Auto merge of #143233 - dianqk:rollup-lcx3278, r=dianqk

Rollup of 14 pull requests

Successful merges:

 - rust-lang/rust#142429 (`tests/ui`: A New Order [13/N])
 - rust-lang/rust#142514 (Miri: handling of SNaN inputs in `f*::pow` operations)
 - rust-lang/rust#143066 (Use let chains in the new solver)
 - rust-lang/rust#143090 (Workaround for memory unsafety in third party DLLs)
 - rust-lang/rust#143118 (`tests/ui`: A New Order [15/N])
 - rust-lang/rust#143159 (Do not freshen `ReError`)
 - rust-lang/rust#143168 (`tests/ui`: A New Order [16/N])
 - rust-lang/rust#143176 (fix typos and improve clarity in documentation)
 - rust-lang/rust#143187 (Add my work email to mailmap)
 - rust-lang/rust#143190 (Use the `new` method for `BasicBlockData` and `Statement`)
 - rust-lang/rust#143195 (`tests/ui`: A New Order [17/N])
 - rust-lang/rust#143196 (Port #[link_section] to the new attribute parsing infrastructure)
 - rust-lang/rust#143199 (Re-disable `tests/run-make/short-ice` on Windows MSVC again)
 - rust-lang/rust#143219 (Show auto trait and blanket impls for `!`)

r? `@ghost`
`@rustbot` modify labels: rollup

8 files changed, 116 insertions, 49 deletions

diff --git a/src/doc/rustc-dev-guide/src/tests/ui.md b/src/doc/rustc-dev-guide/src/tests/ui.md
index 09dc476d68e..f7e62e1eccf 100644
--- a/src/doc/rustc-dev-guide/src/tests/ui.md
+++ b/src/doc/rustc-dev-guide/src/tests/ui.md
@@ -499,7 +499,7 @@ This directive takes comma-separated issue numbers as arguments, or `"unknown"`:
 - `//@ known-bug: rust-lang/chalk#123456`
   (allows arbitrary text before the `#`, which is useful when the issue is on another repo)
 - `//@ known-bug: unknown`
-  (when there is no known issue yet; preferrably open one if it does not already exist)
+  (when there is no known issue yet; preferably open one if it does not already exist)
 
 Do not include [error annotations](#error-annotations) in a test with
 `known-bug`. The test should still include other normal directives and
diff --git a/src/doc/unstable-book/src/language-features/type-alias-impl-trait.md b/src/doc/unstable-book/src/language-features/type-alias-impl-trait.md
index a6fb25a55be..10464e500ec 100644
--- a/src/doc/unstable-book/src/language-features/type-alias-impl-trait.md
+++ b/src/doc/unstable-book/src/language-features/type-alias-impl-trait.md
@@ -64,7 +64,7 @@ struct HaveAlias {
 
 In this example, the concrete type referred to by `Alias` is guaranteed to be the same wherever `Alias` occurs.
 
-> Orginally this feature included type aliases as an associated type of a trait. In [#110237] this was split off to [`impl_trait_in_assoc_type`].
+> Originally this feature included type aliases as an associated type of a trait. In [#110237] this was split off to [`impl_trait_in_assoc_type`].
 
 ### `type_alias_impl_trait` in argument position.
 
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 3cac55493f0..600c564d714 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -753,9 +753,12 @@ impl Item {
             .other_attrs
             .iter()
             .filter_map(|attr| {
+                if let hir::Attribute::Parsed(AttributeKind::LinkSection { name, .. }) = attr {
+                    Some(format!("#[link_section = \"{name}\"]"))
+                }
                 // NoMangle is special cased, as it appears in HTML output, and we want to show it in source form, not HIR printing.
                 // It is also used by cargo-semver-checks.
-                if let hir::Attribute::Parsed(AttributeKind::NoMangle(..)) = attr {
+                else if let hir::Attribute::Parsed(AttributeKind::NoMangle(..)) = attr {
                     Some("#[no_mangle]".to_string())
                 } else if let hir::Attribute::Parsed(AttributeKind::ExportName { name, .. }) = attr
                 {
diff --git a/src/tools/miri/src/intrinsics/mod.rs b/src/tools/miri/src/intrinsics/mod.rs
index ec77a162cdb..ed1851a19ae 100644
--- a/src/tools/miri/src/intrinsics/mod.rs
+++ b/src/tools/miri/src/intrinsics/mod.rs
@@ -191,7 +191,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let [f] = check_intrinsic_arg_count(args)?;
                 let f = this.read_scalar(f)?.to_f32()?;
 
