Auto merge of #133788 - matthiaskrgr:rollup-1p100a8, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #132723 (Unify `sysroot_target_{bin,lib}dir` handling)
 - #133041 (Print name of env var in `--print=deployment-target`)
 - #133325 (Reimplement `~const` trait specialization)
 - #133395 (Add simd_relaxed_fma intrinsic)
 - #133517 (Deeply normalize when computing implied outlives bounds)
 - #133785 (Add const evaluation error UI test.)

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

Author: bors

Diff for: compiler/rustc_codegen_cranelift/src/intrinsics/simd.rs

@@ -415,7 +415,8 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(
             });
         }
 
-        sym::simd_fma => {
+        // FIXME: simd_relaxed_fma doesn't relax to non-fused multiply-add
+        sym::simd_fma | sym::simd_relaxed_fma => {
             intrinsic_args!(fx, args => (a, b, c); intrinsic);
 
             if !a.layout().ty.is_simd() {

Diff for: compiler/rustc_codegen_gcc/src/intrinsic/simd.rs

@@ -772,6 +772,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             sym::simd_flog => "log",
             sym::simd_floor => "floor",
             sym::simd_fma => "fma",
+            sym::simd_relaxed_fma => "fma", // FIXME: this should relax to non-fused multiply-add when necessary
             sym::simd_fpowi => "__builtin_powi",
             sym::simd_fpow => "pow",
             sym::simd_fsin => "sin",

Diff for: compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -1534,6 +1534,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
             sym::simd_flog => ("log", bx.type_func(&[vec_ty], vec_ty)),
             sym::simd_floor => ("floor", bx.type_func(&[vec_ty], vec_ty)),
             sym::simd_fma => ("fma", bx.type_func(&[vec_ty, vec_ty, vec_ty], vec_ty)),
+            sym::simd_relaxed_fma => ("fmuladd", bx.type_func(&[vec_ty, vec_ty, vec_ty], vec_ty)),
             sym::simd_fpowi => ("powi", bx.type_func(&[vec_ty, bx.type_i32()], vec_ty)),
             sym::simd_fpow => ("pow", bx.type_func(&[vec_ty, vec_ty], vec_ty)),
             sym::simd_fsin => ("sin", bx.type_func(&[vec_ty], vec_ty)),
@@ -1572,6 +1573,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
             | sym::simd_fpowi
             | sym::simd_fsin
             | sym::simd_fsqrt
+            | sym::simd_relaxed_fma
             | sym::simd_round
             | sym::simd_trunc
     ) {

Diff for: compiler/rustc_codegen_ssa/src/back/apple.rs

@@ -97,7 +97,7 @@ fn minimum_deployment_target(target: &Target) -> OSVersion {
 }
 
 /// Name of the environment variable used to fetch the deployment target on the given OS.
-fn deployment_target_env_var(os: &str) -> &'static str {
+pub fn deployment_target_env_var(os: &str) -> &'static str {
     match os {
         "macos" => "MACOSX_DEPLOYMENT_TARGET",
         "ios" => "IPHONEOS_DEPLOYMENT_TARGET",

Diff for: compiler/rustc_data_structures/src/obligation_forest/mod.rs

@@ -415,6 +415,10 @@ impl<O: ForestObligation> ObligationForest<O> {
             .collect()
     }
 
+    pub fn has_pending_obligations(&self) -> bool {
+        self.nodes.iter().any(|node| node.state.get() == NodeState::Pending)
+    }
+
     fn insert_into_error_cache(&mut self, index: usize) {
         let node = &self.nodes[index];
         self.error_cache

Diff for: compiler/rustc_driver_impl/src/lib.rs

@@ -867,8 +867,9 @@ fn print_crate_info(
             DeploymentTarget => {
                 if sess.target.is_like_osx {
                     println_info!(
-                        "deployment_target={}",
-                        apple::pretty_version(apple::deployment_target(sess))
+                        "{}={}",
+                        apple::deployment_target_env_var(&sess.target.os),
+                        apple::pretty_version(apple::deployment_target(sess)),
                     )
                 } else {
                     #[allow(rustc::diagnostic_outside_of_impl)]

