Auto merge of #90380 - Mark-Simulacrum:revert-89558-query-stable-lint, r=lcnr

Revert "Add rustc lint, warning when iterating over hashmaps"

Fixes perf regressions introduced in #90235 by temporarily reverting the relevant PR.

Author: bors

compiler/rustc_ast_lowering/src/lib.rs

@@ -35,7 +35,6 @@
 #![feature(iter_zip)]
 #![feature(never_type)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 use rustc_ast::token::{self, Token};
 use rustc_ast::tokenstream::{CanSynthesizeMissingTokens, TokenStream, TokenTree};

compiler/rustc_ast_passes/src/lib.rs

@@ -7,7 +7,6 @@
 #![feature(iter_is_partitioned)]
 #![feature(box_patterns)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 pub mod ast_validation;
 pub mod feature_gate;

compiler/rustc_borrowck/src/lib.rs

@@ -12,7 +12,6 @@
 #![feature(trusted_step)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate rustc_middle;

compiler/rustc_builtin_macros/src/lib.rs

@@ -11,7 +11,6 @@
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 extern crate proc_macro;
 

compiler/rustc_codegen_llvm/src/lib.rs

@@ -13,7 +13,6 @@
 #![feature(iter_zip)]
 #![feature(nll)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 use back::write::{create_informational_target_machine, create_target_machine};
 

compiler/rustc_codegen_ssa/src/lib.rs

@@ -8,7 +8,6 @@
 #![feature(nll)]
 #![feature(associated_type_bounds)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 //! This crate contains codegen code that is used by all codegen backends (LLVM and others).
 //! The backend-agnostic functions of this crate use functions defined in various traits that

compiler/rustc_const_eval/src/lib.rs

@@ -24,7 +24,6 @@ Rust MIR: a lowered representation of Rust.
 #![feature(trusted_step)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_data_structures/src/lib.rs

@@ -27,7 +27,6 @@
 #![feature(thread_id_value)]
 #![allow(rustc::default_hash_types)]
 #![deny(unaligned_references)]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_driver/src/lib.rs

@@ -8,7 +8,6 @@
 #![feature(nll)]
 #![feature(once_cell)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate tracing;
@@ -847,7 +846,7 @@ Available lint options:
     let builtin = sort_lints(sess, builtin);
 
     let (plugin_groups, builtin_groups): (Vec<_>, _) =
-        lint_store.get_lint_groups().partition(|&(.., p)| p);
+        lint_store.get_lint_groups().iter().cloned().partition(|&(.., p)| p);
     let plugin_groups = sort_lint_groups(plugin_groups);
     let builtin_groups = sort_lint_groups(builtin_groups);
 

compiler/rustc_errors/src/lib.rs

@@ -10,7 +10,6 @@
 #![feature(iter_zip)]
 #![feature(let_else)]
 #![feature(nll)]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate rustc_macros;

compiler/rustc_expand/src/lib.rs

@@ -10,7 +10,6 @@
 #![feature(proc_macro_span)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate rustc_macros;

compiler/rustc_feature/src/builtin_attrs.rs

@@ -460,9 +460,6 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // Prevents field reads in the marked trait or method to be considered
     // during dead code analysis.
     rustc_attr!(rustc_trivial_field_reads, Normal, template!(Word), INTERNAL_UNSTABLE),
-    // Used by the `rustc::potential_query_instability` lint to warn methods which
-    // might not be stable during incremental compilation.
-    rustc_attr!(rustc_lint_query_instability, Normal, template!(Word), INTERNAL_UNSTABLE),
 
     // ==========================================================================
     // Internal attributes, Const related:

compiler/rustc_incremental/src/lib.rs

@@ -5,7 +5,6 @@
 #![feature(let_else)]
 #![feature(nll)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate rustc_middle;

compiler/rustc_infer/src/lib.rs

@@ -24,7 +24,6 @@
 #![feature(min_specialization)]
 #![feature(label_break_value)]
 #![recursion_limit = "512"] // For rustdoc
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate rustc_macros;

compiler/rustc_interface/src/lib.rs

@@ -5,7 +5,6 @@
 #![feature(nll)]
 #![feature(once_cell)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 mod callbacks;
 pub mod interface;

compiler/rustc_lint/src/context.rs

@@ -144,11 +144,7 @@ impl LintStore {
         &self.lints
     }
 
-    pub fn get_lint_groups<'t>(
-        &'t self,
-    ) -> impl Iterator<Item = (&'static str, Vec<LintId>, bool)> + 't {
-        // This function is not used in a way which observes the order of lints.
-        #[cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
+    pub fn get_lint_groups<'t>(&'t self) -> Vec<(&'static str, Vec<LintId>, bool)> {
         self.lint_groups
             .iter()
             .filter(|(_, LintGroup { depr, .. })| {
@@ -158,6 +154,7 @@ impl LintStore {
             .map(|(k, LintGroup { lint_ids, from_plugin, .. })| {
                 (*k, lint_ids.clone(), *from_plugin)
             })
+            .collect()
     }
 
     pub fn register_early_pass(

compiler/rustc_lint/src/internal.rs

@@ -5,7 +5,10 @@ use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext}
 use rustc_ast as ast;
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
-use rustc_hir::*;
+use rustc_hir::{
+    GenericArg, HirId, Item, ItemKind, MutTy, Mutability, Node, Path, PathSegment, QPath, Ty,
+    TyKind,
+};
 use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
@@ -48,60 +51,6 @@ impl LateLintPass<'_> for DefaultHashTypes {
     }
 }
 
