Upgrade rust 1.94

[Ziqiao Zhou (ziqiaozhou)]

No description provided.

[Copilot]

Pull request overview

This PR updates the in-tree rustc_codegen_ssa shim and the out-of-tree GPU codegen crates to build against a newer nightly toolchain (Rust 1.94 era), adapting to upstream rustc API/MIR changes and adding a few new backend hooks needed by the newer compiler.

Changes:

• Bump the pinned toolchain (rust-toolchain.toml) and update CI ordering to ensure the crates workspace builds on the new nightly.
• Align codegen and linker/back-end glue with upstream API changes (e.g., Arch/Os/Env/Abi enums, providers.queries, MIR operand changes, diagnostics transport).
• Introduce new codegen hooks/behaviors (LLVM intrinsic call hook, scalable alloca support point, move/copy profiling annotations).

Reviewed changes

Copilot reviewed 44 out of 44 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
rust/compiler/rustc_codegen_ssa/src/traits/intrinsic.rs	Add backend hook for direct LLVM intrinsic calls; adjust VaList wording.
rust/compiler/rustc_codegen_ssa/src/traits/debuginfo.rs	Make DebugInfoBuilderMethods generic over 'tcx; add move-annotation hook.
rust/compiler/rustc_codegen_ssa/src/traits/builder.rs	Thread 'tcx into DebugInfoBuilderMethods; add scalable_alloca API.
rust/compiler/rustc_codegen_ssa/src/traits/backend.rs	Add supported_crate_types/has_zstd defaults; import CrateType.
rust/compiler/rustc_codegen_ssa/src/target_features.rs	Refactor target-feature parsing; add validity checks; split target-spec vs -Ctarget-feature handling.
rust/compiler/rustc_codegen_ssa/src/mir/rvalue.rs	Route stores through move/copy annotation; adjust MIR pattern changes.
rust/compiler/rustc_codegen_ssa/src/mir/place.rs	Use runtime-sized/scalable-vector aware alloca path when needed.
rust/compiler/rustc_codegen_ssa/src/mir/operand.rs	Add move_annotation field and annotated store helper; extend vector ABI handling.
rust/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs	Use Arch enum; hard error on internal linkage for naked fns.
rust/compiler/rustc_codegen_ssa/src/mir/mod.rs	Initialize new move_annotation field for argument locals.
rust/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs	Use Arch enum; update valtree API; refine nullary intrinsic error text.
rust/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs	Avoid spilling certain scalable-vector predicate types on AArch64.
rust/compiler/rustc_codegen_ssa/src/mir/constant.rs	Update valtree API usage and simplify scalar extraction path.
rust/compiler/rustc_codegen_ssa/src/mir/block.rs	Add direct LLVM intrinsic-call codegen path; annotate stores; tailcall indirect-return check.
rust/compiler/rustc_codegen_ssa/src/lib.rs	Adjust crate-level attrs/imports; update provider wiring to providers.queries.
rust/compiler/rustc_codegen_ssa/src/errors.rs	Remove/adjust some diagnostics; add new BPF staticlib diagnostic; add NonScalableType monomorphization diagnostic.
rust/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs	Update internal FIXME comment tag.
rust/compiler/rustc_codegen_ssa/src/common.rs	Switch mingw-gnu detection to Os/Env/Abi enums.
rust/compiler/rustc_codegen_ssa/src/codegen_attrs.rs	Migrate instruction_set parsing to parsed attrs; implement EII attributes; switch sanitizer handling to SanitizerFnAttrs; add RTSAN lint.
rust/compiler/rustc_codegen_ssa/src/base.rs	Switch target OS/arch handling to enums; update allocator shim signature; update windows subsystem handling to parsed attrs.
rust/compiler/rustc_codegen_ssa/src/back/write.rs	Use session sanitizers; add GPU target flag; improve diagnostic transport (spans) and inline-asm error struct.
rust/compiler/rustc_codegen_ssa/src/back/symbol_export.rs	Update provider registration; adjust export semantics for compiler-builtins/EII; migrate arch/os checks to enums.
rust/compiler/rustc_codegen_ssa/src/back/metadata.rs	Update OS/ABI handling to enums; use stable target features sets for RISCV flags.
rust/compiler/rustc_codegen_ssa/src/back/linker.rs	Migrate to WindowsSubsystemKind; switch arch/os/abi comparisons to enums; improve wasm export handling; replace BPF staticlib panic with diagnostic.
rust/compiler/rustc_codegen_ssa/src/back/link/raw_dylib.rs	Switch x86 detection to Arch::X86.
rust/compiler/rustc_codegen_ssa/src/back/link.rs	Adjust tempdir placement; update linked crate source types; update config evaluation API; sanitizer runtime selection changes; windows subsystem type changes.
rust/compiler/rustc_codegen_ssa/src/back/archive.rs	Switch arch comparisons to enums; adjust which error types are re-exported.
rust/compiler/rustc_codegen_ssa/src/back/apple.rs	Switch OS/env/arch comparisons to enums for Apple SDK/platform handling.
rust/compiler/rustc_codegen_ssa/messages.ftl	Remove instruction_set/windows_subsystem messages; add BPF staticlib + NonScalableType messages.
rust-toolchain.toml	Bump pinned nightly to nightly-2026-01-17 (commented 1.94.0).
crates/rustc-gpu/src/driver.rs	Update provider hooking to providers.queries.*.
crates/rustc_codegen_gpu/src/mlir/mod.rs	Update prefer_local API usage.
crates/rustc_codegen_gpu/src/mir_thread_sync_check.rs	Adjust dataflow trait signatures (&self / results visitor API changes).
crates/rustc_codegen_gpu/src/mir_mut_arg_check.rs	Adjust dataflow trait signatures and reachable-results visitor API changes.
crates/rustc_codegen_gpu/src/mir_analysis.rs	Adjust dataflow trait signatures; introduce interior mutability for implicit-flow set.
crates/rustc_codegen_gpu/src/context/ty.rs	Update FieldsShape pattern; add ScalableVector match arm (currently unimplemented).
crates/rustc_codegen_gpu/src/context/mod.rs	Update prefer_local API usage.
crates/rustc_codegen_gpu/src/builder/mod.rs	Add scalable_alloca required trait method (currently unimplemented); propagate move_annotation field.
crates/rustc_codegen_gpu/src/builder/intrinsic.rs	Implement new LLVM-intrinsic hook as a hard error for GPU backend.
crates/rustc_codegen_gpu/src/builder/debug.rs	Update DebugInfoBuilderMethods impl to new 'tcx generic.
crates/rustc_codegen_gpu/src/builder/asm.rs	Switch target arch string acquisition to to_string().
crates/rustc_codegen_gpu/src/backend.rs	Switch target arch string acquisition to to_string().
crates/rustc_codegen_gpu/src/attr.rs	Expand panic-function allowlist.
.github/workflows/rust.yml	Reorder/insert cargo build --workspace step for crates workspace.

