Rollup merge of #129555 - RalfJung:const_float_bits_conv, r=dtolnay

stabilize const_float_bits_conv This stabilizes `const_float_bits_conv`, and thus fixes #72447. With #128596 having landed, this is entirely a libs-only question now. ```rust impl f32 { pub const fn to_bits(self) -> u32; pub const fn from_bits(v: u32) -> Self; pub const fn to_be_bytes(self) -> [u8; 4]; pub const fn to_le_bytes(self) -> [u8; 4] pub const fn to_ne_bytes(self) -> [u8; 4]; pub const fn from_be_bytes(bytes: [u8; 4]) -> Self; pub const fn from_le_bytes(bytes: [u8; 4]) -> Self; pub const fn from_ne_bytes(bytes: [u8; 4]) -> Self; } impl f64 { pub const fn to_bits(self) -> u64; pub const fn from_bits(v: u64) -> Self; pub const fn to_be_bytes(self) -> [u8; 8]; pub const fn to_le_bytes(self) -> [u8; 8] pub const fn to_ne_bytes(self) -> [u8; 8]; pub const fn from_be_bytes(bytes: [u8; 8]) -> Self; pub const fn from_le_bytes(bytes: [u8; 8]) -> Self; pub const fn from_ne_bytes(bytes: [u8; 8]) -> Self; } ```` Cc `@rust-lang/wg-const-eval` `@rust-lang/libs-api`
rust-lang · Sep 7, 2024 · 3b2139b · 3b2139b
2 parents ccf3f6e + 19908ff
commit 3b2139b
Show file tree

Hide file tree

Showing 17 changed files with 223 additions and 84 deletions.
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
@@ -122,7 +122,6 @@
 #![feature(const_cell_into_inner)]
 #![feature(const_eval_select)]
 #![feature(const_exact_div)]
-#![feature(const_float_bits_conv)]
 #![feature(const_float_classify)]
 #![feature(const_fmt_arguments_new)]
 #![feature(const_hash)]
@@ -166,6 +165,8 @@
 #![feature(coverage_attribute)]
 #![feature(do_not_recommend)]
 #![feature(duration_consts_float)]
+#![feature(f128_const)]
+#![feature(f16_const)]
 #![feature(internal_impls_macro)]
 #![feature(ip)]
 #![feature(is_ascii_octdigit)]

diff --git a/library/core/src/num/f128.rs b/library/core/src/num/f128.rs
@@ -914,7 +914,7 @@ impl f128 {
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_bits(self) -> u128 {
         // SAFETY: `u128` is a plain old datatype so we can always transmute to it.
@@ -963,7 +963,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
     pub const fn from_bits(v: u128) -> Self {
         // It turns out the safety issues with sNaN were overblown! Hooray!
         // SAFETY: `u128` is a plain old datatype so we can always transmute from it.
@@ -990,7 +990,7 @@ impl f128 {
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_be_bytes(self) -> [u8; 16] {
         self.to_bits().to_be_bytes()
@@ -1016,7 +1016,7 @@ impl f128 {
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_le_bytes(self) -> [u8; 16] {
         self.to_bits().to_le_bytes()
@@ -1053,7 +1053,7 @@ impl f128 {
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_ne_bytes(self) -> [u8; 16] {
         self.to_bits().to_ne_bytes()
@@ -1081,7 +1081,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
     pub const fn from_be_bytes(bytes: [u8; 16]) -> Self {
         Self::from_bits(u128::from_be_bytes(bytes))
     }
@@ -1108,7 +1108,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
     pub const fn from_le_bytes(bytes: [u8; 16]) -> Self {
         Self::from_bits(u128::from_le_bytes(bytes))
     }
@@ -1145,7 +1145,7 @@ impl f128 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f128", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f128_const", issue = "116909")]
     pub const fn from_ne_bytes(bytes: [u8; 16]) -> Self {
         Self::from_bits(u128::from_ne_bytes(bytes))
     }

