Merge from rustc

21 files changed, 113 insertions, 124 deletions

diff --git a/src/tools/cargo b/src/tools/cargo
-Subproject 34a6a87d8a2330d8c9d578f927489689328a652
+Subproject b1feb75d062444e2cee8b3d2aaa95309d65e9cc
diff --git a/src/tools/clippy/clippy_utils/src/consts.rs b/src/tools/clippy/clippy_utils/src/consts.rs
index cd88ccd87cf..5c9cad2b45d 100644
--- a/src/tools/clippy/clippy_utils/src/consts.rs
+++ b/src/tools/clippy/clippy_utils/src/consts.rs
@@ -6,7 +6,7 @@ use crate::{clip, is_direct_expn_of, sext, unsext};
 use rustc_ast::ast::{self, LitFloatType, LitKind};
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, Item, ItemKind, Node, QPath, UnOp};
+use rustc_hir::{BinOp, BinOpKind, Block, ConstBlock, Expr, ExprKind, HirId, Item, ItemKind, Node, QPath, UnOp};
 use rustc_lexer::tokenize;
 use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::{alloc_range, Scalar};
@@ -412,7 +412,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// Simple constant folding: Insert an expression, get a constant or none.
     pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant<'tcx>> {
         match e.kind {
-            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr(e),
+            ExprKind::ConstBlock(ConstBlock { body, .. }) => self.expr(self.lcx.tcx.hir().body(body).value), ExprKind::DropTemps(e) => self.expr(e),
             ExprKind::Path(ref qpath) => {
                 self.fetch_path_and_apply(qpath, e.hir_id, self.typeck_results.expr_ty(e), |this, result| {
                     let result = mir_to_const(this.lcx, result)?;
@@ -490,7 +490,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// leaves the local crate.
     pub fn expr_is_empty(&mut self, e: &Expr<'_>) -> Option<bool> {
         match e.kind {
-            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr_is_empty(e),
+            ExprKind::ConstBlock(ConstBlock { body, .. }) => self.expr_is_empty(self.lcx.tcx.hir().body(body).value), ExprKind::DropTemps(e) => self.expr_is_empty(e),
             ExprKind::Path(ref qpath) => {
                 if !self
                     .typeck_results
diff --git a/src/tools/clippy/clippy_utils/src/hir_utils.rs b/src/tools/clippy/clippy_utils/src/hir_utils.rs
index c649c179468..36634817fc9 100644
--- a/src/tools/clippy/clippy_utils/src/hir_utils.rs
+++ b/src/tools/clippy/clippy_utils/src/hir_utils.rs
@@ -295,7 +295,7 @@ impl HirEqInterExpr<'_, '_, '_> {
                 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
             },
             (&ExprKind::Closure(_l), &ExprKind::Closure(_r)) => false,
-            (&ExprKind::ConstBlock(lb), &ExprKind::ConstBlock(rb)) => self.eq_expr(lb, rb),
+            (&ExprKind::ConstBlock(lb), &ExprKind::ConstBlock(rb)) => self.eq_body(lb.body, rb.body),
             (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
                 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
             },
@@ -769,8 +769,8 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
                 // closures inherit TypeckResults
                 self.hash_expr(self.cx.tcx.hir().body(body).value);
             },
-            ExprKind::ConstBlock(l_id) => {
-                self.hash_expr(l_id);
+            ExprKind::ConstBlock(ref l_id) => {
+                self.hash_body(l_id.body);
             },
             ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
                 self.hash_expr(e);
diff --git a/src/tools/clippy/tests/ui/arithmetic_side_effects.stderr b/src/tools/clippy/tests/ui/arithmetic_side_effects.stderr
index df14ff396f6..8039c0bfa24 100644
--- a/src/tools/clippy/tests/ui/arithmetic_side_effects.stderr
+++ b/src/tools/clippy/tests/ui/arithmetic_side_effects.stderr
@@ -1,35 +1,11 @@
 error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:188:36
-   |
-LL |     let _ = const { let mut n = 1; n += 1; n };
-   |                                    ^^^^^^
-   |
-   = note: `-D clippy::arithmetic-side-effects` implied by `-D warnings`
-   = help: to override `-D warnings` add `#[allow(clippy::arithmetic_side_effects)]`
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:191:40
-   |
-LL |     let _ = const { let mut n = 1; n = n + 1; n };
-   |                                        ^^^^^
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:194:40
-   |
-LL |     let _ = const { let mut n = 1; n = 1 + n; n };
-   |                                        ^^^^^
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:200:59
-   |
-LL |     let _ = const { let mut n = 1; n = -1; n = -(-1); n = -n; n };
-   |                                                           ^^
-
-error: arithmetic operation that can potentially result in unexpected side-effects
   --> tests/ui/arithmetic_side_effects.rs:304:5
    |
 LL |     _n += 1;
    |     ^^^^^^^
+   |
+   = note: `-D clippy::arithmetic-side-effects` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::arithmetic_side_effects)]`
 