-                let res = fixed_float_value(intrinsic_name, &[f]).unwrap_or_else(||{
+                let res = fixed_float_value(this, intrinsic_name, &[f]).unwrap_or_else(|| {
                     // Using host floats (but it's fine, these operations do not have
                     // guaranteed precision).
                     let host = f.to_host();
@@ -235,7 +235,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let [f] = check_intrinsic_arg_count(args)?;
                 let f = this.read_scalar(f)?.to_f64()?;
 
-                let res = fixed_float_value(intrinsic_name, &[f]).unwrap_or_else(||{
+                let res = fixed_float_value(this, intrinsic_name, &[f]).unwrap_or_else(|| {
                     // Using host floats (but it's fine, these operations do not have
                     // guaranteed precision).
                     let host = f.to_host();
@@ -312,7 +312,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let f1 = this.read_scalar(f1)?.to_f32()?;
                 let f2 = this.read_scalar(f2)?.to_f32()?;
 
-                let res = fixed_float_value(intrinsic_name, &[f1, f2]).unwrap_or_else(|| {
+                let res = fixed_float_value(this, intrinsic_name, &[f1, f2]).unwrap_or_else(|| {
                     // Using host floats (but it's fine, this operation does not have guaranteed precision).
                     let res = f1.to_host().powf(f2.to_host()).to_soft();
 
@@ -330,7 +330,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let f1 = this.read_scalar(f1)?.to_f64()?;
                 let f2 = this.read_scalar(f2)?.to_f64()?;
 
-                let res = fixed_float_value(intrinsic_name, &[f1, f2]).unwrap_or_else(|| {
+                let res = fixed_float_value(this, intrinsic_name, &[f1, f2]).unwrap_or_else(|| {
                     // Using host floats (but it's fine, this operation does not have guaranteed precision).
                     let res = f1.to_host().powf(f2.to_host()).to_soft();
 
@@ -349,7 +349,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let f = this.read_scalar(f)?.to_f32()?;
                 let i = this.read_scalar(i)?.to_i32()?;
 
-                let res = fixed_powi_float_value(f, i).unwrap_or_else(|| {
+                let res = fixed_powi_float_value(this, f, i).unwrap_or_else(|| {
                     // Using host floats (but it's fine, this operation does not have guaranteed precision).
                     let res = f.to_host().powi(i).to_soft();
 
@@ -367,7 +367,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let f = this.read_scalar(f)?.to_f64()?;
                 let i = this.read_scalar(i)?.to_i32()?;
 
-                let res = fixed_powi_float_value(f, i).unwrap_or_else(|| {
+                let res = fixed_powi_float_value(this, f, i).unwrap_or_else(|| {
                     // Using host floats (but it's fine, this operation does not have guaranteed precision).
                     let res = f.to_host().powi(i).to_soft();
 