-declare_tool_lint! {
-    pub rustc::POTENTIAL_QUERY_INSTABILITY,
-    Allow,
-    "require explicit opt-in when using potentially unstable methods or functions",
-    report_in_external_macro: true
-}
-
-declare_lint_pass!(QueryStability => [POTENTIAL_QUERY_INSTABILITY]);
-
-impl LateLintPass<'_> for QueryStability {
-    fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
-        // FIXME(rustdoc): This lint uses typecheck results, causing rustdoc to
-        // error if there are resolution failures.
-        //
-        // As internal lints are currently always run if there are `unstable_options`,
-        // they are added to the lint store of rustdoc. Internal lints are also
-        // not used via the `lint_mod` query. Crate lints run outside of a query
-        // so rustdoc currently doesn't disable them.
-        //
-        // Instead of relying on this, either change crate lints to a query disabled by
-        // rustdoc, only run internal lints if the user is explicitly opting in
-        // or figure out a different way to avoid running lints for rustdoc.
-        if cx.tcx.sess.opts.actually_rustdoc {
-            return;
-        }
-
-        let (def_id, span) = match expr.kind {
-            ExprKind::Path(ref path) if let Some(def_id) = cx.qpath_res(path, expr.hir_id).opt_def_id() => {
-                (def_id, expr.span)
-            }
-            ExprKind::MethodCall(_, span, _, _) if let Some(def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id) => {
-                (def_id, span)
-            },
-            _ => return,
-        };
-
-        let substs = cx.typeck_results().node_substs(expr.hir_id);
-        if let Ok(Some(instance)) = ty::Instance::resolve(cx.tcx, cx.param_env, def_id, substs) {
-            let def_id = instance.def_id();
-            if cx.tcx.has_attr(def_id, sym::rustc_lint_query_instability) {
-                cx.struct_span_lint(POTENTIAL_QUERY_INSTABILITY, span, |lint| {
-                    let msg = format!(
-                        "using `{}` can result in unstable query results",
-                        cx.tcx.item_name(def_id)
-                    );
-                    lint.build(&msg)
-                        .note("if you believe this case to be fine, allow this lint and add a comment explaining your rationale")
-                        .emit();
-                })
-            }
-        }
-    }
-}
-
 declare_tool_lint! {
     pub rustc::USAGE_OF_TY_TYKIND,
     Allow,

compiler/rustc_lint/src/lib.rs

@@ -31,14 +31,12 @@
 #![feature(box_patterns)]
 #![feature(crate_visibility_modifier)]
 #![feature(format_args_capture)]
-#![feature(if_let_guard)]
 #![feature(iter_order_by)]
 #![feature(iter_zip)]
 #![feature(never_type)]
 #![feature(nll)]
 #![feature(control_flow_enum)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate rustc_middle;
@@ -486,8 +484,6 @@ fn register_internals(store: &mut LintStore) {
     store.register_early_pass(|| Box::new(LintPassImpl));
     store.register_lints(&DefaultHashTypes::get_lints());
     store.register_late_pass(|| Box::new(DefaultHashTypes));
-    store.register_lints(&QueryStability::get_lints());
-    store.register_late_pass(|| Box::new(QueryStability));
     store.register_lints(&ExistingDocKeyword::get_lints());
     store.register_late_pass(|| Box::new(ExistingDocKeyword));
     store.register_lints(&TyTyKind::get_lints());
@@ -498,7 +494,6 @@ fn register_internals(store: &mut LintStore) {
         None,
         vec![
             LintId::of(DEFAULT_HASH_TYPES),
-            LintId::of(POTENTIAL_QUERY_INSTABILITY),
             LintId::of(USAGE_OF_TY_TYKIND),
             LintId::of(LINT_PASS_IMPL_WITHOUT_MACRO),
             LintId::of(TY_PASS_BY_REFERENCE),

compiler/rustc_metadata/src/lib.rs

@@ -10,7 +10,6 @@
 #![feature(try_blocks)]
 #![feature(never_type)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 extern crate proc_macro;
 

compiler/rustc_middle/src/lib.rs

@@ -56,7 +56,6 @@
 #![feature(try_reserve_kind)]
 #![feature(nonzero_ops)]
 #![recursion_limit = "512"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate bitflags;

compiler/rustc_mir_build/src/lib.rs

@@ -10,7 +10,6 @@
 #![feature(once_cell)]
 #![feature(min_specialization)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_mir_transform/src/lib.rs

@@ -12,7 +12,6 @@
 #![feature(trusted_step)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_monomorphize/src/lib.rs

@@ -5,7 +5,6 @@
 #![feature(let_else)]
 #![feature(in_band_lifetimes)]
 #![recursion_limit = "256"]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate tracing;