Auto merge of #120903 - matthiaskrgr:rollup-tmsuzth, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #119213 (simd intrinsics: add simd_shuffle_generic and other missing intrinsics)
 - #120272 (Suppress suggestions in derive macro)
 - #120773 (large_assignments: Allow moves into functions)
 - #120874 (Take empty `where` bounds into account when suggesting predicates)
 - #120882 (interpret/write_discriminant: when encoding niched variant, ensure the stored value matches)
 - #120883 (interpret: rename ReadExternStatic → ExternStatic)
 - #120890 (Adapt `llvm-has-rust-patches` validation to take `llvm-config` into account.)
 - #120895 (don't skip coercions for types with errors)
 - #120896 (Print kind of coroutine closure)

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

compiler/rustc_const_eval/messages.ftl

@@ -98,6 +98,8 @@ const_eval_error = {$error_kind ->
 const_eval_exact_div_has_remainder =
     exact_div: {$a} cannot be divided by {$b} without remainder
 
+const_eval_extern_static =
+    cannot access extern static ({$did})
 const_eval_fn_ptr_call =
     function pointers need an RFC before allowed to be called in {const_eval_const_context}s
 const_eval_for_loop_into_iter_non_const =
@@ -172,6 +174,10 @@ const_eval_invalid_meta =
     invalid metadata in wide pointer: total size is bigger than largest supported object
 const_eval_invalid_meta_slice =
     invalid metadata in wide pointer: slice is bigger than largest supported object
+
+const_eval_invalid_niched_enum_variant_written =
+    trying to set discriminant of a {$ty} to the niched variant, but the value does not match
+
 const_eval_invalid_str =
     this string is not valid UTF-8: {$err}
 const_eval_invalid_tag =
@@ -298,8 +304,6 @@ const_eval_raw_ptr_to_int =
     .note = at compile-time, pointers do not have an integer value
     .note2 = avoiding this restriction via `transmute`, `union`, or raw pointers leads to compile-time undefined behavior
 
-const_eval_read_extern_static =
-    cannot read from extern static ({$did})
 const_eval_read_pointer_as_int =
     unable to turn pointer into integer
 const_eval_realloc_or_alloc_with_offset =

compiler/rustc_const_eval/src/errors.rs

@@ -497,6 +497,9 @@ impl<'a> ReportErrorExt for UndefinedBehaviorInfo<'a> {
             ScalarSizeMismatch(_) => const_eval_scalar_size_mismatch,
             UninhabitedEnumVariantWritten(_) => const_eval_uninhabited_enum_variant_written,
             UninhabitedEnumVariantRead(_) => const_eval_uninhabited_enum_variant_read,
+            InvalidNichedEnumVariantWritten { .. } => {
+                const_eval_invalid_niched_enum_variant_written
+            }
             AbiMismatchArgument { .. } => const_eval_incompatible_types,
             AbiMismatchReturn { .. } => const_eval_incompatible_return_types,
         }
@@ -585,6 +588,9 @@ impl<'a> ReportErrorExt for UndefinedBehaviorInfo<'a> {
                 builder.arg("target_size", info.target_size);
                 builder.arg("data_size", info.data_size);
             }
+            InvalidNichedEnumVariantWritten { enum_ty } => {
+                builder.arg("ty", enum_ty.to_string());
+            }
             AbiMismatchArgument { caller_ty, callee_ty }
             | AbiMismatchReturn { caller_ty, callee_ty } => {
                 builder.arg("caller_ty", caller_ty.to_string());
@@ -793,7 +799,7 @@ impl ReportErrorExt for UnsupportedOpInfo {
             UnsupportedOpInfo::ReadPartialPointer(_) => const_eval_partial_pointer_copy,
             UnsupportedOpInfo::ReadPointerAsInt(_) => const_eval_read_pointer_as_int,
             UnsupportedOpInfo::ThreadLocalStatic(_) => const_eval_thread_local_static,
-            UnsupportedOpInfo::ReadExternStatic(_) => const_eval_read_extern_static,
+            UnsupportedOpInfo::ExternStatic(_) => const_eval_extern_static,
         }
     }
     fn add_args<G: EmissionGuarantee>(self, _: &DiagCtxt, builder: &mut DiagnosticBuilder<'_, G>) {
@@ -812,7 +818,7 @@ impl ReportErrorExt for UnsupportedOpInfo {
             OverwritePartialPointer(ptr) | ReadPartialPointer(ptr) => {
                 builder.arg("ptr", ptr);
             }
-            ThreadLocalStatic(did) | ReadExternStatic(did) => {
+            ThreadLocalStatic(did) | ExternStatic(did) => {
                 builder.arg("did", format!("{did:?}"));
             }
         }

