Auto merge of #82688 - GuillaumeGomez:rollup-b754t11, r=GuillaumeGomez

Rollup of 7 pull requests

Successful merges:

 - #80734 (check that first arg to `panic!()` in const is `&str`)
 - #81932 (Always compile rustdoc with debug logging enabled when `download-rustc` is set)
 - #82018 (Remove the dummy cache in `DocContext`; delete RenderInfo)
 - #82598 (Check stability and feature attributes in rustdoc)
 - #82655 (Highlight identifier span instead of whole pattern span in `unused` lint)
 - #82662 (Warn about unknown doc attributes)
 - #82676 (Change twice used large const table to static)

Failed merges:

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

Author: bors

Cargo.lock

@@ -4554,6 +4554,9 @@ dependencies = [
  "serde_json",
  "smallvec 1.6.1",
  "tempfile",
+ "tracing",
+ "tracing-subscriber",
+ "tracing-tree",
 ]
 
 [[package]]

compiler/rustc_mir/src/transform/check_consts/ops.rs

@@ -377,6 +377,18 @@ impl NonConstOp for Panic {
     }
 }
 
+/// A call to a `panic()` lang item where the first argument is _not_ a `&str`.
+#[derive(Debug)]
+pub struct PanicNonStr;
+impl NonConstOp for PanicNonStr {
+    fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
+        ccx.tcx.sess.struct_span_err(
+            span,
+            "argument to `panic!()` in a const context must have type `&str`",
+        )
+    }
+}
+
 #[derive(Debug)]
 pub struct RawPtrComparison;
 impl NonConstOp for RawPtrComparison {

compiler/rustc_mir/src/transform/check_consts/validation.rs

@@ -819,7 +819,7 @@ impl Visitor<'tcx> for Validator<'mir, 'tcx> {
         self.super_terminator(terminator, location);
 
         match &terminator.kind {
-            TerminatorKind::Call { func, .. } => {
+            TerminatorKind::Call { func, args, .. } => {
                 let ConstCx { tcx, body, param_env, .. } = *self.ccx;
                 let caller = self.def_id().to_def_id();
 
@@ -881,9 +881,17 @@ impl Visitor<'tcx> for Validator<'mir, 'tcx> {
                 }
 
                 // At this point, we are calling a function, `callee`, whose `DefId` is known...
-
                 if is_lang_panic_fn(tcx, callee) {
                     self.check_op(ops::Panic);
+
+                    // const-eval of the `begin_panic` fn assumes the argument is `&str`
+                    if Some(callee) == tcx.lang_items().begin_panic_fn() {
+                        match args[0].ty(&self.ccx.body.local_decls, tcx).kind() {
+                            ty::Ref(_, ty, _) if ty.is_str() => (),
+                            _ => self.check_op(ops::PanicNonStr),
+                        }
+                    }
+
                     return;
                 }
 

compiler/rustc_passes/src/check_attr.rs

@@ -544,6 +544,41 @@ impl CheckAttrVisitor<'tcx> {
                         {
                             return false;
                         }
+                    } else if let Some(i_meta) = meta.meta_item() {
+                        if ![
+                            sym::cfg,
+                            sym::hidden,
+                            sym::html_favicon_url,
+                            sym::html_logo_url,
+                            sym::html_no_source,
+                            sym::html_playground_url,
+                            sym::html_root_url,
+                            sym::include,
+                            sym::inline,
+                            sym::issue_tracker_base_url,
+                            sym::masked,
+                            sym::no_default_passes, // deprecated
+                            sym::no_inline,
+                            sym::passes, // deprecated
+                            sym::primitive,
+                            sym::spotlight,
+                            sym::test,
+                        ]
+                        .iter()
+                        .any(|m| i_meta.has_name(*m))
+                        {
+                            self.tcx
+                                .sess
+                                .struct_span_err(
+                                    meta.span(),
+                                    &format!(
+                                        "unknown `doc` attribute `{}`",
+                                        i_meta.name_or_empty(),
+                                    ),
+                                )
+                                .emit();
+                            return false;
+                        }
                     }
                 }
             }

compiler/rustc_passes/src/liveness.rs

@@ -1494,12 +1494,13 @@ impl<'tcx> Liveness<'_, 'tcx> {
         // bindings, and we also consider the first pattern to be the "authoritative" set of ids.
         // However, we should take the ids and spans of variables with the same name from the later
         // patterns so the suggestions to prefix with underscores will apply to those too.
-        let mut vars: FxIndexMap<Symbol, (LiveNode, Variable, Vec<(HirId, Span)>)> = <_>::default();
+        let mut vars: FxIndexMap<Symbol, (LiveNode, Variable, Vec<(HirId, Span, Span)>)> =
+            <_>::default();
 
