Remove side table of future incompatibility info

Moves this information to a direct field of Lint, which is where it
belongs.

3 files changed, 172 insertions, 72 deletions

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 29cc326fab6..4c1093e00ce 100644
--- a/src/librustc/lint/builtin.rs
+++ b/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;
 
@@ -125,7 +126,11 @@ 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! {
@@ -137,13 +142,21 @@ 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! {
@@ -155,56 +168,92 @@ 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! {
@@ -247,7 +296,11 @@ 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! {
@@ -266,19 +319,33 @@ 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! {
@@ -296,7 +363,11 @@ 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! {
@@ -320,13 +391,21 @@ 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! {
@@ -340,7 +419,11 @@ 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! {
@@ -353,7 +436,11 @@ 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`.
@@ -361,7 +448,11 @@ 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! {
@@ -387,25 +478,41 @@ declare_lint! {
 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! {
diff --git a/src/librustc/lint/context.rs b/src/librustc/lint/context.rs
index 6e67c0315cf..97b9f21163d 100644
--- a/src/librustc/lint/context.rs
+++ b/src/librustc/lint/context.rs
@@ -22,7 +22,7 @@ use crate::hir::intravisit as hir_visit;
 use crate::hir::intravisit::Visitor;
 use crate::hir::map::{definitions::DisambiguatedDefPathData, DefPathData};
 use crate::lint::{EarlyLintPass, LateLintPass, EarlyLintPassObject, LateLintPassObject};
-use crate::lint::{Level, Lint, LintId, LintPass, LintBuffer};
+use crate::lint::{Level, Lint, LintId, LintPass, LintBuffer, FutureIncompatibleInfo};
 use crate::lint::builtin::BuiltinLintDiagnostics;
 use crate::lint::levels::{LintLevelSets, LintLevelsBuilder};
 use crate::middle::privacy::AccessLevels;
@@ -38,7 +38,6 @@ use std::default::Default as StdDefault;
 use rustc_data_structures::sync::{ReadGuard, ParallelIterator, join, par_iter};
 use rustc_serialize::{Decoder, Decodable, Encoder, Encodable};
 use syntax::ast;
-use syntax::edition;
 use syntax::util::lev_distance::find_best_match_for_name;
 use syntax::visit as ast_visit;
 use syntax_pos::{MultiSpan, Span, symbol::Symbol};
@@ -69,10 +68,6 @@ pub struct LintStore {
 
     /// Map of registered lint groups to what lints they expand to.
     lint_groups: FxHashMap<&'static str, LintGroup>,
-
-    /// Extra info for future incompatibility lints, describing the
-    /// issue or RFC that caused the incompatibility.
-    future_incompatible: FxHashMap<LintId, FutureIncompatibleInfo>,
 }
 
 /// Lints that are buffered up early on in the `Session` before the
@@ -86,18 +81,6 @@ pub struct BufferedEarlyLint {
     pub diagnostic: BuiltinLintDiagnostics,
 }
 
-/// Extra information for a future incompatibility lint. See the call
-/// to `register_future_incompatible` in `librustc_lint/lib.rs` for
-/// guidelines.
-pub struct FutureIncompatibleInfo {
-    pub id: LintId,
-    /// e.g., a URL for an issue/PR/RFC or error code
-    pub reference: &'static str,
-    /// If this is an edition fixing lint, the edition in which
-    /// this lint becomes obsolete
-    pub edition: Option<edition::Edition>,
-}
-
 /// The target of the `by_name` map, which accounts for renaming/deprecation.
 enum TargetLint {
     /// A direct lint target
@@ -152,7 +135,6 @@ impl LintStore {
             late_passes: vec![],
             late_module_passes: vec![],
             by_name: Default::default(),
-            future_incompatible: Default::default(),
             lint_groups: Default::default(),
         }
     }
@@ -198,36 +180,31 @@ impl LintStore {
             if self.by_name.insert(lint.name_lower(), Id(id)).is_some() {
                 bug!("duplicate specification of lint {}", lint.name_lower())
             }
-        }
-    }
 
