Rollup of 6 pull requests

Cargo.lock

@@ -3537,6 +3537,7 @@ dependencies = [
  "ar_archive_writer",
  "arrayvec",
  "bitflags",
+ "bstr",
  "cc",
  "either",
  "itertools",

compiler/rustc_codegen_ssa/Cargo.toml

@@ -8,6 +8,7 @@ edition = "2021"
 ar_archive_writer = "0.4.2"
 arrayvec = { version = "0.7", default-features = false }
 bitflags = "2.4.1"
+bstr = "1.11.3"
 # Pinned so `cargo update` bumps don't cause breakage. Please also update the
 # `cc` in `rustc_llvm` if you update the `cc` here.
 cc = "=1.2.7"

compiler/rustc_codegen_ssa/src/back/command.rs

@@ -13,6 +13,7 @@ pub(crate) struct Command {
     args: Vec<OsString>,
     env: Vec<(OsString, OsString)>,
     env_remove: Vec<OsString>,
+    env_clear: bool,
 }
 
 #[derive(Clone)]
@@ -36,7 +37,13 @@ impl Command {
     }
 
     fn _new(program: Program) -> Command {
-        Command { program, args: Vec::new(), env: Vec::new(), env_remove: Vec::new() }
+        Command {
+            program,
+            args: Vec::new(),
+            env: Vec::new(),
+            env_remove: Vec::new(),
+            env_clear: false,
+        }
     }
 
     pub(crate) fn arg<P: AsRef<OsStr>>(&mut self, arg: P) -> &mut Command {
@@ -79,6 +86,11 @@ impl Command {
         self
     }
 
+    pub(crate) fn env_clear(&mut self) -> &mut Command {
+        self.env_clear = true;
+        self
+    }
+
     fn _env_remove(&mut self, key: &OsStr) {
         self.env_remove.push(key.to_owned());
     }
@@ -106,6 +118,9 @@ impl Command {
         for k in &self.env_remove {
             ret.env_remove(k);
         }
+        if self.env_clear {
+            ret.env_clear();
+        }
         ret
     }
 

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -991,6 +991,7 @@ fn link_natively(
                     command: cmd,
                     escaped_output,
                     verbose: sess.opts.verbose,
+                    sysroot_dir: sess.sysroot.clone(),
                 };
                 sess.dcx().emit_err(err);
                 // If MSVC's `link.exe` was expected but the return code

compiler/rustc_codegen_ssa/src/back/symbol_export.rs

@@ -577,6 +577,9 @@ pub(crate) fn linking_symbol_name_for_instance_in_crate<'tcx>(
     }
 
     let prefix = match &target.arch[..] {
+        "x86" | "x86_64" if target.is_like_msvc && undecorated.starts_with("?") => {
+            return undecorated;
+        }
         "x86" => Some('_'),
         "x86_64" => None,
         "arm64ec" => Some('#'),

compiler/rustc_codegen_ssa/src/errors.rs

@@ -351,6 +351,7 @@ pub(crate) struct LinkingFailed<'a> {
     pub command: Command,
     pub escaped_output: String,
     pub verbose: bool,
+    pub sysroot_dir: PathBuf,
 }
 
 impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
@@ -364,6 +365,8 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
         if self.verbose {
             diag.note(format!("{:?}", self.command));
         } else {
+            self.command.env_clear();
+
             enum ArgGroup {
                 Regular(OsString),
                 Objects(usize),
@@ -398,26 +401,55 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
                     args.push(ArgGroup::Regular(arg));
                 }
             }
-            self.command.args(args.into_iter().map(|arg_group| match arg_group {
-                ArgGroup::Regular(arg) => arg,
-                ArgGroup::Objects(n) => OsString::from(format!("<{n} object files omitted>")),
-                ArgGroup::Rlibs(dir, rlibs) => {
-                    let mut arg = dir.into_os_string();
-                    arg.push("/{");
-                    let mut first = true;
-                    for rlib in rlibs {
-                        if !first {
-                            arg.push(",");
+            let crate_hash = regex::bytes::Regex::new(r"-[0-9a-f]+\.rlib$").unwrap();
+            self.command.args(args.into_iter().map(|arg_group| {
+                match arg_group {
+                    // SAFETY: we are only matching on ASCII, not any surrogate pairs, so any replacements we do will still be valid.
+                    ArgGroup::Regular(arg) => unsafe {
+                        use bstr::ByteSlice;
+                        OsString::from_encoded_bytes_unchecked(
+                            arg.as_encoded_bytes().replace(
+                                self.sysroot_dir.as_os_str().as_encoded_bytes(),
+                                b"<sysroot>",
+                            ),
+                        )
+                    },
+                    ArgGroup::Objects(n) => OsString::from(format!("<{n} object files omitted>")),
+                    ArgGroup::Rlibs(mut dir, rlibs) => {
+                        let is_sysroot_dir = match dir.strip_prefix(&self.sysroot_dir) {
+                            Ok(short) => {
+                                dir = Path::new("<sysroot>").join(short);
+                                true
+                            }
+                            Err(_) => false,
+                        };
+                        let mut arg = dir.into_os_string();
+                        arg.push("/{");
+                        let mut first = true;
+                        for mut rlib in rlibs {
+                            if !first {
+                                arg.push(",");
+                            }
+                            first = false;
+                            if is_sysroot_dir {
+                                // SAFETY: Regex works one byte at a type, and our regex will not match surrogate pairs (because it only matches ascii).
+                                rlib = unsafe {
+                                    OsString::from_encoded_bytes_unchecked(
+                                        crate_hash
+                                            .replace(rlib.as_encoded_bytes(), b"-*")
+                                            .into_owned(),
+                                    )
+                                };
+                            }
+                            arg.push(rlib);
                         }
-                        first = false;
-                        arg.push(rlib);
+                        arg.push("}.rlib");
+                        arg
                     }
-                    arg.push("}");
-                    arg
                 }
             }));
 
-            diag.note(format!("{:?}", self.command));
+            diag.note(format!("{:?}", self.command).trim_start_matches("env -i").to_owned());
             diag.note("some arguments are omitted. use `--verbose` to show all linker arguments");
         }
 

compiler/rustc_error_codes/src/error_codes/E0433.md

@@ -19,7 +19,7 @@ If you've expected to use a crate name:
 
 ```compile_fail
 use ferris_wheel::BigO;
-// error: failed to resolve: use of undeclared crate or module `ferris_wheel`
+// error: failed to resolve: use of undeclared module or unlinked crate
 ```
 
 Make sure the crate has been added as a dependency in `Cargo.toml`.

compiler/rustc_resolve/src/diagnostics.rs

@@ -24,6 +24,7 @@ use rustc_session::lint::builtin::{
     MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
 };
 use rustc_session::lint::{AmbiguityErrorDiag, BuiltinLintDiag};
+use rustc_session::utils::was_invoked_from_cargo;
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::MacroKind;
@@ -800,7 +801,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     }
                     err.multipart_suggestion(msg, suggestions, applicability);
                 }
-
                 if let Some(ModuleOrUniformRoot::Module(module)) = module
                     && let Some(module) = module.opt_def_id()
                     && let Some(segment) = segment
@@ -2034,13 +2034,23 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 (format!("`_` is not a valid crate or module name"), None)
             } else if self.tcx.sess.is_rust_2015() {
                 (
-                    format!("you might be missing crate `{ident}`"),
+                    format!("use of unresolved module or unlinked crate `{ident}`"),
                     Some((
                         vec![(
                             self.current_crate_outer_attr_insert_span,
                             format!("extern crate {ident};\n"),
                         )],
-                        format!("consider importing the `{ident}` crate"),
+                        if was_invoked_from_cargo() {
+                            format!(
+                                "if you wanted to use a crate named `{ident}`, use `cargo add {ident}` \
+                             to add it to your `Cargo.toml` and import it in your code",
+                            )
+                        } else {
+                            format!(
+                                "you might be missing a crate named `{ident}`, add it to your \
+                                 project and import it in your code",
+                            )
+                        },
                         Applicability::MaybeIncorrect,
                     )),
                 )
@@ -2219,7 +2229,25 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 let descr = binding.res().descr();
                 (format!("{descr} `{ident}` is not a crate or module"), suggestion)
             } else {
-                (format!("use of undeclared crate or module `{ident}`"), suggestion)
+                let suggestion = if suggestion.is_some() {
+                    suggestion
+                } else if was_invoked_from_cargo() {
+                    Some((
+                        vec![],
+                        format!(
+                            "if you wanted to use a crate named `{ident}`, use `cargo add {ident}` \
+                             to add it to your `Cargo.toml`",
+                        ),
+                        Applicability::MaybeIncorrect,
+                    ))
+                } else {
+                    Some((
+                        vec![],
+                        format!("you might be missing a crate named `{ident}`",),
+                        Applicability::MaybeIncorrect,
+                    ))
+                };
+                (format!("use of unresolved module or unlinked crate `{ident}`"), suggestion)
             }
         }
     }

