From 20431706a863f92cb37dc512fef6e48d192aaf2c Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:11:38 +0200 Subject: Merging upstream version 1.66.0+dfsg1. Signed-off-by: Daniel Baumann --- compiler/rustc_middle/src/lint.rs | 329 ++++++++++++++++++++++---------------- 1 file changed, 189 insertions(+), 140 deletions(-) (limited to 'compiler/rustc_middle/src/lint.rs') diff --git a/compiler/rustc_middle/src/lint.rs b/compiler/rustc_middle/src/lint.rs index 2f45222de..79522bd0b 100644 --- a/compiler/rustc_middle/src/lint.rs +++ b/compiler/rustc_middle/src/lint.rs @@ -1,20 +1,20 @@ use std::cmp; use rustc_data_structures::fx::FxHashMap; -use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; -use rustc_errors::{Diagnostic, DiagnosticId, LintDiagnosticBuilder, MultiSpan}; -use rustc_hir::HirId; -use rustc_index::vec::IndexVec; -use rustc_query_system::ich::StableHashingContext; +use rustc_data_structures::sorted_map::SortedMap; +use rustc_errors::{Diagnostic, DiagnosticBuilder, DiagnosticId, DiagnosticMessage, MultiSpan}; +use rustc_hir::{HirId, ItemLocalId}; use rustc_session::lint::{ builtin::{self, FORBIDDEN_LINT_GROUPS}, - FutureIncompatibilityReason, Level, Lint, LintExpectationId, LintId, + FutureIncompatibilityReason, Level, Lint, LintId, }; use rustc_session::Session; use rustc_span::hygiene::MacroKind; use rustc_span::source_map::{DesugaringKind, ExpnKind}; use rustc_span::{symbol, Span, Symbol, DUMMY_SP}; +use crate::ty::TyCtxt; + /// How a lint level was set. #[derive(Clone, Copy, PartialEq, Eq, HashStable, Debug)] pub enum LintLevelSource { @@ -23,7 +23,12 @@ pub enum LintLevelSource { Default, /// Lint level was set by an attribute. - Node(Symbol, Span, Option /* RFC 2383 reason */), + Node { + name: Symbol, + span: Span, + /// RFC 2383 reason + reason: Option, + }, /// Lint level was set by a command-line flag. /// The provided `Level` is the level specified on the command line. @@ -35,7 +40,7 @@ impl LintLevelSource { pub fn name(&self) -> Symbol { match *self { LintLevelSource::Default => symbol::kw::Default, - LintLevelSource::Node(name, _, _) => name, + LintLevelSource::Node { name, .. } => name, LintLevelSource::CommandLine(name, _) => name, } } @@ -43,7 +48,7 @@ impl LintLevelSource { pub fn span(&self) -> Span { match *self { LintLevelSource::Default => DUMMY_SP, - LintLevelSource::Node(_, span, _) => span, + LintLevelSource::Node { span, .. } => span, LintLevelSource::CommandLine(_, _) => DUMMY_SP, } } @@ -52,145 +57,137 @@ impl LintLevelSource { /// A tuple of a lint level and its source. pub type LevelAndSource = (Level, LintLevelSource); -#[derive(Debug, HashStable)] -pub struct LintLevelSets { - pub list: IndexVec, - pub lint_cap: Level, -} - -rustc_index::newtype_index! { - #[derive(HashStable)] - pub struct LintStackIndex { - const COMMAND_LINE = 0, - } -} - -#[derive(Debug, HashStable)] -pub struct LintSet { - // -A,-W,-D flags, a `Symbol` for the flag itself and `Level` for which - // flag. - pub specs: FxHashMap, - - pub parent: LintStackIndex, +/// Return type for the `shallow_lint_levels_on` query. +/// +/// This map represents the set of allowed lints and allowance levels given +/// by the attributes for *a single HirId*. +#[derive(Default, Debug, HashStable)] +pub struct ShallowLintLevelMap { + pub specs: SortedMap>, } -impl LintLevelSets { - pub fn new() -> Self { - LintLevelSets { list: IndexVec::new(), lint_cap: Level::Forbid } - } - - pub fn get_lint_level( - &self, - lint: &'static Lint, - idx: LintStackIndex, - aux: Option<&FxHashMap>, - sess: &Session, - ) -> LevelAndSource { - let (level, mut src) = self.get_lint_id_level(LintId::of(lint), idx, aux); - - // If `level` is none then we actually assume the default level for this - // lint. - let mut level = level.unwrap_or_else(|| lint.default_level(sess.edition())); - - // If we're about to issue a warning, check at the last minute for any - // directives against the warnings "lint". If, for example, there's an - // `allow(warnings)` in scope then we want to respect that instead. - // - // We exempt `FORBIDDEN_LINT_GROUPS` from this because it specifically - // triggers in cases (like #80988) where you have `forbid(warnings)`, - // and so if we turned that into an error, it'd defeat the purpose of the - // future compatibility warning. - if level == Level::Warn && LintId::of(lint) != LintId::of(FORBIDDEN_LINT_GROUPS) { - let (warnings_level, warnings_src) = - self.get_lint_id_level(LintId::of(builtin::WARNINGS), idx, aux); - if let Some(configured_warning_level) = warnings_level { - if configured_warning_level != Level::Warn { - level = configured_warning_level; - src = warnings_src; - } +/// From an initial level and source, verify the effect of special annotations: +/// `warnings` lint level and lint caps. +/// +/// The return of this function is suitable for diagnostics. +pub fn reveal_actual_level( + level: Option, + src: &mut LintLevelSource, + sess: &Session, + lint: LintId, + probe_for_lint_level: impl FnOnce(LintId) -> (Option, LintLevelSource), +) -> Level { + // If `level` is none then we actually assume the default level for this lint. + let mut level = level.unwrap_or_else(|| lint.lint.default_level(sess.edition())); + + // If we're about to issue a warning, check at the last minute for any + // directives against the warnings "lint". If, for example, there's an + // `allow(warnings)` in scope then we want to respect that instead. + // + // We exempt `FORBIDDEN_LINT_GROUPS` from this because it specifically + // triggers in cases (like #80988) where you have `forbid(warnings)`, + // and so if we turned that into an error, it'd defeat the purpose of the + // future compatibility warning. + if level == Level::Warn && lint != LintId::of(FORBIDDEN_LINT_GROUPS) { + let (warnings_level, warnings_src) = probe_for_lint_level(LintId::of(builtin::WARNINGS)); + if let Some(configured_warning_level) = warnings_level { + if configured_warning_level != Level::Warn { + level = configured_warning_level; + *src = warnings_src; } } + } - // Ensure that we never exceed the `--cap-lints` argument - // unless the source is a --force-warn - level = if let LintLevelSource::CommandLine(_, Level::ForceWarn(_)) = src { - level - } else { - cmp::min(level, self.lint_cap) - }; - - if let Some(driver_level) = sess.driver_lint_caps.get(&LintId::of(lint)) { - // Ensure that we never exceed driver level. - level = cmp::min(*driver_level, level); - } + // Ensure that we never exceed the `--cap-lints` argument unless the source is a --force-warn + level = if let LintLevelSource::CommandLine(_, Level::ForceWarn(_)) = src { + level + } else { + cmp::min(level, sess.opts.lint_cap.unwrap_or(Level::Forbid)) + }; - (level, src) + if let Some(driver_level) = sess.driver_lint_caps.get(&lint) { + // Ensure that we never exceed driver level. + level = cmp::min(*driver_level, level); } - pub fn get_lint_id_level( + level +} + +impl ShallowLintLevelMap { + /// Perform a deep probe in the HIR tree looking for the actual level for the lint. + /// This lint level is not usable for diagnostics, it needs to be corrected by + /// `reveal_actual_level` beforehand. + #[instrument(level = "trace", skip(self, tcx), ret)] + fn probe_for_lint_level( &self, + tcx: TyCtxt<'_>, id: LintId, - mut idx: LintStackIndex, - aux: Option<&FxHashMap>, + start: HirId, ) -> (Option, LintLevelSource) { - if let Some(specs) = aux { - if let Some(&(level, src)) = specs.get(&id) { - return (Some(level), src); - } + if let Some(map) = self.specs.get(&start.local_id) + && let Some(&(level, src)) = map.get(&id) + { + return (Some(level), src); } - loop { - let LintSet { ref specs, parent } = self.list[idx]; - if let Some(&(level, src)) = specs.get(&id) { - return (Some(level), src); + + let mut owner = start.owner; + let mut specs = &self.specs; + + for parent in tcx.hir().parent_id_iter(start) { + if parent.owner != owner { + owner = parent.owner; + specs = &tcx.shallow_lint_levels_on(owner).specs; } - if idx == COMMAND_LINE { - return (None, LintLevelSource::Default); + if let Some(map) = specs.get(&parent.local_id) + && let Some(&(level, src)) = map.get(&id) + { + return (Some(level), src); } - idx = parent; } - } -} -#[derive(Debug)] -pub struct LintLevelMap { - /// This is a collection of lint expectations as described in RFC 2383, that - /// can be fulfilled during this compilation session. This means that at least - /// one expected lint is currently registered in the lint store. - /// - /// The [`LintExpectationId`] is stored as a part of the [`Expect`](Level::Expect) - /// lint level. - pub lint_expectations: Vec<(LintExpectationId, LintExpectation)>, - pub sets: LintLevelSets, - pub id_to_set: FxHashMap, -} + (None, LintLevelSource::Default) + } -impl LintLevelMap { - /// If the `id` was previously registered with `register_id` when building - /// this `LintLevelMap` this returns the corresponding lint level and source - /// of the lint level for the lint provided. - /// - /// If the `id` was not previously registered, returns `None`. If `None` is - /// returned then the parent of `id` should be acquired and this function - /// should be called again. - pub fn level_and_source( + /// Fetch and return the user-visible lint level for the given lint at the given HirId. + #[instrument(level = "trace", skip(self, tcx), ret)] + pub fn lint_level_id_at_node( &self, - lint: &'static Lint, - id: HirId, - session: &Session, - ) -> Option { - self.id_to_set.get(&id).map(|idx| self.sets.get_lint_level(lint, *idx, None, session)) + tcx: TyCtxt<'_>, + lint: LintId, + cur: HirId, + ) -> (Level, LintLevelSource) { + let (level, mut src) = self.probe_for_lint_level(tcx, lint, cur); + let level = reveal_actual_level(level, &mut src, tcx.sess, lint, |lint| { + self.probe_for_lint_level(tcx, lint, cur) + }); + (level, src) } } -impl<'a> HashStable> for LintLevelMap { - #[inline] - fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { - let LintLevelMap { ref sets, ref id_to_set, ref lint_expectations } = *self; +impl TyCtxt<'_> { + /// Fetch and return the user-visible lint level for the given lint at the given HirId. + pub fn lint_level_at_node(self, lint: &'static Lint, id: HirId) -> (Level, LintLevelSource) { + self.shallow_lint_levels_on(id.owner).lint_level_id_at_node(self, LintId::of(lint), id) + } - id_to_set.hash_stable(hcx, hasher); - lint_expectations.hash_stable(hcx, hasher); + /// Walks upwards from `id` to find a node which might change lint levels with attributes. + /// It stops at `bound` and just returns it if reached. + pub fn maybe_lint_level_root_bounded(self, mut id: HirId, bound: HirId) -> HirId { + let hir = self.hir(); + loop { + if id == bound { + return bound; + } - hcx.while_hashing_spans(true, |hcx| sets.hash_stable(hcx, hasher)) + if hir.attrs(id).iter().any(|attr| Level::from_attr(attr).is_some()) { + return id; + } + let next = hir.get_parent_node(id); + if next == id { + bug!("lint traversal reached the root of the crate"); + } + id = next; + } } } @@ -261,11 +258,11 @@ pub fn explain_lint_level_source( )); } } - LintLevelSource::Node(lint_attr_name, src, reason) => { + LintLevelSource::Node { name: lint_attr_name, span, reason, .. } => { if let Some(rationale) = reason { err.note(rationale.as_str()); } - err.span_note_once(src, "the lint level is defined here"); + err.span_note_once(span, "the lint level is defined here"); if lint_attr_name.as_str() != name { let level_str = level.as_str(); err.note_once(&format!( @@ -277,23 +274,65 @@ pub fn explain_lint_level_source( } } -pub fn struct_lint_level<'s, 'd>( - sess: &'s Session, +/// The innermost function for emitting lints. +/// +/// If you are loocking to implement a lint, look for higher level functions, +/// for example: +/// - [`TyCtxt::emit_spanned_lint`] +/// - [`TyCtxt::struct_span_lint_hir`] +/// - [`TyCtxt::emit_lint`] +/// - [`TyCtxt::struct_lint_node`] +/// - `LintContext::lookup` +/// +/// ## `decorate` signature +/// +/// The return value of `decorate` is ignored by this function. So what is the +/// point of returning `&'b mut DiagnosticBuilder<'a, ()>`? +/// +/// There are 2 reasons for this signature. +/// +/// First of all, it prevents accidental use