-    pub fn register_future_incompatible(&mut self,
-                                        lints: Vec<FutureIncompatibleInfo>) {
+            if let Some(FutureIncompatibleInfo { edition, .. }) = lint.future_incompatible {
+                if let Some(edition) = edition {
+                    self.lint_groups.entry(edition.lint_name())
+                        .or_insert(LintGroup {
+                            lint_ids: vec![],
+                            from_plugin: lint.is_plugin,
+                            depr: None,
+                        })
+                        .lint_ids.push(id);
+                }
 
-        for edition in edition::ALL_EDITIONS {
-            let lints = lints.iter().filter(|f| f.edition == Some(*edition)).map(|f| f.id)
-                             .collect::<Vec<_>>();
-            if !lints.is_empty() {
-                self.register_group(false, edition.lint_name(), None, lints)
+                self.lint_groups.entry("future_incompatible")
+                    .or_insert(LintGroup {
+                        lint_ids: vec![],
+                        from_plugin: lint.is_plugin,
+                        depr: None,
+                    })
+                    .lint_ids.push(id);
             }
         }
-
-        let mut future_incompatible = Vec::with_capacity(lints.len());
-        for lint in lints {
-            future_incompatible.push(lint.id);
-            self.future_incompatible.insert(lint.id, lint);
-        }
-
-        self.register_group(
-            false,
-            "future_incompatible",
-            None,
-            future_incompatible,
-        );
     }
 
-    pub fn future_incompatible(&self, id: LintId) -> Option<&FutureIncompatibleInfo> {
-        self.future_incompatible.get(&id)
+    pub fn future_incompatible(&self, id: LintId) -> Option<FutureIncompatibleInfo> {
+        id.lint.future_incompatible
     }
 
     pub fn register_group_alias(
diff --git a/src/librustc/lint/mod.rs b/src/librustc/lint/mod.rs
index 76e6a28008a..ba7ec0ed6e4 100644
--- a/src/librustc/lint/mod.rs
+++ b/src/librustc/lint/mod.rs
@@ -45,7 +45,7 @@ use syntax_pos::Span;
 
 pub use crate::lint::context::{LateContext, EarlyContext, LintContext, LintStore,
                         check_crate, check_ast_crate, late_lint_mod, CheckLintNameResult,
-                        FutureIncompatibleInfo, BufferedEarlyLint,};
+                        BufferedEarlyLint,};
 
 /// Specification of a single lint.
 #[derive(Copy, Clone, Debug)]
@@ -77,9 +77,21 @@ pub struct Lint {
     /// `true` if this lint is reported even inside expansions of external macros.
     pub report_in_external_macro: bool,
 
+    pub future_incompatible: Option<FutureIncompatibleInfo>,
+
     pub is_plugin: bool,
 }
 
+/// Extra information for a future incompatibility lint.
+#[derive(Copy, Clone, Debug)]
+pub struct FutureIncompatibleInfo {
+    /// e.g., a URL for an issue/PR/RFC or error code
+    pub reference: &'static str,
+    /// If this is an edition fixing lint, the edition in which
+    /// this lint becomes obsolete
+    pub edition: Option<Edition>,
+}
+
 impl Lint {
     pub const fn default_fields_for_macro() -> Self {
         Lint {
@@ -89,6 +101,7 @@ impl Lint {
             edition_lint_opts: None,
             is_plugin: false,
             report_in_external_macro: false,
+            future_incompatible: None,
         }
     }
 
@@ -122,7 +135,8 @@ macro_rules! declare_lint {
             $vis $NAME, $Level, $desc,
         );
     );
-    ($vis: vis $NAME: ident, $Level: ident, $desc: expr, $($v:ident),*) => (
+    ($vis: vis $NAME: ident, $Level: ident, $desc: expr,
+     $(@future_incompatible = $fi:expr;)? $($v:ident),*) => (
         $vis static $NAME: &$crate::lint::Lint = &$crate::lint::Lint {
             name: stringify!($NAME),
             default_level: $crate::lint::$Level,
@@ -130,6 +144,7 @@ macro_rules! declare_lint {
             edition_lint_opts: None,
             is_plugin: false,
             $($v: true,)*
+            $(future_incompatible: Some($fi),)*
             ..$crate::lint::Lint::default_fields_for_macro()
         };
     );
@@ -171,6 +186,7 @@ macro_rules! declare_tool_lint {
             desc: $desc,
             edition_lint_opts: None,
             report_in_external_macro: $external,
+            future_incompatible: None,
             is_plugin: true,
         };
     );