Rollup merge of #132574 - workingjubilee:abi-in-compiler, r=compiler-errors

compiler: Directly use rustc_abi almost everywhere

Use rustc_abi instead of rustc_target where applicable. This is mostly described by the following substitutions:
```rust
match path_substring {
    rustc_target::spec::abi::Abi => rustc_abi::ExternAbi,
    rustc_target::abi::call => rustc_target::callconv,
    rustc_target::abi => rustc_abi,
}
```

A number of spot-fixes make that not quite the whole story.

The main exception is in 33edc68 where I get a lot more persnickety about how things are imported, especially in `rustc_middle::ty::layout`, not just from where. This includes putting an end to a reexport of `rustc_middle::ty::ReprOptions`, for the same reason that the rest of this change is happening: reexports mostly confound things.

This notably omits rustc_passes and the ast crates, as I'm still examining a question I have about how they do stability checking of `extern "Abi"` strings and if I can simplify their logic. The rustc_abi and rustc_target crates also go untouched because they will be entangled in that cleanup.

r? compiler-errors

compiler/rustc_hir_analysis/src/check/check.rs

@@ -37,7 +37,7 @@ use super::compare_impl_item::{check_type_bounds, compare_impl_method, compare_i
 use super::*;
 use crate::check::intrinsicck::InlineAsmCtxt;
 
-pub fn check_abi(tcx: TyCtxt<'_>, span: Span, abi: Abi) {
+pub fn check_abi(tcx: TyCtxt<'_>, span: Span, abi: ExternAbi) {
     if !tcx.sess.target.is_abi_supported(abi) {
         struct_span_code_err!(
             tcx.dcx(),
@@ -49,7 +49,7 @@ pub fn check_abi(tcx: TyCtxt<'_>, span: Span, abi: Abi) {
     }
 }
 
-pub fn check_abi_fn_ptr(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) {
+pub fn check_abi_fn_ptr(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: ExternAbi) {
     if !tcx.sess.target.is_abi_supported(abi) {
         tcx.node_span_lint(UNSUPPORTED_FN_PTR_CALLING_CONVENTIONS, hir_id, span, |lint| {
             lint.primary_message(format!(
@@ -628,7 +628,7 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) {
                     def_id,
                     tcx.def_ident_span(def_id).unwrap(),
                     i.name,
-                    Abi::Rust,
+                    ExternAbi::Rust,
                 )
             }
             // Everything else is checked entirely within check_item_body
@@ -699,7 +699,7 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) {
             check_abi(tcx, it.span, abi);
 
             match abi {
-                Abi::RustIntrinsic => {
+                ExternAbi::RustIntrinsic => {
                     for item in items {
                         intrinsic::check_intrinsic_type(
                             tcx,

compiler/rustc_hir_analysis/src/check/entry.rs

@@ -1,5 +1,6 @@
 use std::ops::Not;
 
+use rustc_abi::ExternAbi;
 use rustc_hir as hir;
 use rustc_hir::Node;
 use rustc_infer::infer::TyCtxtInferExt;
@@ -9,7 +10,6 @@ use rustc_session::config::EntryFnType;
 use rustc_span::Span;
 use rustc_span::def_id::{CRATE_DEF_ID, DefId, LocalDefId};
 use rustc_span::symbol::sym;
-use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode};
 
@@ -158,7 +158,7 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
         expected_return_type,
         false,
         hir::Safety::Safe,
-        Abi::Rust,
+        ExternAbi::Rust,
     ));
 
     if check_function_signature(
@@ -254,7 +254,7 @@ fn check_start_fn_ty(tcx: TyCtxt<'_>, start_def_id: DefId) {
                 tcx.types.isize,
                 false,
                 hir::Safety::Safe,
-                Abi::Rust,
+                ExternAbi::Rust,
             ));
 
             let _ = check_function_signature(

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -1,6 +1,7 @@
 //! Type-checking for the rust-intrinsic and platform-intrinsic
 //! intrinsics that the compiler exposes.
 