 error: arithmetic operation that can potentially result in unexpected side-effects
   --> tests/ui/arithmetic_side_effects.rs:305:5
@@ -751,5 +727,5 @@ error: arithmetic operation that can potentially result in unexpected side-effec
 LL |     one.sub_assign(1);
    |     ^^^^^^^^^^^^^^^^^
 
-error: aborting due to 125 previous errors
+error: aborting due to 121 previous errors
 
diff --git a/src/tools/clippy/tests/ui/cfg_attr_rustfmt.fixed b/src/tools/clippy/tests/ui/cfg_attr_rustfmt.fixed
index 84dac431169..05d5b3d10ea 100644
--- a/src/tools/clippy/tests/ui/cfg_attr_rustfmt.fixed
+++ b/src/tools/clippy/tests/ui/cfg_attr_rustfmt.fixed
@@ -16,7 +16,7 @@ fn foo(
 
 fn skip_on_statements() {
     #[rustfmt::skip]
-    { 5+3; }
+    5+3;
 }
 
 #[rustfmt::skip]
@@ -33,11 +33,11 @@ mod foo {
 #[clippy::msrv = "1.29"]
 fn msrv_1_29() {
     #[cfg_attr(rustfmt, rustfmt::skip)]
-    { 1+29; }
+    1+29;
 }
 
 #[clippy::msrv = "1.30"]
 fn msrv_1_30() {
     #[rustfmt::skip]
-    { 1+30; }
+    1+30;
 }
diff --git a/src/tools/clippy/tests/ui/cfg_attr_rustfmt.rs b/src/tools/clippy/tests/ui/cfg_attr_rustfmt.rs
index 4ab5c70e13b..bc29e20210e 100644
--- a/src/tools/clippy/tests/ui/cfg_attr_rustfmt.rs
+++ b/src/tools/clippy/tests/ui/cfg_attr_rustfmt.rs
@@ -16,7 +16,7 @@ fn foo(
 
 fn skip_on_statements() {
     #[cfg_attr(rustfmt, rustfmt::skip)]
-    { 5+3; }
+    5+3;
 }
 
 #[cfg_attr(rustfmt, rustfmt_skip)]
@@ -33,11 +33,11 @@ mod foo {
 #[clippy::msrv = "1.29"]
 fn msrv_1_29() {
     #[cfg_attr(rustfmt, rustfmt::skip)]
-    { 1+29; }
+    1+29;
 }
 
 #[clippy::msrv = "1.30"]
 fn msrv_1_30() {
     #[cfg_attr(rustfmt, rustfmt::skip)]
-    { 1+30; }
+    1+30;
 }
diff --git a/src/tools/clippy/tests/ui/std_instead_of_core.fixed b/src/tools/clippy/tests/ui/std_instead_of_core.fixed
index ec4ae2ea13c..6ede7bfcd9f 100644
--- a/src/tools/clippy/tests/ui/std_instead_of_core.fixed
+++ b/src/tools/clippy/tests/ui/std_instead_of_core.fixed
@@ -45,8 +45,8 @@ fn std_instead_of_core() {
 
     let _ = std::env!("PATH");
 
-    // do not lint until `error_in_core` is stable
-    use std::error::Error;
+    use core::error::Error;
+    //~^ ERROR: used import from `std` instead of `core`
 
     // lint items re-exported from private modules, `core::iter::traits::iterator::Iterator`
     use core::iter::Iterator;
diff --git a/src/tools/clippy/tests/ui/std_instead_of_core.rs b/src/tools/clippy/tests/ui/std_instead_of_core.rs
index c12c459c7eb..e22b4f61f3e 100644
--- a/src/tools/clippy/tests/ui/std_instead_of_core.rs
+++ b/src/tools/clippy/tests/ui/std_instead_of_core.rs
@@ -45,8 +45,8 @@ fn std_instead_of_core() {
 
     let _ = std::env!("PATH");
 