diff --git a/library/core/src/num/f16.rs b/library/core/src/num/f16.rs
@@ -925,7 +925,7 @@ impl f16 {
     /// ```
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_bits(self) -> u16 {
         // SAFETY: `u16` is a plain old datatype so we can always transmute to it.
@@ -973,7 +973,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
     pub const fn from_bits(v: u16) -> Self {
         // It turns out the safety issues with sNaN were overblown! Hooray!
         // SAFETY: `u16` is a plain old datatype so we can always transmute from it.
@@ -999,7 +999,7 @@ impl f16 {
     /// ```
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_be_bytes(self) -> [u8; 2] {
         self.to_bits().to_be_bytes()
@@ -1024,7 +1024,7 @@ impl f16 {
     /// ```
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_le_bytes(self) -> [u8; 2] {
         self.to_bits().to_le_bytes()
@@ -1062,7 +1062,7 @@ impl f16 {
     /// ```
     #[inline]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
     #[must_use = "this returns the result of the operation, without modifying the original"]
     pub const fn to_ne_bytes(self) -> [u8; 2] {
         self.to_bits().to_ne_bytes()
@@ -1086,7 +1086,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
     pub const fn from_be_bytes(bytes: [u8; 2]) -> Self {
         Self::from_bits(u16::from_be_bytes(bytes))
     }
@@ -1109,7 +1109,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
     pub const fn from_le_bytes(bytes: [u8; 2]) -> Self {
         Self::from_bits(u16::from_le_bytes(bytes))
     }
@@ -1143,7 +1143,7 @@ impl f16 {
     #[inline]
     #[must_use]
     #[unstable(feature = "f16", issue = "116909")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_unstable(feature = "f16_const", issue = "116909")]
     pub const fn from_ne_bytes(bytes: [u8; 2]) -> Self {
         Self::from_bits(u16::from_ne_bytes(bytes))
     }

diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
@@ -1115,7 +1115,7 @@ impl f32 {
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn to_bits(self) -> u32 {
         // SAFETY: `u32` is a plain old datatype so we can always transmute to it.
@@ -1159,7 +1159,7 @@ impl f32 {
     /// assert_eq!(v, 12.5);
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_bits(v: u32) -> Self {
@@ -1183,7 +1183,7 @@ impl f32 {
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn to_be_bytes(self) -> [u8; 4] {
         self.to_bits().to_be_bytes()
@@ -1204,7 +1204,7 @@ impl f32 {
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn to_le_bytes(self) -> [u8; 4] {
         self.to_bits().to_le_bytes()
@@ -1238,7 +1238,7 @@ impl f32 {
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn to_ne_bytes(self) -> [u8; 4] {
         self.to_bits().to_ne_bytes()
@@ -1256,7 +1256,7 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_be_bytes(bytes: [u8; 4]) -> Self {
@@ -1275,7 +1275,7 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_le_bytes(bytes: [u8; 4]) -> Self {
@@ -1305,7 +1305,7 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_ne_bytes(bytes: [u8; 4]) -> Self {

diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
@@ -1111,7 +1111,7 @@ impl f64 {
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn to_bits(self) -> u64 {
         // SAFETY: `u64` is a plain old datatype so we can always transmute to it.
@@ -1155,7 +1155,7 @@ impl f64 {
     /// assert_eq!(v, 12.5);
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_bits(v: u64) -> Self {
@@ -1179,7 +1179,7 @@ impl f64 {
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn to_be_bytes(self) -> [u8; 8] {
         self.to_bits().to_be_bytes()
@@ -1200,7 +1200,7 @@ impl f64 {
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn to_le_bytes(self) -> [u8; 8] {
         self.to_bits().to_le_bytes()
@@ -1234,7 +1234,7 @@ impl f64 {
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn to_ne_bytes(self) -> [u8; 8] {
         self.to_bits().to_ne_bytes()
@@ -1252,7 +1252,7 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_be_bytes(bytes: [u8; 8]) -> Self {
@@ -1271,7 +1271,7 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_le_bytes(bytes: [u8; 8]) -> Self {
@@ -1301,7 +1301,7 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
-    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
+    #[rustc_const_stable(feature = "const_float_bits_conv", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub const fn from_ne_bytes(bytes: [u8; 8]) -> Self {

