Auto merge of #122637 - matthiaskrgr:rollup-bczj5bp, r=matthiaskrgr

Rollup of 3 pull requests

Successful merges:

 - #121236 (Don't show suggestion if slice pattern is not top-level)
 - #121787 (run change tracker even when config parse fails)
 - #122633 (avoid unnecessary collect())

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

Author: bors

Diff for: compiler/rustc_hir_analysis/src/astconv/errors.rs

@@ -408,10 +408,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                              traits with associated type `{name}`, you could use the \
                              fully-qualified path",
                         ),
-                        traits
-                            .iter()
-                            .map(|trait_str| format!("<Example as {trait_str}>::{name}"))
-                            .collect::<Vec<_>>(),
+                        traits.iter().map(|trait_str| format!("<Example as {trait_str}>::{name}")),
                         Applicability::HasPlaceholders,
                     );
                 }

Diff for: compiler/rustc_hir_typeck/src/pat.rs

@@ -83,6 +83,9 @@ struct PatInfo<'tcx, 'a> {
     binding_mode: BindingMode,
     top_info: TopInfo<'tcx>,
     decl_origin: Option<DeclOrigin<'a>>,
+
+    /// The depth of current pattern
+    current_depth: u32,
 }
 
 impl<'tcx> FnCtxt<'_, 'tcx> {
@@ -152,7 +155,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         decl_origin: Option<DeclOrigin<'tcx>>,
     ) {
         let info = TopInfo { expected, origin_expr, span };
-        let pat_info = PatInfo { binding_mode: INITIAL_BM, top_info: info, decl_origin };
+        let pat_info =
+            PatInfo { binding_mode: INITIAL_BM, top_info: info, decl_origin, current_depth: 0 };
         self.check_pat(pat, expected, pat_info);
     }
 
@@ -163,7 +167,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Conversely, inside this module, `check_pat_top` should never be used.
     #[instrument(level = "debug", skip(self, pat_info))]
     fn check_pat(&self, pat: &'tcx Pat<'tcx>, expected: Ty<'tcx>, pat_info: PatInfo<'tcx, '_>) {
-        let PatInfo { binding_mode: def_bm, top_info: ti, .. } = pat_info;
+        let PatInfo { binding_mode: def_bm, top_info: ti, current_depth, .. } = pat_info;
+
         let path_res = match &pat.kind {
             PatKind::Path(qpath) => Some(
                 self.resolve_ty_and_res_fully_qualified_call(qpath, pat.hir_id, pat.span, None),
@@ -172,8 +177,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
         let adjust_mode = self.calc_adjust_mode(pat, path_res.map(|(res, ..)| res));
         let (expected, def_bm) = self.calc_default_binding_mode(pat, expected, def_bm, adjust_mode);
-        let pat_info =
-            PatInfo { binding_mode: def_bm, top_info: ti, decl_origin: pat_info.decl_origin };
+        let pat_info = PatInfo {
+            binding_mode: def_bm,
+            top_info: ti,
+            decl_origin: pat_info.decl_origin,
+            current_depth: current_depth + 1,
+        };
 
         let ty = match pat.kind {
             PatKind::Wild | PatKind::Err(_) => expected,
@@ -1046,14 +1055,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expected: Ty<'tcx>,
         pat_info: PatInfo<'tcx, '_>,
     ) -> Ty<'tcx> {
-        let PatInfo { binding_mode: def_bm, top_info: ti, decl_origin } = pat_info;
+        let PatInfo { binding_mode: def_bm, top_info: ti, decl_origin, current_depth } = pat_info;
         let tcx = self.tcx;
         let on_error = |e| {
             for pat in subpats {
                 self.check_pat(
                     pat,
                     Ty::new_error(tcx, e),
-                    PatInfo { binding_mode: def_bm, top_info: ti, decl_origin },
+                    PatInfo { binding_mode: def_bm, top_info: ti, decl_origin, current_depth },
                 );
             }
         };
@@ -1120,7 +1129,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.check_pat(
                     subpat,
                     field_ty,
-                    PatInfo { binding_mode: def_bm, top_info: ti, decl_origin },
+                    PatInfo { binding_mode: def_bm, top_info: ti, decl_origin, current_depth },
                 );
 
