Rollup merge of #96370 - compiler-errors:cleanup-report_method_error, r=estebank

Cleanup `report_method_error` a bit

1. Remove an unnecessary indentation level
2. Split out a couple of large functions from this humongo function body
This commit is contained in:
Dylan DPC 2022-04-27 02:47:07 +02:00 committed by GitHub
commit e63da0ba00
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@ -272,207 +272,84 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
(None, true) => "variant",
}
};
// FIXME(eddyb) this indentation is probably unnecessary.
let mut err = {
// Suggest clamping down the type if the method that is being attempted to
// be used exists at all, and the type is an ambiguous numeric type
// ({integer}/{float}).
let mut candidates = all_traits(self.tcx)
.into_iter()
.filter_map(|info| self.associated_value(info.def_id, item_name));
// There are methods that are defined on the primitive types and won't be
// found when exploring `all_traits`, but we also need them to be accurate on
// our suggestions (#47759).
let found_assoc = |ty: Ty<'tcx>| {
simplify_type(tcx, ty, TreatParams::AsPlaceholders)
.and_then(|simp| {
tcx.incoherent_impls(simp)
if self.suggest_constraining_numerical_ty(
tcx, actual, source, span, item_kind, item_name, &ty_str,
) {
return None;
}
span = item_name.span;
// Don't show generic arguments when the method can't be found in any implementation (#81576).
let mut ty_str_reported = ty_str.clone();
if let ty::Adt(_, generics) = actual.kind() {
if generics.len() > 0 {
let mut autoderef = self.autoderef(span, actual);
let candidate_found = autoderef.any(|(ty, _)| {
if let ty::Adt(adt_deref, _) = ty.kind() {
self.tcx
.inherent_impls(adt_deref.did())
.iter()
.find_map(|&id| self.associated_value(id, item_name))
})
.is_some()
};
let found_candidate = candidates.next().is_some()
|| found_assoc(tcx.types.i8)
|| found_assoc(tcx.types.i16)
|| found_assoc(tcx.types.i32)
|| found_assoc(tcx.types.i64)
|| found_assoc(tcx.types.i128)
|| found_assoc(tcx.types.u8)
|| found_assoc(tcx.types.u16)
|| found_assoc(tcx.types.u32)
|| found_assoc(tcx.types.u64)
|| found_assoc(tcx.types.u128)
|| found_assoc(tcx.types.f32)
|| found_assoc(tcx.types.f32);
if let (true, false, SelfSource::MethodCall(expr), true) = (
actual.is_numeric(),
actual.has_concrete_skeleton(),
source,
found_candidate,
) {
let mut err = struct_span_err!(
tcx.sess,
span,
E0689,
"can't call {} `{}` on ambiguous numeric type `{}`",
item_kind,
item_name,
ty_str
);
let concrete_type = if actual.is_integral() { "i32" } else { "f32" };
match expr.kind {
ExprKind::Lit(ref lit) => {
// numeric literal
let snippet = tcx
.sess
.source_map()
.span_to_snippet(lit.span)
.unwrap_or_else(|_| "<numeric literal>".to_owned());
// If this is a floating point literal that ends with '.',
// get rid of it to stop this from becoming a member access.
let snippet = snippet.strip_suffix('.').unwrap_or(&snippet);
err.span_suggestion(
lit.span,
&format!(
"you must specify a concrete type for this numeric value, \
like `{}`",
concrete_type
),
format!("{snippet}_{concrete_type}"),
Applicability::MaybeIncorrect,
);
.filter_map(|def_id| self.associated_value(*def_id, item_name))
.count()
>= 1
} else {
false
}
ExprKind::Path(QPath::Resolved(_, path)) => {
// local binding
if let hir::def::Res::Local(hir_id) = path.res {
let span = tcx.hir().span(hir_id);
let snippet = tcx.sess.source_map().span_to_snippet(span);
let filename = tcx.sess.source_map().span_to_filename(span);
let parent_node =
self.tcx.hir().get(self.tcx.hir().get_parent_node(hir_id));
let msg = format!(
"you must specify a type for this binding, like `{}`",
concrete_type,
);
match (filename, parent_node, snippet) {
(
FileName::Real(_),
Node::Local(hir::Local {
source: hir::LocalSource::Normal,
ty,
..
