Auto merge of #141331 - matthiaskrgr:rollup-k0loxj6, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #137759 (Add `std::os::unix::process::CommandExt::chroot` to safely chroot a child process)
 - #140994 (replace `cc_detect::cc2ar` with `cc::try_get_archiver`)
 - #141213 (Suggest use "{}", self.x instead of {self.x} when resolve x as field of `self`)
 - #141283 (Allow `x perf` to find rustc.exe on Windows)
 - #141284 (Allow trailing comma after argument in query definition)
 - #141317 (typeck: catch `continue`s pointing to blocks)
 - #141318 (Avoid creating an empty identifer in `Symbol::to_ident_string`.)

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

Author: bors

compiler/rustc_hir_typeck/src/expr.rs

@@ -532,14 +532,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ExprKind::Break(destination, ref expr_opt) => {
                 self.check_expr_break(destination, expr_opt.as_deref(), expr)
             }
-            ExprKind::Continue(destination) => {
-                if destination.target_id.is_ok() {
-                    tcx.types.never
-                } else {
-                    // There was an error; make type-check fail.
-                    Ty::new_misc_error(tcx)
-                }
-            }
+            ExprKind::Continue(destination) => self.check_expr_continue(destination, expr),
             ExprKind::Ret(ref expr_opt) => self.check_expr_return(expr_opt.as_deref(), expr),
             ExprKind::Become(call) => self.check_expr_become(call, expr),
             ExprKind::Let(let_expr) => self.check_expr_let(let_expr, expr.hir_id),
@@ -989,6 +982,31 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
+    fn check_expr_continue(
+        &self,
+        destination: hir::Destination,
+        expr: &'tcx hir::Expr<'tcx>,
+    ) -> Ty<'tcx> {
+        if let Ok(target_id) = destination.target_id {
+            if let hir::Node::Expr(hir::Expr { kind: ExprKind::Loop(..), .. }) =
+                self.tcx.hir_node(target_id)
+            {
+                self.tcx.types.never
+            } else {
+                // Liveness linting assumes `continue`s all point to loops. We'll report an error
+                // in `check_mod_loops`, but make sure we don't run liveness (#113379, #121623).
+                let guar = self.dcx().span_delayed_bug(
+                    expr.span,
+                    "found `continue` not pointing to loop, but no error reported",
+                );
+                Ty::new_error(self.tcx, guar)
+            }
+        } else {
+            // There was an error; make type-check fail.
+            Ty::new_misc_error(self.tcx)
+        }
+    }
+
     fn check_expr_return(
         &self,
         expr_opt: Option<&'tcx hir::Expr<'tcx>>,

compiler/rustc_macros/src/query.rs

@@ -51,6 +51,7 @@ impl Parse for Query {
         let key = Pat::parse_single(&arg_content)?;
         arg_content.parse::<Token![:]>()?;
         let arg = arg_content.parse()?;
+        let _ = arg_content.parse::<Option<Token![,]>>()?;
         let result = input.parse()?;
 
         // Parse the query modifiers

compiler/rustc_mir_build/src/builder/mod.rs

@@ -66,8 +66,7 @@ pub fn build_mir<'tcx>(tcx: TyCtxt<'tcx>, def: LocalDefId) -> Body<'tcx> {
                 }
             };
 
-            // this must run before MIR dump, because
-            // "not all control paths return a value" is reported here.
+            // Checking liveness after building the THIR ensures there were no typeck errors.
             //
             // maybe move the check to a MIR pass?
             tcx.ensure_ok().check_liveness(def);

compiler/rustc_passes/src/liveness.rs

@@ -122,7 +122,6 @@ enum LiveNodeKind {
     VarDefNode(Span, HirId),
     ClosureNode,
     ExitNode,
-    ErrNode,
 }
 
 fn live_node_kind_to_string(lnk: LiveNodeKind, tcx: TyCtxt<'_>) -> String {
@@ -133,7 +132,6 @@ fn live_node_kind_to_string(lnk: LiveNodeKind, tcx: TyCtxt<'_>) -> String {
         VarDefNode(s, _) => format!("Var def node [{}]", sm.span_to_diagnostic_string(s)),
         ClosureNode => "Closure node".to_owned(),
         ExitNode => "Exit node".to_owned(),
-        ErrNode => "Error node".to_owned(),
     }
 }
 
