Refactor: diagnostic_outside_of_impl, untranslatable_diagnostic

1. Decouple them.
2. Make logic around `diagnostic_outside_of_impl`'s early exits simpler.
3. Make `untranslatable_diagnostic` run one loop instead of two
   and not allocate an intermediate vec.
4. Overall, reduce the amount of code executed
   when the lints do not end up firing.
This commit is contained in:
Pavel Grigorenko 2024-08-10 21:40:07 +03:00
parent 3cc2a6fdcb
commit e94a4ee219

View File

@ -8,7 +8,7 @@
BinOp, BinOpKind, Expr, ExprKind, GenericArg, HirId, Impl, Item, ItemKind, Node, Pat, PatKind,
Path, PathSegment, QPath, Ty, TyKind,
};
use rustc_middle::ty::{self, Ty as MiddleTy};
use rustc_middle::ty::{self, GenericArgsRef, Ty as MiddleTy};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::hygiene::{ExpnKind, MacroKind};
use rustc_span::symbol::{kw, sym, Symbol};
@ -442,30 +442,33 @@ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
_ => return,
};
// Is the callee marked with `#[rustc_lint_diagnostics]`?
let has_attr = ty::Instance::try_resolve(cx.tcx, cx.param_env, def_id, fn_gen_args)
.ok()
.flatten()
.is_some_and(|inst| cx.tcx.has_attr(inst.def_id(), sym::rustc_lint_diagnostics));
Self::diagnostic_outside_of_impl(cx, span, expr.hir_id, def_id, fn_gen_args);
Self::untranslatable_diagnostic(cx, def_id, &arg_tys_and_spans);
}
}
// Closure: is the type `{D,Subd}iagMessage`?
let is_diag_message = |ty: MiddleTy<'_>| {
if let Some(adt_def) = ty.ty_adt_def()
&& let Some(name) = cx.tcx.get_diagnostic_name(adt_def.did())
&& matches!(name, sym::DiagMessage | sym::SubdiagMessage)
{
true
} else {
false
}
};
impl Diagnostics {
// Is the type `{D,Subd}iagMessage`?
fn is_diag_message<'cx>(cx: &LateContext<'cx>, ty: MiddleTy<'cx>) -> bool {
if let Some(adt_def) = ty.ty_adt_def()
&& let Some(name) = cx.tcx.get_diagnostic_name(adt_def.did())
&& matches!(name, sym::DiagMessage | sym::SubdiagMessage)
{
true
} else {
false
}
}
// Does the callee have one or more `impl Into<{D,Subd}iagMessage>` parameters?
let mut impl_into_diagnostic_message_params = vec![];
fn untranslatable_diagnostic<'cx>(
cx: &LateContext<'cx>,
def_id: DefId,
arg_tys_and_spans: &[(MiddleTy<'cx>, Span)],
) {
let fn_sig = cx.tcx.fn_sig(def_id).instantiate_identity().skip_binder();
let predicates = cx.tcx.predicates_of(def_id).instantiate_identity(cx.tcx).predicates;
for (i, &param_ty) in fn_sig.inputs().iter().enumerate() {
if let ty::Param(p) = param_ty.kind() {
if let ty::Param(sig_param) = param_ty.kind() {
// It is a type parameter. Check if it is `impl Into<{D,Subd}iagMessage>`.
for pred in predicates.iter() {
if let Some(trait_pred) = pred.as_trait_clause()
@ -473,27 +476,53 @@ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
&& trait_ref.self_ty() == param_ty // correct predicate for the param?
&& cx.tcx.is_diagnostic_item(sym::Into, trait_ref.def_id)
&& let ty1 = trait_ref.args.type_at(1)
&& is_diag_message(ty1)
&& Self::is_diag_message(cx, ty1)
{
impl_into_diagnostic_message_params.push((i, p.name));
// Calls to methods with an `impl Into<{D,Subd}iagMessage>` parameter must be passed an arg
// with type `{D,Subd}iagMessage` or `impl Into<{D,Subd}iagMessage>`. Otherwise, emit an
// `UNTRANSLATABLE_DIAGNOSTIC` lint.
let (arg_ty, arg_span) = arg_tys_and_spans[i];
// Is the arg type `{Sub,D}iagMessage`or `impl Into<{Sub,D}iagMessage>`?