compiler/rustc_const_eval/src/interpret/discriminant.rs

@@ -85,6 +85,14 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                     // Write result.
                     let niche_dest = self.project_field(dest, tag_field)?;
                     self.write_immediate(*tag_val, &niche_dest)?;
+                } else {
+                    // The untagged variant is implicitly encoded simply by having a value that is
+                    // outside the niche variants. But what if the data stored here does not
+                    // actually encode this variant? That would be bad! So let's double-check...
+                    let actual_variant = self.read_discriminant(&dest.to_op(self)?)?;
+                    if actual_variant != variant_index {
+                        throw_ub!(InvalidNichedEnumVariantWritten { enum_ty: dest.layout().ty });
+                    }
                 }
             }
         }

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -557,7 +557,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 if self.tcx.is_foreign_item(def_id) {
                     // This is unreachable in Miri, but can happen in CTFE where we actually *do* support
                     // referencing arbitrary (declared) extern statics.
-                    throw_unsup!(ReadExternStatic(def_id));
+                    throw_unsup!(ExternStatic(def_id));
                 }
 
                 // We don't give a span -- statics don't need that, they cannot be generic or associated.

compiler/rustc_errors/src/diagnostic.rs

@@ -516,6 +516,17 @@ impl Diagnostic {
 
     /// Helper for pushing to `self.suggestions`, if available (not disable).
     fn push_suggestion(&mut self, suggestion: CodeSuggestion) {
+        for subst in &suggestion.substitutions {
+            for part in &subst.parts {
+                let span = part.span;
+                let call_site = span.ctxt().outer_expn_data().call_site;
+                if span.in_derive_expansion() && span.overlaps_or_adjacent(call_site) {
+                    // Ignore if spans is from derive macro.
+                    return;
+                }
+            }
+        }
+
         if let Ok(suggestions) = &mut self.suggestions {
             suggestions.push(suggestion);
         }

compiler/rustc_hir_typeck/src/coercion.rs

@@ -186,17 +186,6 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         let b = self.shallow_resolve(b);
         debug!("Coerce.tys({:?} => {:?})", a, b);
 
-        // Just ignore error types.
-        if let Err(guar) = (a, b).error_reported() {
-            // Best-effort try to unify these types -- we're already on the error path,
-            // so this will have the side-effect of making sure we have no ambiguities
-            // due to `[type error]` and `_` not coercing together.
-            let _ = self.commit_if_ok(|_| {
-                self.at(&self.cause, self.param_env).eq(DefineOpaqueTypes::Yes, a, b)
-            });
-            return success(vec![], Ty::new_error(self.fcx.tcx, guar), vec![]);
-        }
-
         // Coercing from `!` to any type is allowed:
         if a.is_never() {
             return success(simple(Adjust::NeverToAny)(b), b, vec![]);

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -356,6 +356,8 @@ pub enum UndefinedBehaviorInfo<'tcx> {
     UninhabitedEnumVariantWritten(VariantIdx),
     /// An uninhabited enum variant is projected.
     UninhabitedEnumVariantRead(VariantIdx),
+    /// Trying to set discriminant to the niched variant, but the value does not match.
+    InvalidNichedEnumVariantWritten { enum_ty: Ty<'tcx> },
     /// ABI-incompatible argument types.
     AbiMismatchArgument { caller_ty: Ty<'tcx>, callee_ty: Ty<'tcx> },
     /// ABI-incompatible return types.
@@ -468,7 +470,7 @@ pub enum UnsupportedOpInfo {
     /// Accessing thread local statics
     ThreadLocalStatic(DefId),
     /// Accessing an unsupported extern static.
-    ReadExternStatic(DefId),
+    ExternStatic(DefId),
 }
 