}),
Ok(ref snippet),
) => {
err.span_suggestion(
// account for `let x: _ = 42;`
// ^^^^
span.to(ty
.as_ref()
.map(|ty| ty.span)
.unwrap_or(span)),
&msg,
format!("{}: {}", snippet, concrete_type),
Applicability::MaybeIncorrect,
);
}
_ => {
err.span_label(span, msg);
}
}
}
}
_ => {}
}
err.emit();
return None;
} else {
span = item_name.span;
// Don't show generic arguments when the method can't be found in any implementation (#81576).
let mut ty_str_reported = ty_str.clone();
if let ty::Adt(_, generics) = actual.kind() {
if generics.len() > 0 {
let mut autoderef = self.autoderef(span, actual);
let candidate_found = autoderef.any(|(ty, _)| {
if let ty::Adt(adt_deref, _) = ty.kind() {
self.tcx
.inherent_impls(adt_deref.did())
.iter()
.filter_map(|def_id| {
self.associated_value(*def_id, item_name)
})
.count()
>= 1
} else {
false
}
});
let has_deref = autoderef.step_count() > 0;
if !candidate_found
&& !has_deref
&& unsatisfied_predicates.is_empty()
{
if let Some((path_string, _)) = ty_str.split_once('<') {
ty_str_reported = path_string.to_string();
}
}
});
let has_deref = autoderef.step_count() > 0;
if !candidate_found && !has_deref && unsatisfied_predicates.is_empty() {
if let Some((path_string, _)) = ty_str.split_once('<') {
ty_str_reported = path_string.to_string();
}
}
let mut err = struct_span_err!(
tcx.sess,
span,
E0599,
"no {} named `{}` found for {} `{}` in the current scope",
item_kind,
item_name,
actual.prefix_string(self.tcx),
ty_str_reported,
);
if let Mode::MethodCall = mode && let SelfSource::MethodCall(cal) = source {
self.suggest_await_before_method(
&mut err, item_name, actual, cal, span,
);
}
if let Some(span) =
tcx.resolutions(()).confused_type_with_std_module.get(&span)
{
if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(*span) {
err.span_suggestion(
*span,
"you are looking for the module in `std`, \
not the primitive type",
format!("std::{}", snippet),
Applicability::MachineApplicable,
);
}
}
if let ty::RawPtr(_) = &actual.kind() {
err.note(
"try using `<*const T>::as_ref()` to get a reference to the \
type behind the pointer: https://doc.rust-lang.org/std/\
primitive.pointer.html#method.as_ref",
);
err.note(
"using `<*const T>::as_ref()` on a pointer \
which is unaligned or points to invalid \
or uninitialized memory is undefined behavior",
);
}
err
}
};
}
let mut err = struct_span_err!(
tcx.sess,
span,
E0599,
"no {} named `{}` found for {} `{}` in the current scope",
item_kind,
item_name,
actual.prefix_string(self.tcx),
ty_str_reported,
);
if actual.references_error() {
err.downgrade_to_delayed_bug();
}
if let Mode::MethodCall = mode && let SelfSource::MethodCall(cal) = source {
self.suggest_await_before_method(
&mut err, item_name, actual, cal, span,
);
}
if let Some(span) = tcx.resolutions(()).confused_type_with_std_module.get(&span) {
if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(*span) {
err.span_suggestion(
*span,
"you are looking for the module in `std`, \
not the primitive type",
format!("std::{}", snippet),
Applicability::MachineApplicable,
);
}
}
if let ty::RawPtr(_) = &actual.kind() {
err.note(
"try using `<*const T>::as_ref()` to get a reference to the \
type behind the pointer: https://doc.rust-lang.org/std/\
primitive.pointer.html#method.as_ref",
);
err.note(
"using `<*const T>::as_ref()` on a pointer \
which is unaligned or points to invalid \
or uninitialized memory is undefined behavior",
);
}
if let Some(def) = actual.ty_adt_def() {
if let Some(full_sp) = tcx.hir().span_if_local(def.did()) {
let def_sp = tcx.sess.source_map().guess_head_span(full_sp);
@ -999,7 +876,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}
}
let mut label_span_not_found = || {
let label_span_not_found = |err: &mut DiagnosticBuilder<'_, _>| {
if unsatisfied_predicates.is_empty() {
err.span_label(span, format!("{item_kind} not found in `{ty_str}`"));
let is_string_or_ref_str = match actual.kind() {
@ -1085,62 +962,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// If the method name is the name of a field with a function or closure type,
// give a helping note that it has to be called as `(x.f)(...)`.