@@ -492,6 +490,9 @@ struct Liveness<'a, 'tcx> {
 impl<'a, 'tcx> Liveness<'a, 'tcx> {
     fn new(ir: &'a mut IrMaps<'tcx>, body_owner: LocalDefId) -> Liveness<'a, 'tcx> {
         let typeck_results = ir.tcx.typeck(body_owner);
+        // Liveness linting runs after building the THIR. We make several assumptions based on
+        // typeck succeeding, e.g. that breaks and continues are well-formed.
+        assert!(typeck_results.tainted_by_errors.is_none());
         // FIXME(#132279): we're in a body here.
         let typing_env = ty::TypingEnv::non_body_analysis(ir.tcx, body_owner);
         let closure_min_captures = typeck_results.closure_min_captures.get(&body_owner);
@@ -976,8 +977,9 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                 // Now that we know the label we're going to,
                 // look it up in the continue loop nodes table
                 self.cont_ln.get(&sc).cloned().unwrap_or_else(|| {
-                    self.ir.tcx.dcx().span_delayed_bug(expr.span, "continue to unknown label");
-                    self.ir.add_live_node(ErrNode)
+                    // Liveness linting happens after building the THIR. Bad labels should already
+                    // have been caught.
+                    span_bug!(expr.span, "continue to unknown label");
                 })
             }
 

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -765,12 +765,24 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                 match candidate {
                     AssocSuggestion::Field(field_span) => {
                         if self_is_available {
-                            err.span_suggestion_verbose(
-                                span.shrink_to_lo(),
-                                "you might have meant to use the available field",
-                                format!("{pre}self."),
-                                Applicability::MachineApplicable,
-                            );
+                            let source_map = self.r.tcx.sess.source_map();
+                            // check if the field is used in a format string, such as `"{x}"`
+                            let field_is_format_named_arg = source_map
+                                .span_to_source(span, |s, start, _| {
+                                    Ok(s.get(start - 1..start) == Some("{"))
+                                });
+                            if let Ok(true) = field_is_format_named_arg {
+                                err.help(
+                                    format!("you might have meant to use the available field in a format string: `\"{{}}\", self.{}`", segment.ident.name),
+                                );
+                            } else {
+                                err.span_suggestion_verbose(
+                                    span.shrink_to_lo(),
+                                    "you might have meant to use the available field",
+                                    format!("{pre}self."),
+                                    Applicability::MaybeIncorrect,
+                                );
+                            }
                         } else {
                             err.span_label(field_span, "a field by that name exists in `Self`");
                         }

compiler/rustc_span/src/symbol.rs

@@ -2592,7 +2592,8 @@ impl Symbol {
     /// (`token_to_string`, `Ident::to_string`), except that symbols don't keep the rawness flag
     /// or edition, so we have to guess the rawness using the global edition.
     pub fn to_ident_string(self) -> String {
-        Ident::with_dummy_span(self).to_string()
+        // Avoid creating an empty identifier, because that asserts in debug builds.
+        if self == kw::Empty { String::new() } else { Ident::with_dummy_span(self).to_string() }
     }
 }
 

library/std/src/os/unix/process.rs

@@ -8,6 +8,7 @@ use cfg_if::cfg_if;
 