of `.emit()` -- it's clear that the +/// builder will be later used and shouldn't be emitted right away (this is +/// especially important because the old API expected you to call `.emit()` in +/// the closure). +/// +/// Second of all, it makes the most common case of adding just a single label +/// /suggestion much nicer, since [`DiagnosticBuilder`] methods return +/// `&mut DiagnosticBuilder`, you can just chain methods, without needed +/// awkward `{ ...; }`: +/// ```ignore pseudo-code +/// struct_lint_level( +/// ..., +/// |lint| lint.span_label(sp, "lbl") +/// // ^^^^^^^^^^^^^^^^^^^^^ returns `&mut DiagnosticBuilder` by default +/// ) +/// ``` +pub fn struct_lint_level( + sess: &Session, lint: &'static Lint, level: Level, src: LintLevelSource, span: Option, - decorate: impl for<'a> FnOnce(LintDiagnosticBuilder<'a, ()>) + 'd, + msg: impl Into, + decorate: impl for<'a, 'b> FnOnce( + &'b mut DiagnosticBuilder<'a, ()>, + ) -> &'b mut DiagnosticBuilder<'a, ()>, ) { // Avoid codegen bloat from monomorphization by immediately doing dyn dispatch of `decorate` to // the "real" work. - fn struct_lint_level_impl<'s, 'd>( - sess: &'s Session, + fn struct_lint_level_impl( + sess: &Session, lint: &'static Lint, level: Level, src: LintLevelSource, span: Option, - decorate: Box FnOnce(LintDiagnosticBuilder<'b, ()>) + 'd>, + msg: impl Into, + decorate: Box< + dyn '_ + + for<'a, 'b> FnOnce( + &'b mut DiagnosticBuilder<'a, ()>, + ) -> &'b mut DiagnosticBuilder<'a, ()>, + >, ) { // Check for future incompatibility lints and issue a stronger warning. let future_incompatible = lint.future_incompatible; @@ -344,6 +383,8 @@ pub fn struct_lint_level<'s, 'd>( (Level::Deny | Level::Forbid, None) => sess.diagnostic().struct_err_lint(""), }; + err.set_is_lint(); + // If this code originates in a foreign macro, aka something that this crate // did not itself author, then it's likely that there's nothing this crate // can do about it. We probably want to skip the lint entirely. @@ -366,6 +407,10 @@ pub fn struct_lint_level<'s, 'd>( } } + // Delay evaluating and setting the primary message until after we've + // suppressed the lint due to macros. + err.set_primary_message(msg); + // Lint diagnostics that are covered by the expect level will not be emitted outside // the compiler. It is therefore not necessary to add any information for the user. // This will therefore directly call the decorate function which will in turn emit @@ -373,12 +418,12 @@ pub fn struct_lint_level<'s, 'd>( if let Level::Expect(_) = level { let name = lint.name_lower(); err.code(DiagnosticId::Lint { name, has_future_breakage, is_force_warn: false }); - decorate(LintDiagnosticBuilder::new(err)); + + decorate(&mut err); + err.emit(); return; } - explain_lint_level_source(lint, level, src, &mut err); - let name = lint.name_lower(); let is_force_warn = matches!(level, Level::ForceWarn(_)); err.code(DiagnosticId::Lint { name, has_future_breakage, is_force_warn }); @@ -417,10 +462,12 @@ pub fn struct_lint_level<'s, 'd>( } } - // Finally, run `decorate`. This function is also responsible for emitting the diagnostic. - decorate(LintDiagnosticBuilder::new(err)); + // Finally, run `decorate`. + decorate(&mut err); + explain_lint_level_source(lint, level, src, &mut *err); + err.emit() } - struct_lint_level_impl(sess, lint, level, src, span, Box::new(decorate)) + struct_lint_level_impl(sess, lint, level, src, span, msg, Box::new(decorate)) } /// Returns whether `span` originates in a foreign crate's external macro. @@ -432,7 +479,9 @@ pub fn in_external_macro(sess: &Session, span: Span) -> bool { match expn_data.kind { ExpnKind::Inlined | ExpnKind::Root - | ExpnKind::Desugaring(DesugaringKind::ForLoop | DesugaringKind::WhileLoop) => false, + | ExpnKind::Desugaring( + DesugaringKind::ForLoop | DesugaringKind::WhileLoop | DesugaringKind::OpaqueTy, + ) => false, ExpnKind::AstPass(_) | ExpnKind::Desugaring(_) => true, // well, it's "external" ExpnKind::Macro(MacroKind::Bang, _) => { // Dummy span for the `def_site` means it's an external macro. -- cgit v1.2.3