Rollup merge of #57730 - Zoxc:combined-ast-validator, r=cramertj
Merge visitors in AST validation Cuts runtime for AST validation on `syntex_syntax` from 31.5 ms to 17 ms.
This commit is contained in:
Mazdak Farrokhzad
GitHub
commit
b0ec43f569
|
|
@ -6,6 +6,7 @@
|
|||
// This pass is supposed to perform only simple checks not requiring name resolution
|
||||
// or type checking or some other kind of complex analysis.
|
||||
|
||||
use std::mem;
|
||||
use rustc::lint;
|
||||
use rustc::session::Session;
|
||||
use syntax::ast::*;
|
||||
|
|
@ -20,9 +21,73 @@ use errors::Applicability;
|
|||
|
||||
struct AstValidator<'a> {
|
||||
session: &'a Session,
|
||||
|
||||
// Used to ban nested `impl Trait`, e.g., `impl Into<impl Debug>`.
|
||||
// Nested `impl Trait` _is_ allowed in associated type position,
|
||||
// e.g `impl Iterator<Item=impl Debug>`
|
||||
outer_impl_trait: Option<Span>,
|
||||
|
||||
// Used to ban `impl Trait` in path projections like `<impl Iterator>::Item`
|
||||
// or `Foo::Bar<impl Trait>`
|
||||
is_impl_trait_banned: bool,
|
||||
}
|
||||
|
||||
impl<'a> AstValidator<'a> {
|
||||
fn with_banned_impl_trait(&mut self, f: impl FnOnce(&mut Self)) {
|
||||
let old = mem::replace(&mut self.is_impl_trait_banned, true);
|
||||
f(self);
|
||||
self.is_impl_trait_banned = old;
|
||||
}
|
||||
|
||||
fn with_impl_trait(&mut self, outer_impl_trait: Option<Span>, f: impl FnOnce(&mut Self)) {
|
||||
let old = mem::replace(&mut self.outer_impl_trait, outer_impl_trait);
|
||||
f(self);
|
||||
self.outer_impl_trait = old;
|
||||
}
|
||||
|
||||
// Mirrors visit::walk_ty, but tracks relevant state
|
||||
fn walk_ty(&mut self, t: &'a Ty) {
|
||||
match t.node {
|
||||
TyKind::ImplTrait(..) => {
|
||||
self.with_impl_trait(Some(t.span), |this| visit::walk_ty(this, t))
|
||||
}
|
||||
TyKind::Path(ref qself, ref path) => {
|
||||
// We allow these:
|
||||
// - `Option<impl Trait>`
|
||||
// - `option::Option<impl Trait>`
|
||||
// - `option::Option<T>::Foo<impl Trait>
|
||||
//
|
||||
// But not these:
|
||||
// - `<impl Trait>::Foo`
|
||||
// - `option::Option<impl Trait>::Foo`.
|
||||
//
|
||||
// To implement this, we disallow `impl Trait` from `qself`
|
||||
// (for cases like `<impl Trait>::Foo>`)
|
||||
// but we allow `impl Trait` in `GenericArgs`
|
||||
// iff there are no more PathSegments.
|
||||
if let Some(ref qself) = *qself {
|
||||
// `impl Trait` in `qself` is always illegal
|
||||
self.with_banned_impl_trait(|this| this.visit_ty(&qself.ty));
|
||||
}
|
||||
|
||||
// Note that there should be a call to visit_path here,
|
||||
// so if any logic is added to process `Path`s a call to it should be
|
||||
// added both in visit_path and here. This code mirrors visit::walk_path.
