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Use Def::Err to signal that an error has already been reported wher…
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…e possible.
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@jseyfried
jseyfried committed Nov 28, 2016
1 parent 39c267a commit cb9f14e
Showing 1 changed file with 48 additions and 63 deletions.
111 changes: 48 additions & 63 deletions src/librustc_resolve/lib.rs
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Expand Up @@ -584,13 +584,9 @@ impl<'a> Visitor for Resolver<'a> {
self.resolve_type(ty);
}
fn visit_poly_trait_ref(&mut self, tref: &ast::PolyTraitRef, m: &ast::TraitBoundModifier) {
match self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0, None) {
Ok(def) => self.record_def(tref.trait_ref.ref_id, def),
Err(_) => {
// error already reported
self.record_def(tref.trait_ref.ref_id, err_path_resolution())
}
}
let def =
self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0, None);
self.record_def(tref.trait_ref.ref_id, def);
visit::walk_poly_trait_ref(self, tref, m);
}
fn visit_variant(&mut self,
Expand Down Expand Up @@ -1205,8 +1201,7 @@ impl<'a> hir::lowering::Resolver for Resolver<'a> {
let namespace = if is_value { ValueNS } else { TypeNS };
match self.resolve_crate_relative_path(path.span, &path.segments, namespace) {
Ok(binding) => path.def = binding.def(),
Err(true) => {}
Err(false) => {
None => {
let path_name = &format!("{}", path);
let error =
ResolutionError::UnresolvedName {
Expand Down Expand Up @@ -1844,12 +1839,11 @@ impl<'a> Resolver<'a> {
match self.resolve_crate_relative_path(prefix.span,
&prefix.segments,
TypeNS) {
Ok(binding) => {
Some(binding) => {
let def = binding.def();
self.record_def(item.id, PathResolution::new(def));
}
Err(true) => self.record_def(item.id, err_path_resolution()),
Err(false) => {
None => {
resolve_error(self,
prefix.span,
ResolutionError::FailedToResolve(
Expand Down Expand Up @@ -1935,14 +1929,14 @@ impl<'a> Resolver<'a> {
trait_path: &Path,
path_depth: usize,
generics: Option<&Generics>)
-> Result<PathResolution, ()> {
self.resolve_path(id, trait_path, path_depth, TypeNS).and_then(|path_res| {
-> PathResolution {
if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS) {
match path_res.base_def {
Def::Trait(_) => {
debug!("(resolving trait) found trait def: {:?}", path_res);
return Ok(path_res);
return path_res;
}
Def::Err => return Err(true),
Def::Err => return err_path_resolution(),
_ => {}
}

Expand All @@ -1963,10 +1957,7 @@ impl<'a> Resolver<'a> {
err.note(&format!("type aliases cannot be used for traits"));
}
err.emit();
Err(true)
}).map_err(|error_reported| {
if error_reported { return }

} else {
// find possible candidates
let trait_name = trait_path.segments.last().unwrap().identifier.name;
let candidates =
Expand All @@ -1988,7 +1979,8 @@ impl<'a> Resolver<'a> {
);

resolve_error(self, trait_path.span, error);
})
}
err_path_resolution()
}

fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
Expand All @@ -2011,16 +2003,13 @@ impl<'a> Resolver<'a> {
let mut new_val = None;
let mut new_id = None;
if let Some(trait_ref) = opt_trait_ref {
if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
&trait_ref.path,
0,
generics) {
assert!(path_res.depth == 0);
self.record_def(trait_ref.ref_id, path_res);
let path_res =
self.resolve_trait_reference(trait_ref.ref_id, &trait_ref.path, 0, generics);
assert!(path_res.depth == 0);
self.record_def(trait_ref.ref_id, path_res);
if path_res.base_def != Def::Err {
new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
new_id = Some(path_res.base_def.def_id());
} else {
self.record_def(trait_ref.ref_id, err_path_resolution());
}
visit::walk_trait_ref(self, trait_ref);
}
Expand Down Expand Up @@ -2276,9 +2265,8 @@ impl<'a> Resolver<'a> {
self.record_def(ty.id, err_path_resolution());

