Rollup of 6 pull requests

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -698,13 +698,11 @@ impl<'a> AstValidator<'a> {
             unreachable!("C variable argument list cannot be used in closures")
         };
 
-        // C-variadics are not yet implemented in const evaluation.
-        if let Const::Yes(const_span) = sig.header.constness {
-            self.dcx().emit_err(errors::ConstAndCVariadic {
-                spans: vec![const_span, variadic_param.span],
-                const_span,
-                variadic_span: variadic_param.span,
-            });
+        if let Const::Yes(_) = sig.header.constness
+            && !self.features.enabled(sym::const_c_variadic)
+        {
+            let msg = format!("c-variadic const function definitions are unstable");
+            feature_err(&self.sess, sym::const_c_variadic, sig.span, msg).emit();
         }
 
         if let Some(coroutine_kind) = sig.header.coroutine_kind {

compiler/rustc_ast_passes/src/errors.rs

@@ -823,17 +823,6 @@ pub(crate) struct ConstAndCoroutine {
     pub coroutine_kind: &'static str,
 }
 
-#[derive(Diagnostic)]
-#[diag("functions cannot be both `const` and C-variadic")]
-pub(crate) struct ConstAndCVariadic {
-    #[primary_span]
-    pub spans: Vec<Span>,
-    #[label("`const` because of this")]
-    pub const_span: Span,
-    #[label("C-variadic because of this")]
-    pub variadic_span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag("functions cannot be both `{$coroutine_kind}` and C-variadic")]
 pub(crate) struct CoroutineAndCVariadic {

compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs

@@ -1178,6 +1178,30 @@ impl<S: Stage> SingleAttributeParser<S> for RustcDiagnosticItemParser {
     }
 }
 
+pub(crate) struct RustcDoNotConstCheckParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcDoNotConstCheckParser {
+    const PATH: &[Symbol] = &[sym::rustc_do_not_const_check];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
+        Allow(Target::Fn),
+        Allow(Target::Method(MethodKind::Inherent)),
+        Allow(Target::Method(MethodKind::TraitImpl)),
+        Allow(Target::Method(MethodKind::Trait { body: false })),
+        Allow(Target::Method(MethodKind::Trait { body: true })),
+    ]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcDoNotConstCheck;
+}
+
+pub(crate) struct RustcNonnullOptimizationGuaranteedParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcNonnullOptimizationGuaranteedParser {
+    const PATH: &[Symbol] = &[sym::rustc_nonnull_optimization_guaranteed];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::Struct)]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcNonnullOptimizationGuaranteed;
+}
+
 pub(crate) struct RustcSymbolName;
 
 impl<S: Stage> SingleAttributeParser<S> for RustcSymbolName {

compiler/rustc_attr_parsing/src/context.rs

@@ -274,6 +274,7 @@ attribute_parsers!(
         Single<WithoutArgs<RustcConversionSuggestionParser>>,
         Single<WithoutArgs<RustcDeallocatorParser>>,
         Single<WithoutArgs<RustcDelayedBugFromInsideQueryParser>>,
+        Single<WithoutArgs<RustcDoNotConstCheckParser>>,
         Single<WithoutArgs<RustcDumpDefParentsParser>>,
         Single<WithoutArgs<RustcDumpItemBoundsParser>>,
         Single<WithoutArgs<RustcDumpPredicatesParser>>,
@@ -295,6 +296,7 @@ attribute_parsers!(
         Single<WithoutArgs<RustcNoImplicitBoundsParser>>,
         Single<WithoutArgs<RustcNoMirInlineParser>>,
         Single<WithoutArgs<RustcNonConstTraitMethodParser>>,
+        Single<WithoutArgs<RustcNonnullOptimizationGuaranteedParser>>,
         Single<WithoutArgs<RustcNounwindParser>>,
         Single<WithoutArgs<RustcObjectLifetimeDefaultParser>>,
         Single<WithoutArgs<RustcOffloadKernelParser>>,

compiler/rustc_codegen_cranelift/patches/0029-sysroot_tests-disable-f16-math.patch

