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Merged
merged 3 commits into from
Mar 2, 2024
Merged

Display short types for unimplemented trait #121739

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c0ce0f3
Display short types for unimplemented trait
jieyouxu Feb 28, 2024
a1dbb61
Unify long type name file and note in note_obligation_cause_code
jieyouxu Feb 28, 2024
62baa67
Avoid silently writing to a file when the involved ty is long
jieyouxu Mar 1, 2024
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33 changes: 26 additions & 7 deletions compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@ use rustc_session::lint::builtin::UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES;
use rustc_span::symbol::{kw, sym, Symbol};
use rustc_span::Span;
use std::iter;
use std::path::PathBuf;

use crate::errors::{
EmptyOnClauseInOnUnimplemented, InvalidOnClauseInOnUnimplemented, NoValueInOnUnimplemented,
Expand Down Expand Up @@ -111,6 +112,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
trait_ref: ty::PolyTraitRef<'tcx>,
obligation: &PredicateObligation<'tcx>,
) -> OnUnimplementedNote {
let mut long_ty_file = None;
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Where is the path of this file being printed?

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So this is a bit awkward, I tried to make sure I don't miss any silent type name being written to file, but now there seems to be a duplicate written to file note lol

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That... should be fine for now. We need to bubble the printing of the file (and passing the file down) more than we do now, but it being duplicated is better than out right losing it.

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That... should be fine for now. We need to bubble the printing of the file (and passing the file down) more than we do now, but it being duplicated is better than out right losing it.

Yeah, there's let mut file = None a bit all over the place right now lol


let (def_id, args) = self
.impl_similar_to(trait_ref, obligation)
.unwrap_or_else(|| (trait_ref.def_id(), trait_ref.skip_binder().args));
Expand Down Expand Up @@ -265,7 +268,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
}));

if let Ok(Some(command)) = OnUnimplementedDirective::of_item(self.tcx, def_id) {
command.evaluate(self.tcx, trait_ref, &flags)
command.evaluate(self.tcx, trait_ref, &flags, &mut long_ty_file)
} else {
OnUnimplementedNote::default()
}
Expand Down Expand Up @@ -657,6 +660,7 @@ impl<'tcx> OnUnimplementedDirective {
tcx: TyCtxt<'tcx>,
trait_ref: ty::TraitRef<'tcx>,
options: &[(Symbol, Option<String>)],
long_ty_file: &mut Option<PathBuf>,
) -> OnUnimplementedNote {
let mut message = None;
let mut label = None;
Expand All @@ -669,6 +673,7 @@ impl<'tcx> OnUnimplementedDirective {
options.iter().filter_map(|(k, v)| v.clone().map(|v| (*k, v))).collect();

for command in self.subcommands.iter().chain(Some(self)).rev() {
debug!(?command);
if let Some(ref condition) = command.condition
&& !attr::eval_condition(condition, &tcx.sess, Some(tcx.features()), &mut |cfg| {
let value = cfg.value.map(|v| {
Expand All @@ -680,7 +685,12 @@ impl<'tcx> OnUnimplementedDirective {
span: cfg.span,
is_diagnostic_namespace_variant: false
}
.format(tcx, trait_ref, &options_map)
.format(
tcx,
trait_ref,
&options_map,
long_ty_file
)
)
});

Expand Down Expand Up @@ -709,10 +719,14 @@ impl<'tcx> OnUnimplementedDirective {
}