@@ -496,52 +496,88 @@ fn apply_random_float_error_to_imm<'tcx>(
 /// - logf32, logf64, log2f32, log2f64, log10f32, log10f64
 /// - powf32, powf64
 ///
+/// # Return
+///
 /// Returns `Some(output)` if the `intrinsic` results in a defined fixed `output` specified in the C standard
 /// (specifically, C23 annex F.10)  when given `args` as arguments. Outputs that are unaffected by a relative error
 /// (such as INF and zero) are not handled here, they are assumed to be handled by the underlying
 /// implementation. Returns `None` if no specific value is guaranteed.
+///
+/// # Note
+///
+/// For `powf*` operations of the form:
+///
+/// - `(SNaN)^(±0)`
+/// - `1^(SNaN)`
+///
+/// The result is implementation-defined:
+/// - musl returns for both `1.0`
+/// - glibc returns for both `NaN`
+///
+/// This discrepancy exists because SNaN handling is not consistently defined across platforms,
+/// and the C standard leaves behavior for SNaNs unspecified.
+///
+/// Miri chooses to adhere to both implementations and returns either one of them non-deterministically.
 fn fixed_float_value<S: Semantics>(
+    ecx: &mut MiriInterpCx<'_>,
     intrinsic_name: &str,
     args: &[IeeeFloat<S>],
 ) -> Option<IeeeFloat<S>> {
     let one = IeeeFloat::<S>::one();
-    match (intrinsic_name, args) {
+    Some(match (intrinsic_name, args) {
         // cos(+- 0) = 1
-        ("cosf32" | "cosf64", [input]) if input.is_zero() => Some(one),
+        ("cosf32" | "cosf64", [input]) if input.is_zero() => one,
 
         // e^0 = 1
-        ("expf32" | "expf64" | "exp2f32" | "exp2f64", [input]) if input.is_zero() => Some(one),
-
-        // 1^y = 1 for any y, even a NaN.
-        ("powf32" | "powf64", [base, _]) if *base == one => Some(one),
+        ("expf32" | "expf64" | "exp2f32" | "exp2f64", [input]) if input.is_zero() => one,
 
         // (-1)^(±INF) = 1
-        ("powf32" | "powf64", [base, exp]) if *base == -one && exp.is_infinite() => Some(one),
+        ("powf32" | "powf64", [base, exp]) if *base == -one && exp.is_infinite() => one,
+
+        // 1^y = 1 for any y, even a NaN
+        ("powf32" | "powf64", [base, exp]) if *base == one => {
+            let rng = ecx.machine.rng.get_mut();
+            // SNaN exponents get special treatment: they might return 1, or a NaN.
+            let return_nan = exp.is_signaling() && ecx.machine.float_nondet && rng.random();
+            // Handle both the musl and glibc cases non-deterministically.
+            if return_nan { ecx.generate_nan(args) } else { one }
+        }
 
-        // FIXME(#4286): The C ecosystem is inconsistent with handling sNaN's, some return 1 others propogate
-        // the NaN. We should return either 1 or the NaN non-deterministically here.
-        // But for now, just handle them all the same.
         // x^(±0) = 1 for any x, even a NaN
-        ("powf32" | "powf64", [_, exp]) if exp.is_zero() => Some(one),
+        ("powf32" | "powf64", [base, exp]) if exp.is_zero() => {
+            let rng = ecx.machine.rng.get_mut();
+            // SNaN bases get special treatment: they might return 1, or a NaN.
+            let return_nan = base.is_signaling() && ecx.machine.float_nondet && rng.random();
+            // Handle both the musl and glibc cases non-deterministically.
+            if return_nan { ecx.generate_nan(args) } else { one }
+        }
 
-        // There are a lot of cases for fixed outputs according to the C Standard, but these are mainly INF or zero
-        // which are not affected by the applied error.
-        _ => None,
-    }
+        // There are a lot of cases for fixed outputs according to the C Standard, but these are
+        // mainly INF or zero which are not affected by the applied error.
+        _ => return None,
+    })
 }
 