@@ -0,0 +1,133 @@
+From 285d5716fcfa6d43a3516d899b73bc85da322c25 Mon Sep 17 00:00:00 2001
+From: xonx <119700621+xonx4l@users.noreply.github.com>
+Date: Sun, 15 Feb 2026 14:06:49 +0000
+Subject: [PATCH] Disable f16 math tests for cranelift
+
+---
+ coretests/tests/floats/mod.rs | 26 +++++++++++++-------------
+ 1 file changed, 13 insertions(+), 13 deletions(-)
+
+diff --git a/coretests/tests/floats/mod.rs b/coretests/tests/floats/mod.rs
+index c61961f8584..d7b4fa20322 100644
+--- a/coretests/tests/floats/mod.rs
++++ b/coretests/tests/floats/mod.rs
+@@ -1534,7 +1534,7 @@ fn s_nan() -> Float {
+     name: powf,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1557,7 +1557,7 @@ fn s_nan() -> Float {
+     name: exp,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1578,7 +1578,7 @@ fn s_nan() -> Float {
+     name: exp2,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1598,7 +1598,7 @@ fn s_nan() -> Float {
+     name: ln,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1620,7 +1620,7 @@ fn s_nan() -> Float {
+     name: log,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1645,7 +1645,7 @@ fn s_nan() -> Float {
+     name: log2,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1668,7 +1668,7 @@ fn s_nan() -> Float {
+     name: log10,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1692,7 +1692,7 @@ fn s_nan() -> Float {
+     name: asinh,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1725,7 +1725,7 @@ fn s_nan() -> Float {
+     name: acosh,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1753,7 +1753,7 @@ fn s_nan() -> Float {
+     name: atanh,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1779,7 +1779,7 @@ fn s_nan() -> Float {
+     name: gamma,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -1814,7 +1814,7 @@ fn s_nan() -> Float {
+     name: ln_gamma,
+     attrs: {
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+@@ -2027,7 +2027,7 @@ fn s_nan() -> Float {
+     attrs: {
+         // FIXME(f16_f128): add math tests when available
+         const: #[cfg(false)],
+-        f16: #[cfg(all(not(miri), target_has_reliable_f16_math))],
++        f16: #[cfg(false)], // FIXME(rust-lang/rustc_codegen_cranelift#1622)
+         f128: #[cfg(all(not(miri), target_has_reliable_f128_math))],
+     },
+     test<Float> {
+-- 
+2.50.1
+

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -180,6 +180,10 @@ impl CodegenBackend for CraneliftCodegenBackend {
             && sess.target.env == Env::Gnu
             && sess.target.abi != Abi::Llvm);
 
+        // FIXME(f128): f128 math operations need f128 math symbols, which currently aren't always
+        // filled in by compiler-builtins. The only libc that provides these currently is glibc.
+        let has_reliable_f128_math = has_reliable_f16_f128 && sess.target.env == Env::Gnu;
+
         TargetConfig {
             target_features,
             unstable_target_features,
@@ -188,7 +192,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
             has_reliable_f16: has_reliable_f16_f128,
             has_reliable_f16_math: has_reliable_f16_f128,
             has_reliable_f128: has_reliable_f16_f128,
-            has_reliable_f128_math: has_reliable_f16_f128,
+            has_reliable_f128_math,
         }
     }
 

compiler/rustc_const_eval/src/check_consts/check.rs

@@ -7,9 +7,10 @@ use std::ops::Deref;
 
 use rustc_data_structures::assert_matches;
 use rustc_errors::{Diag, ErrorGuaranteed};
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
-use rustc_hir::{self as hir, LangItem};
+use rustc_hir::{self as hir, LangItem, find_attr};
 use rustc_index::bit_set::DenseBitSet;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::mir::visit::Visitor;
@@ -215,7 +216,7 @@ impl<'mir, 'tcx> Checker<'mir, 'tcx> {
             return;
         }
 
-        if !tcx.has_attr(def_id, sym::rustc_do_not_const_check) {
+        if !find_attr!(tcx.get_all_attrs(def_id), AttributeKind::RustcDoNotConstCheck) {
             self.visit_body(body);
         }
 
@@ -815,6 +816,10 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                     });
                 }
 
+                if self.tcx.fn_sig(callee).skip_binder().c_variadic() {
+                    self.check_op(ops::FnCallCVariadic)
+                }
+
                 // At this point, we are calling a function, `callee`, whose `DefId` is known...
 
