Auto merge of #147440 - Zalathar:rollup-ncjsxjb, r=Zalathar

Rollup of 8 pull requests

Successful merges:

 - #145608 (Prevent downstream `impl DerefMut for Pin<LocalType>`)
 - #146865 (kcfi: only reify trait methods when dyn-compatible)
 - #147205 (Add a new `wasm32-wasip3` target to Rust)
 - #147390 (Use globals instead of metadata for std::autodiff)
 - #147398 (Fix; correct placement of type inference error for method calls)
 - #147422 (collect-license-metadata: Print a diff of the expected output)
 - #147431 (compiletest: Read the whole test file before parsing directives)
 - #147433 (Fix doc comment)

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

Author: bors

Cargo.lock

@@ -686,6 +686,7 @@ dependencies = [
  "anyhow",
  "serde",
  "serde_json",
+ "similar",
  "spdx-rs",
 ]
 

compiler/rustc_codegen_llvm/src/builder/autodiff.rs

@@ -13,7 +13,7 @@ use crate::builder::{Builder, PlaceRef, UNNAMED};
 use crate::context::SimpleCx;
 use crate::declare::declare_simple_fn;
 use crate::llvm;
-use crate::llvm::{Metadata, TRUE, Type};
+use crate::llvm::{TRUE, Type};
 use crate::value::Value;
 
 pub(crate) fn adjust_activity_to_abi<'tcx>(
@@ -159,32 +159,36 @@ fn match_args_from_caller_to_enzyme<'ll, 'tcx>(
     let mut outer_pos: usize = 0;
     let mut activity_pos = 0;
 
-    let enzyme_const = cx.create_metadata(b"enzyme_const");
-    let enzyme_out = cx.create_metadata(b"enzyme_out");
-    let enzyme_dup = cx.create_metadata(b"enzyme_dup");
-    let enzyme_dupv = cx.create_metadata(b"enzyme_dupv");
-    let enzyme_dupnoneed = cx.create_metadata(b"enzyme_dupnoneed");
-    let enzyme_dupnoneedv = cx.create_metadata(b"enzyme_dupnoneedv");
+    // We used to use llvm's metadata to instruct enzyme how to differentiate a function.
+    // In debug mode we would use incremental compilation which caused the metadata to be
+    // dropped. This is prevented by now using named globals, which are also understood
+    // by Enzyme.
+    let global_const = cx.declare_global("enzyme_const", cx.type_ptr());
+    let global_out = cx.declare_global("enzyme_out", cx.type_ptr());
+    let global_dup = cx.declare_global("enzyme_dup", cx.type_ptr());
+    let global_dupv = cx.declare_global("enzyme_dupv", cx.type_ptr());
+    let global_dupnoneed = cx.declare_global("enzyme_dupnoneed", cx.type_ptr());
+    let global_dupnoneedv = cx.declare_global("enzyme_dupnoneedv", cx.type_ptr());
 
