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resolve: Introduce a new scope for derive helpers

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This commit is contained in:
Vadim Petrochenkov 2019-10-04 01:53:20 +03:00
parent c064630e77
commit a3126a5013
5 changed files with 81 additions and 16 deletions
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9
src/librustc_resolve/diagnostics.rs
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@ -368,6 +368,15 @@ fn early_lookup_typo_candidate(
let mut suggestions = Vec::new();
self.visit_scopes(scope_set, parent_scope, ident, |this, scope, use_prelude, _| {
match scope {
Scope::DeriveHelpers(expn_id) => {
let res = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper);
if filter_fn(res) {
suggestions.extend(this.helper_attrs.get(&expn_id)
.into_iter().flatten().map(|ident| {
TypoSuggestion::from_res(ident.name, res)
}));
}
}
Scope::DeriveHelpersCompat => {
let res = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper);
if filter_fn(res) {

30
src/librustc_resolve/lib.rs
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@ -45,7 +45,7 @@
use syntax::source_map::Spanned;
use syntax::visit::{self, Visitor};
use syntax_expand::base::SyntaxExtension;
use syntax_pos::hygiene::{MacroKind, ExpnId, Transparency, SyntaxContext};
use syntax_pos::hygiene::{MacroKind, ExpnId, ExpnKind, Transparency, SyntaxContext};
use syntax_pos::{Span, DUMMY_SP};
use errors::{Applicability, DiagnosticBuilder};
@ -97,6 +97,7 @@ fn determined(determined: bool) -> Determinacy {
/// but not for late resolution yet.
#[derive(Clone, Copy)]
enum Scope<'a> {
DeriveHelpers(ExpnId),
DeriveHelpersCompat,
MacroRules(LegacyScope<'a>),
CrateRoot,
@ -942,6 +943,8 @@ pub struct Resolver<'a> {
/// Legacy scopes *produced* by expanding the macro invocations,
/// include all the `macro_rules` items and other invocations generated by them.
output_legacy_scopes: FxHashMap<ExpnId, LegacyScope<'a>>,
/// Helper attributes that are in scope for the given expansion.
helper_attrs: FxHashMap<ExpnId, Vec<Ident>>,
/// Avoid duplicated errors for "name already defined".
name_already_seen: FxHashMap<Name, Span>,
@ -1219,6 +1222,7 @@ pub fn new(session: &'a Session,
non_macro_attrs: [non_macro_attr(false), non_macro_attr(true)],
invocation_parent_scopes,
output_legacy_scopes: Default::default(),
helper_attrs: Default::default(),
macro_defs,
local_macro_def_scopes: FxHashMap::default(),
name_already_seen: FxHashMap::default(),
@ -1467,23 +1471,26 @@ fn visit_scopes<T>(
// in prelude, not sure where exactly (creates ambiguities with any other prelude names).
let rust_2015 = ident.span.rust_2015();
let (ns, is_absolute_path) = match scope_set {
ScopeSet::All(ns, _) => (ns, false),
ScopeSet::AbsolutePath(ns) => (ns, true),
ScopeSet::Macro(_) => (MacroNS, false),
let (ns, macro_kind, is_absolute_path) = match scope_set {
ScopeSet::All(ns, _) => (ns, None, false),
ScopeSet::AbsolutePath(ns) => (ns, None, true),
ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false),
};
// Jump out of trait or enum modules, they do not act as scopes.
let module = parent_scope.module.nearest_item_scope();
let mut scope = match ns {
_ if is_absolute_path => Scope::CrateRoot,
TypeNS | ValueNS => Scope::Module(module),
MacroNS => Scope::DeriveHelpersCompat,
MacroNS => Scope::DeriveHelpers(parent_scope.expansion),
};
let mut ident = ident.modern();
let mut use_prelude = !module.no_implicit_prelude;
loop {
let visit = match scope {
// Derive helpers are not in scope when resolving derives in the same container.
Scope::DeriveHelpers(expn_id) =>
!(expn_id == parent_scope.expansion && macro_kind == Some(MacroKind::Derive)),
Scope::DeriveHelpersCompat => true,
Scope::MacroRules(..) => true,
Scope::CrateRoot => true,
@ -1505,6 +1512,17 @@ fn visit_scopes<T>(
}
scope = match scope {
Scope::DeriveHelpers(expn_id) if expn_id != ExpnId::root() => {
// Derive helpers are not visible to code generated by bang or derive macros.
let expn_data = expn_id.expn_data();
match expn_data.kind {
ExpnKind::Root |
ExpnKind::Macro(MacroKind::Bang, _) |
ExpnKind::Macro(MacroKind::Derive, _) => Scope::DeriveHelpersCompat,
_ => Scope::DeriveHelpers(expn_data.parent),
}
}
Scope::DeriveHelpers(..) => Scope::DeriveHelpersCompat,
Scope::DeriveHelpersCompat =>
Scope::MacroRules(parent_scope.legacy),
Scope::MacroRules(legacy_scope) => match legacy_scope {

22
src/librustc_resolve/macros.rs
View File

@ -237,15 +237,23 @@ fn resolve_macro_invocation(
// - Derives in the container need to know whether one of them is a built-in `Copy`.
// FIXME: Try to avoid repeated resolutions for derives here and in expansion.
let mut exts = Vec::new();
let mut helper_attrs = Vec::new();
for path in derives {
exts.push(match self.resolve_macro_path(
path, Some(MacroKind::Derive), &parent_scope, true, force
) {
Ok((Some(ext), _)) => ext,
Ok((Some(ext), _)) => {
let span = path.segments.last().unwrap().ident.span.modern();
helper_attrs.extend(
ext.helper_attrs.iter().map(|name| Ident::new(*name, span))
);
ext
}
Ok(_) | Err(Determinacy::Determined) => self.dummy_ext(MacroKind::Derive),
Err(Determinacy::Undetermined) => return Err(Indeterminate),
})
}
self.helper_attrs.insert(invoc_id, helper_attrs);
return Ok(InvocationRes::DeriveContainer(exts));
}
};
@ -498,6 +506,18 @@ struct Flags: u8 {
Flags::empty(),
));
let result = match scope {
Scope::DeriveHelpers(expn_id) => {
if let Some(attr) = this.helper_attrs.get(&expn_id).and_then(|attrs| {
attrs.iter().rfind(|i| ident == **i)
}) {
let binding = (Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper),
ty::Visibility::Public, attr.span, expn_id)
.to_name_binding(this.arenas);
Ok((binding, Flags::empty()))
} else {
Err(Determinacy::Determined)
}
}
Scope::DeriveHelpersCompat => {
let mut result = Err(Determinacy::Determined);
for derive in parent_scope.derives {

4
src/test/ui/proc-macro/derive-helper-shadowing.rs
View File

@ -1,3 +1,4 @@
// edition:2018
// aux-build:test-macros.rs
#[macro_use]
@ -11,8 +12,7 @@ struct S {
// FIXME No ambiguity, attributes in non-macro positions are not resolved properly
#[empty_helper]
field: [u8; {
// FIXME No ambiguity, derive helpers are not put into scope for non-attributes
use empty_helper;
use empty_helper; //~ ERROR `empty_helper` is ambiguous
// FIXME No ambiguity, derive helpers are not put into scope for inner items
#[empty_helper]

32
src/test/ui/proc-macro/derive-helper-shadowing.stderr
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@ -1,21 +1,39 @@
error[E0659]: `empty_helper` is ambiguous (derive helper attribute vs any other name)
--> $DIR/derive-helper-shadowing.rs:8:3
error[E0659]: `empty_helper` is ambiguous (name vs any other name during import resolution)
--> $DIR/derive-helper-shadowing.rs:15:13
|
LL | #[empty_helper]
| ^^^^^^^^^^^^ ambiguous name
LL | use empty_helper;
| ^^^^^^^^^^^^ ambiguous name
|
note: `empty_helper` could refer to the derive helper attribute defined here
--> $DIR/derive-helper-shadowing.rs:9:10
--> $DIR/derive-helper-shadowing.rs:10:10
|
LL | #[derive(Empty)]
| ^^^^^
note: `empty_helper` could also refer to the attribute macro imported here
--> $DIR/derive-helper-shadowing.rs:6:5
--> $DIR/derive-helper-shadowing.rs:7:5
|
LL | use test_macros::empty_attr as empty_helper;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= help: use `crate::empty_helper` to refer to this attribute macro unambiguously
error: aborting due to previous error
error[E0659]: `empty_helper` is ambiguous (derive helper attribute vs any other name)
--> $DIR/derive-helper-shadowing.rs:9:3
|
LL | #[empty_helper]
| ^^^^^^^^^^^^ ambiguous name
|
note: `empty_helper` could refer to the derive helper attribute defined here
--> $DIR/derive-helper-shadowing.rs:10:10
|
LL | #[derive(Empty)]
| ^^^^^
note: `empty_helper` could also refer to the attribute macro imported here
--> $DIR/derive-helper-shadowing.rs:7:5
|
LL | use test_macros::empty_attr as empty_helper;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= help: use `crate::empty_helper` to refer to this attribute macro unambiguously
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0659`.