-/// Returns `Some(output)` if `powi` (called `pown` in C) results in a fixed value specified in the C standard
-/// (specifically, C23 annex F.10.4.6) when doing `base^exp`. Otherwise, returns `None`.
-fn fixed_powi_float_value<S: Semantics>(base: IeeeFloat<S>, exp: i32) -> Option<IeeeFloat<S>> {
-    match (base.category(), exp) {
-        // x^0 = 1, if x is not a Signaling NaN
-        // FIXME(#4286): The C ecosystem is inconsistent with handling sNaN's, some return 1 others propogate
-        // the NaN. We should return either 1 or the NaN non-deterministically here.
-        // But for now, just handle them all the same.
-        (_, 0) => Some(IeeeFloat::<S>::one()),
-
-        _ => None,
-    }
+/// Returns `Some(output)` if `powi` (called `pown` in C) results in a fixed value specified in the
+/// C standard (specifically, C23 annex F.10.4.6) when doing `base^exp`. Otherwise, returns `None`.
+fn fixed_powi_float_value<S: Semantics>(
+    ecx: &mut MiriInterpCx<'_>,
+    base: IeeeFloat<S>,
+    exp: i32,
+) -> Option<IeeeFloat<S>> {
+    Some(match exp {
+        0 => {
+            let one = IeeeFloat::<S>::one();
+            let rng = ecx.machine.rng.get_mut();
+            let return_nan = ecx.machine.float_nondet && rng.random() && base.is_signaling();
+            // For SNaN treatment, we are consistent with `powf`above.
+            // (We wouldn't have two, unlike powf all implementations seem to agree for powi,
+            // but for now we are maximally conservative.)
+            if return_nan { ecx.generate_nan(&[base]) } else { one }
+        }
+
+        _ => return None,
+    })
 }
 
 /// Given an floating-point operation and a floating-point value, clamps the result to the output
diff --git a/src/tools/miri/tests/pass/float.rs b/src/tools/miri/tests/pass/float.rs
index 6b782f55359..0fec1fb15eb 100644
--- a/src/tools/miri/tests/pass/float.rs
+++ b/src/tools/miri/tests/pass/float.rs
@@ -1066,17 +1066,6 @@ pub fn libm() {
     assert_eq!((-1f32).powf(f32::NEG_INFINITY), 1.0);
     assert_eq!((-1f64).powf(f64::NEG_INFINITY), 1.0);
 
-    // For pow (powf in rust) the C standard says:
-    // x^0 = 1 for all x even a sNaN
-    // FIXME(#4286): this does not match the behavior of all implementations.
-    assert_eq!(SNAN_F32.powf(0.0), 1.0);
-    assert_eq!(SNAN_F64.powf(0.0), 1.0);
-
-    // For pown (powi in rust) the C standard says:
-    // x^0 = 1 for all x even a sNaN
-    // FIXME(#4286): this does not match the behavior of all implementations.
-    assert_eq!(SNAN_F32.powi(0), 1.0);
-    assert_eq!(SNAN_F64.powi(0), 1.0);
 
     assert_eq!(0f32.powi(10), 0.0);
     assert_eq!(0f64.powi(100), 0.0);
@@ -1500,4 +1489,18 @@ fn test_non_determinism() {
     test_operations_f32(12., 5.);
     test_operations_f64(19., 11.);
     test_operations_f128(25., 18.);
+
+
+    // SNaN^0 = (1 | NaN)
+    ensure_nondet(|| f32::powf(SNAN_F32, 0.0).is_nan());
+    ensure_nondet(|| f64::powf(SNAN_F64, 0.0).is_nan());
+
+    // 1^SNaN = (1 | NaN)
+    ensure_nondet(|| f32::powf(1.0, SNAN_F32).is_nan());
+    ensure_nondet(|| f64::powf(1.0, SNAN_F64).is_nan());
+
+    // same as powf (keep it consistent):
+    // x^SNaN = (1 | NaN)
+    ensure_nondet(|| f32::powi(SNAN_F32, 0).is_nan());
+    ensure_nondet(|| f64::powi(SNAN_F64, 0).is_nan());
 }
diff --git a/src/tools/miri/tests/pass/float_nan.rs b/src/tools/miri/tests/pass/float_nan.rs
index cadbbd58af5..3ffdb6868ac 100644
--- a/src/tools/miri/tests/pass/float_nan.rs
+++ b/src/tools/miri/tests/pass/float_nan.rs
@@ -260,6 +260,7 @@ fn test_f32() {
 