+use rustc_abi::ExternAbi;
 use rustc_errors::codes::*;
 use rustc_errors::{DiagMessage, struct_span_code_err};
 use rustc_hir as hir;
@@ -10,7 +11,6 @@ use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::sym;
 use rustc_span::{Span, Symbol};
-use rustc_target::spec::abi::Abi;
 
 use crate::check::check_function_signature;
 use crate::errors::{
@@ -163,7 +163,7 @@ pub fn check_intrinsic_type(
     intrinsic_id: LocalDefId,
     span: Span,
     intrinsic_name: Symbol,
-    abi: Abi,
+    abi: ExternAbi,
 ) {
     let generics = tcx.generics_of(intrinsic_id);
     let param = |n| {
@@ -533,14 +533,14 @@ pub fn check_intrinsic_type(
                     tcx.types.unit,
                     false,
                     hir::Safety::Safe,
-                    Abi::Rust,
+                    ExternAbi::Rust,
                 ));
                 let catch_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
                     [mut_u8, mut_u8],
                     tcx.types.unit,
                     false,
                     hir::Safety::Safe,
-                    Abi::Rust,
+                    ExternAbi::Rust,
                 ));
                 (
                     0,

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -74,7 +74,7 @@ pub mod wfcheck;
 use std::num::NonZero;
 
 pub use check::{check_abi, check_abi_fn_ptr};
-use rustc_abi::VariantIdx;
+use rustc_abi::{ExternAbi, VariantIdx};
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_errors::{Diag, ErrorGuaranteed, pluralize, struct_span_code_err};
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -91,7 +91,6 @@ use rustc_session::parse::feature_err;
 use rustc_span::def_id::CRATE_DEF_ID;
 use rustc_span::symbol::{Ident, kw, sym};
 use rustc_span::{BytePos, DUMMY_SP, Span, Symbol};
-use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::error_reporting::infer::ObligationCauseExt as _;
 use rustc_trait_selection::error_reporting::traits::suggestions::ReturnsVisitor;
@@ -142,8 +141,8 @@ fn get_owner_return_paths(
 /// Forbid defining intrinsics in Rust code,
 /// as they must always be defined by the compiler.
 // FIXME: Move this to a more appropriate place.
-pub fn forbid_intrinsic_abi(tcx: TyCtxt<'_>, sp: Span, abi: Abi) {
-    if let Abi::RustIntrinsic = abi {
+pub fn forbid_intrinsic_abi(tcx: TyCtxt<'_>, sp: Span, abi: ExternAbi) {
+    if let ExternAbi::RustIntrinsic = abi {
         tcx.dcx().span_err(sp, "intrinsic must be in `extern \"rust-intrinsic\" { ... }` block");
     }
 }

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -2,6 +2,7 @@ use std::cell::LazyCell;
 use std::ops::{ControlFlow, Deref};
 
 use hir::intravisit::{self, Visitor};
+use rustc_abi::ExternAbi;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_errors::codes::*;
 use rustc_errors::{Applicability, ErrorGuaranteed, pluralize, struct_span_code_err};
@@ -23,7 +24,6 @@ use rustc_middle::{bug, span_bug};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::{Ident, sym};
 use rustc_span::{DUMMY_SP, Span};
-use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::regions::InferCtxtRegionExt;
 use rustc_trait_selection::traits::misc::{
@@ -1644,7 +1644,7 @@ fn check_fn_or_method<'tcx>(
 
     check_where_clauses(wfcx, span, def_id);
 
-    if sig.abi == Abi::RustCall {
+    if sig.abi == ExternAbi::RustCall {
         let span = tcx.def_span(def_id);
         let has_implicit_self = hir_decl.implicit_self != hir::ImplicitSelfKind::None;
         let mut inputs = sig.inputs().iter().skip(if has_implicit_self { 1 } else { 0 });