                 // `begin_panic` and `panic_display` functions accept generic

compiler/rustc_const_eval/src/check_consts/ops.rs

@@ -75,6 +75,27 @@ impl<'tcx> NonConstOp<'tcx> for FnCallIndirect {
     }
 }
 
+/// A c-variadic function call.
+#[derive(Debug)]
+pub(crate) struct FnCallCVariadic;
+impl<'tcx> NonConstOp<'tcx> for FnCallCVariadic {
+    fn status_in_item(&self, _ccx: &ConstCx<'_, 'tcx>) -> Status {
+        Status::Unstable {
+            gate: sym::const_c_variadic,
+            gate_already_checked: false,
+            safe_to_expose_on_stable: false,
+            is_function_call: true,
+        }
+    }
+
+    fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> Diag<'tcx> {
+        ccx.tcx.sess.create_feature_err(
+            errors::NonConstCVariadicCall { span, kind: ccx.const_kind() },
+            sym::const_c_variadic,
+        )
+    }
+}
+
 /// A call to a function that is in a trait, or has trait bounds that make it conditionally-const.
 #[derive(Debug)]
 pub(crate) struct ConditionallyConstCall<'tcx> {

compiler/rustc_const_eval/src/check_consts/post_drop_elaboration.rs

@@ -1,3 +1,5 @@
+use rustc_hir::attrs::AttributeKind;
+use rustc_hir::find_attr;
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::{self, BasicBlock, Location};
 use rustc_middle::ty::TyCtxt;
@@ -34,7 +36,7 @@ pub fn check_live_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mir::Body<'tcx>) {
         return;
     }
 
-    if tcx.has_attr(body.source.def_id(), sym::rustc_do_not_const_check) {
+    if find_attr!(tcx.get_all_attrs(body.source.def_id()), AttributeKind::RustcDoNotConstCheck) {
         return;
     }
 

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -6,10 +6,11 @@ use rustc_abi::{Align, Size};
 use rustc_ast::Mutability;
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap, IndexEntry};
 use rustc_errors::msg;
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
-use rustc_hir::{self as hir, CRATE_HIR_ID, LangItem};
+use rustc_hir::{self as hir, CRATE_HIR_ID, LangItem, find_attr};
 use rustc_middle::mir::AssertMessage;
-use rustc_middle::mir::interpret::{Pointer, ReportedErrorInfo};
+use rustc_middle::mir::interpret::ReportedErrorInfo;
 use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::layout::{HasTypingEnv, TyAndLayout, ValidityRequirement};
 use rustc_middle::ty::{self, Ty, TyCtxt};
@@ -22,7 +23,7 @@ use super::error::*;
 use crate::errors::{LongRunning, LongRunningWarn};
 use crate::interpret::{
     self, AllocId, AllocInit, AllocRange, ConstAllocation, CtfeProvenance, FnArg, Frame,
-    GlobalAlloc, ImmTy, InterpCx, InterpResult, OpTy, PlaceTy, RangeSet, Scalar,
+    GlobalAlloc, ImmTy, InterpCx, InterpResult, OpTy, PlaceTy, Pointer, RangeSet, Scalar,
     compile_time_machine, err_inval, interp_ok, throw_exhaust, throw_inval, throw_ub,
     throw_ub_custom, throw_unsup, throw_unsup_format,
 };
@@ -440,7 +441,9 @@ impl<'tcx> interpret::Machine<'tcx> for CompileTimeMachine<'tcx> {
             // sensitive check here. But we can at least rule out functions that are not const at
             // all. That said, we have to allow calling functions inside a `const trait`. These
             // *are* const-checked!
-            if !ecx.tcx.is_const_fn(def) || ecx.tcx.has_attr(def, sym::rustc_do_not_const_check) {
+            if !ecx.tcx.is_const_fn(def)
+                || find_attr!(ecx.tcx.get_all_attrs(def), AttributeKind::RustcDoNotConstCheck)
+            {
                 // We certainly do *not* want to actually call the fn
                 // though, so be sure we return here.
                 throw_unsup_format!("calling non-const function `{}`", instance)