Auto merge of #96082 - michaelwoerister:less_impl_stable_hash_via_hash, r=compiler-errors

incr. comp.: Don't export impl_stable_hash_via_hash!() and warn about using it.

Fixes https://github.com/rust-lang/rust/issues/96013.

compiler/rustc_data_structures/src/stable_hasher.rs

@@ -207,9 +207,14 @@ pub trait ToStableHashKey<HCX> {
     fn to_stable_hash_key(&self, hcx: &HCX) -> Self::KeyType;
 }
 
-// Implement HashStable by just calling `Hash::hash()`. This works fine for
-// self-contained values that don't depend on the hashing context `CTX`.
-#[macro_export]
+/// Implement HashStable by just calling `Hash::hash()`.
+///
+/// **WARNING** This is only valid for types that *really* don't need any context for fingerprinting.
+/// But it is easy to misuse this macro (see [#96013](https://github.com/rust-lang/rust/issues/96013)
+/// for examples). Therefore this macro is not exported and should only be used in the limited cases
+/// here in this module.
+///
+/// Use `#[derive(HashStable_Generic)]` instead.
 macro_rules! impl_stable_hash_via_hash {
     ($t:ty) => {
         impl<CTX> $crate::stable_hasher::HashStable<CTX> for $t {
@@ -246,12 +251,14 @@ impl<CTX> HashStable<CTX> for ! {
 }
 
 impl<CTX> HashStable<CTX> for ::std::num::NonZeroU32 {
+    #[inline]
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
         self.get().hash_stable(ctx, hasher)
     }
 }
 
 impl<CTX> HashStable<CTX> for ::std::num::NonZeroUsize {
+    #[inline]
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
         self.get().hash_stable(ctx, hasher)
     }
@@ -272,12 +279,14 @@ impl<CTX> HashStable<CTX> for f64 {
 }
 
 impl<CTX> HashStable<CTX> for ::std::cmp::Ordering {
+    #[inline]
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
         (*self as i8).hash_stable(ctx, hasher);
     }
 }
 
 impl<T1: HashStable<CTX>, CTX> HashStable<CTX> for (T1,) {
+    #[inline]
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
         let (ref _0,) = *self;
         _0.hash_stable(ctx, hasher);

compiler/rustc_errors/src/lib.rs

@@ -37,6 +37,7 @@ pub use rustc_error_messages::{
 };
 pub use rustc_lint_defs::{pluralize, Applicability};
 use rustc_span::source_map::SourceMap;
+use rustc_span::HashStableContext;
 use rustc_span::{Loc, Span};
 
 use std::borrow::Cow;
@@ -1494,6 +1495,7 @@ pub fn add_elided_lifetime_in_path_suggestion(
 /// Useful type to use with `Result<>` indicate that an error has already
 /// been reported to the user, so no need to continue checking.
 #[derive(Clone, Copy, Debug, Encodable, Decodable, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(HashStable_Generic)]
 pub struct ErrorGuaranteed(());
 
 impl ErrorGuaranteed {
@@ -1503,5 +1505,3 @@ impl ErrorGuaranteed {
         ErrorGuaranteed(())
     }
 }
-
-rustc_data_structures::impl_stable_hash_via_hash!(ErrorGuaranteed);

compiler/rustc_hir/src/hir_id.rs

@@ -76,9 +76,10 @@ rustc_index::newtype_index! {
     /// integers starting at zero, so a mapping that maps all or most nodes within
     /// an "item-like" to something else can be implemented by a `Vec` instead of a
     /// tree or hash map.
+    #[derive(HashStable_Generic)]
     pub struct ItemLocalId { .. }
 }
-rustc_data_structures::impl_stable_hash_via_hash!(ItemLocalId);
+
 impl ItemLocalId {
     /// Signal local id which should never be used.
     pub const INVALID: ItemLocalId = ItemLocalId::MAX;