// Keep reporting some errors even if they're ignored above.
if let Err(true) = self.resolve_path(ty.id, path, 0, TypeNS) {
// `resolve_path` already reported the error
} else {
let result = self.resolve_path(ty.id, path, 0, TypeNS);
if result.map(|resolution| resolution.base_def) != Some(Def::Err) {
let kind = if maybe_qself.is_some() {
"associated type"
} else {
Expand Down Expand Up @@ -2420,7 +2408,7 @@ impl<'a> Resolver<'a> {
resolution
}
} else {
if let Err(false) = self.resolve_path(pat_id, path, 0, namespace) {
if self.resolve_path(pat_id, path, 0, namespace).is_none() {
resolve_error(
self,
path.span,
Expand Down Expand Up @@ -2553,26 +2541,28 @@ impl<'a> Resolver<'a> {
}
max_assoc_types = path.segments.len() - qself.position;
// Make sure the trait is valid.
let _ = self.resolve_trait_reference(id, path, max_assoc_types, None);
self.resolve_trait_reference(id, path, max_assoc_types, None);
}
None => {
max_assoc_types = path.segments.len();
}
}

let mut resolution = self.with_no_errors(|this| {
this.resolve_path(id, path, 0, namespace).ok()
this.resolve_path(id, path, 0, namespace)
});
if resolution.map(|res| res.base_def) == Some(Def::Err) { resolution = None; }
for depth in 1..max_assoc_types {
if resolution.is_some() {
break;
}
self.with_no_errors(|this| {
let partial_resolution = this.resolve_path(id, path, depth, TypeNS).ok();
let partial_resolution = this.resolve_path(id, path, depth, TypeNS);
if let Some(Def::Mod(..)) = partial_resolution.map(|r| r.base_def) {
// Modules cannot have associated items
} else {
resolution = partial_resolution;
if resolution.map(|res| res.base_def) == Some(Def::Err) { resolution = None; }
}
});
}
Expand All @@ -2582,7 +2572,7 @@ impl<'a> Resolver<'a> {
/// Skips `path_depth` trailing segments, which is also reflected in the
/// returned value. See `hir::def::PathResolution` for more info.
fn resolve_path(&mut self, id: NodeId, path: &Path, path_depth: usize, namespace: Namespace)
-> Result<PathResolution, bool /* true if an error was reported */ > {
-> Option<PathResolution> {
debug!("resolve_path(id={:?} path={:?}, path_depth={:?})", id, path, path_depth);

let span = path.span;
Expand Down Expand Up @@ -2623,15 +2613,15 @@ impl<'a> Resolver<'a> {
//
// Such behavior is required for backward compatibility.
// The same fallback is used when `a` resolves to nothing.
let def = resolve_identifier_with_fallback(self, Some(span)).ok_or(false);
return def.and_then(|def| self.adjust_local_def(def, span).ok_or(true)).map(mk_res);
let def = resolve_identifier_with_fallback(self, Some(span));
return def.map(|def| mk_res(self.adjust_local_def(def, span)));
}

let unqualified_def = resolve_identifier_with_fallback(self, None);
let qualified_binding = self.resolve_module_relative_path(span, segments, namespace);
match (qualified_binding, unqualified_def) {
(Ok(binding), Some(ref ud)) if binding.def() == ud.def &&
segments[0].identifier.name != "$crate" => {
(Some(binding), Some(ref ud)) if binding.def() == ud.def &&
segments[0].identifier.name != "$crate" => {
self.session
.add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
id,
Expand Down Expand Up @@ -2659,7 +2649,7 @@ impl<'a> Resolver<'a> {
}