|
||||
for (i, segment) in path.segments.iter().enumerate() {
|
||||
// Allow `impl Trait` iff we're on the final path segment
|
||||
if i == path.segments.len() - 1 {
|
||||
self.visit_path_segment(path.span, segment);
|
||||
} else {
|
||||
self.with_banned_impl_trait(|this| {
|
||||
this.visit_path_segment(path.span, segment)
|
||||
});
|
||||
}
|
||||
}
|
||||
}
|
||||
_ => visit::walk_ty(self, t),
|
||||
}
|
||||
}
|
||||
|
||||
fn err_handler(&self) -> &errors::Handler {
|
||||
&self.session.diagnostic()
|
||||
}
|
||||
|
|
@ -267,6 +332,19 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
|
|||
self.no_questions_in_bounds(bounds, "trait object types", false);
|
||||
}
|
||||
TyKind::ImplTrait(_, ref bounds) => {
|
||||
if self.is_impl_trait_banned {
|
||||
struct_span_err!(self.session, ty.span, E0667,
|
||||
"`impl Trait` is not allowed in path parameters").emit();
|
||||
}
|
||||
|
||||
if let Some(outer_impl_trait) = self.outer_impl_trait {
|
||||
struct_span_err!(self.session, ty.span, E0666,
|
||||
"nested `impl Trait` is not allowed")
|
||||
.span_label(outer_impl_trait, "outer `impl Trait`")
|
||||
.span_label(ty.span, "nested `impl Trait` here")
|
||||
.emit();
|
||||
|
||||
}
|
||||
if !bounds.iter()
|
||||
.any(|b| if let GenericBound::Trait(..) = *b { true } else { false }) {
|
||||
self.err_handler().span_err(ty.span, "at least one trait must be specified");
|
||||
|
|
@ -275,7 +353,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
|
|||
_ => {}
|
||||
}
|
||||
|
||||
visit::walk_ty(self, ty)
|
||||
self.walk_ty(ty)
|
||||
}
|
||||
|
||||
fn visit_label(&mut self, label: &'a Label) {
|
||||
|
|
@ -414,6 +492,28 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
|
|||
visit::walk_foreign_item(self, fi)
|
||||
}
|
||||
|
||||
// Mirrors visit::walk_generic_args, but tracks relevant state
|
||||
fn visit_generic_args(&mut self, _: Span, generic_args: &'a GenericArgs) {
|
||||
match *generic_args {
|
||||
GenericArgs::AngleBracketed(ref data) => {
|
||||
walk_list!(self, visit_generic_arg, &data.args);
|
||||
// Type bindings such as `Item=impl Debug` in `Iterator<Item=Debug>`
|
||||
// are allowed to contain nested `impl Trait`.
|
||||
self.with_impl_trait(None, |this| {
|
||||
walk_list!(this, visit_assoc_type_binding, &data.bindings);
|
||||
});
|
||||
}
|
||||
GenericArgs::Parenthesized(ref data) => {
|
||||
walk_list!(self, visit_ty, &data.inputs);
|
||||
if let Some(ref type_) = data.output {
|
||||
// `-> Foo` syntax is essentially an associated type binding,
|
||||
// so it is also allowed to contain nested `impl Trait`.
|
||||
self.with_impl_trait(None, |this| visit::walk_ty(this, type_));
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn visit_generics(&mut self, generics: &'a Generics) {
|
||||
let mut seen_non_lifetime_param = false;
|
||||
let mut seen_default = None;
|
||||
|
|
@ -490,148 +590,10 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
|
|||
}
|
||||
}
|
||||
|
||||
// Bans nested `impl Trait`, e.g., `impl Into<impl Debug>`.
|
||||
// Nested `impl Trait` _is_ allowed in associated type position,
|
||||
// e.g `impl Iterator<Item=impl Debug>`
|
||||
struct NestedImplTraitVisitor<'a> {
|
||||
session: &'a Session,
|
||||
outer_impl_trait: Option<Span>,
|
||||
}
|
||||
|
||||
impl<'a> NestedImplTraitVisitor<'a> {
|
||||
fn with_impl_trait<F>(&mut self, outer_impl_trait: Option<Span>, f: F)
|
||||
where F: FnOnce(&mut NestedImplTraitVisitor<'a>)
|
||||
{
|
||||
let old_outer_impl_trait = self.outer_impl_trait;
|
||||
self.outer_impl_trait = outer_impl_trait;
|
||||
f(self);
|
||||
self.outer_impl_trait = old_outer_impl_trait;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
impl<'a> Visitor<'a> for NestedImplTraitVisitor<'a> {
|
||||
fn visit_ty(&mut self, t: &'a Ty) {
|
||||
if let TyKind::ImplTrait(..) = t.node {
|
||||
if let Some(outer_impl_trait) = self.outer_impl_trait {
|
||||
struct_span_err!(self.session, t.span, E0666,
|
||||
"nested `impl Trait` is not allowed")
|
||||
.span_label(outer_impl_trait, "outer `impl Trait`")
|
||||
.span_label(t.span, "nested `impl Trait` here")
|
||||
.emit();
|
||||
|
||||
}
|
||||
self.with_impl_trait(Some(t.span), |this| visit::walk_ty(this, t));
|
||||
} else {
|
||||
visit::walk_ty(self, t);
|
||||
}
|
||||
}
|
||||
fn visit_generic_args(&mut self, _: Span, generic_args: &'a GenericArgs) {
|
||||
match *generic_args {
|
||||
GenericArgs::AngleBracketed(ref data) => {
|
||||
for arg in &data.args {
|
||||
self.visit_generic_arg(arg)
|
||||
}
|
||||
for type_binding in &data.bindings {
|
||||
// Type bindings such as `Item=impl Debug` in `Iterator<Item=Debug>`
|
||||
// are allowed to contain nested `impl Trait`.