-    // do not lint until `error_in_core` is stable
     use std::error::Error;
+    //~^ ERROR: used import from `std` instead of `core`
 
     // lint items re-exported from private modules, `core::iter::traits::iterator::Iterator`
     use std::iter::Iterator;
diff --git a/src/tools/clippy/tests/ui/std_instead_of_core.stderr b/src/tools/clippy/tests/ui/std_instead_of_core.stderr
index 8f920511cc5..22cb9db7050 100644
--- a/src/tools/clippy/tests/ui/std_instead_of_core.stderr
+++ b/src/tools/clippy/tests/ui/std_instead_of_core.stderr
@@ -50,6 +50,12 @@ LL |     let cell_absolute = ::std::cell::Cell::new(8u32);
    |                           ^^^ help: consider importing the item from `core`: `core`
 
 error: used import from `std` instead of `core`
+  --> tests/ui/std_instead_of_core.rs:48:9
+   |
+LL |     use std::error::Error;
+   |         ^^^ help: consider importing the item from `core`: `core`
+
+error: used import from `std` instead of `core`
   --> tests/ui/std_instead_of_core.rs:52:9
    |
 LL |     use std::iter::Iterator;
@@ -79,5 +85,5 @@ LL |     use alloc::slice::from_ref;
    = note: `-D clippy::alloc-instead-of-core` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::alloc_instead_of_core)]`
 
-error: aborting due to 12 previous errors
+error: aborting due to 13 previous errors
 
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 28c766f7e17..dbe016b8305 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -15,7 +15,7 @@ use crate::errors::{self, Error, ErrorKind};
 use crate::header::TestProps;
 use crate::json;
 use crate::read2::{read2_abbreviated, Truncated};
-use crate::util::{add_dylib_path, dylib_env_var, logv, PathBufExt};
+use crate::util::{add_dylib_path, copy_dir_all, dylib_env_var, logv, PathBufExt};
 use crate::ColorConfig;
 use colored::Colorize;
 use miropt_test_tools::{files_for_miropt_test, MiroptTest, MiroptTestFile};
@@ -3471,6 +3471,21 @@ impl<'test> TestCx<'test> {
         let rmake_out_dir = base_dir.join("rmake_out");
         create_dir_all(&rmake_out_dir).unwrap();
 
+        // Copy all input files (apart from rmake.rs) to the temporary directory,
+        // so that the input directory structure from `tests/run-make/<test>` is mirrored
+        // to the `rmake_out` directory.
+        for path in walkdir::WalkDir::new(&self.testpaths.file).min_depth(1) {
+            let path = path.unwrap().path().to_path_buf();
+            if path.file_name().is_some_and(|s| s != "rmake.rs") {
+                let target = rmake_out_dir.join(path.strip_prefix(&self.testpaths.file).unwrap());
+                if path.is_dir() {
+                    copy_dir_all(&path, target).unwrap();
+                } else {
+                    fs::copy(&path, target).unwrap();
+                }
+            }
+        }
+
         // HACK: assume stageN-target, we only want stageN.
         let stage = self.config.stage_id.split('-').next().unwrap();
 
@@ -3528,21 +3543,13 @@ impl<'test> TestCx<'test> {
             .arg(&self.testpaths.file.join("rmake.rs"))
             .env("TARGET", &self.config.target)
             .env("PYTHON", &self.config.python)
-            .env("S", &src_root)
             .env("RUST_BUILD_STAGE", &self.config.stage_id)
             .env("RUSTC", cwd.join(&self.config.rustc_path))
-            .env("TMPDIR", &rmake_out_dir)
             .env("LD_LIB_PATH_ENVVAR", dylib_env_var())
             .env(dylib_env_var(), &host_dylib_env_paths)
             .env("HOST_RPATH_DIR", cwd.join(&self.config.compile_lib_path))
             .env("TARGET_RPATH_DIR", cwd.join(&self.config.run_lib_path))
-            .env("LLVM_COMPONENTS", &self.config.llvm_components)
-            // We for sure don't want these tests to run in parallel, so make
-            // sure they don't have access to these vars if we run via `make`
-            // at the top level
-            .env_remove("MAKEFLAGS")
-            .env_remove("MFLAGS")
-            .env_remove("CARGO_MAKEFLAGS");
+            .env("LLVM_COMPONENTS", &self.config.llvm_components);
 