// Resolve a local definition, potentially adjusting for closures.
fn adjust_local_def(&mut self, local_def: LocalDef, span: Span) -> Option<Def> {
fn adjust_local_def(&mut self, local_def: LocalDef, span: Span) -> Def {
let ribs = match local_def.ribs {
Some((ns, i)) => &self.ribs[ns][i + 1..],
None => &[] as &[_],
Expand Down Expand Up @@ -2705,14 +2695,14 @@ impl<'a> Resolver<'a> {
resolve_error(self,
span,
ResolutionError::CannotCaptureDynamicEnvironmentInFnItem);
return None;
return Def::Err;
}
ConstantItemRibKind => {
// Still doesn't deal with upvars
resolve_error(self,
span,
ResolutionError::AttemptToUseNonConstantValueInConstant);
return None;
return Def::Err;
}
}
}
Expand All @@ -2731,28 +2721,27 @@ impl<'a> Resolver<'a> {
resolve_error(self,
span,
ResolutionError::TypeParametersFromOuterFunction);
return None;
return Def::Err;
}
ConstantItemRibKind => {
// see #9186
resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
return None;
return Def::Err;
}
}
}
}
_ => {}
}
return Some(def);
return def;
}

// resolve a "module-relative" path, e.g. a::b::c
fn resolve_module_relative_path(&mut self,
span: Span,
segments: &[ast::PathSegment],
namespace: Namespace)
-> Result<&'a NameBinding<'a>,
bool /* true if an error was reported */> {
-> Option<&'a NameBinding<'a>> {
let module_path =
segments.split_last().unwrap().1.iter().map(|ps| ps.identifier).collect::<Vec<_>>();

Expand All @@ -2761,22 +2750,20 @@ impl<'a> Resolver<'a> {
if let Some((span, msg)) = err {
resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
}
return Err(true);
return Some(self.dummy_binding);
}
Indeterminate => return Err(false),
Indeterminate => return None,
Success(module) => module,
};

let name = segments.last().unwrap().identifier.name;
let result = self.resolve_name_in_module(module, name, namespace, false, Some(span));
result.success().ok_or(false)
self.resolve_name_in_module(module, name, namespace, false, Some(span)).success()
}

/// Invariant: This must be called only during main resolution, not during
/// import resolution.
fn resolve_crate_relative_path<T>(&mut self, span: Span, segments: &[T], namespace: Namespace)
-> Result<&'a NameBinding<'a>,
bool /* true if an error was reported */>
-> Option<&'a NameBinding<'a>>
where T: Named,
{
let module_path = segments.split_last().unwrap().1.iter().map(T::ident).collect::<Vec<_>>();
Expand All @@ -2787,17 +2774,16 @@ impl<'a> Resolver<'a> {
if let Some((span, msg)) = err {
resolve_error(self, span, ResolutionError::FailedToResolve(&msg));
}
return Err(true);
return Some(self.dummy_binding);
}

Indeterminate => return Err(false),
Indeterminate => return None,

Success(module) => module,
};

let name = segments.last().unwrap().ident().name;
let result = self.resolve_name_in_module(module, name, namespace, false, Some(span));
result.success().ok_or(false)
self.resolve_name_in_module(module, name, namespace, false, Some(span)).success()
}

fn with_no_errors<T, F>(&mut self, f: F) -> T
Expand Down Expand Up @@ -2963,7 +2949,7 @@ impl<'a> Resolver<'a> {

self.record_def(expr.id, err_path_resolution());

if let Ok(Def::Struct(..)) = type_res.map(|r| r.base_def) {
if let Some(Def::Struct(..)) = type_res.map(|r| r.base_def) {
let error_variant =
ResolutionError::StructVariantUsedAsFunction(&path_name);
let mut err = resolve_struct_error(self, expr.span, error_variant);
Expand All @@ -2979,9 +2965,8 @@ impl<'a> Resolver<'a> {
err.emit();
} else {
// Keep reporting some errors even if they're ignored above.
if let Err(true) = self.resolve_path(expr.id, path, 0, ValueNS) {
// `resolve_path` already reported the error
} else {
let result = self.resolve_path(expr.id, path, 0, ValueNS);
if result.map(|resolution| resolution.base_def) != Some(Def::Err) {
let mut method_scope = false;
let mut is_static = false;
self.ribs[ValueNS].iter().rev().all(|rib| {
Expand Down

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