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Unbundle late combined pass, filter late passes before linting
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Alexendoo committed Sep 29, 2023
1 parent c545019 commit 3909491
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Showing 36 changed files with 243 additions and 546 deletions.
1 change: 1 addition & 0 deletions Cargo.lock
Original file line number Diff line number Diff line change
Expand Up @@ -4095,6 +4095,7 @@ dependencies = [
"rustc_graphviz",
"rustc_hir",
"rustc_index",
"rustc_lint_defs",
"rustc_macros",
"rustc_query_system",
"rustc_serialize",
Expand Down
11 changes: 6 additions & 5 deletions compiler/rustc_lint/src/builtin.rs
Original file line number Diff line number Diff line change
Expand Up @@ -7,10 +7,7 @@
//! To add a new lint to rustc, declare it here using `declare_lint!()`.
//! Then add code to emit the new lint in the appropriate circumstances.
//! You can do that in an existing `LintPass` if it makes sense, or in a
//! new `LintPass`, or using `Session::add_lint` elsewhere in the
//! compiler. Only do the latter if the check can't be written cleanly as a
//! `LintPass` (also, note that such lints will need to be defined in
//! `rustc_session::lint::builtin`, not here).
//! new `LintPass`.
//!
//! If you define a new `EarlyLintPass`, you will also need to add it to the
//! `add_early_builtin!` or `add_early_builtin_with_new!` invocation in
Expand Down Expand Up @@ -39,13 +36,14 @@ use crate::{
BuiltinUnstableFeatures, BuiltinUnusedDocComment, BuiltinUnusedDocCommentSub,
BuiltinWhileTrue, SuggestChangingAssocTypes,
},
EarlyContext, EarlyLintPass, LateContext, LateLintPass, Level, LintContext,
EarlyContext, EarlyLintPass, LateContext, LateLintPass, Level, LintContext, LintId,
};
use rustc_ast::attr;
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_data_structures::fx::FxHashSet;
use rustc_errors::{Applicability, DecorateLint, MultiSpan};
use rustc_feature::{deprecated_attributes, AttributeGate, BuiltinAttribute, GateIssue, Stability};
use rustc_hir as hir;
Expand Down Expand Up @@ -1523,6 +1521,9 @@ declare_lint_pass!(
/// unused within this crate, even though downstream crates can't use it
/// without producing an error.
UnusedBrokenConst => []
fn is_enabled(&self, _: &FxHashSet<LintId>) -> bool {
true
}
);

impl<'tcx> LateLintPass<'tcx> for UnusedBrokenConst {
Expand Down
12 changes: 12 additions & 0 deletions compiler/rustc_lint/src/context.rs
Original file line number Diff line number Diff line change
Expand Up @@ -509,6 +509,9 @@ pub struct LateContext<'tcx> {

/// We are only looking at one module
pub only_module: bool,

#[cfg(debug_assertions)]
pub(super) permitted_lints: Cell<Option<&'static [&'static str]>>,
}

/// Context for lint checking of the AST, after expansion, before lowering to HIR.
Expand Down Expand Up @@ -1067,6 +1070,15 @@ impl<'tcx> LintContext for LateContext<'tcx> {
&'b mut DiagnosticBuilder<'a, ()>,
) -> &'b mut DiagnosticBuilder<'a, ()>,
) {
#[cfg(debug_assertions)]
if let Some(permitted) = self.permitted_lints.get() {
assert!(
permitted.contains(&lint.name),
"unexpected lint {} emitted from pass. permitted: {permitted:?}",
lint.name
);
}

let hir_id = self.last_node_with_lint_attrs;

match span {
Expand Down
18 changes: 5 additions & 13 deletions compiler/rustc_lint/src/internal.rs
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,6 @@ use rustc_hir::{def_id::DefId, Expr, ExprKind, GenericArg, PatKind, Path, PathSe
use rustc_hir::{HirId, Impl, Item, ItemKind, Node, Pat, Ty, TyKind};
use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::hygiene::{ExpnKind, MacroKind};
use rustc_span::symbol::{kw, sym, Symbol};
use rustc_span::Span;