OnUnimplementedNote {
label: label.map(|l| l.format(tcx, trait_ref, &options_map)),
message: message.map(|m| m.format(tcx, trait_ref, &options_map)),
notes: notes.into_iter().map(|n| n.format(tcx, trait_ref, &options_map)).collect(),
parent_label: parent_label.map(|e_s| e_s.format(tcx, trait_ref, &options_map)),
label: label.map(|l| l.format(tcx, trait_ref, &options_map, long_ty_file)),
message: message.map(|m| m.format(tcx, trait_ref, &options_map, long_ty_file)),
notes: notes
.into_iter()
.map(|n| n.format(tcx, trait_ref, &options_map, long_ty_file))
.collect(),
parent_label: parent_label
.map(|e_s| e_s.format(tcx, trait_ref, &options_map, long_ty_file)),
append_const_msg,
}
}
Expand Down Expand Up @@ -814,6 +828,7 @@ impl<'tcx> OnUnimplementedFormatString {
tcx: TyCtxt<'tcx>,
trait_ref: ty::TraitRef<'tcx>,
options: &FxHashMap<Symbol, String>,
long_ty_file: &mut Option<PathBuf>,
) -> String {
let name = tcx.item_name(trait_ref.def_id);
let trait_str = tcx.def_path_str(trait_ref.def_id);
Expand All @@ -824,7 +839,11 @@ impl<'tcx> OnUnimplementedFormatString {
.filter_map(|param| {
let value = match param.kind {
GenericParamDefKind::Type { .. } | GenericParamDefKind::Const { .. } => {
trait_ref.args[param.index as usize].to_string()
if let Some(ty) = trait_ref.args[param.index as usize].as_type() {
tcx.short_ty_string(ty, long_ty_file)
} else {
trait_ref.args[param.index as usize].to_string()
}
}
GenericParamDefKind::Lifetime => return None,
};
Expand Down
61 changes: 22 additions & 39 deletions compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -2676,6 +2676,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
) where
T: ToPredicate<'tcx>,
{
let mut long_ty_file = None;

let tcx = self.tcx;
let predicate = predicate.to_predicate(tcx);
match *cause_code {
Expand Down Expand Up @@ -2858,21 +2860,13 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
}
}
ObligationCauseCode::Coercion { source, target } => {
let mut file = None;
let source = tcx.short_ty_string(self.resolve_vars_if_possible(source), &mut file);
let target = tcx.short_ty_string(self.resolve_vars_if_possible(target), &mut file);
let source =
tcx.short_ty_string(self.resolve_vars_if_possible(source), &mut long_ty_file);
let target =
tcx.short_ty_string(self.resolve_vars_if_possible(target), &mut long_ty_file);
err.note(with_forced_trimmed_paths!(format!(
"required for the cast from `{source}` to `{target}`",
)));
if let Some(file) = file {
err.note(format!(
"the full name for the type has been written to '{}'",
file.display(),
));
err.note(
"consider using `--verbose` to print the full type name to the console",
);
}
}
ObligationCauseCode::RepeatElementCopy {
is_constable,
Expand Down Expand Up @@ -3175,8 +3169,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
// Don't print the tuple of capture types
'print: {
if !is_upvar_tys_infer_tuple {
let mut file = None;
let ty_str = tcx.short_ty_string(ty, &mut file);
let ty_str = tcx.short_ty_string(ty, &mut long_ty_file);
let msg = format!("required because it appears within the type `{ty_str}`");
match ty.kind() {
ty::Adt(def, _) => match tcx.opt_item_ident(def.did()) {
Expand Down Expand Up @@ -3274,9 +3267,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
let mut parent_trait_pred =
self.resolve_vars_if_possible(data.derived.parent_trait_pred);
let parent_def_id = parent_trait_pred.def_id();
let mut file = None;
let self_ty_str =
tcx.short_ty_string(parent_trait_pred.skip_binder().self_ty(), &mut file);
let self_ty_str = tcx
.short_ty_string(parent_trait_pred.skip_binder().self_ty(), &mut long_ty_file);
let trait_name = parent_trait_pred.print_modifiers_and_trait_path().to_string();
let msg = format!("required for `{self_ty_str}` to implement `{trait_name}`");
let mut is_auto_trait = false;
Expand Down Expand Up @@ -3334,15 +3326,6 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
}
};