if let SelfSource::MethodCall(expr) = source {
let field_receiver =
self.autoderef(span, rcvr_ty).find_map(|(ty, _)| match ty.kind() {
ty::Adt(def, substs) if !def.is_enum() => {
let variant = &def.non_enum_variant();
self.tcx.find_field_index(item_name, variant).map(|index| {
let field = &variant.fields[index];
let field_ty = field.ty(tcx, substs);
(field, field_ty)
})
}
_ => None,
});
if let Some((field, field_ty)) = field_receiver {
let scope = self.tcx.parent_module(self.body_id).to_def_id();
let is_accessible = field.vis.is_accessible_from(scope, self.tcx);
if is_accessible {
if self.is_fn_ty(field_ty, span) {
let expr_span = expr.span.to(item_name.span);
err.multipart_suggestion(
&format!(
"to call the function stored in `{}`, \
surround the field access with parentheses",
item_name,
),
vec![
(expr_span.shrink_to_lo(), '('.to_string()),
(expr_span.shrink_to_hi(), ')'.to_string()),
],
Applicability::MachineApplicable,
);
} else {
let call_expr = self
.tcx
.hir()
.expect_expr(self.tcx.hir().get_parent_node(expr.hir_id));
if let Some(span) = call_expr.span.trim_start(item_name.span) {
err.span_suggestion(
span,
"remove the arguments",
String::new(),
Applicability::MaybeIncorrect,
);
}
}
}
let field_kind = if is_accessible { "field" } else { "private field" };
err.span_label(item_name.span, format!("{}, not a method", field_kind));
} else if lev_candidate.is_none() && !custom_span_label {
label_span_not_found();
if !self.suggest_field_call(span, rcvr_ty, expr, item_name, &mut err)
&& lev_candidate.is_none()
&& !custom_span_label
{
label_span_not_found(&mut err);
}
} else if !custom_span_label {
label_span_not_found();
label_span_not_found(&mut err);
}
if let SelfSource::MethodCall(expr) = source
@ -1327,6 +1156,187 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
None
}
fn suggest_field_call(
&self,
span: Span,
rcvr_ty: Ty<'tcx>,
expr: &hir::Expr<'_>,
item_name: Ident,
err: &mut DiagnosticBuilder<'tcx, ErrorGuaranteed>,
) -> bool {
let tcx = self.tcx;
let field_receiver = self.autoderef(span, rcvr_ty).find_map(|(ty, _)| match ty.kind() {
ty::Adt(def, substs) if !def.is_enum() => {
let variant = &def.non_enum_variant();
tcx.find_field_index(item_name, variant).map(|index| {
let field = &variant.fields[index];
let field_ty = field.ty(tcx, substs);
(field, field_ty)
})
}
_ => None,
});
if let Some((field, field_ty)) = field_receiver {
let scope = tcx.parent_module(self.body_id).to_def_id();
let is_accessible = field.vis.is_accessible_from(scope, tcx);
if is_accessible {
if self.is_fn_ty(field_ty, span) {
let expr_span = expr.span.to(item_name.span);
err.multipart_suggestion(
&format!(
"to call the function stored in `{}`, \
surround the field access with parentheses",
item_name,
),
vec![
(expr_span.shrink_to_lo(), '('.to_string()),
(expr_span.shrink_to_hi(), ')'.to_string()),
],
Applicability::MachineApplicable,
);
} else {
let call_expr = tcx.hir().expect_expr(tcx.hir().get_parent_node(expr.hir_id));
if let Some(span) = call_expr.span.trim_start(item_name.span) {