Expand Down Expand Up @@ -284,18 +283,11 @@ impl EarlyLintPass for LintPassImpl {
if let ast::ItemKind::Impl(box ast::Impl { of_trait: Some(lint_pass), .. }) = &item.kind {
if let Some(last) = lint_pass.path.segments.last() {
if last.ident.name == sym::LintPass {
let expn_data = lint_pass.path.span.ctxt().outer_expn_data();
let call_site = expn_data.call_site;
if expn_data.kind != ExpnKind::Macro(MacroKind::Bang, sym::impl_lint_pass)
&& call_site.ctxt().outer_expn_data().kind
!= ExpnKind::Macro(MacroKind::Bang, sym::declare_lint_pass)
{
cx.emit_spanned_lint(
LINT_PASS_IMPL_WITHOUT_MACRO,
lint_pass.path.span,
LintPassByHand,
);
}
cx.emit_spanned_lint(
LINT_PASS_IMPL_WITHOUT_MACRO,
lint_pass.path.span,
LintPassByHand,
);
}
}
}
Expand Down
98 changes: 76 additions & 22 deletions compiler/rustc_lint/src/late.rs
Original file line number Diff line number Diff line change
Expand Up @@ -14,14 +14,16 @@
//! upon. As the ast is traversed, this keeps track of the current lint level
//! for all lint attributes.
use crate::{passes::LateLintPassObject, LateContext, LateLintPass, LintStore};
use crate::{passes::LateLintPassObject, LateContext, LateLintPass, Level, LintId, LintStore};
use rustc_ast as ast;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::stack::ensure_sufficient_stack;
use rustc_data_structures::sync::join;
use rustc_hir as hir;
use rustc_hir::def_id::{LocalDefId, LocalModDefId};
use rustc_hir::intravisit as hir_visit;
use rustc_middle::hir::nested_filter;
use rustc_middle::lint::{reveal_actual_level, LintLevelSource};
use rustc_middle::ty::{self, TyCtxt};
use rustc_session::lint::LintPass;
use rustc_span::Span;
Expand Down Expand Up @@ -315,8 +317,7 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas

// Combines multiple lint passes into a single pass, at runtime. Each
// `check_foo` method in `$methods` within this pass simply calls `check_foo`
// once per `$pass`. Compare with `declare_combined_late_lint_pass`, which is
// similar, but combines lint passes at compile time.
// once per `$pass`.
struct RuntimeCombinedLateLintPass<'a, 'tcx> {
passes: &'a mut [LateLintPassObject<'tcx>],
}
Expand All @@ -333,6 +334,8 @@ macro_rules! impl_late_lint_pass {
impl<'tcx> LateLintPass<'tcx> for RuntimeCombinedLateLintPass<'_, 'tcx> {
$(fn $f(&mut self, context: &LateContext<'tcx>, $($param: $arg),*) {
for pass in self.passes.iter_mut() {
#[cfg(debug_assertions)]
context.permitted_lints.set(pass.lint_names());
pass.$f(context, $($param),*);
}
})*
Expand All @@ -342,11 +345,7 @@ macro_rules! impl_late_lint_pass {

crate::late_lint_methods!(impl_late_lint_pass, []);

pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
tcx: TyCtxt<'tcx>,
module_def_id: LocalModDefId,
builtin_lints: T,
) {
pub fn late_lint_mod(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
let context = LateContext {
tcx,
enclosing_body: None,
Expand All @@ -357,20 +356,20 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
last_node_with_lint_attrs: tcx.hir().local_def_id_to_hir_id(module_def_id),
generics: None,
only_module: true,
#[cfg(debug_assertions)]
permitted_lints: Cell::new(None),
};

