Merge pull request rust-lang#19223 from ChayimFriedman2/implied-targe…

…t-feature

fix: Support target features implications in target_feature 1.1

.typos.toml

@@ -18,6 +18,8 @@ extend-ignore-re = [
     "INOUT",
     "optin",
     "=Pn",
+    # ignore `// spellchecker:off` until `// spellchecker:on`
+    "(?s)(#|//)\\s*spellchecker:off.*?\\n\\s*(#|//)\\s*spellchecker:on",
 ]
 
 [default.extend-words]

crates/hir-ty/src/lib.rs

@@ -36,6 +36,7 @@ mod inhabitedness;
 mod interner;
 mod lower;
 mod mapping;
+mod target_feature;
 mod tls;
 mod utils;
 
@@ -107,10 +108,9 @@ pub use mapping::{
     to_foreign_def_id, to_placeholder_idx,
 };
 pub use method_resolution::check_orphan_rules;
+pub use target_feature::TargetFeatures;
 pub use traits::TraitEnvironment;
-pub use utils::{
-    all_super_traits, direct_super_traits, is_fn_unsafe_to_call, TargetFeatures, Unsafety,
-};
+pub use utils::{all_super_traits, direct_super_traits, is_fn_unsafe_to_call, Unsafety};
 pub use variance::Variance;
 
