverage-map --skip coverage-run --skip library --skip tidyselftest`
Build completed unsuccessfully in 0:20:21
  local time: Tue Oct 28 12:22:27 UTC 2025
  network time: Tue, 28 Oct 2025 12:22:27 GMT
##[error]Process completed with exit code 1.