let is_translatable = Self::is_diag_message(cx, arg_ty)
|| matches!(arg_ty.kind(), ty::Param(arg_param) if arg_param.name == sig_param.name);
if !is_translatable {
cx.emit_span_lint(
UNTRANSLATABLE_DIAGNOSTIC,
arg_span,
UntranslatableDiag,
);
}
}
}
}
}
}
// Is the callee interesting?
if !has_attr && impl_into_diagnostic_message_params.is_empty() {
fn diagnostic_outside_of_impl<'cx>(
cx: &LateContext<'cx>,
span: Span,
current_id: HirId,
def_id: DefId,
fn_gen_args: GenericArgsRef<'cx>,
) {
// Is the callee marked with `#[rustc_lint_diagnostics]`?
let Some(inst) =
ty::Instance::try_resolve(cx.tcx, cx.param_env, def_id, fn_gen_args).ok().flatten()
else {
return;
}
};
let has_attr = cx.tcx.has_attr(inst.def_id(), sym::rustc_lint_diagnostics);
if !has_attr {
return;
};
// Is the parent method marked with `#[rustc_lint_diagnostics]`?
let mut parent_has_attr = false;
for (hir_id, _parent) in cx.tcx.hir().parent_iter(expr.hir_id) {
for (hir_id, _parent) in cx.tcx.hir().parent_iter(current_id) {
if let Some(owner_did) = hir_id.as_owner()
&& cx.tcx.has_attr(owner_did, sym::rustc_lint_diagnostics)
{
parent_has_attr = true;
break;
// The parent method is marked with `#[rustc_lint_diagnostics]`
return;
}
}
@ -502,37 +531,22 @@ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
// - inside a parent function that is itself marked with `#[rustc_lint_diagnostics]`.
//
// Otherwise, emit a `DIAGNOSTIC_OUTSIDE_OF_IMPL` lint.
if has_attr && !parent_has_attr {
let mut is_inside_appropriate_impl = false;
for (_hir_id, parent) in cx.tcx.hir().parent_iter(expr.hir_id) {
debug!(?parent);
if let Node::Item(Item { kind: ItemKind::Impl(impl_), .. }) = parent
&& let Impl { of_trait: Some(of_trait), .. } = impl_
&& let Some(def_id) = of_trait.trait_def_id()
&& let Some(name) = cx.tcx.get_diagnostic_name(def_id)
&& matches!(name, sym::Diagnostic | sym::Subdiagnostic | sym::LintDiagnostic)
{
is_inside_appropriate_impl = true;
break;
}
}
debug!(?is_inside_appropriate_impl);
if !is_inside_appropriate_impl {
cx.emit_span_lint(DIAGNOSTIC_OUTSIDE_OF_IMPL, span, DiagOutOfImpl);
let mut is_inside_appropriate_impl = false;
for (_hir_id, parent) in cx.tcx.hir().parent_iter(current_id) {
debug!(?parent);
if let Node::Item(Item { kind: ItemKind::Impl(impl_), .. }) = parent
&& let Impl { of_trait: Some(of_trait), .. } = impl_
&& let Some(def_id) = of_trait.trait_def_id()
&& let Some(name) = cx.tcx.get_diagnostic_name(def_id)
&& matches!(name, sym::Diagnostic | sym::Subdiagnostic | sym::LintDiagnostic)
{
is_inside_appropriate_impl = true;
break;
}
}
// Calls to methods with an `impl Into<{D,Subd}iagMessage>` parameter must be passed an arg
// with type `{D,Subd}iagMessage` or `impl Into<{D,Subd}iagMessage>`. Otherwise, emit an
// `UNTRANSLATABLE_DIAGNOSTIC` lint.
for (param_i, param_i_p_name) in impl_into_diagnostic_message_params {
// Is the arg type `{Sub,D}iagMessage`or `impl Into<{Sub,D}iagMessage>`?
let (arg_ty, arg_span) = arg_tys_and_spans[param_i];
let is_translatable = is_diag_message(arg_ty)
|| matches!(arg_ty.kind(), ty::Param(p) if p.name == param_i_p_name);
if !is_translatable {
cx.emit_span_lint(UNTRANSLATABLE_DIAGNOSTIC, arg_span, UntranslatableDiag);
}
debug!(?is_inside_appropriate_impl);
if !is_inside_appropriate_impl {
cx.emit_span_lint(DIAGNOSTIC_OUTSIDE_OF_IMPL, span, DiagOutOfImpl);
}
}
}