 pub use chalk_ir::{

crates/hir-ty/src/target_feature.rs

@@ -0,0 +1,261 @@
+//! Stuff for handling `#[target_feature]` (needed for unsafe check).
+
+use std::sync::LazyLock;
+
+use hir_def::attr::Attrs;
+use hir_def::tt;
+use intern::{sym, Symbol};
+use rustc_hash::{FxHashMap, FxHashSet};
+
+#[derive(Debug, Default)]
+pub struct TargetFeatures {
+    pub(crate) enabled: FxHashSet<Symbol>,
+}
+
+impl TargetFeatures {
+    pub fn from_attrs(attrs: &Attrs) -> Self {
+        let mut result = TargetFeatures::from_attrs_no_implications(attrs);
+        result.expand_implications();
+        result
+    }
+
+    fn expand_implications(&mut self) {
+        let all_implications = LazyLock::force(&TARGET_FEATURE_IMPLICATIONS);
+        let mut queue = self.enabled.iter().cloned().collect::<Vec<_>>();
+        while let Some(feature) = queue.pop() {
+            if let Some(implications) = all_implications.get(&feature) {
+                for implication in implications {
+                    if self.enabled.insert(implication.clone()) {
+                        queue.push(implication.clone());
+                    }
+                }
+            }
+        }
+    }
+
+    /// Retrieves the target features from the attributes, and does not expand the target features implied by them.
+    pub(crate) fn from_attrs_no_implications(attrs: &Attrs) -> Self {
+        let enabled = attrs
+            .by_key(&sym::target_feature)
+            .tt_values()
+            .filter_map(|tt| {
+                match tt.token_trees().flat_tokens() {
+                    [
+                        tt::TokenTree::Leaf(tt::Leaf::Ident(enable_ident)),
+                        tt::TokenTree::Leaf(tt::Leaf::Punct(tt::Punct { char: '=', .. })),
+                        tt::TokenTree::Leaf(tt::Leaf::Literal(tt::Literal { kind: tt::LitKind::Str, symbol: features, .. })),
+                    ] if enable_ident.sym == sym::enable => Some(features),
+                    _ => None,
+                }
+            })
+            .flat_map(|features| features.as_str().split(',').map(Symbol::intern))
+            .collect();
+        Self { enabled }
+    }
+}
+
+// List of the target features each target feature implies.
+// Ideally we'd depend on rustc for this, but rustc_target doesn't compile on stable,
+// and t-compiler prefers for it to stay this way.
+
+static TARGET_FEATURE_IMPLICATIONS: LazyLock<FxHashMap<Symbol, Box<[Symbol]>>> =
+    LazyLock::new(|| {
+        let mut result = FxHashMap::<Symbol, FxHashSet<Symbol>>::default();
+        for &(feature_str, implications) in TARGET_FEATURE_IMPLICATIONS_RAW {
+            let feature = Symbol::intern(feature_str);
+            let implications = implications.iter().copied().map(Symbol::intern);
+            // Some target features appear in two archs, e.g. Arm and x86.
+            // Sometimes they contain different implications, e.g. `aes`.
+            // We should probably choose by the active arch, but for now just merge them.
+            result.entry(feature).or_default().extend(implications);
+        }
+        let mut result = result
+            .into_iter()
+            .map(|(feature, implications)| (feature, Box::from_iter(implications)))
+            .collect::<FxHashMap<_, _>>();
+        result.shrink_to_fit();
+        result
+    });
+
+// spellchecker:off
+const TARGET_FEATURE_IMPLICATIONS_RAW: &[(&str, &[&str])] = &[
+    // Arm
+    ("aes", &["neon"]),
+    ("dotprod", &["neon"]),
+    ("fp-armv8", &["vfp4"]),
+    ("fp16", &["neon"]),
+    ("i8mm", &["neon"]),
+    ("neon", &["vfp3"]),
+    ("sha2", &["neon"]),
+    ("v6", &["v5te"]),
+    ("v6k", &["v6"]),
+    ("v6t2", &["v6k", "thumb2"]),
+    ("v7", &["v6t2"]),
+    ("v8", &["v7"]),
+    ("vfp3", &["vfp2", "d32"]),
+    ("vfp4", &["vfp3"]),
+    // Aarch64
+    ("aes", &["neon"]),
+    ("dotprod", &["neon"]),
+    ("dpb2", &["dpb"]),
+    ("f32mm", &["sve"]),
+    ("f64mm", &["sve"]),
+    ("fcma", &["neon"]),
+    ("fhm", &["fp16"]),
+    ("fp16", &["neon"]),
+    ("fp8", &["faminmax", "lut", "bf16"]),
+    ("fp8dot2", &["fp8dot4"]),
+    ("fp8dot4", &["fp8fma"]),
+    ("fp8fma", &["fp8"]),
+    ("jsconv", &["neon"]),
+    ("lse128", &["lse"]),
+    ("rcpc2", &["rcpc"]),
+    ("rcpc3", &["rcpc2"]),
+    ("rdm", &["neon"]),
+    ("sha2", &["neon"]),
+    ("sha3", &["sha2"]),
+    ("sm4", &["neon"]),
+    ("sme", &["bf16"]),
+    ("sme-b16b16", &["bf16", "sme2", "sve-b16b16"]),
+    ("sme-f16f16", &["sme2"]),
+    ("sme-f64f64", &["sme"]),
+    ("sme-f8f16", &["sme-f8f32"]),
+    ("sme-f8f32", &["sme2", "fp8"]),