         if std::env::var_os("COMPILETEST_FORCE_STAGE0").is_some() {
             let mut stage0_sysroot = build_root.clone();
@@ -3572,7 +3579,7 @@ impl<'test> TestCx<'test> {
         let target_rpath_env_path = env::join_paths(target_rpath_env_path).unwrap();
 
         let mut cmd = Command::new(&recipe_bin);
-        cmd.current_dir(&self.testpaths.file)
+        cmd.current_dir(&rmake_out_dir)
             .stdout(Stdio::piped())
             .stderr(Stdio::piped())
             .env("LD_LIB_PATH_ENVVAR", dylib_env_var())
@@ -3580,19 +3587,12 @@ impl<'test> TestCx<'test> {
             .env(dylib_env_var(), &dylib_env_paths)
             .env("TARGET", &self.config.target)
             .env("PYTHON", &self.config.python)
-            .env("S", &src_root)
+            .env("SOURCE_ROOT", &src_root)
             .env("RUST_BUILD_STAGE", &self.config.stage_id)
             .env("RUSTC", cwd.join(&self.config.rustc_path))
-            .env("TMPDIR", &rmake_out_dir)
             .env("HOST_RPATH_DIR", cwd.join(&self.config.compile_lib_path))
             .env("TARGET_RPATH_DIR", cwd.join(&self.config.run_lib_path))
-            .env("LLVM_COMPONENTS", &self.config.llvm_components)
-            // We for sure don't want these tests to run in parallel, so make
-            // sure they don't have access to these vars if we run via `make`
-            // at the top level
-            .env_remove("MAKEFLAGS")
-            .env_remove("MFLAGS")
-            .env_remove("CARGO_MAKEFLAGS");
+            .env("LLVM_COMPONENTS", &self.config.llvm_components);
 
         if let Some(ref rustdoc) = self.config.rustdoc_path {
             cmd.env("RUSTDOC", cwd.join(rustdoc));
diff --git a/src/tools/compiletest/src/util.rs b/src/tools/compiletest/src/util.rs
index 09a7f0395cf..ec20bda8c18 100644
--- a/src/tools/compiletest/src/util.rs
+++ b/src/tools/compiletest/src/util.rs
@@ -1,7 +1,7 @@
 use crate::common::Config;
 use std::env;
 use std::ffi::OsStr;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process::Command;
 
 use tracing::*;
@@ -76,3 +76,17 @@ pub fn add_dylib_path(cmd: &mut Command, paths: impl Iterator<Item = impl Into<P
     let new_paths = paths.map(Into::into).chain(old_paths.into_iter().flatten());
     cmd.env(dylib_env_var(), env::join_paths(new_paths).unwrap());
 }
+
+pub fn copy_dir_all(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> std::io::Result<()> {
+    std::fs::create_dir_all(&dst)?;
+    for entry in std::fs::read_dir(src)? {
+        let entry = entry?;
+        let ty = entry.file_type()?;
+        if ty.is_dir() {
+            copy_dir_all(entry.path(), dst.as_ref().join(entry.file_name()))?;
+        } else {
+            std::fs::copy(entry.path(), dst.as_ref().join(entry.file_name()))?;
+        }
+    }
+    Ok(())
+}
diff --git a/src/tools/run-make-support/src/cc.rs b/src/tools/run-make-support/src/cc.rs
index 1472a39305e..b33004974bf 100644
--- a/src/tools/run-make-support/src/cc.rs
+++ b/src/tools/run-make-support/src/cc.rs
@@ -1,9 +1,7 @@
 use std::path::Path;
 use std::process::Command;
 
-use crate::{
-    bin_name, cygpath_windows, env_var, handle_failed_output, is_msvc, is_windows, tmp_dir, uname,
-};
+use crate::{bin_name, cygpath_windows, env_var, handle_failed_output, is_msvc, is_windows, uname};
 
 /// Construct a new platform-specific C compiler invocation.
 ///
@@ -54,8 +52,7 @@ impl Cc {
         self
     }
 
