Auto merge of #3916 - rust-lang:rustup-2024-09-26, r=RalfJung

Automatic Rustup

Author: bors

Diff for: Cargo.lock

@@ -524,7 +524,7 @@ checksum = "1462739cb27611015575c0c11df5df7601141071f07518d56fcc1be504cbec97"
 
 [[package]]
 name = "clippy"
-version = "0.1.82"
+version = "0.1.83"
 dependencies = [
  "anstream",
  "cargo_metadata 0.18.1",
@@ -547,13 +547,13 @@ dependencies = [
  "termize",
  "tokio",
  "toml 0.7.8",
- "ui_test 0.25.0",
+ "ui_test",
  "walkdir",
 ]
 
 [[package]]
 name = "clippy_config"
-version = "0.1.82"
+version = "0.1.83"
 dependencies = [
  "itertools",
  "serde",
@@ -576,7 +576,7 @@ dependencies = [
 
 [[package]]
 name = "clippy_lints"
-version = "0.1.82"
+version = "0.1.83"
 dependencies = [
  "arrayvec",
  "cargo_metadata 0.18.1",
@@ -600,7 +600,7 @@ dependencies = [
 
 [[package]]
 name = "clippy_utils"
-version = "0.1.82"
+version = "0.1.83"
 dependencies = [
  "arrayvec",
  "clippy_config",
@@ -902,7 +902,7 @@ dependencies = [
 
 [[package]]
 name = "declare_clippy_lint"
-version = "0.1.82"
+version = "0.1.83"
 dependencies = [
  "itertools",
  "quote",
@@ -2269,7 +2269,7 @@ dependencies = [
  "rustc_version",
  "smallvec",
  "tempfile",
- "ui_test 0.26.5",
+ "ui_test",
  "windows-sys 0.52.0",
 ]
 
@@ -5485,33 +5485,6 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed646292ffc8188ef8ea4d1e0e0150fb15a5c2e12ad9b8fc191ae7a8a7f3c4b9"
 
-[[package]]
-name = "ui_test"
-version = "0.25.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7e4f339f62edc873975c47115f9e71c5454ddaa37c1142b42fc0b2672c8dacb"
-dependencies = [
- "annotate-snippets 0.11.4",
- "anyhow",
- "bstr",
- "cargo-platform",
- "cargo_metadata 0.18.1",
- "color-eyre",
- "colored",
- "comma",
- "crossbeam-channel",
- "indicatif",
- "lazy_static",
- "levenshtein",
- "prettydiff",
- "regex",
- "rustc_version",
- "rustfix",
- "serde",
- "serde_json",
- "spanned",
-]
-
 [[package]]
 name = "ui_test"
 version = "0.26.5"

Diff for: compiler/rustc_ast_passes/src/feature_gate.rs

@@ -4,9 +4,9 @@ use rustc_ast::{NodeId, PatKind, attr, token};
 use rustc_feature::{AttributeGate, BUILTIN_ATTRIBUTE_MAP, BuiltinAttribute, Features, GateIssue};
 use rustc_session::Session;
 use rustc_session::parse::{feature_err, feature_err_issue, feature_warn};
-use rustc_span::Span;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::sym;
+use rustc_span::{Span, Symbol};
 use rustc_target::spec::abi;
 use thin_vec::ThinVec;
 
@@ -483,6 +483,8 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
 pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
     maybe_stage_features(sess, features, krate);
     check_incompatible_features(sess, features);
+    check_new_solver_banned_features(sess, features);
+
     let mut visitor = PostExpansionVisitor { sess, features };
 
     let spans = sess.psess.gated_spans.spans.borrow();
@@ -662,3 +664,22 @@ fn check_incompatible_features(sess: &Session, features: &Features) {
         }
     }
 }
+
+fn check_new_solver_banned_features(sess: &Session, features: &Features) {
+    if !sess.opts.unstable_opts.next_solver.is_some_and(|n| n.globally) {
+        return;
+    }
+
+    // Ban GCE with the new solver, because it does not implement GCE correctly.
+    if let Some(&(_, gce_span, _)) = features
+        .declared_lang_features
+        .iter()
+        .find(|&&(feat, _, _)| feat == sym::generic_const_exprs)
+    {
+        sess.dcx().emit_err(errors::IncompatibleFeatures {
+            spans: vec![gce_span],
+            f1: Symbol::intern("-Znext-solver=globally"),
+            f2: sym::generic_const_exprs,
+        });
+    }
+}

Diff for: compiler/rustc_borrowck/src/facts.rs

@@ -1,7 +1,7 @@
 use std::error::Error;
 use std::fmt::Debug;
 use std::fs::{self, File};
-use std::io::{BufWriter, Write};
+use std::io::Write;
 use std::path::Path;
 
 use polonius_engine::{AllFacts as PoloniusFacts, Atom};
@@ -127,7 +127,7 @@ impl<'w> FactWriter<'w> {
         T: FactRow,
     {
         let file = &self.dir.join(file_name);
-        let mut file = BufWriter::new(File::create(file)?);
+        let mut file = File::create_buffered(file)?;
         for row in rows {
             row.write(&mut file, self.location_table)?;
         }