err.span_suggestion(
span,
"remove the arguments",
String::new(),
Applicability::MaybeIncorrect,
);
}
}
}
let field_kind = if is_accessible { "field" } else { "private field" };
err.span_label(item_name.span, format!("{}, not a method", field_kind));
return true;
}
false
}
fn suggest_constraining_numerical_ty(
&self,
tcx: TyCtxt<'tcx>,
actual: Ty<'tcx>,
source: SelfSource<'_>,
span: Span,
item_kind: &str,
item_name: Ident,
ty_str: &str,
) -> bool {
let found_candidate = all_traits(self.tcx)
.into_iter()
.any(|info| self.associated_value(info.def_id, item_name).is_some());
let found_assoc = |ty: Ty<'tcx>| {
simplify_type(tcx, ty, TreatParams::AsPlaceholders)
.and_then(|simp| {
tcx.incoherent_impls(simp)
.iter()
.find_map(|&id| self.associated_value(id, item_name))
})
.is_some()
};
let found_candidate = found_candidate
|| found_assoc(tcx.types.i8)
|| found_assoc(tcx.types.i16)
|| found_assoc(tcx.types.i32)
|| found_assoc(tcx.types.i64)
|| found_assoc(tcx.types.i128)
|| found_assoc(tcx.types.u8)
|| found_assoc(tcx.types.u16)
|| found_assoc(tcx.types.u32)
|| found_assoc(tcx.types.u64)
|| found_assoc(tcx.types.u128)
|| found_assoc(tcx.types.f32)
|| found_assoc(tcx.types.f32);
if found_candidate
&& actual.is_numeric()
&& !actual.has_concrete_skeleton()
&& let SelfSource::MethodCall(expr) = source
{
let mut err = struct_span_err!(
tcx.sess,
span,
E0689,
"can't call {} `{}` on ambiguous numeric type `{}`",
item_kind,
item_name,
ty_str
);
let concrete_type = if actual.is_integral() { "i32" } else { "f32" };
match expr.kind {
ExprKind::Lit(ref lit) => {
// numeric literal
let snippet = tcx
.sess
.source_map()
.span_to_snippet(lit.span)
.unwrap_or_else(|_| "<numeric literal>".to_owned());
// If this is a floating point literal that ends with '.',
// get rid of it to stop this from becoming a member access.
let snippet = snippet.strip_suffix('.').unwrap_or(&snippet);
err.span_suggestion(
lit.span,
&format!(
"you must specify a concrete type for this numeric value, \
like `{}`",
concrete_type
),
format!("{snippet}_{concrete_type}"),
Applicability::MaybeIncorrect,
);
}
ExprKind::Path(QPath::Resolved(_, path)) => {
// local binding
if let hir::def::Res::Local(hir_id) = path.res {
let span = tcx.hir().span(hir_id);
let snippet = tcx.sess.source_map().span_to_snippet(span);
let filename = tcx.sess.source_map().span_to_filename(span);
let parent_node =
self.tcx.hir().get(self.tcx.hir().get_parent_node(hir_id));
let msg = format!(
"you must specify a type for this binding, like `{}`",
concrete_type,
);
match (filename, parent_node, snippet) {
(
FileName::Real(_),
Node::Local(hir::Local {
source: hir::LocalSource::Normal,
ty,
..
}),
Ok(ref snippet),
) => {
err.span_suggestion(
// account for `let x: _ = 42;`
// ^^^^
span.to(ty.as_ref().map(|ty| ty.span).unwrap_or(span)),
&msg,
format!("{}: {}", snippet, concrete_type),
Applicability::MaybeIncorrect,
);
}
_ => {
err.span_label(span, msg);
}
}
}
}
_ => {}
}
err.emit();
return true;
}
false
}
crate fn note_unmet_impls_on_type(
&self,
err: &mut Diagnostic,