|
||||
self.with_impl_trait(None, |this| visit::walk_ty(this, &type_binding.ty));
|
||||
}
|
||||
}
|
||||
GenericArgs::Parenthesized(ref data) => {
|
||||
for type_ in &data.inputs {
|
||||
self.visit_ty(type_);
|
||||
}
|
||||
if let Some(ref type_) = data.output {
|
||||
// `-> Foo` syntax is essentially an associated type binding,
|
||||
// so it is also allowed to contain nested `impl Trait`.
|
||||
self.with_impl_trait(None, |this| visit::walk_ty(this, type_));
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn visit_mac(&mut self, _mac: &Spanned<Mac_>) {
|
||||
// covered in AstValidator
|
||||
}
|
||||
}
|
||||
|
||||
// Bans `impl Trait` in path projections like `<impl Iterator>::Item` or `Foo::Bar<impl Trait>`.
|
||||
struct ImplTraitProjectionVisitor<'a> {
|
||||
session: &'a Session,
|
||||
is_banned: bool,
|
||||
}
|
||||
|
||||
impl<'a> ImplTraitProjectionVisitor<'a> {
|
||||
fn with_ban<F>(&mut self, f: F)
|
||||
where F: FnOnce(&mut ImplTraitProjectionVisitor<'a>)
|
||||
{
|
||||
let old_is_banned = self.is_banned;
|
||||
self.is_banned = true;
|
||||
f(self);
|
||||
self.is_banned = old_is_banned;
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a> Visitor<'a> for ImplTraitProjectionVisitor<'a> {
|
||||
fn visit_ty(&mut self, t: &'a Ty) {
|
||||
match t.node {
|
||||
TyKind::ImplTrait(..) => {
|
||||
if self.is_banned {
|
||||
struct_span_err!(self.session, t.span, E0667,
|
||||
"`impl Trait` is not allowed in path parameters").emit();
|
||||
}
|
||||
}
|
||||
TyKind::Path(ref qself, ref path) => {
|
||||
// We allow these:
|
||||
// - `Option<impl Trait>`
|
||||
// - `option::Option<impl Trait>`
|
||||
// - `option::Option<T>::Foo<impl Trait>
|
||||
//
|
||||
// But not these:
|
||||
// - `<impl Trait>::Foo`
|
||||
// - `option::Option<impl Trait>::Foo`.
|
||||
//
|
||||
// To implement this, we disallow `impl Trait` from `qself`
|
||||
// (for cases like `<impl Trait>::Foo>`)
|
||||
// but we allow `impl Trait` in `GenericArgs`
|
||||
// iff there are no more PathSegments.
|
||||
if let Some(ref qself) = *qself {
|
||||
// `impl Trait` in `qself` is always illegal
|
||||
self.with_ban(|this| this.visit_ty(&qself.ty));
|
||||
}
|
||||
|
||||
for (i, segment) in path.segments.iter().enumerate() {
|
||||
// Allow `impl Trait` iff we're on the final path segment
|
||||
if i == path.segments.len() - 1 {
|
||||
visit::walk_path_segment(self, path.span, segment);
|
||||
} else {
|
||||
self.with_ban(|this|
|
||||
visit::walk_path_segment(this, path.span, segment));
|
||||
}
|
||||
}
|
||||
}
|
||||
_ => visit::walk_ty(self, t),
|
||||
}
|
||||
}
|
||||
|
||||
fn visit_mac(&mut self, _mac: &Spanned<Mac_>) {
|
||||
// covered in AstValidator
|
||||
}
|
||||
}
|
||||
|
||||
pub fn check_crate(session: &Session, krate: &Crate) {
|
||||
visit::walk_crate(
|
||||
&mut NestedImplTraitVisitor {
|
||||
session,
|
||||
outer_impl_trait: None,
|
||||
}, krate);
|
||||
|
||||
visit::walk_crate(
|
||||
&mut ImplTraitProjectionVisitor {
|
||||
session,
|
||||
is_banned: false,
|
||||
}, krate);
|
||||
|
||||
visit::walk_crate(&mut AstValidator { session }, krate)
|
||||
visit::walk_crate(&mut AstValidator {
|
||||
session,
|
||||
outer_impl_trait: None,
|
||||
is_impl_trait_banned: false,
|
||||
}, krate)
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue