Auto merge of #117627 - matthiaskrgr:rollup-22w6fp8, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - #117578 (Derive `TyEncodable`/`TyDecodable` in `rustc_type_ir`)
 - #117592 (Use the correct span when emitting the `env!` result)
 - #117609 (Distinguish crates with the same name in type errors)
 - #117613 (Remove from vacation and compiler review group)
 - #117615 (Couple of small changes)

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

Author: bors

compiler/rustc_builtin_macros/src/env.rs

@@ -108,7 +108,7 @@ pub fn expand_env<'cx>(
 
             return DummyResult::any(sp);
         }
-        Some(value) => cx.expr_str(sp, value),
+        Some(value) => cx.expr_str(span, value),
     };
     MacEager::expr(e)
 }

compiler/rustc_codegen_ssa/src/traits/backend.rs

@@ -104,11 +104,7 @@ pub trait CodegenBackend {
         outputs: &OutputFilenames,
     ) -> Result<(CodegenResults, FxIndexMap<WorkProductId, WorkProduct>), ErrorGuaranteed>;
 
-    /// This is called on the returned `Box<dyn Any>` from `join_codegen`
-    ///
-    /// # Panics
-    ///
-    /// Panics when the passed `Box<dyn Any>` was not returned by `join_codegen`.
+    /// This is called on the returned `CodegenResults` from `join_codegen`
     fn link(
         &self,
         sess: &Session,

compiler/rustc_driver_impl/src/lib.rs

@@ -41,6 +41,7 @@ use rustc_session::cstore::MetadataLoader;
 use rustc_session::getopts::{self, Matches};
 use rustc_session::lint::{Lint, LintId};
 use rustc_session::{config, EarlyErrorHandler, Session};
+use rustc_span::def_id::LOCAL_CRATE;
 use rustc_span::source_map::FileLoader;
 use rustc_span::symbol::sym;
 use rustc_span::FileName;
@@ -421,8 +422,12 @@ fn run_compiler(
                     // effects of writing the dep-info and reporting errors.
                     queries.global_ctxt()?.enter(|tcx| tcx.output_filenames(()));
                 } else {
-                    let krate = queries.parse()?.steal();
-                    pretty::print(sess, *ppm, pretty::PrintExtra::AfterParsing { krate });
+                    let krate = queries.parse()?;
+                    pretty::print(
+                        sess,
+                        *ppm,
+                        pretty::PrintExtra::AfterParsing { krate: &*krate.borrow() },
+                    );
                 }
                 trace!("finished pretty-printing");
                 return early_exit();
@@ -477,8 +482,7 @@ fn run_compiler(
             }
 
             if sess.opts.unstable_opts.print_vtable_sizes {
-                let crate_name =
-                    compiler.session().opts.crate_name.as_deref().unwrap_or("<UNKNOWN_CRATE>");
+                let crate_name = queries.global_ctxt()?.enter(|tcx| tcx.crate_name(LOCAL_CRATE));
 
                 sess.code_stats.print_vtable_sizes(crate_name);
             }

compiler/rustc_driver_impl/src/pretty.rs

@@ -217,7 +217,7 @@ fn write_or_print(out: &str, sess: &Session) {
 // Extra data for pretty-printing, the form of which depends on what kind of
 // pretty-printing we are doing.
 pub enum PrintExtra<'tcx> {
-    AfterParsing { krate: ast::Crate },
+    AfterParsing { krate: &'tcx ast::Crate },
     NeedsAstMap { tcx: TyCtxt<'tcx> },
 }
 

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -1824,6 +1824,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                             let expected_defid = expected_adt.did();
 
                             diagnostic.note(format!("{found_name} and {expected_name} have similar names, but are actually distinct types"));
+                            let have_same_crate_name = self.tcx.crate_name(found_defid.krate) == self.tcx.crate_name(expected_defid.krate);
                             for (defid, name) in
                                 [(found_defid, found_name), (expected_defid, expected_name)]
                             {
@@ -1843,7 +1844,15 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                                     format!("{name} is defined in the current crate")
                                 } else {
                                     let crate_name = self.tcx.crate_name(defid.krate);
-                                    format!("{name} is defined in crate `{crate_name}`")
+                                    diagnostic.span_note(def_span, format!("{name} is defined in crate `{crate_name}`"));
+
+                                    // If these are named the same, give a hint about why the compiler thinks they're different.
+                                    if have_same_crate_name {
+                                        let crate_paths = self.tcx.crate_extern_paths(defid.krate);
+                                        diagnostic.note(format!("`{crate_name}` was loaded from {}", crate_paths[0].display()));
+                                    }
+
+                                    continue;
                                 };
                                 diagnostic.span_note(def_span, msg);
                             }

compiler/rustc_macros/src/serialize.rs

@@ -5,11 +5,16 @@ use syn::spanned::Spanned;
 
 pub fn type_decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
     let decoder_ty = quote! { __D };
-    if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
-        s.add_impl_generic(parse_quote! { 'tcx });
-    }
-    s.add_impl_generic(parse_quote! {#decoder_ty: ::rustc_type_ir::codec::TyDecoder<I = ::rustc_middle::ty::TyCtxt<'tcx>>});
-    s.add_bounds(synstructure::AddBounds::Generics);
+    let bound = if s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
+        quote! { <I = ::rustc_middle::ty::TyCtxt<'tcx>> }
+    } else if s.ast().generics.type_params().any(|ty| ty.ident == "I") {
+        quote! { <I = I> }
+    } else {
+        quote! {}
+    };
+
+    s.add_impl_generic(parse_quote! {#decoder_ty: ::rustc_type_ir::codec::TyDecoder #bound });
+    s.add_bounds(synstructure::AddBounds::Fields);
 
     decodable_body(s, decoder_ty)
 }
@@ -97,12 +102,17 @@ fn decode_field(field: &syn::Field) -> proc_macro2::TokenStream {
 }
 
 pub fn type_encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
-    if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
-        s.add_impl_generic(parse_quote! {'tcx});
-    }
+    let bound = if s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
+        quote! { <I = ::rustc_middle::ty::TyCtxt<'tcx>> }
+    } else if s.ast().generics.type_params().any(|ty| ty.ident == "I") {
+        quote! { <I = I> }
+    } else {
+        quote! {}
+    };
+
     let encoder_ty = quote! { __E };
-    s.add_impl_generic(parse_quote! {#encoder_ty: ::rustc_type_ir::codec::TyEncoder<I = ::rustc_middle::ty::TyCtxt<'tcx>>});
-    s.add_bounds(synstructure::AddBounds::Generics);
+    s.add_impl_generic(parse_quote! {#encoder_ty: ::rustc_type_ir::codec::TyEncoder #bound });
+    s.add_bounds(synstructure::AddBounds::Fields);
 
     encodable_body(s, encoder_ty, false)
 }

compiler/rustc_session/src/code_stats.rs

@@ -226,7 +226,7 @@ impl CodeStats {
         }
     }
 
-    pub fn print_vtable_sizes(&self, crate_name: &str) {
+    pub fn print_vtable_sizes(&self, crate_name: Symbol) {
         let mut infos =
             std::mem::take(&mut *self.vtable_sizes.lock()).into_values().collect::<Vec<_>>();
 

compiler/rustc_type_ir/src/canonical.rs

@@ -3,18 +3,17 @@ use std::hash::Hash;
 use std::ops::ControlFlow;
 
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
-use rustc_serialize::{Decodable, Encodable};
 
 use crate::fold::{FallibleTypeFolder, TypeFoldable};
 use crate::visit::{TypeVisitable, TypeVisitor};
-use crate::TyDecoder;
-use crate::{HashStableContext, Interner, TyEncoder, UniverseIndex};
+use crate::{HashStableContext, Interner, UniverseIndex};
 
 /// A "canonicalized" type `V` is one where all free inference
 /// variables have been rewritten to "canonical vars". These are
 /// numbered starting from 0 in order of first appearance.
 #[derive(derivative::Derivative)]
 #[derivative(Clone(bound = "V: Clone"), Hash(bound = "V: Hash"))]
+#[derive(TyEncodable, TyDecodable)]
 pub struct Canonical<I: Interner, V> {
     pub value: V,
     pub max_universe: UniverseIndex,
@@ -127,27 +126,3 @@ where
         self.variables.visit_with(folder)
     }
 }
-
-impl<I: Interner, E: TyEncoder<I = I>, V: Encodable<E>> Encodable<E> for Canonical<I, V>
-where
-    I::CanonicalVars: Encodable<E>,
-{
-    fn encode(&self, s: &mut E) {
-        self.value.encode(s);
-        self.max_universe.encode(s);
-        self.variables.encode(s);
-    }
-}
-
-impl<I: Interner, D: TyDecoder<I = I>, V: Decodable<D>> Decodable<D> for Canonical<I, V>
-where
-    I::CanonicalVars: Decodable<D>,
-{
-    fn decode(d: &mut D) -> Self {
-        Canonical {
-            value: Decodable::decode(d),
-            max_universe: Decodable::decode(d),
-            variables: Decodable::decode(d),
-        }
-    }
-}

compiler/rustc_type_ir/src/const_kind.rs

@@ -1,12 +1,8 @@
 use rustc_data_structures::stable_hasher::HashStable;
 use rustc_data_structures::stable_hasher::StableHasher;
-use rustc_serialize::{Decodable, Decoder, Encodable};
 use std::fmt;
 
