Auto merge of #127657 - matthiaskrgr:rollup-qtuuo4o, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #126502 (Ignore allocation bytes in some mir-opt tests)
 - #126606 (Guard against calling `libc::exit` multiple times on Linux.)
 - #126922 (add lint for inline asm labels that look like binary)
 - #127295 (CFI: Support provided methods on traits)
 - #127310 (Fix import suggestion ice)
 - #127535 (Fire unsafe_code lint on unsafe extern blocks)
 - #127631 (Remove `fully_normalize`)
 - #127632 (Implement `precise_capturing` support for rustdoc)

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

Author: bors

compiler/rustc_hir/src/hir.rs

@@ -2708,6 +2708,13 @@ impl PreciseCapturingArg<'_> {
             PreciseCapturingArg::Param(param) => param.hir_id,
         }
     }
+
+    pub fn name(self) -> Symbol {
+        match self {
+            PreciseCapturingArg::Lifetime(lt) => lt.ident.name,
+            PreciseCapturingArg::Param(param) => param.ident.name,
+        }
+    }
 }
 
 /// We need to have a [`Node`] for the [`HirId`] that we attach the type/const param

compiler/rustc_interface/src/tests.rs

@@ -691,6 +691,7 @@ fn test_unstable_options_tracking_hash() {
     untracked!(dump_mir, Some(String::from("abc")));
     untracked!(dump_mir_dataflow, true);
     untracked!(dump_mir_dir, String::from("abc"));
+    untracked!(dump_mir_exclude_alloc_bytes, true);
     untracked!(dump_mir_exclude_pass_number, true);
     untracked!(dump_mir_graphviz, true);
     untracked!(dump_mono_stats, SwitchWithOptPath::Enabled(Some("mono-items-dir/".into())));

compiler/rustc_lint/messages.ftl

@@ -52,10 +52,6 @@ lint_builtin_allow_internal_unsafe =
 lint_builtin_anonymous_params = anonymous parameters are deprecated and will be removed in the next edition
     .suggestion = try naming the parameter or explicitly ignoring it
 
-lint_builtin_asm_labels = avoid using named labels in inline assembly
-    .help = only local labels of the form `<number>:` should be used in inline asm
-    .note = see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
-
 lint_builtin_clashing_extern_diff_name = `{$this}` redeclares `{$orig}` with a different signature
     .previous_decl_label = `{$orig}` previously declared here
     .mismatch_label = this signature doesn't match the previous declaration
@@ -163,6 +159,8 @@ lint_builtin_unreachable_pub = unreachable `pub` {$what}
 
 lint_builtin_unsafe_block = usage of an `unsafe` block
 
+lint_builtin_unsafe_extern_block = usage of an `unsafe extern` block
+
 lint_builtin_unsafe_impl = implementation of an `unsafe` trait
 
 lint_builtin_unsafe_trait = declaration of an `unsafe` trait
@@ -403,6 +401,19 @@ lint_incomplete_include =
 
 lint_inner_macro_attribute_unstable = inner macro attributes are unstable
 
+lint_invalid_asm_label_binary = avoid using labels containing only the digits `0` and `1` in inline assembly
+    .label = use a different label that doesn't start with `0` or `1`
+    .note = an LLVM bug makes these labels ambiguous with a binary literal number
+    .note = see <https://bugs.llvm.org/show_bug.cgi?id=36144> for more information
+
+lint_invalid_asm_label_format_arg = avoid using named labels in inline assembly
+    .help = only local labels of the form `<number>:` should be used in inline asm
+    .note1 = format arguments may expand to a non-numeric value
+    .note2 = see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+lint_invalid_asm_label_named = avoid using named labels in inline assembly
+    .help = only local labels of the form `<number>:` should be used in inline asm
+    .note = see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information
+lint_invalid_asm_label_no_span = the label may be declared in the expansion of a macro
 lint_invalid_crate_type_value = invalid `crate_type` value
     .suggestion = did you mean
 