         pat.each_binding(|_, hir_id, pat_sp, ident| {
             let ln = entry_ln.unwrap_or_else(|| self.live_node(hir_id, pat_sp));
             let var = self.variable(hir_id, ident.span);
-            let id_and_sp = (hir_id, pat_sp);
+            let id_and_sp = (hir_id, pat_sp, ident.span);
             vars.entry(self.ir.variable_name(var))
                 .and_modify(|(.., hir_ids_and_spans)| hir_ids_and_spans.push(id_and_sp))
                 .or_insert_with(|| (ln, var, vec![id_and_sp]));
@@ -1508,15 +1509,21 @@ impl<'tcx> Liveness<'_, 'tcx> {
         for (_, (ln, var, hir_ids_and_spans)) in vars {
             if self.used_on_entry(ln, var) {
                 let id = hir_ids_and_spans[0].0;
-                let spans = hir_ids_and_spans.into_iter().map(|(_, sp)| sp).collect();
+                let spans =
+                    hir_ids_and_spans.into_iter().map(|(_, _, ident_span)| ident_span).collect();
                 on_used_on_entry(spans, id, ln, var);
             } else {
                 self.report_unused(hir_ids_and_spans, ln, var);
             }
         }
     }
 
-    fn report_unused(&self, hir_ids_and_spans: Vec<(HirId, Span)>, ln: LiveNode, var: Variable) {
+    fn report_unused(
+        &self,
+        hir_ids_and_spans: Vec<(HirId, Span, Span)>,
+        ln: LiveNode,
+        var: Variable,
+    ) {
         let first_hir_id = hir_ids_and_spans[0].0;
 
         if let Some(name) = self.should_warn(var).filter(|name| name != "self") {
@@ -1530,62 +1537,78 @@ impl<'tcx> Liveness<'_, 'tcx> {
                 self.ir.tcx.struct_span_lint_hir(
                     lint::builtin::UNUSED_VARIABLES,
                     first_hir_id,
-                    hir_ids_and_spans.into_iter().map(|(_, sp)| sp).collect::<Vec<_>>(),
+                    hir_ids_and_spans
+                        .into_iter()
+                        .map(|(_, _, ident_span)| ident_span)
+                        .collect::<Vec<_>>(),
                     |lint| {
                         lint.build(&format!("variable `{}` is assigned to, but never used", name))
                             .note(&format!("consider using `_{}` instead", name))
                             .emit();
                     },
                 )
             } else {
-                self.ir.tcx.struct_span_lint_hir(
-                    lint::builtin::UNUSED_VARIABLES,
-                    first_hir_id,
-                    hir_ids_and_spans.iter().map(|(_, sp)| *sp).collect::<Vec<_>>(),
-                    |lint| {
-                        let mut err = lint.build(&format!("unused variable: `{}`", name));
-
-                        let (shorthands, non_shorthands): (Vec<_>, Vec<_>) =
-                            hir_ids_and_spans.into_iter().partition(|(hir_id, span)| {
-                                let var = self.variable(*hir_id, *span);
-                                self.ir.variable_is_shorthand(var)
-                            });
-
-                        let mut shorthands = shorthands
-                            .into_iter()
-                            .map(|(_, span)| (span, format!("{}: _", name)))
-                            .collect::<Vec<_>>();
-
-                        // If we have both shorthand and non-shorthand, prefer the "try ignoring
-                        // the field" message, and suggest `_` for the non-shorthands. If we only
-                        // have non-shorthand, then prefix with an underscore instead.
-                        if !shorthands.is_empty() {
-                            shorthands.extend(
-                                non_shorthands
-                                    .into_iter()
-                                    .map(|(_, span)| (span, "_".to_string()))
-                                    .collect::<Vec<_>>(),
-                            );
+                let (shorthands, non_shorthands): (Vec<_>, Vec<_>) =
+                    hir_ids_and_spans.iter().copied().partition(|(hir_id, _, ident_span)| {
+                        let var = self.variable(*hir_id, *ident_span);
+                        self.ir.variable_is_shorthand(var)
+                    });
 
