bors bd53aa3bf7 Auto merge of #129317 - compiler-errors:expectation-subtyping, r=lcnr ... Use equality when relating formal and expected type in arg checking #129059 uncovered an interesting issue in argument checking. When we check arguments, we create three sets of types: * Formals * Expected * Actuals The **actuals** are the types of the argument expressions themselves. The **formals** are the types from the signature that we're checking. The **expected** types are the formal types, but passed through `expected_inputs_for_expected_outputs`: a971212545/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs (L691-L725) This method attempts to constrain the formal inputs by relating the [expectation](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir_typeck/expectation/enum.Expectation.html) of the call expression and the formal output. When we check an argument, we get the expression's actual type, and then we first attempt to coerce it to the expected type: a971212545/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs (L280-L293) Then we subtype the expected type and the formal type: a971212545/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs (L299-L305) However, since we are now recording the right coercion target (since #129059), we now end up recording the expected type to the typeck results, rather than the actual. Since that expected type was [fudged](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_infer/infer/struct.InferCtxt.html#method.fudge_inference_if_ok), it has fresh variables. And since the expected type is only subtyped against the formal type, if that expected type has a bivariant parameter, it will likely remain unconstrained since `Covariant * Bivariant = Bivariant` according to [xform](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/enum.Variance.html#method.xform). This leads to an unconstrained type variable in writeback. AFAICT, there's no reason for us to be using subtyping here, though. The expected output is already related to the expectation by subtyping: a971212545/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs (L713) So the formals don't need "another" indirection of subtyping in the argument checking... So I've changed it to use equality here. We could alternatively fix this by requiring WF for all the expected types to constrain their bivariant parameters, but this seems a bit overkill. Fixes #129286		2024-09-02 16:08:50 +00:00
..
rustc	Link std statically in rustc_driver	2024-08-11 04:16:53 +02:00
rustc_abi	ABI compat check: detect unadjusted ABI mismatches	2024-08-27 09:04:59 +02:00
rustc_arena	compiler: Remove feature(new_uninit)	2024-08-27 10:17:05 -07:00
rustc_ast	Create opaque definitions in resolver.	2024-08-31 20:14:43 +00:00
rustc_ast_ir	Add warn(unreachable_pub) to several crates.	2024-08-16 08:46:13 +10:00
rustc_ast_lowering	Rollup merge of #129493 - cjgillot:early-opaque-def, r=petrochenkov	2024-09-01 03:58:04 +02:00
rustc_ast_passes	Create opaque definitions in resolver.	2024-08-31 20:14:43 +00:00
rustc_ast_pretty	Add warn(unreachable_pub) to rustc_ast_pretty.	2024-08-16 08:46:46 +10:00
rustc_attr	Rollup merge of #126013 - nnethercote:unreachable_pub, r=Urgau	2024-08-27 00:41:57 +02:00
rustc_baked_icu_data	Don't add warn(unreachable_pub) to rustc_baked_icu.	2024-08-16 08:46:52 +10:00
rustc_borrowck	Rollup merge of #129767 - nnethercote:rm-extern-crate-tracing-4, r=jieyouxu	2024-08-31 14:46:11 +02:00
rustc_builtin_macros	Rollup merge of #123940 - kornelski:remove-derived-debug, r=Urgau	2024-08-29 16:21:46 +02:00
rustc_codegen_cranelift	introduce PrettyPrintMirOptions for cosmetic MIR dump options	2024-08-30 07:07:28 +00:00
rustc_codegen_gcc	Rollup merge of #128731 - RalfJung:simd-shuffle-vector, r=workingjubilee	2024-08-27 01:46:50 -05:00
rustc_codegen_llvm	interpret, codegen: tweak some comments and checks regarding Box with custom allocator	2024-08-31 11:29:02 +02:00
rustc_codegen_ssa	Revert "Auto merge of #127537 - veluca93:struct_tf, r=BoxyUwU"	2024-09-01 16:35:53 +02:00
rustc_const_eval	Auto merge of #129831 - matthiaskrgr:rollup-befq6zx, r=matthiaskrgr	2024-08-31 20:59:27 +00:00
rustc_data_structures	Update stacker to 0.1.17	2024-08-28 15:02:41 -07:00
rustc_driver	Use tidy to sort crate attributes for all compiler crates.	2024-06-12 15:49:10 +10:00
rustc_driver_impl	Rollup merge of #129667 - dev-ardi:rustc_driver-cleanup, r=michaelwoerister	2024-08-28 17:12:19 +02:00
rustc_error_codes	Add warn(unreachable_pub) to rustc_error_codes.	2024-08-27 11:49:59 +10:00
rustc_error_messages	Add warn(unreachable_pub) to rustc_error_messages.	2024-08-27 11:52:08 +10:00
rustc_errors	Remove attr_id from stable lint ids.	2024-08-31 14:01:07 +00:00
rustc_expand	Add warn(unreachable_pub) to rustc_expand.	2024-08-27 12:40:38 +10:00
