Rollup merge of rust-lang#65193 - Mark-Simulacrum:lockless-lintstore, r=nikomatsakis

Lockless LintStore

This removes mutability from the lint store after registration. Each commit stands alone, for the most part, though they don't make sense out of sequence.

The intent here is to move LintStore to a more parallel-friendly architecture, although also just a cleaner one from an implementation perspective. Specifically, this has the following changes:
 * We no longer implicitly register lints when registering lint passes
    * For the most part this means that registration calls now likely want to call something like:
       `lint_store.register_lints(&Pass::get_lints())` as well as `register_*_pass`.
    * In theory this is a simplification as it's much easier for folks to just register lints and then have passes that implement whichever lint however they want, rather than necessarily tying passes to lints.
 * Lint passes still have a list of associated lints, but a followup PR could plausibly change that
   * This list must be known for a given pass type, not instance, i.e., `fn get_lints()` is the signature instead of `fn get_lints(&self)` as before.
 * We do not store pass objects, instead storing constructor functions. This means we always get new passes when running lints (this happens approximately once though for a given compiler session, so no behavior change is expected).
 * Registration API is _much_ simpler: generally all functions are just taking `Fn() -> PassObject` rather than several different `bool`s.

Author: Centril

Cargo.lock

@@ -3483,6 +3483,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_errors",
  "rustc_interface",
+ "rustc_lint",
  "rustc_metadata",
  "rustc_mir",
  "rustc_plugin",

src/librustc/lint/builtin.rs

@@ -4,11 +4,12 @@
 //! compiler code, rather than using their own custom pass. Those
 //! lints are all available in `rustc_lint::builtin`.
 
-use crate::lint::{LintPass, LateLintPass, LintArray};
+use crate::lint::{LintPass, LateLintPass, LintArray, FutureIncompatibleInfo};
 use crate::middle::stability;
 use crate::session::Session;
 use errors::{Applicability, DiagnosticBuilder, pluralise};
 use syntax::ast;
+use syntax::edition::Edition;
 use syntax::source_map::Span;
 use syntax::symbol::Symbol;
 
@@ -22,7 +23,7 @@ declare_lint! {
     pub CONST_ERR,
     Deny,
     "constant evaluation detected erroneous expression",
-    report_in_external_macro: true
+    report_in_external_macro
 }
 
 declare_lint! {
@@ -71,7 +72,7 @@ declare_lint! {
     pub UNREACHABLE_CODE,
     Warn,
     "detects unreachable code paths",
-    report_in_external_macro: true
+    report_in_external_macro
 }
 
 declare_lint! {
@@ -131,7 +132,11 @@ declare_lint! {
 declare_lint! {
     pub PRIVATE_IN_PUBLIC,
     Warn,
-    "detect private items in public interfaces not caught by the old implementation"
+    "detect private items in public interfaces not caught by the old implementation",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
+        edition: None,
+    };
 }
 
 declare_lint! {
@@ -143,13 +148,21 @@ declare_lint! {
 declare_lint! {
     pub PUB_USE_OF_PRIVATE_EXTERN_CRATE,
     Deny,
-    "detect public re-exports of private extern crates"
+    "detect public re-exports of private extern crates",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub INVALID_TYPE_PARAM_DEFAULT,
     Deny,
-    "type parameter default erroneously allowed in invalid location"
+    "type parameter default erroneously allowed in invalid location",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
+        edition: None,
+    };
 }
 
 declare_lint! {
@@ -161,63 +174,99 @@ declare_lint! {
 declare_lint! {
     pub SAFE_EXTERN_STATICS,
     Deny,
-    "safe access to extern statics was erroneously allowed"
+    "safe access to extern statics was erroneously allowed",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub SAFE_PACKED_BORROWS,
     Warn,
-    "safe borrows of fields of packed structs were was erroneously allowed"
+    "safe borrows of fields of packed structs were was erroneously allowed",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #46043 <https://github.com/rust-lang/rust/issues/46043>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub PATTERNS_IN_FNS_WITHOUT_BODY,
     Warn,
-    "patterns in functions without body were erroneously allowed"
+    "patterns in functions without body were erroneously allowed",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub LEGACY_DIRECTORY_OWNERSHIP,
     Deny,
     "non-inline, non-`#[path]` modules (e.g., `mod foo;`) were erroneously allowed in some files \
-     not named `mod.rs`"
+     not named `mod.rs`",
+     @future_incompatible = FutureIncompatibleInfo {
+         reference: "issue #37872 <https://github.com/rust-lang/rust/issues/37872>",
+         edition: None,
+     };
 }
 
 declare_lint! {
     pub LEGACY_CONSTRUCTOR_VISIBILITY,
     Deny,
-    "detects use of struct constructors that would be invisible with new visibility rules"
+    "detects use of struct constructors that would be invisible with new visibility rules",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub MISSING_FRAGMENT_SPECIFIER,
     Deny,
-    "detects missing fragment specifiers in unused `macro_rules!` patterns"
+    "detects missing fragment specifiers in unused `macro_rules!` patterns",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
     Deny,
-    "detects parenthesized generic parameters in type and module names"
+    "detects parenthesized generic parameters in type and module names",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub LATE_BOUND_LIFETIME_ARGUMENTS,
     Warn,
-    "detects generic lifetime arguments in path segments with late bound lifetime parameters"
+    "detects generic lifetime arguments in path segments with late bound lifetime parameters",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #42868 <https://github.com/rust-lang/rust/issues/42868>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub ORDER_DEPENDENT_TRAIT_OBJECTS,
     Deny,
-    "trait-object types were treated as different depending on marker-trait order"
+    "trait-object types were treated as different depending on marker-trait order",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #56484 <https://github.com/rust-lang/rust/issues/56484>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub DEPRECATED,
     Warn,
     "detects use of deprecated items",
-    report_in_external_macro: true
+    report_in_external_macro
 }
 
