Auto merge of rust-lang#151490 - JonathanBrouwer:rollup-ovStnQE, r=JonathanBrouwer

Rollup of 11 pull requests

Successful merges:

 - rust-lang#151001 (rustdoc: render doc(hidden) as a code attribute)
 - rust-lang#151042 (fix fallback impl for select_unpredictable intrinsic)
 - rust-lang#151220 (option: Use Option::map in Option::cloned)
 - rust-lang#151260 (Handle unevaluated ConstKind in in_operand)
 - rust-lang#151296 (MGCA: Fix incorrect pretty printing of valtree arrays)
 - rust-lang#151423 (Move assert_matches to planned stable path)
 - rust-lang#151441 (Fix ICE: Don't try to evaluate type_consts when eagerly collecting items)
 - rust-lang#151465 (codegen: clarify some variable names around function calls)
 - rust-lang#151468 (fix `f16` doctest FIXMEs)
 - rust-lang#151469 (llvm: Tolerate dead_on_return attribute changes)
 - rust-lang#151476 (Avoid `-> ()` in derived functions.)

r? @ghost

Author: bors

compiler/rustc_builtin_macros/src/deriving/generic/mod.rs

@@ -986,16 +986,6 @@ impl<'a> MethodDef<'a> {
         f(cx, span, &substructure)
     }
 
-    fn get_ret_ty(
-        &self,
-        cx: &ExtCtxt<'_>,
-        trait_: &TraitDef<'_>,
-        generics: &Generics,
-        type_ident: Ident,
-    ) -> Box<ast::Ty> {
-        self.ret_ty.to_ty(cx, trait_.span, type_ident, generics)
-    }
-
     fn is_static(&self) -> bool {
         !self.explicit_self
     }
@@ -1068,10 +1058,14 @@ impl<'a> MethodDef<'a> {
             self_arg.into_iter().chain(nonself_args).collect()
         };
 
-        let ret_type = self.get_ret_ty(cx, trait_, generics, type_ident);
+        let ret_type = if let Ty::Unit = &self.ret_ty {
+            ast::FnRetTy::Default(span)
+        } else {
+            ast::FnRetTy::Ty(self.ret_ty.to_ty(cx, span, type_ident, generics))
+        };
 
         let method_ident = Ident::new(self.name, span);
-        let fn_decl = cx.fn_decl(args, ast::FnRetTy::Ty(ret_type));
+        let fn_decl = cx.fn_decl(args, ret_type);
         let body_block = body.into_block(cx, span);
 
         let trait_lo_sp = span.shrink_to_lo();

compiler/rustc_codegen_llvm/src/builder.rs

@@ -1397,12 +1397,12 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     fn call(
         &mut self,
         llty: &'ll Type,
-        fn_call_attrs: Option<&CodegenFnAttrs>,
+        caller_attrs: Option<&CodegenFnAttrs>,
         fn_abi: Option<&FnAbi<'tcx, Ty<'tcx>>>,
         llfn: &'ll Value,
         args: &[&'ll Value],
         funclet: Option<&Funclet<'ll>>,
-        instance: Option<Instance<'tcx>>,
+        callee_instance: Option<Instance<'tcx>>,
     ) -> &'ll Value {
         debug!("call {:?} with args ({:?})", llfn, args);
 
@@ -1414,10 +1414,10 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         }
 
         // Emit CFI pointer type membership test
-        self.cfi_type_test(fn_call_attrs, fn_abi, instance, llfn);
+        self.cfi_type_test(caller_attrs, fn_abi, callee_instance, llfn);
 
         // Emit KCFI operand bundle
-        let kcfi_bundle = self.kcfi_operand_bundle(fn_call_attrs, fn_abi, instance, llfn);
+        let kcfi_bundle = self.kcfi_operand_bundle(caller_attrs, fn_abi, callee_instance, llfn);
         if let Some(kcfi_bundle) = kcfi_bundle.as_ref().map(|b| b.as_ref()) {
             bundles.push(kcfi_bundle);
         }
@@ -1435,17 +1435,17 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             )
         };
 
-        if let Some(instance) = instance {
+        if let Some(callee_instance) = callee_instance {
             // Attributes on the function definition being called
-            let fn_defn_attrs = self.cx.tcx.codegen_fn_attrs(instance.def_id());
-            if let Some(fn_call_attrs) = fn_call_attrs
+            let callee_attrs = self.cx.tcx.codegen_fn_attrs(callee_instance.def_id());
+            if let Some(caller_attrs) = caller_attrs
                 // If there is an inline attribute and a target feature that matches
                 // we will add the attribute to the callsite otherwise we'll omit
                 // this and not add the attribute to prevent soundness issues.
-                && let Some(inlining_rule) = attributes::inline_attr(&self.cx, self.cx.tcx, instance)
+                && let Some(inlining_rule) = attributes::inline_attr(&self.cx, self.cx.tcx, callee_instance)
                 && self.cx.tcx.is_target_feature_call_safe(
-                    &fn_defn_attrs.target_features,
-                    &fn_call_attrs.target_features.iter().cloned().chain(
+                    &callee_attrs.target_features,
+                    &caller_attrs.target_features.iter().cloned().chain(
                         self.cx.tcx.sess.target_features.iter().map(|feat| TargetFeature {
                             name: *feat,
                             kind: TargetFeatureKind::Implied,
@@ -1470,14 +1470,15 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     fn tail_call(
         &mut self,
         llty: Self::Type,
-        fn_attrs: Option<&CodegenFnAttrs>,
+        caller_attrs: Option<&CodegenFnAttrs>,
         fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
         llfn: Self::Value,
         args: &[Self::Value],
         funclet: Option<&Self::Funclet>,
-        instance: Option<Instance<'tcx>>,
+        callee_instance: Option<Instance<'tcx>>,
     ) {
-        let call = self.call(llty, fn_attrs, Some(fn_abi), llfn, args, funclet, instance);
+        let call =
+            self.call(llty, caller_attrs, Some(fn_abi), llfn, args, funclet, callee_instance);
         llvm::LLVMSetTailCallKind(call, llvm::TailCallKind::MustTail);
 
         match &fn_abi.ret.mode {

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -199,12 +199,12 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
         // do an invoke, otherwise do a call.
         let fn_ty = bx.fn_decl_backend_type(fn_abi);
 
-        let fn_attrs = if bx.tcx().def_kind(fx.instance.def_id()).has_codegen_attrs() {
+        let caller_attrs = if bx.tcx().def_kind(fx.instance.def_id()).has_codegen_attrs() {
             Some(bx.tcx().codegen_instance_attrs(fx.instance.def))
         } else {
             None
         };
-        let fn_attrs = fn_attrs.as_deref();
+        let caller_attrs = caller_attrs.as_deref();
 
         if !fn_abi.can_unwind {
             unwind = mir::UnwindAction::Unreachable;
@@ -233,7 +233,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
         };
 
         if kind == CallKind::Tail {
-            bx.tail_call(fn_ty, fn_attrs, fn_abi, fn_ptr, llargs, self.funclet(fx), instance);
+            bx.tail_call(fn_ty, caller_attrs, fn_abi, fn_ptr, llargs, self.funclet(fx), instance);
             return MergingSucc::False;
         }
 
@@ -245,7 +245,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
             };
             let invokeret = bx.invoke(
                 fn_ty,
-                fn_attrs,
+                caller_attrs,
                 Some(fn_abi),
                 fn_ptr,
                 llargs,
@@ -268,8 +268,15 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
             }
             MergingSucc::False
         } else {
-            let llret =
-                bx.call(fn_ty, fn_attrs, Some(fn_abi), fn_ptr, llargs, self.funclet(fx), instance);
+            let llret = bx.call(
+                fn_ty,
+                caller_attrs,
+                Some(fn_abi),
+                fn_ptr,
+                llargs,
+                self.funclet(fx),
+                instance,
+            );
             if fx.mir[self.bb].is_cleanup {
                 bx.apply_attrs_to_cleanup_callsite(llret);
             }

compiler/rustc_codegen_ssa/src/traits/builder.rs

@@ -600,10 +600,13 @@ pub trait BuilderMethods<'a, 'tcx>:
     ///
     /// ## Arguments
     ///
-    /// The `fn_attrs`, `fn_abi`, and `instance` arguments are Options because they are advisory.
-    /// They relate to optional codegen enhancements like LLVM CFI, and do not affect ABI per se.
-    /// Any ABI-related transformations should be handled by different, earlier stages of codegen.
-    /// For instance, in the caller of `BuilderMethods::call`.
+    /// `caller_attrs` are the attributes of the surrounding caller; they have nothing to do with
+    /// the callee.
+    ///
+    /// The `caller_attrs`, `fn_abi`, and `callee_instance` arguments are Options because they are
+    /// advisory. They relate to optional codegen enhancements like LLVM CFI, and do not affect ABI
+    /// per se. Any ABI-related transformations should be handled by different, earlier stages of
+    /// codegen. For instance, in the caller of `BuilderMethods::call`.
     ///
     /// This means that a codegen backend which disregards `fn_attrs`, `fn_abi`, and `instance`
     /// should still do correct codegen, and code should not be miscompiled if they are omitted.
@@ -620,23 +623,23 @@ pub trait BuilderMethods<'a, 'tcx>:
     fn call(
         &mut self,
         llty: Self::Type,
-        fn_attrs: Option<&CodegenFnAttrs>,
+        caller_attrs: Option<&CodegenFnAttrs>,
         fn_abi: Option<&FnAbi<'tcx, Ty<'tcx>>>,
         fn_val: Self::Value,
         args: &[Self::Value],
         funclet: Option<&Self::Funclet>,
-        instance: Option<Instance<'tcx>>,
+        callee_instance: Option<Instance<'tcx>>,
     ) -> Self::Value;
 
     fn tail_call(
         &mut self,
         llty: Self::Type,
-        fn_attrs: Option<&CodegenFnAttrs>,
+        caller_attrs: Option<&CodegenFnAttrs>,
         fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
         llfn: Self::Value,
         args: &[Self::Value],
         funclet: Option<&Self::Funclet>,
-        instance: Option<Instance<'tcx>>,
+        callee_instance: Option<Instance<'tcx>>,
     );
 
     fn zext(&mut self, val: Self::Value, dest_ty: Self::Type) -> Self::Value;

compiler/rustc_const_eval/src/check_consts/qualifs.rs

@@ -343,17 +343,18 @@ where
 
     // Check the qualifs of the value of `const` items.
     let uneval = match constant.const_ {
-        Const::Ty(_, ct)
-            if matches!(
-                ct.kind(),
-                ty::ConstKind::Param(_) | ty::ConstKind::Error(_) | ty::ConstKind::Value(_)
-            ) =>
-        {
-            None
-        }
-        Const::Ty(_, c) => {
-            bug!("expected ConstKind::Param or ConstKind::Value here, found {:?}", c)
-        }
+        Const::Ty(_, ct) => match ct.kind() {
+            ty::ConstKind::Param(_) | ty::ConstKind::Error(_) => None,
+            // Unevaluated consts in MIR bodies don't have associated MIR (e.g. `#[type_const]`).
+            ty::ConstKind::Unevaluated(_) => None,
+            // FIXME(mgca): Investigate whether using `None` for `ConstKind::Value` is overly
+            // strict, and if instead we should be doing some kind of value-based analysis.
+            ty::ConstKind::Value(_) => None,
+            _ => bug!(
+                "expected ConstKind::Param, ConstKind::Value, ConstKind::Unevaluated, or ConstKind::Error here, found {:?}",
+                ct
+            ),
+        },
         Const::Unevaluated(uv, _) => Some(uv),
         Const::Val(..) => None,
     };
@@ -364,10 +365,8 @@ where
         // check performed after the promotion. Verify that with an assertion.
         assert!(promoted.is_none() || Q::ALLOW_PROMOTED);
 
-        // Don't peak inside trait associated constants, also `#[type_const] const` items
-        // don't have bodies so there's nothing to look at
-        if promoted.is_none() && cx.tcx.trait_of_assoc(def).is_none() && !cx.tcx.is_type_const(def)
-        {
+        // Don't peak inside trait associated constants.
+        if promoted.is_none() && cx.tcx.trait_of_assoc(def).is_none() {
             let qualifs = cx.tcx.at(constant.span).mir_const_qualif(def);
 
             if !Q::in_qualifs(&qualifs) {

compiler/rustc_data_structures/src/lib.rs

@@ -41,8 +41,11 @@
 // have to worry about it being moved to a different module in std during stabilization.
 // FIXME(#151359): Remove this when `feature(assert_matches)` is stable in stage0.
 // (This doesn't necessarily need to be fixed during the beta bump itself.)
+#[cfg(bootstrap)]
 pub use std::assert_matches::{assert_matches, debug_assert_matches};
 use std::fmt;
+#[cfg(not(bootstrap))]
+pub use std::{assert_matches, debug_assert_matches};
 
 pub use atomic_ref::AtomicRef;
 pub use ena::{snapshot_vec, undo_log, unify};

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -527,6 +527,12 @@ LLVMRustCreateAttrNoValue(LLVMContextRef C, LLVMRustAttributeKind RustAttr) {
         *unwrap(C), CaptureInfo(CaptureComponents::Address |
                                 CaptureComponents::ReadProvenance)));
   }
+#endif
+#if LLVM_VERSION_GE(23, 0)
+  if (RustAttr == LLVMRustAttributeKind::DeadOnReturn) {
+    return wrap(Attribute::getWithDeadOnReturnInfo(*unwrap(C),
+                                                   llvm::DeadOnReturnInfo()));
+  }
 #endif
   return wrap(Attribute::get(*unwrap(C), fromRust(RustAttr)));
 }

compiler/rustc_middle/src/ty/consts/valtree.rs

@@ -147,7 +147,12 @@ impl<'tcx> Value<'tcx> {
             _ => return None,
         }
 
-        Some(tcx.arena.alloc_from_iter(self.to_branch().into_iter().map(|ct| ct.to_leaf().to_u8())))
+        // We create an iterator that yields `Option<u8>`
+        let iterator = self.to_branch().into_iter().map(|ct| Some(ct.try_to_leaf()?.to_u8()));
+        // If there is `None` in the iterator, then the array is not a valid array of u8s and we return `None`
+        let bytes: Vec<u8> = iterator.collect::<Option<Vec<u8>>>()?;
+
+        Some(tcx.arena.alloc_from_iter(bytes))
     }
 
     /// Converts to a `ValTreeKind::Leaf` value, `panic`'ing

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

@@ -1911,14 +1911,16 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
                     return Ok(());
                 }
             },
-            (ty::ValTreeKind::Branch(_), ty::Array(t, _)) if t == u8_type => {
-                let bytes = cv.try_to_raw_bytes(self.tcx()).unwrap_or_else(|| {
-                    bug!("expected to convert valtree to raw bytes for type {:?}", t)
-                });
+            // If it is a branch with an array, and this array can be printed as raw bytes, then dump its bytes
+            (ty::ValTreeKind::Branch(_), ty::Array(t, _))
+                if t == u8_type
+                    && let Some(bytes) = cv.try_to_raw_bytes(self.tcx()) =>
+            {
                 write!(self, "*")?;
                 self.pretty_print_byte_str(bytes)?;
                 return Ok(());
             }
+            // Otherwise, print the array separated by commas (or if it's a tuple)
             (ty::ValTreeKind::Branch(fields), ty::Array(..) | ty::Tuple(..)) => {
                 let fields_iter = fields.iter().copied();
 

compiler/rustc_monomorphize/src/collector.rs

@@ -1563,11 +1563,22 @@ impl<'v> RootCollector<'_, 'v> {
                 // If we're collecting items eagerly, then recurse into all constants.
                 // Otherwise the value is only collected when explicitly mentioned in other items.
                 if self.strategy == MonoItemCollectionStrategy::Eager {
-                    if !self.tcx.generics_of(id.owner_id).own_requires_monomorphization()
-                        && let Ok(val) = self.tcx.const_eval_poly(id.owner_id.to_def_id())
-                    {
-                        collect_const_value(self.tcx, val, self.output);
+                    let def_id = id.owner_id.to_def_id();
+                    // Type Consts don't have bodies to evaluate
+                    // nor do they make sense as a static.
+                    if self.tcx.is_type_const(def_id) {
+                        // FIXME(mgca): Is this actually what we want? We may want to
+                        // normalize to a ValTree then convert to a const allocation and
+                        // collect that?
+                        return;
+                    }
+                    if self.tcx.generics_of(id.owner_id).own_requires_monomorphization() {
+                        return;
                     }
+                    let Ok(val) = self.tcx.const_eval_poly(def_id) else {
+                        return;
+                    };
+                    collect_const_value(self.tcx, val, self.output);
                 }
             }
             DefKind::Impl { of_trait: true } => {