-    /// Specify `-o` or `-Fe`/`-Fo` depending on platform/compiler. This assumes that the executable
-    /// is under `$TMPDIR`.
+    /// Specify `-o` or `-Fe`/`-Fo` depending on platform/compiler.
     pub fn out_exe(&mut self, name: &str) -> &mut Self {
         // Ref: tools.mk (irrelevant lines omitted):
         //
@@ -69,13 +66,13 @@ impl Cc {
         // ```
 
         if is_msvc() {
-            let fe_path = cygpath_windows(tmp_dir().join(bin_name(name)));
-            let fo_path = cygpath_windows(tmp_dir().join(format!("{name}.obj")));
+            let fe_path = cygpath_windows(bin_name(name));
+            let fo_path = cygpath_windows(format!("{name}.obj"));
             self.cmd.arg(format!("-Fe:{fe_path}"));
             self.cmd.arg(format!("-Fo:{fo_path}"));
         } else {
             self.cmd.arg("-o");
-            self.cmd.arg(tmp_dir().join(name));
+            self.cmd.arg(name);
         }
 
         self
diff --git a/src/tools/run-make-support/src/clang.rs b/src/tools/run-make-support/src/clang.rs
index 63c5af17c1d..7d9246b5222 100644
--- a/src/tools/run-make-support/src/clang.rs
+++ b/src/tools/run-make-support/src/clang.rs
@@ -1,7 +1,7 @@
 use std::path::Path;
 use std::process::Command;
 
-use crate::{bin_name, env_var, handle_failed_output, tmp_dir};
+use crate::{bin_name, env_var, handle_failed_output};
 
 /// Construct a new `clang` invocation. `clang` is not always available for all targets.
 pub fn clang() -> Clang {
@@ -30,11 +30,11 @@ impl Clang {
         self
     }
 
-    /// Specify the name of the executable. The executable will be placed under `$TMPDIR`, and the
-    /// extension will be determined by [`bin_name`].
+    /// Specify the name of the executable. The executable will be placed under the current directory
+    /// and the extension will be determined by [`bin_name`].
     pub fn out_exe(&mut self, name: &str) -> &mut Self {
         self.cmd.arg("-o");
-        self.cmd.arg(tmp_dir().join(bin_name(name)));
+        self.cmd.arg(bin_name(name));
         self
     }
 
diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index d74a0272a62..0d167960c16 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -45,11 +45,6 @@ pub fn env_var_os(name: &str) -> OsString {
     }
 }
 
-/// Path of `TMPDIR` (a temporary build directory, not under `/tmp`).
-pub fn tmp_dir() -> PathBuf {
-    env_var_os("TMPDIR").into()
-}
-
 /// `TARGET`
 pub fn target() -> String {
     env_var("TARGET")
@@ -70,12 +65,6 @@ pub fn is_darwin() -> bool {
     target().contains("darwin")
 }
 
-/// Construct a path to a static library under `$TMPDIR` given the library name. This will return a
-/// path with `$TMPDIR` joined with platform-and-compiler-specific library name.
-pub fn static_lib(name: &str) -> PathBuf {
-    tmp_dir().join(static_lib_name(name))
-}
-
 pub fn python_command() -> Command {
     let python_path = env_var("PYTHON");
     Command::new(python_path)
@@ -89,7 +78,7 @@ pub fn htmldocck() -> Command {
 
 /// Path to the root rust-lang/rust source checkout.
 pub fn source_root() -> PathBuf {
-    env_var("S").into()
+    env_var("SOURCE_ROOT").into()
 }
 
 /// Construct the static library name based on the platform.
@@ -116,12 +105,6 @@ pub fn static_lib_name(name: &str) -> String {
     if is_msvc() { format!("{name}.lib") } else { format!("lib{name}.a") }
 }
 
-/// Construct a path to a dynamic library under `$TMPDIR` given the library name. This will return a
-/// path with `$TMPDIR` joined with platform-and-compiler-specific library name.
-pub fn dynamic_lib(name: &str) -> PathBuf {
-    tmp_dir().join(dynamic_lib_name(name))
-}
-
 /// Construct the dynamic library name based on the platform.
 pub fn dynamic_lib_name(name: &str) -> String {
     // See tools.mk (irrelevant lines omitted):
@@ -159,14 +142,7 @@ pub fn dynamic_lib_extension() -> &'static str {
     }
 }
 