compiler/rustc_lint/src/builtin.rs

@@ -30,13 +30,13 @@ use crate::{
         BuiltinExplicitOutlivesSuggestion, BuiltinFeatureIssueNote, BuiltinIncompleteFeatures,
         BuiltinIncompleteFeaturesHelp, BuiltinInternalFeatures, BuiltinKeywordIdents,
         BuiltinMissingCopyImpl, BuiltinMissingDebugImpl, BuiltinMissingDoc,
-        BuiltinMutablesTransmutes, BuiltinNamedAsmLabel, BuiltinNoMangleGeneric,
-        BuiltinNonShorthandFieldPatterns, BuiltinSpecialModuleNameUsed, BuiltinTrivialBounds,
-        BuiltinTypeAliasGenericBounds, BuiltinTypeAliasGenericBoundsSuggestion,
-        BuiltinTypeAliasWhereClause, BuiltinUngatedAsyncFnTrackCaller, BuiltinUnpermittedTypeInit,
+        BuiltinMutablesTransmutes, BuiltinNoMangleGeneric, BuiltinNonShorthandFieldPatterns,
+        BuiltinSpecialModuleNameUsed, BuiltinTrivialBounds, BuiltinTypeAliasGenericBounds,
+        BuiltinTypeAliasGenericBoundsSuggestion, BuiltinTypeAliasWhereClause,
+        BuiltinUngatedAsyncFnTrackCaller, BuiltinUnpermittedTypeInit,
         BuiltinUnpermittedTypeInitSub, BuiltinUnreachablePub, BuiltinUnsafe,
         BuiltinUnstableFeatures, BuiltinUnusedDocComment, BuiltinUnusedDocCommentSub,
-        BuiltinWhileTrue, SuggestChangingAssocTypes,
+        BuiltinWhileTrue, InvalidAsmLabel, SuggestChangingAssocTypes,
     },
     EarlyContext, EarlyLintPass, LateContext, LateLintPass, Level, LintContext,
 };
@@ -45,7 +45,7 @@ use rustc_ast::tokenstream::{TokenStream, TokenTree};
 use rustc_ast::visit::{FnCtxt, FnKind};
 use rustc_ast::{self as ast, *};
 use rustc_ast_pretty::pprust::{self, expr_to_string};
-use rustc_errors::{Applicability, LintDiagnostic, MultiSpan};
+use rustc_errors::{Applicability, LintDiagnostic};
 use rustc_feature::{deprecated_attributes, AttributeGate, BuiltinAttribute, GateIssue, Stability};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -69,7 +69,6 @@ use rustc_target::abi::Abi;
 use rustc_trait_selection::infer::{InferCtxtExt, TyCtxtInferExt};
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_trait_selection::traits::{self, misc::type_allowed_to_implement_copy};
-use tracing::debug;
 
 use crate::nonstandard_style::{method_context, MethodLateContext};
 
@@ -326,6 +325,12 @@ impl EarlyLintPass for UnsafeCode {
                 self.report_unsafe(cx, it.span, BuiltinUnsafe::GlobalAsm);
             }
 
+            ast::ItemKind::ForeignMod(ForeignMod { safety, .. }) => {
+                if let Safety::Unsafe(_) = safety {
+                    self.report_unsafe(cx, it.span, BuiltinUnsafe::UnsafeExternBlock);
+                }
+            }
+
             _ => {}
         }
     }
@@ -2728,10 +2733,52 @@ declare_lint! {
     "named labels in inline assembly",
 }
 
-declare_lint_pass!(NamedAsmLabels => [NAMED_ASM_LABELS]);
+declare_lint! {
+    /// The `binary_asm_labels` lint detects the use of numeric labels containing only binary
+    /// digits in the inline `asm!` macro.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// # #![feature(asm_experimental_arch)]
+    /// use std::arch::asm;
+    ///
+    /// fn main() {
+    ///     unsafe {
+    ///         asm!("0: jmp 0b");
+    ///     }
+    /// }
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// A [LLVM bug] causes this code to fail to compile because it interprets the `0b` as a binary
+    /// literal instead of a reference to the previous local label `0`. Note that even though the
+    /// bug is marked as fixed, it only fixes a specific usage of intel syntax within standalone
+    /// files, not inline assembly. To work around this bug, don't use labels that could be
+    /// confused with a binary literal.
+    ///
+    /// See the explanation in [Rust By Example] for more details.
+    ///
+    /// [LLVM bug]: https://bugs.llvm.org/show_bug.cgi?id=36144
+    /// [Rust By Example]: https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels
+    pub BINARY_ASM_LABELS,
+    Deny,
+    "labels in inline assembly containing only 0 or 1 digits",
+}
+
+declare_lint_pass!(AsmLabels => [NAMED_ASM_LABELS, BINARY_ASM_LABELS]);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum AsmLabelKind {
+    Named,
+    FormatArg,
+    Binary,
+}
 
-impl<'tcx> LateLintPass<'tcx> for NamedAsmLabels {
-    #[allow(rustc::diagnostic_outside_of_impl)]
+impl<'tcx> LateLintPass<'tcx> for AsmLabels {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>) {
         if let hir::Expr {
             kind: hir::ExprKind::InlineAsm(hir::InlineAsm { template_strs, options, .. }),
@@ -2759,7 +2806,8 @@ impl<'tcx> LateLintPass<'tcx> for NamedAsmLabels {
                     None
                 };
 