-use crate::{
-    DebruijnIndex, DebugWithInfcx, HashStableContext, InferCtxtLike, Interner, TyDecoder,
-    TyEncoder, WithInfcx,
-};
+use crate::{DebruijnIndex, DebugWithInfcx, HashStableContext, InferCtxtLike, Interner, WithInfcx};
 
 use self::ConstKind::*;
 
@@ -20,6 +16,7 @@ use self::ConstKind::*;
     Ord = "feature_allow_slow_enum",
     Hash(bound = "")
 )]
+#[derive(TyEncodable, TyDecodable)]
 pub enum ConstKind<I: Interner> {
     /// A const generic parameter.
     Param(I::ParamConst),
@@ -92,67 +89,6 @@ where
     }
 }
 
-impl<I: Interner, D: TyDecoder<I = I>> Decodable<D> for ConstKind<I>
-where
-    I::ParamConst: Decodable<D>,
-    I::InferConst: Decodable<D>,
-    I::BoundConst: Decodable<D>,
-    I::PlaceholderConst: Decodable<D>,
-    I::AliasConst: Decodable<D>,
-    I::ValueConst: Decodable<D>,
-    I::ErrorGuaranteed: Decodable<D>,
-    I::ExprConst: Decodable<D>,
-{
-    fn decode(d: &mut D) -> Self {
-        match Decoder::read_usize(d) {
-            0 => Param(Decodable::decode(d)),
-            1 => Infer(Decodable::decode(d)),
-            2 => Bound(Decodable::decode(d), Decodable::decode(d)),
-            3 => Placeholder(Decodable::decode(d)),
-            4 => Unevaluated(Decodable::decode(d)),
-            5 => Value(Decodable::decode(d)),
-            6 => Error(Decodable::decode(d)),
-            7 => Expr(Decodable::decode(d)),
-            _ => panic!(
-                "{}",
-                format!(
-                    "invalid enum variant tag while decoding `{}`, expected 0..{}",
-                    "ConstKind", 8,
-                )
-            ),
-        }
-    }
-}
-
-impl<I: Interner, E: TyEncoder<I = I>> Encodable<E> for ConstKind<I>
-where
-    I::ParamConst: Encodable<E>,
-    I::InferConst: Encodable<E>,
-    I::BoundConst: Encodable<E>,
-    I::PlaceholderConst: Encodable<E>,
-    I::AliasConst: Encodable<E>,
-    I::ValueConst: Encodable<E>,
-    I::ErrorGuaranteed: Encodable<E>,
-    I::ExprConst: Encodable<E>,
-{
-    fn encode(&self, e: &mut E) {
-        let disc = const_kind_discriminant(self);
-        match self {
-            Param(p) => e.emit_enum_variant(disc, |e| p.encode(e)),
-            Infer(i) => e.emit_enum_variant(disc, |e| i.encode(e)),
-            Bound(d, b) => e.emit_enum_variant(disc, |e| {
-                d.encode(e);
-                b.encode(e);
-            }),
-            Placeholder(p) => e.emit_enum_variant(disc, |e| p.encode(e)),
-            Unevaluated(u) => e.emit_enum_variant(disc, |e| u.encode(e)),
-            Value(v) => e.emit_enum_variant(disc, |e| v.encode(e)),
-            Error(er) => e.emit_enum_variant(disc, |e| er.encode(e)),
-            Expr(ex) => e.emit_enum_variant(disc, |e| ex.encode(e)),
-        }
-    }
-}
-
 impl<I: Interner> PartialEq for ConstKind<I> {
     fn eq(&self, other: &Self) -> bool {
         match (self, other) {

compiler/rustc_type_ir/src/lib.rs

@@ -10,6 +10,8 @@
 #![deny(rustc::diagnostic_outside_of_impl)]
 #![allow(internal_features)]
 
+extern crate self as rustc_type_ir;
+
 #[macro_use]
 extern crate bitflags;
 #[macro_use]