Rollup merge of rust-lang#99058 - michaelwoerister:remove-stable-set-and-map, r=nagisa

Remove the unused StableSet and StableMap types from rustc_data_structures.

The current implementation is not "stable" in the same sense that `HashStable` and `StableHasher` are stable, i.e. across compilation sessions. So, in my opinion, it's better to remove those types (which are basically unused anyway) than to give the wrong impression that these are safe for incr. comp.

I plan to provide new "stable" collection types soon that can be used to replace `FxHashMap` and `FxHashSet` in query results (see [draft](michaelwoerister@69d03ac)). It's unsound that `HashMap` and `HashSet` implement `HashStable` (see rust-lang#98890 for a recent P-critical bug caused by this) -- so we should make some progress there.

Author: Dylan-DPC

compiler/rustc_ast_lowering/src/asm.rs

@@ -4,8 +4,7 @@ use super::LoweringContext;
 
 use rustc_ast::ptr::P;
 use rustc_ast::*;
-use rustc_data_structures::fx::FxHashMap;
-use rustc_data_structures::stable_set::FxHashSet;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -1,6 +1,6 @@
 //! Error reporting machinery for lifetime errors.
 
-use rustc_data_structures::stable_set::FxHashSet;
+use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, MultiSpan};
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::Visitor;

compiler/rustc_codegen_gcc/src/abi.rs

@@ -1,6 +1,6 @@
 use gccjit::{ToLValue, ToRValue, Type};
 use rustc_codegen_ssa::traits::{AbiBuilderMethods, BaseTypeMethods};
-use rustc_data_structures::stable_set::FxHashSet;
+use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::bug;
 use rustc_middle::ty::Ty;
 use rustc_target::abi::call::{CastTarget, FnAbi, PassMode, Reg, RegKind};

compiler/rustc_codegen_gcc/src/builder.rs

@@ -30,7 +30,7 @@ use rustc_codegen_ssa::traits::{
     OverflowOp,
     StaticBuilderMethods,
 };
-use rustc_data_structures::stable_set::FxHashSet;
+use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
 use rustc_middle::ty::layout::{FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasParamEnv, HasTyCtxt, LayoutError, LayoutOfHelpers, TyAndLayout};
 use rustc_span::Span;

compiler/rustc_data_structures/src/lib.rs

@@ -61,12 +61,10 @@ pub mod sip128;
 pub mod small_c_str;
 pub mod small_str;
 pub mod snapshot_map;
-pub mod stable_map;
 pub mod svh;
 pub use ena::snapshot_vec;
 pub mod memmap;
 pub mod sorted_map;
-pub mod stable_set;
 #[macro_use]
 pub mod stable_hasher;
 mod atomic_ref;

compiler/rustc_data_structures/src/stable_map.rs

@@ -3,7 +3,7 @@ use crate::{
     CodeSuggestion, DiagnosticMessage, EmissionGuarantee, Level, LintDiagnosticBuilder, MultiSpan,
     SubdiagnosticMessage, Substitution, SubstitutionPart, SuggestionStyle,
 };
-use rustc_data_structures::stable_map::FxHashMap;
+use rustc_data_structures::fx::FxHashMap;
 use rustc_error_messages::FluentValue;
 use rustc_hir as hir;
 use rustc_lint_defs::{Applicability, LintExpectationId};

compiler/rustc_data_structures/src/stable_set.rs

@@ -11,7 +11,7 @@ use crate::def_id::DefId;
 use crate::{MethodKind, Target};
 
 use rustc_ast as ast;
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_macros::HashStable_Generic;
 use rustc_span::symbol::{kw, sym, Symbol};
@@ -134,8 +134,8 @@ macro_rules! language_item_table {
         }
 
         /// A mapping from the name of the lang item to its order and the form it must be of.
-        pub static ITEM_REFS: LazyLock<FxHashMap<Symbol, (usize, Target)>> = LazyLock::new(|| {
-            let mut item_refs = FxHashMap::default();
+        pub static ITEM_REFS: LazyLock<FxIndexMap<Symbol, (usize, Target)>> = LazyLock::new(|| {
+            let mut item_refs = FxIndexMap::default();
             $( item_refs.insert($module::$name, (LangItem::$variant as usize, $target)); )*
             item_refs
         });

compiler/rustc_errors/src/diagnostic.rs

@@ -1,7 +1,7 @@
 use crate::def::{CtorOf, DefKind, Res};
 use crate::def_id::DefId;
 use crate::hir::{self, HirId, PatKind};
-use rustc_data_structures::stable_set::FxHashSet;
+use rustc_data_structures::fx::FxHashSet;
 use rustc_span::hygiene::DesugaringKind;
 use rustc_span::symbol::Ident;
 use rustc_span::Span;