     while activity_pos < inputs.len() {
         let diff_activity = inputs[activity_pos as usize];
         // Duplicated arguments received a shadow argument, into which enzyme will write the
         // gradient.
-        let (activity, duplicated): (&Metadata, bool) = match diff_activity {
+        let (activity, duplicated): (&llvm::Value, bool) = match diff_activity {
             DiffActivity::None => panic!("not a valid input activity"),
-            DiffActivity::Const => (enzyme_const, false),
-            DiffActivity::Active => (enzyme_out, false),
-            DiffActivity::ActiveOnly => (enzyme_out, false),
-            DiffActivity::Dual => (enzyme_dup, true),
-            DiffActivity::Dualv => (enzyme_dupv, true),
-            DiffActivity::DualOnly => (enzyme_dupnoneed, true),
-            DiffActivity::DualvOnly => (enzyme_dupnoneedv, true),
-            DiffActivity::Duplicated => (enzyme_dup, true),
-            DiffActivity::DuplicatedOnly => (enzyme_dupnoneed, true),
-            DiffActivity::FakeActivitySize(_) => (enzyme_const, false),
+            DiffActivity::Const => (global_const, false),
+            DiffActivity::Active => (global_out, false),
+            DiffActivity::ActiveOnly => (global_out, false),
+            DiffActivity::Dual => (global_dup, true),
+            DiffActivity::Dualv => (global_dupv, true),
+            DiffActivity::DualOnly => (global_dupnoneed, true),
+            DiffActivity::DualvOnly => (global_dupnoneedv, true),
+            DiffActivity::Duplicated => (global_dup, true),
+            DiffActivity::DuplicatedOnly => (global_dupnoneed, true),
+            DiffActivity::FakeActivitySize(_) => (global_const, false),
         };
         let outer_arg = outer_args[outer_pos];
-        args.push(cx.get_metadata_value(activity));
+        args.push(activity);
         if matches!(diff_activity, DiffActivity::Dualv) {
             let next_outer_arg = outer_args[outer_pos + 1];
             let elem_bytes_size: u64 = match inputs[activity_pos + 1] {
@@ -244,7 +248,7 @@ fn match_args_from_caller_to_enzyme<'ll, 'tcx>(
                     assert_eq!(cx.type_kind(next_outer_ty3), TypeKind::Integer);
                     args.push(next_outer_arg2);
                 }
-                args.push(cx.get_metadata_value(enzyme_const));
+                args.push(global_const);
                 args.push(next_outer_arg);
                 outer_pos += 2 + 2 * iterations;
                 activity_pos += 2;
@@ -353,13 +357,13 @@ pub(crate) fn generate_enzyme_call<'ll, 'tcx>(
     let mut args = Vec::with_capacity(num_args as usize + 1);
     args.push(fn_to_diff);
 
-    let enzyme_primal_ret = cx.create_metadata(b"enzyme_primal_return");
+    let global_primal_ret = cx.declare_global("enzyme_primal_return", cx.type_ptr());
     if matches!(attrs.ret_activity, DiffActivity::Dual | DiffActivity::Active) {
-        args.push(cx.get_metadata_value(enzyme_primal_ret));
+        args.push(global_primal_ret);
     }
     if attrs.width > 1 {
-        let enzyme_width = cx.create_metadata(b"enzyme_width");
-        args.push(cx.get_metadata_value(enzyme_width));
+        let global_width = cx.declare_global("enzyme_width", cx.type_ptr());
+        args.push(global_width);
         args.push(cx.get_const_int(cx.type_i64(), attrs.width as u64));
     }
 

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -7,9 +7,8 @@ use rustc_attr_parsing::is_doc_alias_attrs_contain_symbol;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::sso::SsoHashSet;
 use rustc_errors::Applicability;
-use rustc_hir as hir;
-use rustc_hir::HirId;
 use rustc_hir::def::DefKind;
+use rustc_hir::{self as hir, ExprKind, HirId, Node};
 use rustc_hir_analysis::autoderef::{self, Autoderef};
 use rustc_infer::infer::canonical::{Canonical, OriginalQueryValues, QueryResponse};
 use rustc_infer::infer::{BoundRegionConversionTime, DefineOpaqueTypes, InferOk, TyCtxtInferExt};
@@ -486,13 +485,25 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let ty = self.resolve_vars_if_possible(ty.value);
                 let guar = match *ty.kind() {
                     ty::Infer(ty::TyVar(_)) => {
+                        // We want to get the variable name that the method
+                        // is being called on. If it is a method call.
+                        let err_span = match (mode, self.tcx.hir_node(scope_expr_id)) {
+                            (
+                                Mode::MethodCall,
+                                Node::Expr(hir::Expr {
+                                    kind: ExprKind::MethodCall(_, recv, ..),
+                                    ..
+                                }),
+                            ) => recv.span,
+                            _ => span,
+                        };
+
                         let raw_ptr_call = bad_ty.reached_raw_pointer
                             && !self.tcx.features().arbitrary_self_types();
-                        // FIXME: Ideally we'd use the span of the self-expr here,
-                        // not of the method path.
+
                         let mut err = self.err_ctxt().emit_inference_failure_err(
                             self.body_id,
-                            span,
+                            err_span,
                             ty.into(),
                             TypeAnnotationNeeded::E0282,
                             !raw_ptr_call,