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

@@ -6,6 +6,7 @@
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
+#![feature(file_buffered)]
 #![feature(let_chains)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]

Diff for: compiler/rustc_codegen_cranelift/src/unsize.rs

@@ -34,7 +34,22 @@ pub(crate) fn unsized_info<'tcx>(
             let old_info =
                 old_info.expect("unsized_info: missing old info for trait upcasting coercion");
             if data_a.principal_def_id() == data_b.principal_def_id() {
-                // A NOP cast that doesn't actually change anything, should be allowed even with invalid vtables.
+                // Codegen takes advantage of the additional assumption, where if the
+                // principal trait def id of what's being casted doesn't change,
+                // then we don't need to adjust the vtable at all. This
+                // corresponds to the fact that `dyn Tr<A>: Unsize<dyn Tr<B>>`
+                // requires that `A = B`; we don't allow *upcasting* objects
+                // between the same trait with different args. If we, for
+                // some reason, were to relax the `Unsize` trait, it could become
+                // unsound, so let's assert here that the trait refs are *equal*.
+                //
+                // We can use `assert_eq` because the binders should have been anonymized,
+                // and because higher-ranked equality now requires the binders are equal.
+                debug_assert_eq!(
+                    data_a.principal(),
+                    data_b.principal(),
+                    "NOP unsize vtable changed principal trait ref: {data_a} -> {data_b}"
+                );
                 return old_info;
             }
 

Diff for: compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -808,8 +808,7 @@ struct ThinLTOKeysMap {
 impl ThinLTOKeysMap {
     fn save_to_file(&self, path: &Path) -> io::Result<()> {
         use std::io::Write;
-        let file = File::create(path)?;
-        let mut writer = io::BufWriter::new(file);
+        let mut writer = File::create_buffered(path)?;
         // The entries are loaded back into a hash map in `load_from_file()`, so
         // the order in which we write them to file here does not matter.
         for (module, key) in &self.keys {
@@ -821,8 +820,8 @@ impl ThinLTOKeysMap {
     fn load_from_file(path: &Path) -> io::Result<Self> {
         use std::io::BufRead;
         let mut keys = BTreeMap::default();
-        let file = File::open(path)?;
-        for line in io::BufReader::new(file).lines() {
+        let file = File::open_buffered(path)?;
+        for line in file.lines() {
             let line = line?;
             let mut split = line.split(' ');
             let module = split.next().unwrap();

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

@@ -11,6 +11,7 @@
 #![feature(assert_matches)]
 #![feature(exact_size_is_empty)]
 #![feature(extern_types)]
+#![feature(file_buffered)]
 #![feature(hash_raw_entry)]
 #![feature(impl_trait_in_assoc_type)]
 #![feature(iter_intersperse)]

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

@@ -1087,16 +1087,17 @@ fn link_natively(
     let strip = sess.opts.cg.strip;
 
     if sess.target.is_like_osx {
+        let stripcmd = "/usr/bin/strip";
         match (strip, crate_type) {
             (Strip::Debuginfo, _) => {
-                strip_symbols_with_external_utility(sess, "strip", out_filename, Some("-S"))
+                strip_symbols_with_external_utility(sess, stripcmd, out_filename, Some("-S"))
             }
             // Per the manpage, `-x` is the maximum safe strip level for dynamic libraries. (#93988)
             (Strip::Symbols, CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro) => {
-                strip_symbols_with_external_utility(sess, "strip", out_filename, Some("-x"))
+                strip_symbols_with_external_utility(sess, stripcmd, out_filename, Some("-x"))
             }
             (Strip::Symbols, _) => {
-                strip_symbols_with_external_utility(sess, "strip", out_filename, None)
+                strip_symbols_with_external_utility(sess, stripcmd, out_filename, None)
             }
             (Strip::None, _) => {}
         }

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

@@ -1,9 +1,8 @@
 use std::ffi::{OsStr, OsString};
 use std::fs::{self, File};
 use std::io::prelude::*;
-use std::io::{self, BufWriter};
 use std::path::{Path, PathBuf};
-use std::{env, iter, mem, str};
+use std::{env, io, iter, mem, str};
 
 use cc::windows_registry;
 use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
@@ -754,7 +753,7 @@ impl<'a> Linker for GccLinker<'a> {
         if self.sess.target.is_like_osx {
             // Write a plain, newline-separated list of symbols
             let res: io::Result<()> = try {
-                let mut f = BufWriter::new(File::create(&path)?);
+                let mut f = File::create_buffered(&path)?;
                 for sym in symbols {
                     debug!("  _{sym}");
                     writeln!(f, "_{sym}")?;
@@ -765,7 +764,7 @@ impl<'a> Linker for GccLinker<'a> {
             }
         } else if is_windows {
             let res: io::Result<()> = try {
-                let mut f = BufWriter::new(File::create(&path)?);
+                let mut f = File::create_buffered(&path)?;
 