diff --git a/src/tools/clippy/clippy_lints/src/transmute/mod.rs b/src/tools/clippy/clippy_lints/src/transmute/mod.rs
@@ -619,10 +619,10 @@ impl<'tcx> LateLintPass<'tcx> for Transmute {
                 | transmute_ref_to_ref::check(cx, e, from_ty, to_ty, arg, const_context)
                 | transmute_ptr_to_ptr::check(cx, e, from_ty, to_ty, arg, &self.msrv)
                 | transmute_int_to_bool::check(cx, e, from_ty, to_ty, arg)
-                | transmute_int_to_float::check(cx, e, from_ty, to_ty, arg, const_context)
+                | transmute_int_to_float::check(cx, e, from_ty, to_ty, arg)
                 | transmute_int_to_non_zero::check(cx, e, from_ty, to_ty, arg)
-                | transmute_float_to_int::check(cx, e, from_ty, to_ty, arg, const_context)
-                | transmute_num_to_bytes::check(cx, e, from_ty, to_ty, arg, const_context)
+                | transmute_float_to_int::check(cx, e, from_ty, to_ty, arg)
+                | transmute_num_to_bytes::check(cx, e, from_ty, to_ty, arg)
                 | (unsound_collection_transmute::check(cx, e, from_ty, to_ty)
                     || transmute_undefined_repr::check(cx, e, from_ty, to_ty))
                 | (eager_transmute::check(cx, e, arg, from_ty, to_ty));

diff --git a/src/tools/clippy/clippy_lints/src/transmute/transmute_float_to_int.rs b/src/tools/clippy/clippy_lints/src/transmute/transmute_float_to_int.rs
@@ -15,10 +15,9 @@ pub(super) fn check<'tcx>(
     from_ty: Ty<'tcx>,
     to_ty: Ty<'tcx>,
     mut arg: &'tcx Expr<'_>,
-    const_context: bool,
 ) -> bool {
     match (&from_ty.kind(), &to_ty.kind()) {
-        (ty::Float(float_ty), ty::Int(_) | ty::Uint(_)) if !const_context => {
+        (ty::Float(float_ty), ty::Int(_) | ty::Uint(_)) => {
             span_lint_and_then(
                 cx,
                 TRANSMUTE_FLOAT_TO_INT,

diff --git a/src/tools/clippy/clippy_lints/src/transmute/transmute_int_to_float.rs b/src/tools/clippy/clippy_lints/src/transmute/transmute_int_to_float.rs
@@ -14,10 +14,9 @@ pub(super) fn check<'tcx>(
     from_ty: Ty<'tcx>,
     to_ty: Ty<'tcx>,
     arg: &'tcx Expr<'_>,
-    const_context: bool,
 ) -> bool {
     match (&from_ty.kind(), &to_ty.kind()) {
-        (ty::Int(_) | ty::Uint(_), ty::Float(_)) if !const_context => {
+        (ty::Int(_) | ty::Uint(_), ty::Float(_)) => {
             span_lint_and_then(
                 cx,
                 TRANSMUTE_INT_TO_FLOAT,

diff --git a/src/tools/clippy/clippy_lints/src/transmute/transmute_num_to_bytes.rs b/src/tools/clippy/clippy_lints/src/transmute/transmute_num_to_bytes.rs
@@ -14,18 +14,12 @@ pub(super) fn check<'tcx>(
     from_ty: Ty<'tcx>,
     to_ty: Ty<'tcx>,
     arg: &'tcx Expr<'_>,
-    const_context: bool,
 ) -> bool {
     match (&from_ty.kind(), &to_ty.kind()) {
         (ty::Int(_) | ty::Uint(_) | ty::Float(_), ty::Array(arr_ty, _)) => {
             if !matches!(arr_ty.kind(), ty::Uint(UintTy::U8)) {
                 return false;
             }
-            if matches!(from_ty.kind(), ty::Float(_)) && const_context {
-                // TODO: Remove when const_float_bits_conv is stabilized
-                // rust#72447
-                return false;
-            }
 
             span_lint_and_then(
                 cx,