Diff for: compiler/rustc_hir_analysis/messages.ftl

@@ -113,8 +113,6 @@ hir_analysis_const_param_ty_impl_on_unsized =
     the trait `ConstParamTy` may not be implemented for this type
     .label = type is not `Sized`
 
-hir_analysis_const_specialize = cannot specialize on const impl with non-const impl
-
 hir_analysis_copy_impl_on_non_adt =
     the trait `Copy` cannot be implemented for this type
     .label = type is not a structure or enumeration

Diff for: compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -641,7 +641,9 @@ pub fn check_intrinsic_type(
             | sym::simd_round
             | sym::simd_trunc => (1, 0, vec![param(0)], param(0)),
             sym::simd_fpowi => (1, 0, vec![param(0), tcx.types.i32], param(0)),
-            sym::simd_fma => (1, 0, vec![param(0), param(0), param(0)], param(0)),
+            sym::simd_fma | sym::simd_relaxed_fma => {
+                (1, 0, vec![param(0), param(0), param(0)], param(0))
+            }
             sym::simd_gather => (3, 0, vec![param(0), param(1), param(2)], param(0)),
             sym::simd_masked_load => (3, 0, vec![param(0), param(1), param(2)], param(2)),
             sym::simd_masked_store => (3, 0, vec![param(0), param(1), param(2)], tcx.types.unit),

Diff for: compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -117,13 +117,12 @@ where
     }
     f(&mut wfcx)?;
 
-    let assumed_wf_types = wfcx.ocx.assumed_wf_types_and_report_errors(param_env, body_def_id)?;
-
     let errors = wfcx.select_all_or_error();
     if !errors.is_empty() {
         return Err(infcx.err_ctxt().report_fulfillment_errors(errors));
     }
 
+    let assumed_wf_types = wfcx.ocx.assumed_wf_types_and_report_errors(param_env, body_def_id)?;
     debug!(?assumed_wf_types);
 
     let infcx_compat = infcx.fork();

Diff for: compiler/rustc_hir_analysis/src/errors.rs

@@ -1079,13 +1079,6 @@ pub(crate) struct EmptySpecialization {
     pub base_impl_span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(hir_analysis_const_specialize)]
-pub(crate) struct ConstSpecialize {
-    #[primary_span]
-    pub span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag(hir_analysis_static_specialize)]
 pub(crate) struct StaticSpecialize {

Diff for: compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs

@@ -66,7 +66,6 @@
 //! on traits with methods can.
 
 use rustc_data_structures::fx::FxHashSet;
-use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
@@ -134,7 +133,6 @@ fn check_always_applicable(
         unconstrained_parent_impl_args(tcx, impl2_def_id, impl2_args)
     };
 
-    res = res.and(check_constness(tcx, impl1_def_id, impl2_node, span));
     res = res.and(check_static_lifetimes(tcx, &parent_args, span));
     res = res.and(check_duplicate_params(tcx, impl1_args, parent_args, span));
     res = res.and(check_predicates(tcx, impl1_def_id, impl1_args, impl2_node, impl2_args, span));
@@ -157,30 +155,6 @@ fn check_has_items(
     Ok(())
 }
 
-/// Check that the specializing impl `impl1` is at least as const as the base
-/// impl `impl2`
-fn check_constness(
-    tcx: TyCtxt<'_>,
-    impl1_def_id: LocalDefId,
-    impl2_node: Node,
-    span: Span,
-) -> Result<(), ErrorGuaranteed> {
-    if impl2_node.is_from_trait() {
-        // This isn't a specialization
-        return Ok(());
-    }
-
-    let impl1_constness = tcx.constness(impl1_def_id.to_def_id());
-    let impl2_constness = tcx.constness(impl2_node.def_id());
-
-    if let hir::Constness::Const = impl2_constness {
-        if let hir::Constness::NotConst = impl1_constness {
-            return Err(tcx.dcx().emit_err(errors::ConstSpecialize { span }));
-        }
-    }
-    Ok(())
-}
-
 /// Given a specializing impl `impl1`, and the base impl `impl2`, returns two
 /// generic parameters `(S1, S2)` that equate their trait references.
 /// The returned types are expressed in terms of the generics of `impl1`.