 use crate::ffi::OsStr;
 use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+use crate::path::Path;
 use crate::sealed::Sealed;
 use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 use crate::{io, process, sys};
@@ -197,6 +198,18 @@ pub trait CommandExt: Sealed {
     /// ```
     #[stable(feature = "process_set_process_group", since = "1.64.0")]
     fn process_group(&mut self, pgroup: i32) -> &mut process::Command;
+
+    /// Set the root of the child process. This calls `chroot` in the child process before executing
+    /// the command.
+    ///
+    /// This happens before changing to the directory specified with
+    /// [`process::Command::current_dir`], and that directory will be relative to the new root.
+    ///
+    /// If no directory has been specified with [`process::Command::current_dir`], this will set the
+    /// directory to `/`, to avoid leaving the current directory outside the chroot. (This is an
+    /// intentional difference from the underlying `chroot` system call.)
+    #[unstable(feature = "process_chroot", issue = "141298")]
+    fn chroot<P: AsRef<Path>>(&mut self, dir: P) -> &mut process::Command;
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -242,6 +255,11 @@ impl CommandExt for process::Command {
         self.as_inner_mut().pgroup(pgroup);
         self
     }
+
+    fn chroot<P: AsRef<Path>>(&mut self, dir: P) -> &mut process::Command {
+        self.as_inner_mut().chroot(dir.as_ref());
+        self
+    }
 }
 
 /// Unix-specific extensions to [`process::ExitStatus`] and

library/std/src/sys/process/unix/common.rs

@@ -88,6 +88,7 @@ pub struct Command {
 
     program_kind: ProgramKind,
     cwd: Option<CString>,
+    chroot: Option<CString>,
     uid: Option<uid_t>,
     gid: Option<gid_t>,
     saw_nul: bool,
@@ -182,6 +183,7 @@ impl Command {
             program_kind,
             env: Default::default(),
             cwd: None,
+            chroot: None,
             uid: None,
             gid: None,
             saw_nul,
@@ -206,6 +208,7 @@ impl Command {
             program_kind,
             env: Default::default(),
             cwd: None,
+            chroot: None,
             uid: None,
             gid: None,
             saw_nul,
@@ -254,6 +257,12 @@ impl Command {
     pub fn pgroup(&mut self, pgroup: pid_t) {
         self.pgroup = Some(pgroup);
     }
+    pub fn chroot(&mut self, dir: &Path) {
+        self.chroot = Some(os2c(dir.as_os_str(), &mut self.saw_nul));
+        if self.cwd.is_none() {
+            self.cwd(&OsStr::new("/"));
+        }
+    }
 
     #[cfg(target_os = "linux")]
     pub fn create_pidfd(&mut self, val: bool) {
@@ -326,6 +335,10 @@ impl Command {
     pub fn get_pgroup(&self) -> Option<pid_t> {
         self.pgroup
     }
+    #[allow(dead_code)]
+    pub fn get_chroot(&self) -> Option<&CStr> {
+        self.chroot.as_deref()
+    }
 
     pub fn get_closures(&mut self) -> &mut Vec<Box<dyn FnMut() -> io::Result<()> + Send + Sync>> {
         &mut self.closures

library/std/src/sys/process/unix/unix.rs

@@ -323,6 +323,15 @@ impl Command {
                 cvt(libc::setuid(u as uid_t))?;
             }
         }
+        if let Some(chroot) = self.get_chroot() {
+            #[cfg(not(target_os = "fuchsia"))]
+            cvt(libc::chroot(chroot.as_ptr()))?;
+            #[cfg(target_os = "fuchsia")]
+            return Err(io::const_error!(
+                io::ErrorKind::Unsupported,
+                "chroot not supported by fuchsia"
+            ));
+        }
         if let Some(cwd) = self.get_cwd() {
             cvt(libc::chdir(cwd.as_ptr()))?;
         }
@@ -447,6 +456,7 @@ impl Command {
             || (self.env_saw_path() && !self.program_is_path())
             || !self.get_closures().is_empty()
             || self.get_groups().is_some()
+            || self.get_chroot().is_some()
         {
             return Ok(None);
         }

library/std/src/sys/process/unix/vxworks.rs

@@ -27,6 +27,12 @@ impl Command {
                 "nul byte found in provided data",
             ));
         }
+        if self.get_chroot().is_some() {
+            return Err(io::const_error!(
+                ErrorKind::Unsupported,
+                "chroot not supported by vxworks",
+            ));
+        }
         let (ours, theirs) = self.setup_io(default, needs_stdin)?;
         let mut p = Process { pid: 0, status: None };