-/// Construct a path to a rust library (rlib) under `$TMPDIR` given the library name. This will return a
-/// path with `$TMPDIR` joined with the library name.
-pub fn rust_lib(name: &str) -> PathBuf {
-    tmp_dir().join(rust_lib_name(name))
-}
-
-/// Generate the name a rust library (rlib) would have. If you want the complete path, use
-/// [`rust_lib`] instead.
+/// Construct a rust library (rlib) name.
 pub fn rust_lib_name(name: &str) -> String {
     format!("lib{name}.rlib")
 }
@@ -176,6 +152,11 @@ pub fn bin_name(name: &str) -> String {
     if is_windows() { format!("{name}.exe") } else { name.to_string() }
 }
 
+/// Return the current working directory.
+pub fn cwd() -> PathBuf {
+    env::current_dir().unwrap()
+}
+
 /// Use `cygpath -w` on a path to get a Windows path string back. This assumes that `cygpath` is
 /// available on the platform!
 #[track_caller]
@@ -227,7 +208,7 @@ pub fn set_host_rpath(cmd: &mut Command) {
     let ld_lib_path_envvar = env_var("LD_LIB_PATH_ENVVAR");
     cmd.env(&ld_lib_path_envvar, {
         let mut paths = vec![];
-        paths.push(PathBuf::from(env_var("TMPDIR")));
+        paths.push(cwd());
         paths.push(PathBuf::from(env_var("HOST_RPATH_DIR")));
         for p in env::split_paths(&env_var(&ld_lib_path_envvar)) {
             paths.push(p.to_path_buf());
@@ -315,6 +296,27 @@ pub fn assert_not_contains(haystack: &str, needle: &str) {
     }
 }
 
+/// This function is designed for running commands in a temporary directory
+/// that is cleared after the function ends.
+///
+/// What this function does:
+/// 1) Creates a temporary directory (`tmpdir`)
+/// 2) Copies all files from the current directory to `tmpdir`
+/// 3) Changes the current working directory to `tmpdir`
+/// 4) Calls `callback`
+/// 5) Switches working directory back to the original one
+/// 6) Removes `tmpdir`
+pub fn run_in_tmpdir<F: FnOnce()>(callback: F) {
+    let original_dir = cwd();
+    let tmpdir = original_dir.join("../temporary-directory");
+    copy_dir_all(".", &tmpdir);
+
+    env::set_current_dir(&tmpdir).unwrap();
+    callback();
+    env::set_current_dir(original_dir).unwrap();
+    fs::remove_dir_all(tmpdir).unwrap();
+}
+
 /// Implement common helpers for command wrappers. This assumes that the command wrapper is a struct
 /// containing a `cmd: Command` field and a `output` function. The provided helpers are:
 ///
diff --git a/src/tools/run-make-support/src/run.rs b/src/tools/run-make-support/src/run.rs
index 8d8eafba99b..b607c583e32 100644
--- a/src/tools/run-make-support/src/run.rs
+++ b/src/tools/run-make-support/src/run.rs
@@ -2,19 +2,19 @@ use std::env;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Output};
 
-use crate::{env_var, is_windows};
+use crate::{cwd, env_var, is_windows};
 
 use super::handle_failed_output;
 
 fn run_common(name: &str) -> (Command, Output) {
     let mut bin_path = PathBuf::new();
-    bin_path.push(env_var("TMPDIR"));
+    bin_path.push(cwd());
     bin_path.push(name);
     let ld_lib_path_envvar = env_var("LD_LIB_PATH_ENVVAR");
     let mut cmd = Command::new(bin_path);
     cmd.env(&ld_lib_path_envvar, {
         let mut paths = vec![];
-        paths.push(PathBuf::from(env_var("TMPDIR")));
+        paths.push(cwd());
         for p in env::split_paths(&env_var("TARGET_RPATH_ENV")) {
             paths.push(p.to_path_buf());
         }
diff --git a/src/tools/run-make-support/src/rustc.rs b/src/tools/run-make-support/src/rustc.rs
index e923c3cf4ad..a64dd9d30cf 100644
--- a/src/tools/run-make-support/src/rustc.rs
+++ b/src/tools/run-make-support/src/rustc.rs
@@ -3,7 +3,7 @@ use std::io::Write;
 use std::path::Path;
 use std::process::{Command, Output, Stdio};
 