Diff for: compiler/rustc_infer/src/traits/engine.rs

@@ -84,6 +84,8 @@ pub trait TraitEngine<'tcx, E: 'tcx>: 'tcx {
         self.collect_remaining_errors(infcx)
     }
 
+    fn has_pending_obligations(&self) -> bool;
+
     fn pending_obligations(&self) -> PredicateObligations<'tcx>;
 
     /// Among all pending obligations, collect those are stalled on a inference variable which has

Diff for: compiler/rustc_span/src/symbol.rs

@@ -1844,6 +1844,7 @@ symbols! {
         simd_reduce_mul_unordered,
         simd_reduce_or,
         simd_reduce_xor,
+        simd_relaxed_fma,
         simd_rem,
         simd_round,
         simd_saturating_add,

Diff for: compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -199,6 +199,10 @@ where
         errors
     }
 
+    fn has_pending_obligations(&self) -> bool {
+        !self.obligations.pending.is_empty() || !self.obligations.overflowed.is_empty()
+    }
+
     fn pending_obligations(&self) -> PredicateObligations<'tcx> {
         self.obligations.clone_pending()
     }

Diff for: compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -213,6 +213,10 @@ where
         }
     }
 
+    fn has_pending_obligations(&self) -> bool {
+        self.predicates.has_pending_obligations()
+    }
+
     fn pending_obligations(&self) -> PredicateObligations<'tcx> {
         self.predicates.map_pending_obligations(|o| o.obligation.clone())
     }

Diff for: compiler/rustc_trait_selection/src/traits/normalize.rs

@@ -7,6 +7,7 @@ use rustc_infer::traits::{
     FromSolverError, Normalized, Obligation, PredicateObligations, TraitEngine,
 };
 use rustc_macros::extension;
+use rustc_middle::span_bug;
 use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
 use rustc_middle::ty::{
     self, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable, TypeVisitable, TypeVisitableExt,
@@ -63,10 +64,18 @@ impl<'tcx> At<'_, 'tcx> {
         if self.infcx.next_trait_solver() {
             crate::solve::deeply_normalize(self, value)
         } else {
+            if fulfill_cx.has_pending_obligations() {
+                let pending_obligations = fulfill_cx.pending_obligations();
+                span_bug!(
+                    pending_obligations[0].cause.span,
+                    "deeply_normalize should not be called with pending obligations: \
+                    {pending_obligations:#?}"
+                );
+            }
             let value = self
                 .normalize(value)
                 .into_value_registering_obligations(self.infcx, &mut *fulfill_cx);
-            let errors = fulfill_cx.select_where_possible(self.infcx);
+            let errors = fulfill_cx.select_all_or_error(self.infcx);
             let value = self.infcx.resolve_vars_if_possible(value);
             if errors.is_empty() { Ok(value) } else { Err(errors) }
         }

Diff for: compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs

@@ -59,12 +59,16 @@ pub fn compute_implied_outlives_bounds_inner<'tcx>(
     param_env: ty::ParamEnv<'tcx>,
     ty: Ty<'tcx>,
 ) -> Result<Vec<OutlivesBound<'tcx>>, NoSolution> {
-    let normalize_op = |ty| {
-        let ty = ocx.normalize(&ObligationCause::dummy(), param_env, ty);
+    let normalize_op = |ty| -> Result<_, NoSolution> {
+        // We must normalize the type so we can compute the right outlives components.
+        // for example, if we have some constrained param type like `T: Trait<Out = U>`,
+        // and we know that `&'a T::Out` is WF, then we want to imply `U: 'a`.
+        let ty = ocx
+            .deeply_normalize(&ObligationCause::dummy(), param_env, ty)
+            .map_err(|_| NoSolution)?;
         if !ocx.select_all_or_error().is_empty() {
             return Err(NoSolution);
         }
-        let ty = ocx.infcx.resolve_vars_if_possible(ty);
         let ty = OpportunisticRegionResolver::new(&ocx.infcx).fold_ty(ty);
         Ok(ty)
     };