                 self.tcx.check_stability(
@@ -2134,7 +2143,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // The expected type must be an array or slice, but was neither, so error.
             _ => {
                 let guar = expected.error_reported().err().unwrap_or_else(|| {
-                    self.error_expected_array_or_slice(span, expected, pat_info.top_info)
+                    self.error_expected_array_or_slice(span, expected, pat_info)
                 });
                 let err = Ty::new_error(self.tcx, guar);
                 (err, Some(err), err)
@@ -2273,8 +2282,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         span: Span,
         expected_ty: Ty<'tcx>,
-        ti: TopInfo<'tcx>,
+        pat_info: PatInfo<'tcx, '_>,
     ) -> ErrorGuaranteed {
+        let PatInfo { top_info: ti, current_depth, .. } = pat_info;
+
         let mut err = struct_span_code_err!(
             self.dcx(),
             span,
@@ -2292,9 +2303,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             && let Some(_) = ti.origin_expr
             && let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span)
         {
-            let ty = self.resolve_vars_if_possible(ti.expected);
-            let is_slice_or_array_or_vector = self.is_slice_or_array_or_vector(ty);
-            match is_slice_or_array_or_vector.1.kind() {
+            let resolved_ty = self.resolve_vars_if_possible(ti.expected);
+            let (is_slice_or_array_or_vector, resolved_ty) =
+                self.is_slice_or_array_or_vector(resolved_ty);
+            match resolved_ty.kind() {
                 ty::Adt(adt_def, _)
                     if self.tcx.is_diagnostic_item(sym::Option, adt_def.did())
                         || self.tcx.is_diagnostic_item(sym::Result, adt_def.did()) =>
@@ -2309,7 +2321,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
                 _ => (),
             }
-            if is_slice_or_array_or_vector.0 {
+
+            let is_top_level = current_depth <= 1;
+            if is_slice_or_array_or_vector && is_top_level {
                 err.span_suggestion(
                     span,
                     "consider slicing here",

Diff for: src/bootstrap/src/bin/main.rs

@@ -15,7 +15,8 @@ use std::{
 };
 
 use bootstrap::{
-    find_recent_config_change_ids, t, Build, Config, Subcommand, CONFIG_CHANGE_HISTORY,
+    find_recent_config_change_ids, human_readable_changes, t, Build, Config, Subcommand,
+    CONFIG_CHANGE_HISTORY,
 };
 
 fn main() {
@@ -164,14 +165,7 @@ fn check_version(config: &Config) -> Option<String> {
         }
 
         msg.push_str("There have been changes to x.py since you last updated:\n");
-
-        for change in changes {
-            msg.push_str(&format!("  [{}] {}\n", change.severity, change.summary));
-            msg.push_str(&format!(
-                "    - PR Link https://github.com/rust-lang/rust/pull/{}\n",
-                change.change_id
-            ));
-        }
+        msg.push_str(&human_readable_changes(&changes));
 
         msg.push_str("NOTE: to silence this warning, ");
         msg.push_str(&format!(

Diff for: src/bootstrap/src/core/config/config.rs

@@ -606,7 +606,8 @@ impl Target {
 #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 pub(crate) struct TomlConfig {
     changelog_seen: Option<usize>, // FIXME: Deprecated field. Remove it at 2024.
-    change_id: Option<usize>,
+    #[serde(flatten)]
+    change_id: ChangeIdWrapper,
     build: Option<Build>,
     install: Option<Install>,
     llvm: Option<Llvm>,
@@ -616,6 +617,16 @@ pub(crate) struct TomlConfig {
     profile: Option<String>,
 }
 
+/// Since we use `#[serde(deny_unknown_fields)]` on `TomlConfig`, we need a wrapper type
+/// for the "change-id" field to parse it even if other fields are invalid. This ensures
+/// that if deserialization fails due to other fields, we can still provide the changelogs
+/// to allow developers to potentially find the reason for the failure in the logs..
+#[derive(Deserialize, Default)]
+pub(crate) struct ChangeIdWrapper {
+    #[serde(alias = "change-id")]
+    pub(crate) inner: Option<usize>,
+}
+
 /// Describes how to handle conflicts in merging two [`TomlConfig`]
 #[derive(Copy, Clone, Debug)]
 enum ReplaceOpt {
@@ -657,7 +668,7 @@ impl Merge for TomlConfig {
             }
         }
         self.changelog_seen.merge(changelog_seen, replace);
-        self.change_id.merge(change_id, replace);
+        self.change_id.inner.merge(change_id.inner, replace);
         do_merge(&mut self.build, build, replace);
         do_merge(&mut self.install, install, replace);
         do_merge(&mut self.llvm, llvm, replace);
@@ -1210,6 +1221,20 @@ impl Config {
             toml::from_str(&contents)
                 .and_then(|table: toml::Value| TomlConfig::deserialize(table))
                 .unwrap_or_else(|err| {
+                    if let Ok(Some(changes)) = toml::from_str(&contents)
+                        .and_then(|table: toml::Value| ChangeIdWrapper::deserialize(table))
+                        .and_then(|change_id| {
+                            Ok(change_id.inner.map(|id| crate::find_recent_config_change_ids(id)))
+                        })
+                    {
+                        if !changes.is_empty() {
+                            println!(
+                                "WARNING: There have been changes to x.py since you last updated:\n{}",
+                                crate::human_readable_changes(&changes)
+                            );
+                        }
+                    }
+
                     eprintln!("failed to parse TOML configuration '{}': {err}", file.display());
                     exit!(2);
                 })
@@ -1376,7 +1401,7 @@ impl Config {
         toml.merge(override_toml, ReplaceOpt::Override);
 
         config.changelog_seen = toml.changelog_seen;
-        config.change_id = toml.change_id;
+        config.change_id = toml.change_id.inner;
 
         let Build {
             build,

Diff for: src/bootstrap/src/core/config/tests.rs

@@ -1,4 +1,4 @@
-use super::{flags::Flags, Config};
+use super::{flags::Flags, ChangeIdWrapper, Config};
 use crate::core::config::{LldMode, TomlConfig};
 
 use clap::CommandFactory;
@@ -237,3 +237,20 @@ fn rust_lld() {
     assert!(matches!(parse("rust.use-lld = true").lld_mode, LldMode::External));
     assert!(matches!(parse("rust.use-lld = false").lld_mode, LldMode::Unused));
 }
+
+#[test]
+#[should_panic]
+fn parse_config_with_unknown_field() {
+    parse("unknown-key = 1");
+}
+
+#[test]
+fn parse_change_id_with_unknown_field() {
+    let config = r#"
+        change-id = 3461
+        unknown-key = 1
+    "#;
+
+    let change_id_wrapper: ChangeIdWrapper = toml::from_str(config).unwrap();
+    assert_eq!(change_id_wrapper.inner, Some(3461));
+}

Diff for: src/bootstrap/src/lib.rs

@@ -50,7 +50,9 @@ mod utils;
 pub use core::builder::PathSet;
 pub use core::config::flags::Subcommand;
 pub use core::config::Config;
-pub use utils::change_tracker::{find_recent_config_change_ids, CONFIG_CHANGE_HISTORY};
+pub use utils::change_tracker::{
+    find_recent_config_change_ids, human_readable_changes, CONFIG_CHANGE_HISTORY,
+};
 
 const LLVM_TOOLS: &[&str] = &[
     "llvm-cov",      // used to generate coverage report

Diff for: src/bootstrap/src/utils/change_tracker.rs

@@ -60,6 +60,20 @@ pub fn find_recent_config_change_ids(current_id: usize) -> Vec<ChangeInfo> {
         .collect()
 }
 
+pub fn human_readable_changes(changes: &[ChangeInfo]) -> String {
+    let mut message = String::new();
+
+    for change in changes {
+        message.push_str(&format!("  [{}] {}\n", change.severity, change.summary));
+        message.push_str(&format!(
+            "    - PR Link https://github.com/rust-lang/rust/pull/{}\n",
+            change.change_id
+        ));
+    }
+
+    message
+}
+
 /// Keeps track of major changes made to the bootstrap configuration.
 ///
 /// If you make any major changes (such as adding new values or changing default values),

Diff for: tests/ui/suggestions/suppress-consider-slicing-issue-120605.rs

@@ -0,0 +1,20 @@
+pub struct Struct {
+    a: Vec<Struct>,
+}
+
+impl Struct {
+    pub fn test(&self) {
+        if let [Struct { a: [] }] = &self.a {
+            //~^ ERROR expected an array or slice
+            //~| ERROR expected an array or slice
+            println!("matches!")
+        }
+
+        if let [Struct { a: [] }] = &self.a[..] {
+            //~^ ERROR expected an array or slice
+            println!("matches!")
+        }
+    }
+}
+
+fn main() {}

Diff for: tests/ui/suggestions/suppress-consider-slicing-issue-120605.stderr

@@ -0,0 +1,23 @@
+error[E0529]: expected an array or slice, found `Vec<Struct>`
+  --> $DIR/suppress-consider-slicing-issue-120605.rs:7:16
+   |
+LL |         if let [Struct { a: [] }] = &self.a {
+   |                ^^^^^^^^^^^^^^^^^^   ------- help: consider slicing here: `&self.a[..]`
+   |                |
+   |                pattern cannot match with input type `Vec<Struct>`
+
+error[E0529]: expected an array or slice, found `Vec<Struct>`
+  --> $DIR/suppress-consider-slicing-issue-120605.rs:7:29
+   |
+LL |         if let [Struct { a: [] }] = &self.a {
+   |                             ^^ pattern cannot match with input type `Vec<Struct>`
+
+error[E0529]: expected an array or slice, found `Vec<Struct>`
+  --> $DIR/suppress-consider-slicing-issue-120605.rs:13:29
+   |
+LL |         if let [Struct { a: [] }] = &self.a[..] {
+   |                             ^^ pattern cannot match with input type `Vec<Struct>`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0529`.