if let Some(file) = file {
err.note(format!(
"the full type name has been written to '{}'",
file.display(),
));
err.note(
"consider using `--verbose` to print the full type name to the console",
);
}
let mut parent_predicate = parent_trait_pred;
let mut data = &data.derived;
let mut count = 0;
Expand Down Expand Up @@ -3383,22 +3366,14 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
count,
pluralize!(count)
));
let mut file = None;
let self_ty =
tcx.short_ty_string(parent_trait_pred.skip_binder().self_ty(), &mut file);
let self_ty = tcx.short_ty_string(
parent_trait_pred.skip_binder().self_ty(),
&mut long_ty_file,
);
err.note(format!(
"required for `{self_ty}` to implement `{}`",
parent_trait_pred.print_modifiers_and_trait_path()
));
if let Some(file) = file {
err.note(format!(
"the full type name has been written to '{}'",
file.display(),
));
err.note(
"consider using `--verbose` to print the full type name to the console",
);
}
}
// #74711: avoid a stack overflow
ensure_sufficient_stack(|| {
Expand Down Expand Up @@ -3507,7 +3482,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
}
ObligationCauseCode::OpaqueReturnType(expr_info) => {
if let Some((expr_ty, expr_span)) = expr_info {
let expr_ty = with_forced_trimmed_paths!(self.ty_to_string(expr_ty));
let expr_ty = self.tcx.short_ty_string(expr_ty, &mut long_ty_file);
err.span_label(
expr_span,
with_forced_trimmed_paths!(format!(
Expand All @@ -3517,6 +3492,14 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
}
}
}

if let Some(file) = long_ty_file {
err.note(format!(
"the full name for the type has been written to '{}'",
file.display(),
));
err.note("consider using `--verbose` to print the full type name to the console");
}
}

#[instrument(
Expand Down
3 changes: 2 additions & 1 deletion compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -389,6 +389,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
kind: _,
} = *obligation.cause.code()
{
debug!("ObligationCauseCode::CompareImplItemObligation");
return self.report_extra_impl_obligation(
span,
impl_item_def_id,
Expand Down Expand Up @@ -439,7 +440,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
)
})
.unwrap_or_default();
let file_note = file.map(|file| format!(
let file_note = file.as_ref().map(|file| format!(
"the full trait has been written to '{}'",
file.display(),
));
Expand Down
17 changes: 17 additions & 0 deletions tests/ui/traits/on_unimplemented_long_types.rs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
//@ compile-flags: --diagnostic-width=60 -Z write-long-types-to-disk=yes
//@ normalize-stderr-test: "long-type-\d+" -> "long-type-hash"

pub fn foo() -> impl std::fmt::Display {
//~^ ERROR doesn't implement `std::fmt::Display`
Some(Some(Some(Some(Some(Some(Some(Some(Some(Some(Some(
Some(Some(Some(Some(Some(Some(Some(Some(Some(Some(Some(
Some(Some(Some(Some(Some(Some(Some(Some(Some(Some(Some(
Some(Some(Some(Some(Some(Some(Some(Some(Some(Some(Some(
Some(Some(Some(Some(Some(Some(Some(Some(())))))))),
))))))))))),
))))))))))),
))))))))))),
)))))))))))
}

fn main() {}
23 changes: 23 additions & 0 deletions tests/ui/traits/on_unimplemented_long_types.stderr
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Original file line number Diff line number Diff line change
@@ -0,0 +1,23 @@
error[E0277]: `Option<Option<Option<...>>>` doesn't implement `std::fmt::Display`
--> $DIR/on_unimplemented_long_types.rs:4:17
|
LL | pub fn foo() -> impl std::fmt::Display {
| ^^^^^^^^^^^^^^^^^^^^^^ `Option<Option<Option<...>>>` cannot be formatted with the default formatter
LL |
LL | / Some(Some(Some(Some(Some(Some(Some(Some(Some(S...
LL | | Some(Some(Some(Some(Some(Some(Some(Some(So...
LL | | Some(Some(Some(Some(Some(Some(Some(Som...
LL | | Some(Some(Some(Some(Some(Some(Some...
... |
LL | | ))))))))))),
LL | | )))))))))))
| |_______________- return type was inferred to be `Option<Option<Option<...>>>` here
|
= help: the trait `std::fmt::Display` is not implemented for `Option<Option<Option<...>>>`
= note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
= note: the full name for the type has been written to '$TEST_BUILD_DIR/traits/on_unimplemented_long_types/on_unimplemented_long_types.long-type-hash.txt'
= note: consider using `--verbose` to print the full type name to the console

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0277`.