                 // .def file similar to MSVC one but without LIBRARY section
                 // because LD doesn't like when it's empty
@@ -781,7 +780,7 @@ impl<'a> Linker for GccLinker<'a> {
         } else {
             // Write an LD version script
             let res: io::Result<()> = try {
-                let mut f = BufWriter::new(File::create(&path)?);
+                let mut f = File::create_buffered(&path)?;
                 writeln!(f, "{{")?;
                 if !symbols.is_empty() {
                     writeln!(f, "  global:")?;
@@ -1059,7 +1058,7 @@ impl<'a> Linker for MsvcLinker<'a> {
 
         let path = tmpdir.join("lib.def");
         let res: io::Result<()> = try {
-            let mut f = BufWriter::new(File::create(&path)?);
+            let mut f = File::create_buffered(&path)?;
 
             // Start off with the standard module name header and then go
             // straight to exports.
@@ -1648,7 +1647,7 @@ impl<'a> Linker for AixLinker<'a> {
     fn export_symbols(&mut self, tmpdir: &Path, _crate_type: CrateType, symbols: &[String]) {
         let path = tmpdir.join("list.exp");
         let res: io::Result<()> = try {
-            let mut f = BufWriter::new(File::create(&path)?);
+            let mut f = File::create_buffered(&path)?;
             // FIXME: use llvm-nm to generate export list.
             for symbol in symbols {
                 debug!("  _{symbol}");
@@ -1961,7 +1960,7 @@ impl<'a> Linker for BpfLinker<'a> {
     fn export_symbols(&mut self, tmpdir: &Path, _crate_type: CrateType, symbols: &[String]) {
         let path = tmpdir.join("symbols");
         let res: io::Result<()> = try {
-            let mut f = BufWriter::new(File::create(&path)?);
+            let mut f = File::create_buffered(&path)?;
             for sym in symbols {
                 writeln!(f, "{sym}")?;
             }

Diff for: compiler/rustc_codegen_ssa/src/base.rs

@@ -37,6 +37,7 @@ use crate::back::write::{
     submit_codegened_module_to_llvm, submit_post_lto_module_to_llvm, submit_pre_lto_module_to_llvm,
 };
 use crate::common::{self, IntPredicate, RealPredicate, TypeKind};
+use crate::meth::load_vtable;
 use crate::mir::operand::OperandValue;
 use crate::mir::place::PlaceRef;
 use crate::traits::*;
@@ -124,8 +125,28 @@ fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             let old_info =
                 old_info.expect("unsized_info: missing old info for trait upcasting coercion");
             if data_a.principal_def_id() == data_b.principal_def_id() {
-                // A NOP cast that doesn't actually change anything, should be allowed even with
-                // invalid vtables.
+                // Codegen takes advantage of the additional assumption, where if the
+                // principal trait def id of what's being casted doesn't change,
+                // then we don't need to adjust the vtable at all. This
+                // corresponds to the fact that `dyn Tr<A>: Unsize<dyn Tr<B>>`
+                // requires that `A = B`; we don't allow *upcasting* objects
+                // between the same trait with different args. If we, for
+                // some reason, were to relax the `Unsize` trait, it could become
+                // unsound, so let's assert here that the trait refs are *equal*.
+                //
+                // We can use `assert_eq` because the binders should have been anonymized,
+                // and because higher-ranked equality now requires the binders are equal.
+                debug_assert_eq!(
+                    data_a.principal(),
+                    data_b.principal(),
+                    "NOP unsize vtable changed principal trait ref: {data_a} -> {data_b}"
+                );
+
+                // A NOP cast that doesn't actually change anything, let's avoid any
+                // unnecessary work. This relies on the assumption that if the principal
+                // traits are equal, then the associated type bounds (`dyn Trait<Assoc=T>`)
+                // are also equal, which is ensured by the fact that normalization is
+                // a function and we do not allow overlapping impls.
                 return old_info;
             }
 
@@ -135,14 +156,8 @@ fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 
             if let Some(entry_idx) = vptr_entry_idx {
                 let ptr_size = bx.data_layout().pointer_size;
-                let ptr_align = bx.data_layout().pointer_align.abi;
                 let vtable_byte_offset = u64::try_from(entry_idx).unwrap() * ptr_size.bytes();
-                let gep = bx.inbounds_ptradd(old_info, bx.const_usize(vtable_byte_offset));
-                let new_vptr = bx.load(bx.type_ptr(), gep, ptr_align);
-                bx.nonnull_metadata(new_vptr);
-                // VTable loads are invariant.
-                bx.set_invariant_load(new_vptr);
-                new_vptr
+                load_vtable(bx, old_info, bx.type_ptr(), vtable_byte_offset, source, true)
             } else {
                 old_info
             }

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

@@ -6,6 +6,7 @@
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
+#![feature(file_buffered)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(negative_impls)]