-                let mut found_labels = Vec::new();
+                // diagnostics are emitted per-template, so this is created here as opposed to the outer loop
+                let mut spans = Vec::new();
 
                 // A semicolon might not actually be specified as a separator for all targets, but
                 // it seems like LLVM accepts it always.
@@ -2782,16 +2830,21 @@ impl<'tcx> LateLintPass<'tcx> for NamedAsmLabels {
 
                         // Whether a { bracket has been seen and its } hasn't been found yet.
                         let mut in_bracket = false;
+                        let mut label_kind = AsmLabelKind::Named;
 
-                        // A label starts with an ASCII alphabetic character or . or _
                         // A label can also start with a format arg, if it's not a raw asm block.
                         if !raw && start == '{' {
                             in_bracket = true;
+                            label_kind = AsmLabelKind::FormatArg;
+                        } else if matches!(start, '0' | '1') {
+                            // Binary labels have only the characters `0` or `1`.
+                            label_kind = AsmLabelKind::Binary;
                         } else if !(start.is_ascii_alphabetic() || matches!(start, '.' | '_')) {
+                            // Named labels start with ASCII letters, `.` or `_`.
+                            // anything else is not a label
                             break 'label_loop;
                         }
 
-                        // Labels continue with ASCII alphanumeric characters, _, or $
                         for c in chars {
                             // Inside a template format arg, any character is permitted for the
                             // puproses of label detection because we assume that it can be
@@ -2812,34 +2865,60 @@ impl<'tcx> LateLintPass<'tcx> for NamedAsmLabels {
                             } else if !raw && c == '{' {
                                 // Start of a format arg.
                                 in_bracket = true;
+                                label_kind = AsmLabelKind::FormatArg;
                             } else {
-                                if !(c.is_ascii_alphanumeric() || matches!(c, '_' | '$')) {
+                                let can_continue = match label_kind {
+                                    // Format arg labels are considered to be named labels for the purposes
+                                    // of continuing outside of their {} pair.
+                                    AsmLabelKind::Named | AsmLabelKind::FormatArg => {
+                                        c.is_ascii_alphanumeric() || matches!(c, '_' | '$')
+                                    }
+                                    AsmLabelKind::Binary => matches!(c, '0' | '1'),
+                                };
+
+                                if !can_continue {
                                     // The potential label had an invalid character inside it, it
                                     // cannot be a label.
                                     break 'label_loop;
                                 }
                             }
                         }
 
-                        // If all characters passed the label checks, this is likely a label.
-                        found_labels.push(possible_label);
+                        // If all characters passed the label checks, this is a label.
+                        spans.push((find_label_span(possible_label), label_kind));
                         start_idx = idx + 1;
                     }
                 }
 
-                debug!("NamedAsmLabels::check_expr(): found_labels: {:#?}", &found_labels);
-
-                if found_labels.len() > 0 {
-                    let spans = found_labels
-                        .into_iter()
-                        .filter_map(|label| find_label_span(label))
-                        .collect::<Vec<Span>>();
-                    // If there were labels but we couldn't find a span, combine the warnings and
-                    // use the template span.
-                    let target_spans: MultiSpan =
-                        if spans.len() > 0 { spans.into() } else { (*template_span).into() };
-
-                    cx.emit_span_lint(NAMED_ASM_LABELS, target_spans, BuiltinNamedAsmLabel);
+                for (span, label_kind) in spans {
+                    let missing_precise_span = span.is_none();
+                    let span = span.unwrap_or(*template_span);
+                    match label_kind {
+                        AsmLabelKind::Named => {
+                            cx.emit_span_lint(
+                                NAMED_ASM_LABELS,
+                                span,
+                                InvalidAsmLabel::Named { missing_precise_span },
+                            );
+                        }
+                        AsmLabelKind::FormatArg => {
+                            cx.emit_span_lint(
+                                NAMED_ASM_LABELS,
+                                span,
+                                InvalidAsmLabel::FormatArg { missing_precise_span },
+                            );
+                        }
+                        AsmLabelKind::Binary => {
+                            // the binary asm issue only occurs when using intel syntax
+                            if !options.contains(InlineAsmOptions::ATT_SYNTAX) {
+                                cx.emit_span_lint(
+                                    BINARY_ASM_LABELS,
+                                    span,
+                                    InvalidAsmLabel::Binary { missing_precise_span, span },
+                                )
+                            }
+                        }
+                    };
                 }
             }
         }

compiler/rustc_lint/src/lib.rs

@@ -225,7 +225,7 @@ late_lint_methods!(
             NoopMethodCall: NoopMethodCall,
             EnumIntrinsicsNonEnums: EnumIntrinsicsNonEnums,
             InvalidAtomicOrdering: InvalidAtomicOrdering,
-            NamedAsmLabels: NamedAsmLabels,
+            AsmLabels: AsmLabels,
             OpaqueHiddenInferredBound: OpaqueHiddenInferredBound,
             MultipleSupertraitUpcastable: MultipleSupertraitUpcastable,
             MapUnitFn: MapUnitFn,

