Remove unsized arg handling in ArgAbiBuilderMethods::store_fn_arg implementations
#146485
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Rollup of 7 pull requests Successful merges: - #146458 (Add parallel-frontend-threads to bootstrap.toml and enable multi-threaded parallel compilation) - #146485 (Remove unsized arg handling in `ArgAbiBuilderMethods::store_fn_arg` implementations) - #146536 (clean up several trait related UI tests) - #146598 (Make llvm_enzyme a regular cargo feature) - #146647 (Move `#[rustc_coherence_is_core]` to the `crate_level` file) - #146654 (Do not use `git -C dir`) - #146681 (Add space after brace in `Box<[T]>::new_uninit_slice` example) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup merge of #146485 - zachs18:store_fn_arg-no-unsized, r=davidtwco Remove unsized arg handling in `ArgAbiBuilderMethods::store_fn_arg` implementations ... since it is unreachable and would ICE anyway. These branches are unreachable with how `store_fn_arg` is currently used (where it is called, unsized arguments are either: 1. not (yet) supported, or 2. handled differently)[^1], and even if they were reachable, they would ICE anyway, since they call [`OperandValue::store`](https://doc.rust-lang.org/nightly/nightly-rustc/src/rustc_codegen_ssa/mir/operand.rs.html#855-861), which calls [`OperandValue::store_with_flags`](https://doc.rust-lang.org/nightly/nightly-rustc/src/rustc_codegen_ssa/mir/operand.rs.html#887-926) which [panics on any unsized layout](https://doc.rust-lang.org/nightly/nightly-rustc/src/rustc_codegen_ssa/mir/operand.rs.html#900-903). Also updates the `bug!` message in `store_arg` to not suggest `store_fn_arg` for unsized args. [^1]: `store_fn_arg` is only nontrivially[^2] called in `compiler/rustc_codegen_ssa/src/mir/mod.rs` for: Line 428 `extern "rust-call"` tuple (un)splitting, which does not support unsized arguments, Line 496 which is only for sized `PassMode::Indirect` (`meta_attrs: None`) arguments, and Line 521 which is only for non-`PassMode::Indirect` arguments which can never be unsized. [^2]: `<Bx as ArgAbiBuilderMethods>::store_fn_arg` is what is actually called, but codegen_llvm and codegen_gcc's builders both delegate to their own `codegen_crate::ArgAbiExt::store_fn_arg`, which contain the actual implementations that are changed in this PR.
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…zelmann Rollup of 7 pull requests Successful merges: - rust-lang#146458 (Add parallel-frontend-threads to bootstrap.toml and enable multi-threaded parallel compilation) - rust-lang#146485 (Remove unsized arg handling in `ArgAbiBuilderMethods::store_fn_arg` implementations) - rust-lang#146536 (clean up several trait related UI tests) - rust-lang#146598 (Make llvm_enzyme a regular cargo feature) - rust-lang#146647 (Move `#[rustc_coherence_is_core]` to the `crate_level` file) - rust-lang#146654 (Do not use `git -C dir`) - rust-lang#146681 (Add space after brace in `Box<[T]>::new_uninit_slice` example) r? `@ghost` `@rustbot` modify labels: rollup
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... since it is unreachable and would ICE anyway.
These branches are unreachable with how
store_fn_argis currently used (where it is called, unsized arguments are either: 1. not (yet) supported, or 2. handled differently)1, and even if they were reachable, they would ICE anyway, since they callOperandValue::store, which callsOperandValue::store_with_flagswhich panics on any unsized layout.Also updates the
bug!message instore_argto not suggeststore_fn_argfor unsized args.Footnotes
store_fn_argis only nontrivially2 called incompiler/rustc_codegen_ssa/src/mir/mod.rsfor: Line 428extern "rust-call"tuple (un)splitting, which does not support unsized arguments, Line 496 which is only for sizedPassMode::Indirect(meta_attrs: None) arguments, and Line 521 which is only for non-PassMode::Indirectarguments which can never be unsized. ↩<Bx as ArgAbiBuilderMethods>::store_fn_argis what is actually called, but codegen_llvm and codegen_gcc's builders both delegate to their owncodegen_crate::ArgAbiExt::store_fn_arg, which contain the actual implementations that are changed in this PR. ↩