 declare_lint! {
@@ -253,7 +302,11 @@ declare_lint! {
 declare_lint! {
     pub TYVAR_BEHIND_RAW_POINTER,
     Warn,
-    "raw pointer to an inference variable"
+    "raw pointer to an inference variable",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #46906 <https://github.com/rust-lang/rust/issues/46906>",
+        edition: Some(Edition::Edition2018),
+    };
 }
 
 declare_lint! {
@@ -272,19 +325,33 @@ declare_lint! {
     pub ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
     Allow,
     "fully qualified paths that start with a module name \
-     instead of `crate`, `self`, or an extern crate name"
+     instead of `crate`, `self`, or an extern crate name",
+     @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #53130 <https://github.com/rust-lang/rust/issues/53130>",
+        edition: Some(Edition::Edition2018),
+     };
 }
 
 declare_lint! {
     pub ILLEGAL_FLOATING_POINT_LITERAL_PATTERN,
     Warn,
-    "floating-point literals cannot be used in patterns"
+    "floating-point literals cannot be used in patterns",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub UNSTABLE_NAME_COLLISIONS,
     Warn,
-    "detects name collision with an existing but unstable method"
+    "detects name collision with an existing but unstable method",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #48919 <https://github.com/rust-lang/rust/issues/48919>",
+        edition: None,
+        // Note: this item represents future incompatibility of all unstable functions in the
+        //       standard library, and thus should never be removed or changed to an error.
+    };
 }
 
 declare_lint! {
@@ -302,7 +369,11 @@ declare_lint! {
 declare_lint! {
     pub DUPLICATE_MACRO_EXPORTS,
     Deny,
-    "detects duplicate macro exports"
+    "detects duplicate macro exports",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #35896 <https://github.com/rust-lang/rust/issues/35896>",
+        edition: Some(Edition::Edition2018),
+    };
 }
 
 declare_lint! {
@@ -326,13 +397,21 @@ declare_lint! {
 declare_lint! {
     pub WHERE_CLAUSES_OBJECT_SAFETY,
     Warn,
-    "checks the object safety of where clauses"
+    "checks the object safety of where clauses",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #51443 <https://github.com/rust-lang/rust/issues/51443>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
     Warn,
-    "detects proc macro derives using inaccessible names from parent modules"
+    "detects proc macro derives using inaccessible names from parent modules",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #50504 <https://github.com/rust-lang/rust/issues/50504>",
+        edition: None,
+    };
 }
 
 declare_lint! {
@@ -346,7 +425,11 @@ declare_lint! {
     pub MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
     Deny,
     "macro-expanded `macro_export` macros from the current crate \
-     cannot be referred to by absolute paths"
+     cannot be referred to by absolute paths",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #52234 <https://github.com/rust-lang/rust/issues/52234>",
+        edition: None,
+    };
 }
 
 declare_lint! {
@@ -359,15 +442,23 @@ declare_lint! {
     pub INDIRECT_STRUCTURAL_MATCH,
     // defaulting to allow until rust-lang/rust#62614 is fixed.
     Allow,
-    "pattern with const indirectly referencing non-`#[structural_match]` type"
+    "pattern with const indirectly referencing non-`#[structural_match]` type",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #62411 <https://github.com/rust-lang/rust/issues/62411>",
+        edition: None,
+    };
 }
 
 /// Some lints that are buffered from `libsyntax`. See `syntax::early_buffered_lints`.
 pub mod parser {
     declare_lint! {
         pub ILL_FORMED_ATTRIBUTE_INPUT,
         Warn,
-        "ill-formed attribute inputs that were previously accepted and used in practice"
+        "ill-formed attribute inputs that were previously accepted and used in practice",
+        @future_incompatible = super::FutureIncompatibleInfo {
+            reference: "issue #57571 <https://github.com/rust-lang/rust/issues/57571>",
+            edition: None,
+        };
     }
 
     declare_lint! {
@@ -387,31 +478,47 @@ declare_lint! {
     pub DEPRECATED_IN_FUTURE,
     Allow,
     "detects use of items that will be deprecated in a future version",
-    report_in_external_macro: true
+    report_in_external_macro
 }
 
 declare_lint! {
     pub AMBIGUOUS_ASSOCIATED_ITEMS,
     Deny,
-    "ambiguous associated items"
+    "ambiguous associated items",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #57644 <https://github.com/rust-lang/rust/issues/57644>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub NESTED_IMPL_TRAIT,
     Warn,
-    "nested occurrence of `impl Trait` type"
+    "nested occurrence of `impl Trait` type",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #59014 <https://github.com/rust-lang/rust/issues/59014>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub MUTABLE_BORROW_RESERVATION_CONFLICT,
     Warn,
-    "reservation of a two-phased borrow conflicts with other shared borrows"
+    "reservation of a two-phased borrow conflicts with other shared borrows",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #59159 <https://github.com/rust-lang/rust/issues/59159>",
+        edition: None,
+    };
 }
 
 declare_lint! {
     pub SOFT_UNSTABLE,
     Deny,
-    "a feature gate that doesn't break dependent crates"
+    "a feature gate that doesn't break dependent crates",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #64266 <https://github.com/rust-lang/rust/issues/64266>",
+        edition: None,
+    };
 }
 
 declare_lint_pass! {