compiler/rustc_lint_defs/src/lib.rs

@@ -8,6 +8,7 @@ use rustc_ast::node_id::{NodeId, NodeMap};
 use rustc_ast::{AttrId, Attribute};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
 use rustc_error_messages::MultiSpan;
+use rustc_hir::HashStableContext;
 use rustc_hir::HirId;
 use rustc_span::edition::Edition;
 use rustc_span::{sym, symbol::Ident, Span, Symbol};
@@ -146,7 +147,7 @@ impl<HCX: rustc_hir::HashStableContext> ToStableHashKey<HCX> for LintExpectation
 /// Setting for how to handle a lint.
 ///
 /// See: <https://doc.rust-lang.org/rustc/lints/levels.html>
-#[derive(Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Debug, Hash)]
+#[derive(Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Debug, Hash, HashStable_Generic)]
 pub enum Level {
     /// The `allow` level will not issue any message.
     Allow,
@@ -174,8 +175,6 @@ pub enum Level {
     Forbid,
 }
 
-rustc_data_structures::impl_stable_hash_via_hash!(Level);
-
 impl Level {
     /// Converts a level to a lower-case string.
     pub fn as_str(self) -> &'static str {

compiler/rustc_session/src/config.rs

@@ -3,14 +3,14 @@
 
 pub use crate::options::*;
 
-use crate::lint;
 use crate::search_paths::SearchPath;
 use crate::utils::{CanonicalizedPath, NativeLib, NativeLibKind};
 use crate::{early_error, early_warn, Session};
+use crate::{lint, HashStableContext};
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::impl_stable_hash_via_hash;
 
+use rustc_data_structures::stable_hasher::ToStableHashKey;
 use rustc_target::abi::{Align, TargetDataLayout};
 use rustc_target::spec::{LinkerFlavor, SplitDebuginfo, Target, TargetTriple, TargetWarnings};
 use rustc_target::spec::{PanicStrategy, SanitizerSet, TARGETS};
@@ -78,7 +78,7 @@ pub enum CFProtection {
     Full,
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Hash, HashStable_Generic)]
 pub enum OptLevel {
     No,         // -O0
     Less,       // -O1
@@ -88,8 +88,6 @@ pub enum OptLevel {
     SizeMin,    // -Oz
 }
 
-impl_stable_hash_via_hash!(OptLevel);
-
 /// This is what the `LtoCli` values get mapped to after resolving defaults and
 /// and taking other command line options into account.
 ///
@@ -230,15 +228,13 @@ impl SwitchWithOptPath {
     }
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable_Generic)]
 #[derive(Encodable, Decodable)]
 pub enum SymbolManglingVersion {
     Legacy,
     V0,
 }
 
-impl_stable_hash_via_hash!(SymbolManglingVersion);
-
 #[derive(Clone, Copy, Debug, PartialEq, Hash)]
 pub enum DebugInfo {
     None,
@@ -277,7 +273,7 @@ impl FromStr for SplitDwarfKind {
     }
 }
 
-#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, PartialOrd, Ord)]
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, PartialOrd, Ord, HashStable_Generic)]
 #[derive(Encodable, Decodable)]
 pub enum OutputType {
     Bitcode,
@@ -290,7 +286,13 @@ pub enum OutputType {
     DepInfo,
 }
 
-impl_stable_hash_via_hash!(OutputType);
+impl<HCX: HashStableContext> ToStableHashKey<HCX> for OutputType {
+    type KeyType = Self;
+
+    fn to_stable_hash_key(&self, _: &HCX) -> Self::KeyType {
+        *self
+    }
+}
 
 impl OutputType {
     fn is_compatible_with_codegen_units_and_single_output_file(&self) -> bool {
@@ -396,7 +398,7 @@ pub enum TrimmedDefPaths {
 /// *Do not* switch `BTreeMap` out for an unsorted container type! That would break
 /// dependency tracking for command-line arguments. Also only hash keys, since tracking
 /// should only depend on the output types, not the paths they're written to.
-#[derive(Clone, Debug, Hash)]
+#[derive(Clone, Debug, Hash, HashStable_Generic)]
 pub struct OutputTypes(BTreeMap<OutputType, Option<PathBuf>>);
 
 impl OutputTypes {
@@ -585,7 +587,7 @@ impl Input {
     }
 }
 
-#[derive(Clone, Hash, Debug)]
+#[derive(Clone, Hash, Debug, HashStable_Generic)]
 pub struct OutputFilenames {
     pub out_directory: PathBuf,
     filestem: String,
@@ -594,8 +596,6 @@ pub struct OutputFilenames {
     pub outputs: OutputTypes,
 }
 