// Note: `passes` is often empty. In that case, it's faster to run
// `builtin_lints` directly rather than bundling it up into the
// `RuntimeCombinedLateLintPass`.
let mut passes: Vec<_> =
unerased_lint_store(tcx).late_module_passes.iter().map(|mk_pass| (mk_pass)(tcx)).collect();
if passes.is_empty() {
late_lint_mod_inner(tcx, module_def_id, context, builtin_lints);
} else {
passes.push(Box::new(builtin_lints));
let pass = RuntimeCombinedLateLintPass { passes: &mut passes[..] };
late_lint_mod_inner(tcx, module_def_id, context, pass);
}
let enabled_lints = tcx.enabled_lints(());

let mut passes: Vec<_> = unerased_lint_store(tcx)
.late_module_passes
.iter()
.map(|mk_pass| (mk_pass)(tcx))
.filter(|pass| pass.is_enabled(enabled_lints))
.collect();
let pass = RuntimeCombinedLateLintPass { passes: &mut passes[..] };
late_lint_mod_inner(tcx, module_def_id, context, pass);
}

fn late_lint_mod_inner<'tcx, T: LateLintPass<'tcx>>(
Expand Down Expand Up @@ -398,9 +397,18 @@ fn late_lint_mod_inner<'tcx, T: LateLintPass<'tcx>>(
}

fn late_lint_crate<'tcx>(tcx: TyCtxt<'tcx>) {
// Trigger check for duplicate diagnostic items
let _ = tcx.all_diagnostic_items(());

let enabled_lints = tcx.enabled_lints(());

// Note: `passes` is often empty.
let mut passes: Vec<_> =
unerased_lint_store(tcx).late_passes.iter().map(|mk_pass| (mk_pass)(tcx)).collect();
let mut passes: Vec<_> = unerased_lint_store(tcx)
.late_passes
.iter()
.map(|mk_pass| (mk_pass)(tcx))
.filter(|pass| pass.is_enabled(enabled_lints))
.collect();

if passes.is_empty() {
return;
Expand All @@ -416,6 +424,8 @@ fn late_lint_crate<'tcx>(tcx: TyCtxt<'tcx>) {
last_node_with_lint_attrs: hir::CRATE_HIR_ID,
generics: None,
only_module: false,
#[cfg(debug_assertions)]
permitted_lints: Cell::new(None),
};

let pass = RuntimeCombinedLateLintPass { passes: &mut passes[..] };
Expand Down Expand Up @@ -456,3 +466,47 @@ pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>) {
},
);
}

pub(crate) fn enabled_lints(tcx: TyCtxt<'_>) -> FxHashSet<LintId> {
let get_level = |spec: Option<&FxHashMap<_, _>>, lint| match spec.and_then(|m| m.get(&lint)) {
Some(&(level, source)) => (Some(level), source),
None => (None, LintLevelSource::Default),
};
let may_lint_shallow = |spec: Option<&FxHashMap<_, _>>, level, mut source, lint| {
let actual =
reveal_actual_level(level, &mut source, tcx.sess, lint, |lint| get_level(spec, lint));

actual > Level::Allow
};

let root_lints =
tcx.shallow_lint_levels_on(hir::CRATE_OWNER_ID).specs.get(&hir::CRATE_HIR_ID.local_id);

let mut enabled: FxHashSet<_> = unerased_lint_store(tcx)
.get_lints()
.iter()
.map(|lint| LintId::of(lint))
.filter(|&lint| {
let (level, source) = get_level(root_lints, lint);
may_lint_shallow(root_lints, level, source, lint)
})
.collect();

for (def_id, maybe_owner) in tcx.hir().krate().owners.iter_enumerated() {
if let hir::MaybeOwner::Owner(_) = maybe_owner {
enabled.extend(
tcx.shallow_lint_levels_on(hir::OwnerId { def_id })
.specs
.values()
.flat_map(|spec| {
spec.iter().filter(|&(&lint, &(level, source))| {
may_lint_shallow(Some(spec), Some(level), source, lint)
})
})
.map(|(&lint, _)| lint),
);
}
}

enabled
}
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