+    ("sme-fa64", &["sme", "sve2"]),
+    ("sme-i16i64", &["sme"]),
+    ("sme2", &["sme"]),
+    ("sme2p1", &["sme2"]),
+    ("ssve-fp8dot2", &["ssve-fp8dot4"]),
+    ("ssve-fp8dot4", &["ssve-fp8fma"]),
+    ("ssve-fp8fma", &["sme2", "fp8"]),
+    ("sve", &["neon"]),
+    ("sve-b16b16", &["bf16"]),
+    ("sve2", &["sve"]),
+    ("sve2-aes", &["sve2", "aes"]),
+    ("sve2-bitperm", &["sve2"]),
+    ("sve2-sha3", &["sve2", "sha3"]),
+    ("sve2-sm4", &["sve2", "sm4"]),
+    ("sve2p1", &["sve2"]),
+    ("v8.1a", &["crc", "lse", "rdm", "pan", "lor", "vh"]),
+    ("v8.2a", &["v8.1a", "ras", "dpb"]),
+    ("v8.3a", &["v8.2a", "rcpc", "paca", "pacg", "jsconv"]),
+    ("v8.4a", &["v8.3a", "dotprod", "dit", "flagm"]),
+    ("v8.5a", &["v8.4a", "ssbs", "sb", "dpb2", "bti"]),
+    ("v8.6a", &["v8.5a", "bf16", "i8mm"]),
+    ("v8.7a", &["v8.6a", "wfxt"]),
+    ("v8.8a", &["v8.7a", "hbc", "mops"]),
+    ("v8.9a", &["v8.8a", "cssc"]),
+    ("v9.1a", &["v9a", "v8.6a"]),
+    ("v9.2a", &["v9.1a", "v8.7a"]),
+    ("v9.3a", &["v9.2a", "v8.8a"]),
+    ("v9.4a", &["v9.3a", "v8.9a"]),
+    ("v9.5a", &["v9.4a"]),
+    ("v9a", &["v8.5a", "sve2"]),
+    // x86
+    ("aes", &["sse2"]),
+    ("amx-bf16", &["amx-tile"]),
+    ("amx-complex", &["amx-tile"]),
+    ("amx-fp16", &["amx-tile"]),
+    ("amx-int8", &["amx-tile"]),
+    ("avx", &["sse4.2"]),
+    ("avx2", &["avx"]),
+    ("avx512bf16", &["avx512bw"]),
+    ("avx512bitalg", &["avx512bw"]),
+    ("avx512bw", &["avx512f"]),
+    ("avx512cd", &["avx512f"]),
+    ("avx512dq", &["avx512f"]),
+    ("avx512f", &["avx2", "fma", "f16c"]),
+    ("avx512fp16", &["avx512bw", "avx512vl", "avx512dq"]),
+    ("avx512ifma", &["avx512f"]),
+    ("avx512vbmi", &["avx512bw"]),
+    ("avx512vbmi2", &["avx512bw"]),
+    ("avx512vl", &["avx512f"]),
+    ("avx512vnni", &["avx512f"]),
+    ("avx512vp2intersect", &["avx512f"]),
+    ("avx512vpopcntdq", &["avx512f"]),
+    ("avxifma", &["avx2"]),
+    ("avxneconvert", &["avx2"]),
+    ("avxvnni", &["avx2"]),
+    ("avxvnniint16", &["avx2"]),
+    ("avxvnniint8", &["avx2"]),
+    ("f16c", &["avx"]),
+    ("fma", &["avx"]),
+    ("gfni", &["sse2"]),
+    ("kl", &["sse2"]),
+    ("pclmulqdq", &["sse2"]),
+    ("sha", &["sse2"]),
+    ("sha512", &["avx2"]),
+    ("sm3", &["avx"]),
+    ("sm4", &["avx2"]),
+    ("sse2", &["sse"]),
+    ("sse3", &["sse2"]),
+    ("sse4.1", &["ssse3"]),
+    ("sse4.2", &["sse4.1"]),
+    ("sse4a", &["sse3"]),
+    ("ssse3", &["sse3"]),
+    ("vaes", &["avx2", "aes"]),
+    ("vpclmulqdq", &["avx", "pclmulqdq"]),
+    ("widekl", &["kl"]),
+    ("xop", &[/*"fma4", */ "avx", "sse4a"]),
+    ("xsavec", &["xsave"]),
+    ("xsaveopt", &["xsave"]),
+    ("xsaves", &["xsave"]),
+    // Hexagon
+    ("hvx-length128b", &["hvx"]),
+    // PowerPC
+    ("power10-vector", &["power9-vector"]),
+    ("power8-altivec", &["altivec"]),
+    ("power8-crypto", &["power8-altivec"]),
+    ("power8-vector", &["vsx", "power8-altivec"]),
+    ("power9-altivec", &["power8-altivec"]),
+    ("power9-vector", &["power8-vector", "power9-altivec"]),
+    ("vsx", &["altivec"]),
+    // MIPS
+    // RISC-V
+    ("a", &["zaamo", "zalrsc"]),
+    ("d", &["f"]),
+    ("zabha", &["zaamo"]),
+    ("zdinx", &["zfinx"]),
+    ("zfh", &["zfhmin"]),
+    ("zfhmin", &["f"]),
+    ("zhinx", &["zhinxmin"]),
+    ("zhinxmin", &["zfinx"]),
+    ("zk", &["zkn", "zkr", "zkt"]),
+    ("zkn", &["zbkb", "zbkc", "zbkx", "zkne", "zknd", "zknh"]),
+    ("zks", &["zbkb", "zbkc", "zbkx", "zksed", "zksh"]),
+    // WASM
+    ("relaxed-simd", &["simd128"]),
+    // BPF
+    ("alu32", &[]),
+    // CSKY
+    ("10e60", &["7e10"]),
+    ("2e3", &["e2"]),
+    ("3e3r2", &["3e3r1", "doloop"]),
+    ("3e3r3", &["doloop"]),
+    ("3e7", &["2e3"]),
+    ("7e10", &["3e7"]),
+    ("e1", &["elrw"]),
+    ("e2", &["e2"]),
+    ("mp", &["2e3"]),
+    ("mp1e2", &["3e7"]),
+    // LoongArch
+    ("d", &["f"]),
+    ("lasx", &["lsx"]),
+    ("lsx", &["d"]),
+    // IBM Z
+    ("nnp-assist", &["vector"]),
+    ("vector-enhancements-1", &["vector"]),
+    ("vector-enhancements-2", &["vector-enhancements-1"]),
+    ("vector-packed-decimal", &["vector"]),
+    ("vector-packed-decimal-enhancement", &["vector-packed-decimal"]),
+    ("vector-packed-decimal-enhancement-2", &["vector-packed-decimal-enhancement"]),
+    // SPARC
+    // m68k
+    ("isa-68010", &["isa-68000"]),
+    ("isa-68020", &["isa-68010"]),
+    ("isa-68030", &["isa-68020"]),
+    ("isa-68040", &["isa-68030", "isa-68882"]),
+    ("isa-68060", &["isa-68040"]),
+    ("isa-68882", &["isa-68881"]),
+];
+// spellchecker:on