-impl_stable_hash_via_hash!(OutputFilenames);
-
 pub const RLINK_EXT: &str = "rlink";
 pub const RUST_CGU_EXT: &str = "rcgu";
 pub const DWARF_OBJECT_EXT: &str = "dwo";
@@ -808,15 +808,14 @@ impl DebuggingOptions {
 }
 
 // The type of entry function, so users can have their own entry functions
-#[derive(Copy, Clone, PartialEq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Hash, Debug, HashStable_Generic)]
 pub enum EntryFnType {
     Main,
     Start,
 }
 
-impl_stable_hash_via_hash!(EntryFnType);
-
 #[derive(Copy, PartialEq, PartialOrd, Clone, Ord, Eq, Hash, Debug, Encodable, Decodable)]
+#[derive(HashStable_Generic)]
 pub enum CrateType {
     Executable,
     Dylib,
@@ -826,8 +825,6 @@ pub enum CrateType {
     ProcMacro,
 }
 
-impl_stable_hash_via_hash!(CrateType);
-
 impl CrateType {
     /// When generated, is this crate type an archive?
     pub fn is_archive(&self) -> bool {

compiler/rustc_session/src/search_paths.rs

@@ -26,7 +26,7 @@ pub struct SearchPathFile {
     pub file_name_str: String,
 }
 
-#[derive(PartialEq, Clone, Copy, Debug, Hash, Eq, Encodable, Decodable)]
+#[derive(PartialEq, Clone, Copy, Debug, Hash, Eq, Encodable, Decodable, HashStable_Generic)]
 pub enum PathKind {
     Native,
     Crate,
@@ -36,8 +36,6 @@ pub enum PathKind {
     All,
 }
 
-rustc_data_structures::impl_stable_hash_via_hash!(PathKind);
-
 impl PathKind {
     pub fn matches(&self, kind: PathKind) -> bool {
         match (self, kind) {

compiler/rustc_session/src/utils.rs

@@ -18,6 +18,7 @@ impl Session {
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]
+#[derive(HashStable_Generic)]
 pub enum NativeLibKind {
     /// Static library (e.g. `libfoo.a` on Linux or `foo.lib` on Windows/MSVC)
     Static {
@@ -57,9 +58,8 @@ impl NativeLibKind {
     }
 }
 
-rustc_data_structures::impl_stable_hash_via_hash!(NativeLibKind);
-
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]
+#[derive(HashStable_Generic)]
 pub struct NativeLib {
     pub name: String,
     pub new_name: Option<String>,
@@ -73,8 +73,6 @@ impl NativeLib {
     }
 }
 
-rustc_data_structures::impl_stable_hash_via_hash!(NativeLib);
-
 /// A path that has been canonicalized along with its original, non-canonicalized form
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct CanonicalizedPath {

compiler/rustc_span/src/lib.rs

@@ -1130,6 +1130,7 @@ impl ExternalSource {
 pub struct OffsetOverflowError;
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]
+#[derive(HashStable_Generic)]
 pub enum SourceFileHashAlgorithm {
     Md5,
     Sha1,
@@ -1149,8 +1150,6 @@ impl FromStr for SourceFileHashAlgorithm {
     }
 }
 
-rustc_data_structures::impl_stable_hash_via_hash!(SourceFileHashAlgorithm);
-
 /// The hash of the on-disk source file used for debug info.
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 #[derive(HashStable_Generic, Encodable, Decodable)]