-use crate::{env_var, handle_failed_output, set_host_rpath, tmp_dir};
+use crate::{cwd, env_var, handle_failed_output, set_host_rpath};
 
 /// Construct a new `rustc` invocation.
 pub fn rustc() -> Rustc {
@@ -28,7 +28,7 @@ fn setup_common() -> Command {
     let rustc = env_var("RUSTC");
     let mut cmd = Command::new(rustc);
     set_host_rpath(&mut cmd);
-    cmd.arg("--out-dir").arg(tmp_dir()).arg("-L").arg(tmp_dir());
+    cmd.arg("-L").arg(cwd());
     cmd
 }
 
diff --git a/src/tools/rust-installer/src/compression.rs b/src/tools/rust-installer/src/compression.rs
index 4e840dbfbb4..40c7c597e9b 100644
--- a/src/tools/rust-installer/src/compression.rs
+++ b/src/tools/rust-installer/src/compression.rs
@@ -214,22 +214,16 @@ impl Write for CombinedEncoder {
     }
 
     fn write_all(&mut self, buf: &[u8]) -> std::io::Result<()> {
-        self.encoders
-            .par_iter_mut()
-            .map(|w| w.write_all(buf))
-            .collect::<std::io::Result<Vec<()>>>()?;
-        Ok(())
+        self.encoders.par_iter_mut().try_for_each(|w| w.write_all(buf))
     }
 
     fn flush(&mut self) -> std::io::Result<()> {
-        self.encoders.par_iter_mut().map(|w| w.flush()).collect::<std::io::Result<Vec<()>>>()?;
-        Ok(())
+        self.encoders.par_iter_mut().try_for_each(Write::flush)
     }
 }
 
 impl Encoder for CombinedEncoder {
     fn finish(self: Box<Self>) -> Result<(), Error> {
-        self.encoders.into_par_iter().map(|e| e.finish()).collect::<Result<Vec<()>, Error>>()?;
-        Ok(())
+        self.encoders.into_par_iter().try_for_each(Encoder::finish)
     }
 }
diff --git a/src/tools/rustdoc-gui/.eslintrc.js b/src/tools/rustdoc-gui/.eslintrc.js
index f4aadc07199..3eccbc74cb9 100644
--- a/src/tools/rustdoc-gui/.eslintrc.js
+++ b/src/tools/rustdoc-gui/.eslintrc.js
@@ -6,7 +6,7 @@ module.exports = {
     },
     "extends": "eslint:recommended",
     "parserOptions": {
-        "ecmaVersion": 2018,
+        "ecmaVersion": 2019,
         "sourceType": "module"
     },
     "rules": {
diff --git a/src/tools/rustdoc-js/.eslintrc.js b/src/tools/rustdoc-js/.eslintrc.js
index b9d0e251c24..3eccbc74cb9 100644
--- a/src/tools/rustdoc-js/.eslintrc.js
+++ b/src/tools/rustdoc-js/.eslintrc.js
@@ -6,7 +6,7 @@ module.exports = {
     },
     "extends": "eslint:recommended",
     "parserOptions": {
-        "ecmaVersion": 8,
+        "ecmaVersion": 2019,
         "sourceType": "module"
     },
     "rules": {
diff --git a/src/tools/rustfmt/tests/source/attrib.rs b/src/tools/rustfmt/tests/source/attrib.rs
index fc13cd02b03..d45fba55224 100644
--- a/src/tools/rustfmt/tests/source/attrib.rs
+++ b/src/tools/rustfmt/tests/source/attrib.rs
@@ -214,8 +214,8 @@ type Os = NoSource;
 // #3313
 fn stmt_expr_attributes() {
     let foo ;
-    (#[must_use]
-   foo) = false ;
+    #[must_use]
+   foo = false ;
 }
 
 // #3509
diff --git a/src/tools/rustfmt/tests/target/attrib.rs b/src/tools/rustfmt/tests/target/attrib.rs
index 7b3309676de..7e61f68d76a 100644
--- a/src/tools/rustfmt/tests/target/attrib.rs
+++ b/src/tools/rustfmt/tests/target/attrib.rs
@@ -248,8 +248,8 @@ type Os = NoSource;
 // #3313
 fn stmt_expr_attributes() {
     let foo;
-    (#[must_use]
-    foo) = false;
+    #[must_use]
+    foo = false;
 }
 
 // #3509