compiler/rustc_middle/src/thir.rs

@@ -839,7 +839,7 @@ pub enum PatKind<'tcx> {
     ///   exhaustiveness to cover exactly its own value, similar to `&str`, but these values are
     ///   much simpler.
     /// * raw pointers derived from integers, other raw pointers will have already resulted in an
-    //    error.
+    ///   error.
     /// * `String`, if `string_deref_patterns` is enabled.
     Constant {
         value: ty::Value<'tcx>,

compiler/rustc_middle/src/ty/instance.rs

@@ -618,11 +618,11 @@ impl<'tcx> Instance<'tcx> {
                         // be directly reified because it's closure-like. The reify can handle the
                         // unresolved instance.
                         resolved = Instance { def: InstanceKind::ReifyShim(def_id, reason), args }
-                    // Reify `Trait::method` implementations
-                    // FIXME(maurer) only reify it if it is a vtable-safe function
+                    // Reify `Trait::method` implementations if the trait is dyn-compatible.
                     } else if let Some(assoc) = tcx.opt_associated_item(def_id)
                         && let AssocContainer::Trait | AssocContainer::TraitImpl(Ok(_)) =
                             assoc.container
+                        && tcx.is_dyn_compatible(assoc.container_id(tcx))
                     {
                         // If this function could also go in a vtable, we need to `ReifyShim` it with
                         // KCFI because it can only attach one type per function.

compiler/rustc_span/src/symbol.rs

@@ -309,6 +309,7 @@ symbols! {
         PathBuf,
         Pending,
         PinCoerceUnsized,
+        PinDerefMutHelper,
         Pointer,
         Poll,
         ProcMacro,

compiler/rustc_target/src/spec/mod.rs

@@ -1624,6 +1624,7 @@ supported_targets! {
     ("wasm32v1-none", wasm32v1_none),
     ("wasm32-wasip1", wasm32_wasip1),
     ("wasm32-wasip2", wasm32_wasip2),
+    ("wasm32-wasip3", wasm32_wasip3),
     ("wasm32-wasip1-threads", wasm32_wasip1_threads),
     ("wasm32-wali-linux-musl", wasm32_wali_linux_musl),
     ("wasm64-unknown-unknown", wasm64_unknown_unknown),

compiler/rustc_target/src/spec/targets/wasm32_wasip3.rs

@@ -0,0 +1,20 @@
+//! The `wasm32-wasip3` target is the next in the chain of `wasm32-wasip1`, then
+//! `wasm32-wasip2`, then WASIp3. The main feature of WASIp3 is native async
+//! support in the component model itself.
+//!
+//! Like `wasm32-wasip2` this target produces a component by default. Support
+//! for `wasm32-wasip3` is very early as of the time of this writing so
+//! components produced will still import WASIp2 APIs, but that's ok since it's
+//! all component-model-level imports anyway. Over time the imports of the
+//! standard library will change to WASIp3.
+
+use crate::spec::Target;
+
+pub(crate) fn target() -> Target {
+    // As of now WASIp3 is a lightly edited wasip2 target, so start with that
+    // and this may grow over time as more features are supported.
+    let mut target = super::wasm32_wasip2::target();
+    target.llvm_target = "wasm32-wasip3".into();
+    target.options.env = "p3".into();
+    target
+}

compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs

@@ -3476,6 +3476,24 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                     // can do about it. As far as they are concerned, `?` is compiler magic.
                     return;
                 }
+                if tcx.is_diagnostic_item(sym::PinDerefMutHelper, parent_def_id) {
+                    let parent_predicate =
+                        self.resolve_vars_if_possible(data.derived.parent_trait_pred);
+
+                    // Skip PinDerefMutHelper in suggestions, but still show downstream suggestions.
+                    ensure_sufficient_stack(|| {
+                        self.note_obligation_cause_code(
+                            body_id,
+                            err,
+                            parent_predicate,
+                            param_env,
+                            &data.derived.parent_code,
+                            obligated_types,
+                            seen_requirements,
+                        )
+                    });
+                    return;
+                }
                 let self_ty_str =
                     tcx.short_string(parent_trait_pred.skip_binder().self_ty(), err.long_ty_path());
                 let trait_name = tcx.short_string(

library/core/src/pin.rs

@@ -1689,9 +1689,89 @@ impl<Ptr: [const] Deref> const Deref for Pin<Ptr> {
     }
 }
 