compiler/rustc_target/src/callconv/s390x.rs

@@ -38,9 +38,17 @@ where
     }
 
     let size = arg.layout.size;
-    if size.bits() <= 128 && arg.layout.is_single_vector_element(cx, size) {
-        arg.cast_to(Reg { kind: RegKind::Vector, size });
-        return;
+    if size.bits() <= 128 {
+        if let BackendRepr::Vector { .. } = arg.layout.backend_repr {
+            // pass non-wrapped vector types using `PassMode::Direct`
+            return;
+        }
+
+        if arg.layout.is_single_vector_element(cx, size) {
+            // pass non-transparant wrappers around a vector as `PassMode::Cast`
+            arg.cast_to(Reg { kind: RegKind::Vector, size });
+            return;
+        }
     }
     if !arg.layout.is_aggregate() && size.bits() <= 64 {
         arg.extend_integer_width_to(64);

src/tools/compiletest/src/runtest/run_make.rs

@@ -414,6 +414,8 @@ impl TestCx<'_> {
             // Provide path to checkout root. This is the top-level directory containing
             // rust-lang/rust checkout.
             .env("SOURCE_ROOT", &source_root)
+            // Path to the build directory. This is usually the same as `source_root.join("build").join("host")`.
+            .env("BUILD_ROOT", &build_root)
             // Provide path to stage-corresponding rustc.
             .env("RUSTC", &self.config.rustc_path)
             // Provide the directory to libraries that are needed to run the *compiler*. This is not

src/tools/miri/tests/fail/rustc-error2.rs

@@ -4,7 +4,7 @@ struct Struct<T>(T);
 impl<T> std::ops::Deref for Struct<T> {
     type Target = dyn Fn(T);
     fn deref(&self) -> &assert_mem_uninitialized_valid::Target {
-        //~^ERROR: undeclared crate or module
+        //~^ERROR: use of unresolved module or unlinked crate
         unimplemented!()
     }
 }

src/tools/miri/tests/fail/rustc-error2.stderr

@@ -1,8 +1,10 @@
-error[E0433]: failed to resolve: use of undeclared crate or module `assert_mem_uninitialized_valid`
+error[E0433]: failed to resolve: use of unresolved module or unlinked crate `assert_mem_uninitialized_valid`
   --> tests/fail/rustc-error2.rs:LL:CC
    |
 LL |     fn deref(&self) -> &assert_mem_uninitialized_valid::Target {
-   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ use of undeclared crate or module `assert_mem_uninitialized_valid`
+   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `assert_mem_uninitialized_valid`
+   |
+   = help: you might be missing a crate named `assert_mem_uninitialized_valid`
 
 error: aborting due to 1 previous error
 

src/tools/run-make-support/src/command.rs

@@ -388,9 +388,15 @@ impl CompletedProcess {
         self
     }
 
+    /// Check the **exit status** of the process. On Unix, this is *not* the **wait status**.
+    ///
+    /// See [`std::process::ExitStatus::code`]. This is not to be confused with
+    /// [`std::process::ExitCode`].
     #[track_caller]
     pub fn assert_exit_code(&self, code: i32) -> &Self {
-        assert!(self.output.status.code() == Some(code));
+        // FIXME(jieyouxu): this should really be named `exit_status`, because std has an `ExitCode`
+        // that means a different thing.
+        assert_eq!(self.output.status.code(), Some(code));
         self
     }
 }

src/tools/run-make-support/src/external_deps/rustc.rs

@@ -1,5 +1,6 @@
 use std::ffi::{OsStr, OsString};
-use std::path::Path;
+use std::path::{Path, PathBuf};
+use std::str::FromStr as _;
 