 /// Error information for when the program exhausted the resources granted to it

compiler/rustc_middle/src/ty/diagnostics.rs

@@ -358,11 +358,17 @@ pub fn suggest_constraining_type_params<'a>(
         //      trait Foo<T=()> {... }
         //                     - insert: `where T: Zar`
         if matches!(param.kind, hir::GenericParamKind::Type { default: Some(_), .. }) {
+            // If we are here and the where clause span is of non-zero length
+            // it means we're dealing with an empty where clause like this:
+            //      fn foo<X>(x: X) where { ... }
+            // In that case we don't want to add another "where" (Fixes #120838)
+            let where_prefix = if generics.where_clause_span.is_empty() { " where" } else { "" };
+
             // Suggest a bound, but there is no existing `where` clause *and* the type param has a
             // default (`<T=Foo>`), so we suggest adding `where T: Bar`.
             suggestions.push((
                 generics.tail_span_for_predicate_suggestion(),
-                format!(" where {param_name}: {constraint}"),
+                format!("{where_prefix} {param_name}: {constraint}"),
                 SuggestChangingConstraintsMessage::RestrictTypeFurther { ty: param_name },
             ));
             continue;

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -877,7 +877,24 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
             ty::CoroutineClosure(did, args) => {
                 p!(write("{{"));
                 if !self.should_print_verbose() {
-                    p!(write("coroutine-closure"));
+                    match self.tcx().coroutine_kind(self.tcx().coroutine_for_closure(did)).unwrap()
+                    {
+                        hir::CoroutineKind::Desugared(
+                            hir::CoroutineDesugaring::Async,
+                            hir::CoroutineSource::Closure,
+                        ) => p!("async closure"),
+                        hir::CoroutineKind::Desugared(
+                            hir::CoroutineDesugaring::AsyncGen,
+                            hir::CoroutineSource::Closure,
+                        ) => p!("async gen closure"),
+                        hir::CoroutineKind::Desugared(
+                            hir::CoroutineDesugaring::Gen,
+                            hir::CoroutineSource::Closure,
+                        ) => p!("gen closure"),
+                        _ => unreachable!(
+                            "coroutine from coroutine-closure should have CoroutineSource::Closure"
+                        ),
+                    }
                     // FIXME(eddyb) should use `def_span`.
                     if let Some(did) = did.as_local() {
                         if self.tcx().sess.opts.unstable_opts.span_free_formats {

compiler/rustc_monomorphize/src/collector.rs

@@ -666,7 +666,15 @@ impl<'a, 'tcx> MirUsedCollector<'a, 'tcx> {
         debug!(?def_id, ?fn_span);
 
         for arg in args {
-            if let Some(too_large_size) = self.operand_size_if_too_large(limit, &arg.node) {
+            // Moving args into functions is typically implemented with pointer
+            // passing at the llvm-ir level and not by memcpy's. So always allow
+            // moving args into functions.
+            let operand: &mir::Operand<'tcx> = &arg.node;
+            if let mir::Operand::Move(_) = operand {
+                continue;
+            }
+
+            if let Some(too_large_size) = self.operand_size_if_too_large(limit, operand) {
                 self.lint_large_assignment(limit.0, too_large_size, location, arg.span);
             };
         }

compiler/rustc_span/src/lib.rs

@@ -625,6 +625,13 @@ impl Span {
         span.lo < other.hi && other.lo < span.hi
     }
 
+    /// Returns `true` if `self` touches or adjoins `other`.
+    pub fn overlaps_or_adjacent(self, other: Span) -> bool {
+        let span = self.data();
+        let other = other.data();
+        span.lo <= other.hi && other.lo <= span.hi
+    }
+
     /// Returns `true` if the spans are equal with regards to the source text.
     ///
     /// Use this instead of `==` when either span could be generated code,

library/core/src/intrinsics/simd.rs

@@ -190,14 +190,27 @@ extern "platform-intrinsic" {
     ///
     /// `T` must be a vector.
     ///
-    /// `U` must be a const array of `i32`s.
+    /// `U` must be a **const** array of `i32`s. This means it must either refer to a named
+    /// const or be given as an inline const expression (`const { ... }`).
     ///
     /// `V` must be a vector with the same element type as `T` and the same length as `U`.
     ///
-    /// Concatenates `x` and `y`, then returns a new vector such that each element is selected from
-    /// the concatenation by the matching index in `idx`.
+    /// Returns a new vector such that element `i` is selected from `xy[idx[i]]`, where `xy`
+    /// is the concatenation of `x` and `y`. It is a compile-time error if `idx[i]` is out-of-bounds
+    /// of `xy`.
     pub fn simd_shuffle<T, U, V>(x: T, y: T, idx: U) -> V;
 
+    /// Shuffle two vectors by const indices.
+    ///
+    /// `T` must be a vector.
+    ///
+    /// `U` must be a vector with the same element type as `T` and the same length as `IDX`.
+    ///
+    /// Returns a new vector such that element `i` is selected from `xy[IDX[i]]`, where `xy`
+    /// is the concatenation of `x` and `y`. It is a compile-time error if `IDX[i]` is out-of-bounds
+    /// of `xy`.
+    pub fn simd_shuffle_generic<T, U, const IDX: &'static [u32]>(x: T, y: T) -> U;
+
     /// Read a vector of pointers.
     ///
     /// `T` must be a vector.
@@ -232,6 +245,9 @@ extern "platform-intrinsic" {
     /// corresponding value in `val` to the pointer.
     /// Otherwise if the corresponding value in `mask` is `0`, do nothing.
     ///
+    /// The stores happen in left-to-right order.
+    /// (This is relevant in case two of the stores overlap.)
+    ///
     /// # Safety
     /// Unmasked values in `T` must be writeable as if by `<ptr>::write` (e.g. aligned to the element
     /// type).
@@ -468,4 +484,36 @@ extern "platform-intrinsic" {
     ///
     /// `T` must be a vector of integers.
     pub fn simd_cttz<T>(x: T) -> T;
+
+    /// Round up each element to the next highest integer-valued float.
+    ///
+    /// `T` must be a vector of floats.
+    pub fn simd_ceil<T>(x: T) -> T;
+
+    /// Round down each element to the next lowest integer-valued float.
+    ///
+    /// `T` must be a vector of floats.
+    pub fn simd_floor<T>(x: T) -> T;
+
+    /// Round each element to the closest integer-valued float.
+    /// Ties are resolved by rounding away from 0.
+    ///
+    /// `T` must be a vector of floats.
+    pub fn simd_round<T>(x: T) -> T;
+
+    /// Return the integer part of each element as an integer-valued float.
+    /// In other words, non-integer values are truncated towards zero.
+    ///
+    /// `T` must be a vector of floats.
+    pub fn simd_trunc<T>(x: T) -> T;
+
+    /// Takes the square root of each element.
+    ///
+    /// `T` must be a vector of floats.
+    pub fn simd_fsqrt<T>(x: T) -> T;
+
+    /// Computes `(x*y) + z` for each element, but without any intermediate rounding.
+    ///
+    /// `T` must be a vector of floats.
+    pub fn simd_fma<T>(x: T, y: T, z: T) -> T;
 }

src/bootstrap/src/core/config/config.rs

@@ -1810,10 +1810,9 @@ impl Config {
                     target.llvm_config = Some(config.src.join(s));
                 }
                 if let Some(patches) = cfg.llvm_has_rust_patches {
-                    assert_eq!(
-                        config.submodules,
-                        Some(false),
-                        "cannot set `llvm-has-rust-patches` for a managed submodule (set `build.submodules = false` if you want to apply patches)"
+                    assert!(
+                        config.submodules == Some(false) || cfg.llvm_config.is_some(),
+                        "use of `llvm-has-rust-patches` is restricted to cases where either submodules are disabled or llvm-config been provided"
                     );
                     target.llvm_has_rust_patches = Some(patches);
                 }