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[Copilot]

The documentation and the constant value disagree: the comment says the default move/copy annotation threshold is 64 bytes (cache line), but the constant is set to 65. Either update the constant to 64, or adjust the comment and/or the comparison logic so the documented threshold matches the actual behavior.

[Copilot]

target_spec_to_backend_features will panic! if the target spec features string contains an item without a leading +/-. That turns a user-provided/custom target spec mistake into an ICE. Please emit a proper diagnostic (ideally a fatal error pointing at the invalid target spec field) instead of panicking.

[Copilot]

operand_local leaves the new Operand::RuntimeChecks variant as todo!(), which will panic during MIR analysis if it is encountered. Please either treat it like Operand::Constant (return None), or handle it explicitly in a way that preserves the analysis invariants so GPU codegen doesn’t crash on MIR containing runtime-check operands.

Suggested change

	Operand::RuntimeChecks(runtime_checks) => todo!(),
	Operand::RuntimeChecks(_) => None,

[Copilot]

The if condition here is extremely long and currently formatted in a way that makes it difficult to read and review. Please refactor it (e.g. extract into a well-named boolean / helper) and/or reformat it to improve maintainability and reduce the risk of future mistakes when this logic changes.

Suggested change

	if
	// if this is a default impl
	i.is_default
	// iterate over all implementations *in the current crate*
	// (this is ok since we generate codegen fn attrs in the local crate)
	// if any of them is *not default* then don't emit the alias.
	&& tcx.externally_implementable_items(LOCAL_CRATE).get(&foreign_item).expect("at least one").1.iter().any(|(_, imp)| !imp.is_default)
	let has_non_default_impl_in_current_crate =
	tcx.externally_implementable_items(LOCAL_CRATE)
	// iterate over all implementations *in the current crate*
	// (this is ok since we generate codegen fn attrs in the local crate)
	// if any of them is *not default* then don't emit the alias.
	.get(&foreign_item)
	.expect("at least one")
	.1
	.iter()
	.any(|(_, imp)| !imp.is_default);
	if
	// if this is a default impl
	i.is_default && has_non_default_impl_in_current_crate