compiler/rustc_lint/src/lints.rs

@@ -81,6 +81,8 @@ pub enum BuiltinUnsafe {
     AllowInternalUnsafe,
     #[diag(lint_builtin_unsafe_block)]
     UnsafeBlock,
+    #[diag(lint_builtin_unsafe_extern_block)]
+    UnsafeExternBlock,
     #[diag(lint_builtin_unsafe_trait)]
     UnsafeTrait,
     #[diag(lint_builtin_unsafe_impl)]
@@ -2047,10 +2049,32 @@ pub struct UnitBindingsDiag {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(lint_builtin_asm_labels)]
-#[help]
-#[note]
-pub struct BuiltinNamedAsmLabel;
+pub enum InvalidAsmLabel {
+    #[diag(lint_invalid_asm_label_named)]
+    #[help]
+    #[note]
+    Named {
+        #[note(lint_invalid_asm_label_no_span)]
+        missing_precise_span: bool,
+    },
+    #[diag(lint_invalid_asm_label_format_arg)]
+    #[help]
+    #[note(lint_note1)]
+    #[note(lint_note2)]
+    FormatArg {
+        #[note(lint_invalid_asm_label_no_span)]
+        missing_precise_span: bool,
+    },
+    #[diag(lint_invalid_asm_label_binary)]
+    #[note]
+    Binary {
+        #[note(lint_invalid_asm_label_no_span)]
+        missing_precise_span: bool,
+        // hack to get a label on the whole span, must match the emitted span
+        #[label]
+        span: Span,
+    },
+}
 
 #[derive(Subdiagnostic)]
 pub enum UnexpectedCfgCargoHelp {

compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs

@@ -5,8 +5,7 @@ use rustc_middle::ty::print::{PrintTraitPredicateExt as _, TraitPredPrintModifie
 use rustc_middle::ty::{self, fold::BottomUpFolder, Ty, TypeFoldable};
 use rustc_session::{declare_lint, declare_lint_pass};
 use rustc_span::{symbol::kw, Span};
-use rustc_trait_selection::traits;
-use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
+use rustc_trait_selection::traits::{self, ObligationCtxt};
 
 use crate::{LateContext, LateLintPass, LintContext};
 
@@ -130,24 +129,26 @@ impl<'tcx> LateLintPass<'tcx> for OpaqueHiddenInferredBound {
                     .iter_instantiated_copied(cx.tcx, proj.projection_term.args)
                 {
                     let assoc_pred = assoc_pred.fold_with(proj_replacer);
-                    let Ok(assoc_pred) = traits::fully_normalize(
-                        infcx,
+
+                    let ocx = ObligationCtxt::new(infcx);
+                    let assoc_pred =
+                        ocx.normalize(&traits::ObligationCause::dummy(), cx.param_env, assoc_pred);
+                    if !ocx.select_all_or_error().is_empty() {
+                        // Can't normalize for some reason...?
+                        continue;
+                    }
+
+                    ocx.register_obligation(traits::Obligation::new(
+                        cx.tcx,
                         traits::ObligationCause::dummy(),
                         cx.param_env,
                         assoc_pred,
-                    ) else {
-                        continue;
-                    };
+                    ));
 
                     // If that predicate doesn't hold modulo regions (but passed during type-check),
                     // then we must've taken advantage of the hack in `project_and_unify_types` where
                     // we replace opaques with inference vars. Emit a warning!
-                    if !infcx.predicate_must_hold_modulo_regions(&traits::Obligation::new(
-                        cx.tcx,
-                        traits::ObligationCause::dummy(),
-                        cx.param_env,
-                        assoc_pred,
-                    )) {
+                    if !ocx.select_all_or_error().is_empty() {
                         // If it's a trait bound and an opaque that doesn't satisfy it,
                         // then we can emit a suggestion to add the bound.
                         let add_bound = match (proj_term.kind(), assoc_pred.kind().skip_binder()) {

compiler/rustc_middle/src/mir/pretty.rs

@@ -1545,6 +1545,9 @@ impl<'a, 'tcx, Prov: Provenance, Extra, Bytes: AllocBytes> std::fmt::Display
             // We are done.
             return write!(w, " {{}}");
         }
+        if tcx.sess.opts.unstable_opts.dump_mir_exclude_alloc_bytes {
+            return write!(w, " {{ .. }}");
+        }
         // Write allocation bytes.
         writeln!(w, " {{")?;
         write_allocation_bytes(tcx, alloc, w, "    ")?;