src/tools/miri/tests/fail/enum-set-discriminant-niche-variant-wrong.rs

@@ -0,0 +1,31 @@
+#![feature(core_intrinsics)]
+#![feature(custom_mir)]
+
+use std::intrinsics::mir::*;
+use std::num::NonZeroI32;
+
+// We define our own option type so that we can control the varian indices.
+#[allow(unused)]
+enum Option<T> {
+    None,
+    Some(T),
+}
+use Option::*;
+
+#[custom_mir(dialect = "runtime", phase = "optimized")]
+fn set_discriminant(ptr: &mut Option<NonZeroI32>) {
+    mir! {
+        {
+            // We set the discriminant to `Some`, which is a NOP since this is the niched variant.
+            // However, the enum is actually encoding `None` currently! That's not good...
+            SetDiscriminant(*ptr, 1);
+            //~^ ERROR: trying to set discriminant of a Option<std::num::NonZero<i32>> to the niched variant, but the value does not match
+            Return()
+        }
+    }
+}
+
+pub fn main() {
+    let mut v = None;
+    set_discriminant(&mut v);
+}

src/tools/miri/tests/fail/enum-set-discriminant-niche-variant-wrong.stderr

@@ -0,0 +1,20 @@
+error: Undefined Behavior: trying to set discriminant of a Option<std::num::NonZero<i32>> to the niched variant, but the value does not match
+  --> $DIR/enum-set-discriminant-niche-variant-wrong.rs:LL:CC
+   |
+LL |             SetDiscriminant(*ptr, 1);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^ trying to set discriminant of a Option<std::num::NonZero<i32>> to the niched variant, but the value does not match
+   |
+   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
+   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
+   = note: BACKTRACE:
+   = note: inside `set_discriminant` at $DIR/enum-set-discriminant-niche-variant-wrong.rs:LL:CC
+note: inside `main`
+  --> $DIR/enum-set-discriminant-niche-variant-wrong.rs:LL:CC
+   |
+LL |     set_discriminant(&mut v);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+

tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.panic-abort.mir

@@ -1,6 +1,6 @@
 // MIR for `main::{closure#0}::{closure#0}` 0 coroutine_closure_by_move
 
-fn main::{closure#0}::{closure#0}(_1: {coroutine-closure@$DIR/async_closure_shims.rs:39:33: 39:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10} {
+fn main::{closure#0}::{closure#0}(_1: {async closure@$DIR/async_closure_shims.rs:39:33: 39:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10} {
     let mut _0: {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10};
 
     bb0: {

tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.panic-unwind.mir

@@ -1,6 +1,6 @@
 // MIR for `main::{closure#0}::{closure#0}` 0 coroutine_closure_by_move
 
-fn main::{closure#0}::{closure#0}(_1: {coroutine-closure@$DIR/async_closure_shims.rs:39:33: 39:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10} {
+fn main::{closure#0}::{closure#0}(_1: {async closure@$DIR/async_closure_shims.rs:39:33: 39:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10} {
     let mut _0: {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10};
 
     bb0: {

tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_mut.0.panic-abort.mir

@@ -1,6 +1,6 @@
 // MIR for `main::{closure#0}::{closure#0}` 0 coroutine_closure_by_mut
 
-fn main::{closure#0}::{closure#0}(_1: &mut {coroutine-closure@$DIR/async_closure_shims.rs:39:33: 39:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10} {
+fn main::{closure#0}::{closure#0}(_1: &mut {async closure@$DIR/async_closure_shims.rs:39:33: 39:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10} {
     debug a => _2;
     debug b => ((*_1).0: i32);
     let mut _0: {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10};

tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_mut.0.panic-unwind.mir

@@ -1,6 +1,6 @@
 // MIR for `main::{closure#0}::{closure#0}` 0 coroutine_closure_by_mut
 
-fn main::{closure#0}::{closure#0}(_1: &mut {coroutine-closure@$DIR/async_closure_shims.rs:39:33: 39:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10} {
+fn main::{closure#0}::{closure#0}(_1: &mut {async closure@$DIR/async_closure_shims.rs:39:33: 39:52}, _2: i32) -> {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10} {
     debug a => _2;
     debug b => ((*_1).0: i32);
     let mut _0: {async closure body@$DIR/async_closure_shims.rs:39:53: 42:10};