+                // If we have both shorthand and non-shorthand, prefer the "try ignoring
+                // the field" message, and suggest `_` for the non-shorthands. If we only
+                // have non-shorthand, then prefix with an underscore instead.
+                if !shorthands.is_empty() {
+                    let shorthands = shorthands
+                        .into_iter()
+                        .map(|(_, pat_span, _)| (pat_span, format!("{}: _", name)))
+                        .chain(
+                            non_shorthands
+                                .into_iter()
+                                .map(|(_, pat_span, _)| (pat_span, "_".to_string())),
+                        )
+                        .collect::<Vec<_>>();
+
+                    self.ir.tcx.struct_span_lint_hir(
+                        lint::builtin::UNUSED_VARIABLES,
+                        first_hir_id,
+                        hir_ids_and_spans
+                            .iter()
+                            .map(|(_, pat_span, _)| *pat_span)
+                            .collect::<Vec<_>>(),
+                        |lint| {
+                            let mut err = lint.build(&format!("unused variable: `{}`", name));
                             err.multipart_suggestion(
                                 "try ignoring the field",
                                 shorthands,
                                 Applicability::MachineApplicable,
                             );
-                        } else {
+                            err.emit()
+                        },
+                    );
+                } else {
+                    let non_shorthands = non_shorthands
+                        .into_iter()
+                        .map(|(_, _, ident_span)| (ident_span, format!("_{}", name)))
+                        .collect::<Vec<_>>();
+
+                    self.ir.tcx.struct_span_lint_hir(
+                        lint::builtin::UNUSED_VARIABLES,
+                        first_hir_id,
+                        hir_ids_and_spans
+                            .iter()
+                            .map(|(_, _, ident_span)| *ident_span)
+                            .collect::<Vec<_>>(),
+                        |lint| {
+                            let mut err = lint.build(&format!("unused variable: `{}`", name));
                             err.multipart_suggestion(
                                 "if this is intentional, prefix it with an underscore",
-                                non_shorthands
-                                    .into_iter()
-                                    .map(|(_, span)| (span, format!("_{}", name)))
-                                    .collect::<Vec<_>>(),
+                                non_shorthands,
                                 Applicability::MachineApplicable,
                             );
-                        }
-
-                        err.emit()
-                    },
-                );
+                            err.emit()
+                        },
+                    );
+                }
             }
         }
     }

library/core/src/num/dec2flt/table.rs

@@ -5,7 +5,7 @@ pub const MIN_E: i16 = -305;
 pub const MAX_E: i16 = 305;
 
 #[rustfmt::skip]
-pub const POWERS: ([u64; 611], [i16; 611]) = (
+pub static POWERS: ([u64; 611], [i16; 611]) = (
     [
         0xe0b62e2929aba83c,
         0x8c71dcd9ba0b4926,

library/std/src/os/mod.rs

@@ -23,6 +23,7 @@ pub use crate::sys::windows_ext as windows;
 pub mod linux;
 
 #[cfg(doc)]
+#[stable(feature = "wasi_ext_doc", since = "1.35.0")]
 pub use crate::sys::wasi_ext as wasi;
 
 // If we're not documenting libstd then we just expose the main modules as we otherwise would.

library/std/src/sys/mod.rs

@@ -111,7 +111,7 @@ cfg_if::cfg_if! {
 cfg_if::cfg_if! {
     if #[cfg(target_os = "wasi")] {
         // On WASI we'll document what's already available
-        #[stable(feature = "rust1", since = "1.0.0")]
+        #[stable(feature = "wasi_ext_doc", since = "1.35.0")]
         pub use self::ext as wasi_ext;
     } else if #[cfg(any(target_os = "hermit",
                         target_arch = "wasm32",
@@ -125,6 +125,7 @@ cfg_if::cfg_if! {
     } else {
         // On other platforms like Windows document the bare bones of WASI
         #[path = "wasi/ext/mod.rs"]
+        #[stable(feature = "wasi_ext_doc", since = "1.35.0")]
         pub mod wasi_ext;
     }
 }

src/etc/dec2flt_table.py

@@ -113,7 +113,7 @@ def print_proper_powers():
     print()
     print("#[rustfmt::skip]")
     typ = "([u64; {0}], [i16; {0}])".format(len(powers))
-    print("pub const POWERS: ", typ, " = (", sep='')
+    print("pub static POWERS: ", typ, " = (", sep='')
     print("    [")
     for z in powers:
         print("        0x{:x},".format(z.sig))

src/librustdoc/Cargo.toml

@@ -19,6 +19,13 @@ tempfile = "3"
 itertools = "0.9"
 regex = "1"
 rustdoc-json-types = { path = "../rustdoc-json-types" }
+tracing = "0.1"
+tracing-tree = "0.1.6"
+
+[dependencies.tracing-subscriber]
+version = "0.2.13"
+default-features = false
+features = ["fmt", "env-filter", "smallvec", "parking_lot", "ansi"]
 
 [dev-dependencies]
 expect-test = "1.0"