     // Intrinsics
     let nan = F32::nan(Neg, Quiet, 0).as_f32();
+    let snan = F32::nan(Neg, Signaling, 1).as_f32();
     check_all_outcomes(
         HashSet::from_iter([F32::nan(Pos, Quiet, 0), F32::nan(Neg, Quiet, 0)]),
         || F32::from(f32::min(nan, nan)),
@@ -313,6 +314,18 @@ fn test_f32() {
         HashSet::from_iter([F32::nan(Pos, Quiet, 0), F32::nan(Neg, Quiet, 0)]),
         || F32::from(nan.ln_gamma().0),
     );
+    check_all_outcomes(
+        HashSet::from_iter([
+            F32::from(1.0),
+            F32::nan(Pos, Quiet, 0),
+            F32::nan(Neg, Quiet, 0),
+            F32::nan(Pos, Quiet, 1),
+            F32::nan(Neg, Quiet, 1),
+            F32::nan(Pos, Signaling, 1),
+            F32::nan(Neg, Signaling, 1),
+        ]),
+        || F32::from(snan.powf(0.0)),
+    );
 }
 
 fn test_f64() {
@@ -376,6 +389,7 @@ fn test_f64() {
 
     // Intrinsics
     let nan = F64::nan(Neg, Quiet, 0).as_f64();
+    let snan = F64::nan(Neg, Signaling, 1).as_f64();
     check_all_outcomes(
         HashSet::from_iter([F64::nan(Pos, Quiet, 0), F64::nan(Neg, Quiet, 0)]),
         || F64::from(f64::min(nan, nan)),
@@ -433,6 +447,18 @@ fn test_f64() {
         HashSet::from_iter([F64::nan(Pos, Quiet, 0), F64::nan(Neg, Quiet, 0)]),
         || F64::from(nan.ln_gamma().0),
     );
+    check_all_outcomes(
+        HashSet::from_iter([
+            F64::from(1.0),
+            F64::nan(Pos, Quiet, 0),
+            F64::nan(Neg, Quiet, 0),
+            F64::nan(Pos, Quiet, 1),
+            F64::nan(Neg, Quiet, 1),
+            F64::nan(Pos, Signaling, 1),
+            F64::nan(Neg, Signaling, 1),
+        ]),
+        || F64::from(snan.powf(0.0)),
+    );
 }
 
 fn test_casts() {
diff --git a/src/tools/rust-installer/README.md b/src/tools/rust-installer/README.md
index 99d8e5ca4cf..505ffe4093f 100644
--- a/src/tools/rust-installer/README.md
+++ b/src/tools/rust-installer/README.md
@@ -51,7 +51,7 @@ To combine installers.
 
 * Make install.sh not have to be customized, pull it's data from a
   config file.
-* Be more resiliant to installation failures, particularly if the disk
+* Be more resilient to installation failures, particularly if the disk
   is full.
 * Pre-install and post-uninstall scripts.
 * Allow components to depend on or contradict other components.
diff --git a/src/tools/tidy/src/issues.txt b/src/tools/tidy/src/issues.txt
index 7e27e0258c2..4f9af6d53dd 100644
--- a/src/tools/tidy/src/issues.txt
+++ b/src/tools/tidy/src/issues.txt
@@ -1368,7 +1368,6 @@ ui/infinite/issue-41731-infinite-macro-println.rs
 ui/intrinsics/issue-28575.rs
 ui/intrinsics/issue-84297-reifying-copy.rs
 ui/invalid/issue-114435-layout-type-err.rs
-ui/issue-11881.rs
 ui/issue-15924.rs
 ui/issue-16822.rs
 ui/issues-71798.rs