 use crate::command::Command;
 use crate::env::env_var;
@@ -390,3 +391,10 @@ impl Rustc {
         self
     }
 }
+
+/// Query the sysroot path corresponding `rustc --print=sysroot`.
+#[track_caller]
+pub fn sysroot() -> PathBuf {
+    let path = rustc().print("sysroot").run().stdout_utf8();
+    PathBuf::from_str(path.trim()).unwrap()
+}

src/tools/run-make-support/src/lib.rs

@@ -90,7 +90,7 @@ pub use artifact_names::{
 /// Path-related helpers.
 pub use path_helpers::{
     cwd, filename_contains, filename_not_in_denylist, has_extension, has_prefix, has_suffix,
-    not_contains, path, shallow_find_files, source_root,
+    not_contains, path, shallow_find_files, build_root, source_root,
 };
 
 /// Helpers for scoped test execution where certain properties are attempted to be maintained.

src/tools/run-make-support/src/path_helpers.rs

@@ -34,6 +34,12 @@ pub fn source_root() -> PathBuf {
     env_var("SOURCE_ROOT").into()
 }
 
+/// Path to the build directory root.
+#[must_use]
+pub fn build_root() -> PathBuf {
+    env_var("BUILD_ROOT").into()
+}
+
 /// Browse the directory `path` non-recursively and return all files which respect the parameters
 /// outlined by `closure`.
 #[track_caller]

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -1,3 +1,2 @@
 run-make/split-debuginfo/Makefile
 run-make/symbol-mangling-hashed/Makefile
-run-make/translation/Makefile

src/tools/tidy/src/deps.rs

@@ -253,6 +253,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "bitflags",
     "blake3",
     "block-buffer",
+    "bstr",
     "byteorder", // via ruzstd in object in thorin-dwp
     "cc",
     "cfg-if",

tests/assembly/x86_64-bigint-helpers.rs

@@ -2,6 +2,9 @@
 //@ assembly-output: emit-asm
 //@ compile-flags: --crate-type=lib -O -C target-cpu=x86-64-v4
 //@ compile-flags: -C llvm-args=-x86-asm-syntax=intel
+//@ revisions: llvm-pre-20 llvm-20
+//@ [llvm-20] min-llvm-version: 20
+//@ [llvm-pre-20] max-llvm-major-version: 19
 
 #![no_std]
 #![feature(bigint_helper_methods)]
@@ -20,12 +23,16 @@ pub unsafe extern "sysv64" fn bigint_chain_carrying_add(
     n: usize,
     mut carry: bool,
 ) -> bool {
-    // CHECK: mov [[TEMP:r..]], qword ptr [rsi + 8*[[IND:r..]] + 8]
-    // CHECK: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 8]
-    // CHECK: mov qword ptr [rdi + 8*[[IND]] + 8], [[TEMP]]
-    // CHECK: mov [[TEMP]], qword ptr [rsi + 8*[[IND]] + 16]
-    // CHECK: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 16]
-    // CHECK: mov qword ptr [rdi + 8*[[IND]] + 16], [[TEMP]]
+    // llvm-pre-20: mov [[TEMP:r..]], qword ptr [rsi + 8*[[IND:r..]] + 8]
+    // llvm-pre-20: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 8]
+    // llvm-pre-20: mov qword ptr [rdi + 8*[[IND]] + 8], [[TEMP]]
+    // llvm-pre-20: mov [[TEMP]], qword ptr [rsi + 8*[[IND]] + 16]
+    // llvm-pre-20: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 16]
+    // llvm-pre-20: mov qword ptr [rdi + 8*[[IND]] + 16], [[TEMP]]
+    // llvm-20: adc [[TEMP:r..]], qword ptr [rdx + 8*[[IND:r..]]]
+    // llvm-20: mov qword ptr [rdi + 8*[[IND]]], [[TEMP]]
+    // llvm-20: mov [[TEMP]], qword ptr [rsi + 8*[[IND]] + 8]
+    // llvm-20: adc [[TEMP]], qword ptr [rdx + 8*[[IND]] + 8]
     for i in 0..n {
         (*dest.add(i), carry) = u64::carrying_add(*src1.add(i), *src2.add(i), carry);
     }