rustc_feature	Revert "Auto merge of #127537 - veluca93:struct_tf, r=BoxyUwU"	2024-09-01 16:35:53 +02:00
rustc_fluent_macro	Add warn(unreachable_pub) to rustc_fluent_macro.	2024-08-27 12:56:54 +10:00
rustc_fs_util	Reformat use declarations.	2024-07-29 08:26:52 +10:00
rustc_graphviz	Add warn(unreachable_pub) to rustc_graphviz.	2024-08-27 12:58:29 +10:00
rustc_hir	Revert "Auto merge of #127537 - veluca93:struct_tf, r=BoxyUwU"	2024-09-01 16:35:53 +02:00
rustc_hir_analysis	Rollup merge of #129767 - nnethercote:rm-extern-crate-tracing-4, r=jieyouxu	2024-08-31 14:46:11 +02:00
rustc_hir_pretty	Add warn(unreachable_pub) to rustc_hir_pretty.	2024-08-27 13:25:40 +10:00
rustc_hir_typeck	Auto merge of #129317 - compiler-errors:expectation-subtyping, r=lcnr	2024-09-02 16:08:50 +00:00
rustc_incremental	Add warn(unreachable_pub) to rustc_incremental.	2024-08-27 14:30:20 +10:00
rustc_index	Rollup merge of #129401 - workingjubilee:partial-initialization-of-stabilization, r=dtolnay,joboet	2024-08-28 19:12:52 -07:00
rustc_index_macros	Remove usage of specialization from newtype_index!	2024-06-30 16:42:53 +00:00
rustc_infer	Rollup merge of #129767 - nnethercote:rm-extern-crate-tracing-4, r=jieyouxu	2024-08-31 14:46:11 +02:00
rustc_interface	make -Z mir-include-spans a dedicated enum	2024-08-30 07:14:19 +00:00
rustc_lexer	Add warn(unreachable_pub) to rustc_lexer.	2024-08-27 15:12:46 +10:00
rustc_lint	Rollup merge of #129678 - compiler-errors:type-ir-inherent, r=fmease	2024-09-02 04:19:28 +02:00
rustc_lint_defs	Auto merge of #127313 - cjgillot:single-expect, r=jieyouxu	2024-09-01 15:50:48 +00:00
rustc_llvm	Rollup merge of #129749 - krasimirgg:llvm-20-lto, r=nikic	2024-08-31 14:46:09 +02:00
rustc_log	Reformat use declarations.	2024-07-29 08:26:52 +10:00
rustc_macros	Add warn(unreachable_pub) to rustc_metadata.	2024-08-29 20:13:06 +10:00
rustc_metadata	Revert "Auto merge of #127537 - veluca93:struct_tf, r=BoxyUwU"	2024-09-01 16:35:53 +02:00
rustc_middle	Auto merge of #129854 - Kobzol:revert-127537, r=lqd	2024-09-01 19:46:46 +00:00
rustc_mir_build	Revert "Auto merge of #127537 - veluca93:struct_tf, r=BoxyUwU"	2024-09-01 16:35:53 +02:00
rustc_mir_dataflow	Add warn(unreachable_pub) to rustc_mir_dataflow.	2024-08-29 20:13:06 +10:00
rustc_mir_transform	Rollup merge of #129738 - nnethercote:rustc_mir_transform-cleanups, r=cjgillot	2024-09-02 04:19:28 +02:00
rustc_monomorphize	Add warn(unreachable_pub) to rustc_monomorphize.	2024-08-29 20:13:06 +10:00
rustc_next_trait_solver	Deny imports of rustc_type_ir::inherent outside of type ir + new trait solver	2024-09-01 12:16:18 -04:00
rustc_parse	Rollup merge of #120221 - compiler-errors:statements-are-not-patterns, r=nnethercote	2024-08-31 10:08:51 +02:00
rustc_parse_format	Add warn(unreachable_pub) to rustc_parse_format.	2024-08-29 20:13:06 +10:00
rustc_passes	Revert "Auto merge of #127537 - veluca93:struct_tf, r=BoxyUwU"	2024-09-01 16:35:53 +02:00
rustc_pattern_analysis	Add warn(unreachable_pub) to rustc_pattern_analysis.	2024-08-29 20:18:44 +10:00
rustc_privacy	Add warn(unreachable_pub) to rustc_privacy.	2024-08-29 20:18:44 +10:00
rustc_query_impl	Add warn(unreachable_pub) to rustc_query_impl.	2024-08-29 20:18:44 +10:00
rustc_query_system	Add warn(unreachable_pub) to rustc_query_system.	2024-08-29 20:18:44 +10:00
rustc_resolve	Replace walk with visit so we dont skip outermost expr kind in def collector	2024-09-01 11:16:50 -04:00
rustc_sanitizers	Rollup merge of #129345 - compiler-errors:scratch4, r=jieyouxu	2024-08-21 18:15:06 +02:00
rustc_serialize	Reformat use declarations.	2024-07-29 08:26:52 +10:00
rustc_session	make -Z mir-include-spans a dedicated enum	2024-08-30 07:14:19 +00:00
rustc_smir	Stop using a special inner body for the coroutine by-move body for async closures	2024-08-26 18:44:19 -04:00
rustc_span	Revert "Auto merge of #127537 - veluca93:struct_tf, r=BoxyUwU"	2024-09-01 16:35:53 +02:00
rustc_symbol_mangling	Stop using a special inner body for the coroutine by-move body for async closures	2024-08-26 18:44:19 -04:00
rustc_target	Rollup merge of #129842 - no1wudi:master, r=saethlin	2024-09-02 04:19:30 +02:00
rustc_trait_selection	Revert "Auto merge of #127537 - veluca93:struct_tf, r=BoxyUwU"	2024-09-01 16:35:53 +02:00
rustc_traits	Remove redundant type ops	2024-08-14 14:18:17 -04:00
rustc_transmute	Removes dead code from the compiler	2024-08-25 13:41:39 +08:00
rustc_ty_utils	Auto merge of #128506 - compiler-errors:by-move-body, r=cjgillot	2024-08-27 23:30:24 +00:00
rustc_type_ir	Deny imports of rustc_type_ir::inherent outside of type ir + new trait solver	2024-09-01 12:16:18 -04:00
rustc_type_ir_macros	Reformat use declarations.	2024-07-29 08:26:52 +10:00
stable_mir	Introduce methods for obtaining Location for statements and terminators	2024-08-23 12:45:38 -04:00