+mod helper {
+    /// Helper that prevents downstream crates from implementing `DerefMut` for `Pin`.
+    ///
+    /// The `Pin` type implements the unsafe trait `PinCoerceUnsized`, which essentially requires
+    /// that the type does not have a malicious `Deref` or `DerefMut` impl. However, without this
+    /// helper module, downstream crates are able to write `impl DerefMut for Pin<LocalType>` as
+    /// long as it does not overlap with the impl provided by stdlib. This is because `Pin` is
+    /// `#[fundamental]`, so stdlib promises to never implement traits for `Pin` that it does not
+    /// implement today.
+    ///
+    /// However, this is problematic. Downstream crates could implement `DerefMut` for
+    /// `Pin<&LocalType>`, and they could do so maliciously. To prevent this, the implementation for
+    /// `Pin` delegates to this helper module. Since `helper::Pin` is not `#[fundamental]`, the
+    /// orphan rules assume that stdlib might implement `helper::DerefMut` for `helper::Pin<&_>` in
+    /// the future. Because of this, downstream crates can no longer provide an implementation of
+    /// `DerefMut` for `Pin<&_>`, as it might overlap with a trait impl that, according to the
+    /// orphan rules, the stdlib could introduce without a breaking change in a future release.
+    ///
+    /// See <https://github.com/rust-lang/rust/issues/85099> for the issue this fixes.
+    #[repr(transparent)]
+    #[unstable(feature = "pin_derefmut_internals", issue = "none")]
+    #[allow(missing_debug_implementations)]
+    pub struct PinHelper<Ptr> {
+        pointer: Ptr,
+    }
+
+    #[unstable(feature = "pin_derefmut_internals", issue = "none")]
+    #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
+    #[rustc_diagnostic_item = "PinDerefMutHelper"]
+    pub const trait PinDerefMutHelper {
+        type Target: ?Sized;
+        fn deref_mut(&mut self) -> &mut Self::Target;
+    }
+
+    #[unstable(feature = "pin_derefmut_internals", issue = "none")]
+    #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
+    impl<Ptr: [const] super::DerefMut> const PinDerefMutHelper for PinHelper<Ptr>
+    where
+        Ptr::Target: crate::marker::Unpin,
+    {
+        type Target = Ptr::Target;
+
+        #[inline(always)]
+        fn deref_mut(&mut self) -> &mut Ptr::Target {
+            &mut self.pointer
+        }
+    }
+}
+
 #[stable(feature = "pin", since = "1.33.0")]
 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
-impl<Ptr: [const] DerefMut<Target: Unpin>> const DerefMut for Pin<Ptr> {
+#[cfg(not(doc))]
+impl<Ptr> const DerefMut for Pin<Ptr>
+where
+    Ptr: [const] Deref,
+    helper::PinHelper<Ptr>: [const] helper::PinDerefMutHelper<Target = Self::Target>,
+{
+    #[inline]
+    fn deref_mut(&mut self) -> &mut Ptr::Target {
+        // SAFETY: Pin and PinHelper have the same layout, so this is equivalent to
+        // `&mut self.pointer` which is safe because `Target: Unpin`.
+        helper::PinDerefMutHelper::deref_mut(unsafe {
+            &mut *(self as *mut Pin<Ptr> as *mut helper::PinHelper<Ptr>)
+        })
+    }
+}
+
+/// The `Target` type is restricted to `Unpin` types as it's not safe to obtain a mutable reference
+/// to a pinned value.
+///
+/// For soundness reasons, implementations of `DerefMut` for `Pin<T>` are rejected even when `T` is
+/// a local type not covered by this impl block. (Since `Pin` is [fundamental], such implementations
+/// would normally be possible.)
+///
+/// [fundamental]: ../../reference/items/implementations.html#r-items.impl.trait.fundamental
+#[stable(feature = "pin", since = "1.33.0")]
+#[rustc_const_unstable(feature = "const_convert", issue = "143773")]
+#[cfg(doc)]
+impl<Ptr> const DerefMut for Pin<Ptr>
+where
+    Ptr: [const] DerefMut,
+    <Ptr as Deref>::Target: Unpin,
+{
     fn deref_mut(&mut self) -> &mut Ptr::Target {
         Pin::get_mut(Pin::as_mut(self))
     }