crates/hir-ty/src/utils.rs

@@ -9,18 +9,16 @@ use chalk_ir::{
     DebruijnIndex,
 };
 use hir_def::{
-    attr::Attrs,
     db::DefDatabase,
     generics::{WherePredicate, WherePredicateTypeTarget},
     lang_item::LangItem,
     resolver::{HasResolver, TypeNs},
-    tt,
     type_ref::{TraitBoundModifier, TypeRef},
     EnumId, EnumVariantId, FunctionId, Lookup, OpaqueInternableThing, TraitId, TypeAliasId,
     TypeOrConstParamId,
 };
 use hir_expand::name::Name;
-use intern::{sym, Symbol};
+use intern::sym;
 use rustc_abi::TargetDataLayout;
 use rustc_hash::FxHashSet;
 use smallvec::{smallvec, SmallVec};
@@ -32,8 +30,8 @@ use crate::{
     db::HirDatabase,
     layout::{Layout, TagEncoding},
     mir::pad16,
-    ChalkTraitId, Const, ConstScalar, GenericArg, Interner, Substitution, TraitRef, TraitRefExt,
-    Ty, WhereClause,
+    ChalkTraitId, Const, ConstScalar, GenericArg, Interner, Substitution, TargetFeatures, TraitRef,
+    TraitRefExt, Ty, WhereClause,
 };
 
 pub(crate) fn fn_traits(
@@ -267,32 +265,6 @@ impl<'a> ClosureSubst<'a> {
     }
 }
 
-#[derive(Debug, Default)]
-pub struct TargetFeatures {
-    enabled: FxHashSet<Symbol>,
-}
-
-impl TargetFeatures {
-    pub fn from_attrs(attrs: &Attrs) -> Self {
-        let enabled = attrs
-            .by_key(&sym::target_feature)
-            .tt_values()
-            .filter_map(|tt| {
-                match tt.token_trees().flat_tokens() {
-                    [
-                        tt::TokenTree::Leaf(tt::Leaf::Ident(enable_ident)),
-                        tt::TokenTree::Leaf(tt::Leaf::Punct(tt::Punct { char: '=', .. })),
-                        tt::TokenTree::Leaf(tt::Leaf::Literal(tt::Literal { kind: tt::LitKind::Str, symbol: features, .. })),
-                    ] if enable_ident.sym == sym::enable => Some(features),
-                    _ => None,
-                }
-            })
-            .flat_map(|features| features.as_str().split(',').map(Symbol::intern))
-            .collect();
-        Self { enabled }
-    }
-}
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Unsafety {
     Safe,
@@ -314,7 +286,8 @@ pub fn is_fn_unsafe_to_call(
 
     if data.has_target_feature() {
         // RFC 2396 <https://rust-lang.github.io/rfcs/2396-target-feature-1.1.html>.
-        let callee_target_features = TargetFeatures::from_attrs(&db.attrs(func.into()));
+        let callee_target_features =
+            TargetFeatures::from_attrs_no_implications(&db.attrs(func.into()));
         if !caller_target_features.enabled.is_superset(&callee_target_features.enabled) {
             return Unsafety::Unsafe;
         }

crates/ide-diagnostics/src/handlers/missing_unsafe.rs

@@ -854,7 +854,7 @@ fn main() {
 #[target_feature(enable = "avx")]
 fn foo() {}
 
-#[target_feature(enable = "avx,avx2")]
+#[target_feature(enable = "avx2")]
 fn bar() {
     foo();
 }