From df2518955275c3a912dda8951a570abd2daddac4 Mon Sep 17 00:00:00 2001
From: Takayuki Maeda <41065217+TaKO8Ki@users.noreply.github.com>
Date: Thu, 28 Apr 2022 16:54:28 +0900
Subject: [PATCH] suggest calling `Self::associated_function()`
do not suggest when trait_ref is some
Update compiler/rustc_resolve/src/late/diagnostics.rs
Co-authored-by: lcnr <rust@lcnr.de>
use helper struct
add a test for functions with some params
refactor debug log
---
compiler/rustc_resolve/src/late.rs | 5 +
.../rustc_resolve/src/late/diagnostics.rs | 109 ++++++++++++------
src/test/ui/resolve/issue-2356.stderr | 10 ++
.../ui/suggestions/assoc_fn_without_self.rs | 20 ++++
.../suggestions/assoc_fn_without_self.stderr | 37 ++++++
5 files changed, 147 insertions(+), 34 deletions(-)
create mode 100644 src/test/ui/suggestions/assoc_fn_without_self.rs
create mode 100644 src/test/ui/suggestions/assoc_fn_without_self.stderr
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 50055f8030c..ff2ab152ca4 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -470,6 +470,9 @@ struct DiagnosticMetadata<'ast> {
current_where_predicate: Option<&'ast WherePredicate>,
current_type_path: Option<&'ast Ty>,
+
+ /// The current impl items (used to suggest).
+ current_impl_items: Option<&'ast [P<AssocItem>]>,
}
struct LateResolutionVisitor<'a, 'b, 'ast> {
@@ -1478,7 +1481,9 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
items: ref impl_items,
..
}) => {
+ self.diagnostic_metadata.current_impl_items = Some(impl_items);
self.resolve_implementation(generics, of_trait, &self_ty, item.id, impl_items);
+ self.diagnostic_metadata.current_impl_items = None;
}
ItemKind::Trait(box Trait { ref generics, ref bounds, ref items, .. }) => {
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index d77cc917e2f..82d2d9ce26e 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -6,7 +6,7 @@ use crate::path_names_to_string;
use crate::{Finalize, Module, ModuleKind, ModuleOrUniformRoot};
use crate::{PathResult, PathSource, Segment};
-use rustc_ast::visit::FnKind;
+use rustc_ast::visit::{FnCtxt, FnKind};
use rustc_ast::{
self as ast, AssocItemKind, Expr, ExprKind, GenericParam, GenericParamKind, Item, ItemKind,
NodeId, Path, Ty, TyKind,
@@ -144,15 +144,22 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
let is_enum_variant = &|res| matches!(res, Res::Def(DefKind::Variant, _));
// Make the base error.
+ struct BaseError<'a> {
+ msg: String,
+ fallback_label: String,
+ span: Span,
+ could_be_expr: bool,
+ suggestion: Option<(Span, &'a str, String)>,
+ }
let mut expected = source.descr_expected();
let path_str = Segment::names_to_string(path);
let item_str = path.last().unwrap().ident;
- let (base_msg, fallback_label, base_span, could_be_expr) = if let Some(res) = res {
- (
- format!("expected {}, found {} `{}`", expected, res.descr(), path_str),
- format!("not a {}", expected),
+ let base_error = if let Some(res) = res {
+ BaseError {
+ msg: format!("expected {}, found {} `{}`", expected, res.descr(), path_str),
+ fallback_label: format!("not a {expected}"),
span,
- match res {
+ could_be_expr: match res {
Res::Def(DefKind::Fn, _) => {
// Verify whether this is a fn call or an Fn used as a type.
self.r
@@ -171,22 +178,49 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
| Res::Local(_) => true,
_ => false,
},
- )
+ suggestion: None,
+ }
} else {
let item_span = path.last().unwrap().ident.span;
- let (mod_prefix, mod_str) = if path.len() == 1 {
- (String::new(), "this scope".to_string())
+ let (mod_prefix, mod_str, suggestion) = if path.len() == 1 {
+ debug!(?self.diagnostic_metadata.current_impl_items);
+ debug!(?self.diagnostic_metadata.current_function);
+ let suggestion = if let Some(items) = self.diagnostic_metadata.current_impl_items
+ && let Some((fn_kind, _)) = self.diagnostic_metadata.current_function
+ && self.current_trait_ref.is_none()
+ && let Some(FnCtxt::Assoc(_)) = fn_kind.ctxt()
+ && let Some(item) = items.iter().find(|i| {
+ if let AssocItemKind::Fn(fn_) = &i.kind
+ && !fn_.sig.decl.has_self()
+ && i.ident.name == item_str.name
+ {
+ debug!(?item_str.name);
+ debug!(?fn_.sig.decl.inputs);
+ return true
+ }
+ false
+ })
+ {
+ Some((
+ item_span,
+ "consider using the associated function",
+ format!("Self::{}", item.ident)
+ ))
+ } else {
+ None
+ };
+ (String::new(), "this scope".to_string(), suggestion)
} else if path.len() == 2 && path[0].ident.name == kw::PathRoot {
if self.r.session.edition() > Edition::Edition2015 {
// In edition 2018 onwards, the `::foo` syntax may only pull from the extern prelude
// which overrides all other expectations of item type
expected = "crate";
- (String::new(), "the list of imported crates".to_string())
+ (String::new(), "the list of imported crates".to_string(), None)
} else {
- (String::new(), "the crate root".to_string())
+ (String::new(), "the crate root".to_string(), None)
}
} else if path.len() == 2 && path[0].ident.name == kw::Crate {
- (String::new(), "the crate root".to_string())
+ (String::new(), "the crate root".to_string(), None)
} else {
let mod_path = &path[..path.len() - 1];
let mod_prefix = match self.resolve_path(mod_path, Some(TypeNS), Finalize::No) {
@@ -194,22 +228,28 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
_ => None,
}
.map_or_else(String::new, |res| format!("{} ", res.descr()));
- (mod_prefix, format!("`{}`", Segment::names_to_string(mod_path)))
+ (mod_prefix, format!("`{}`", Segment::names_to_string(mod_path)), None)
};
- (
- format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
- if path_str == "async" && expected.starts_with("struct") {
+ BaseError {
+ msg: format!("cannot find {expected} `{item_str}` in {mod_prefix}{mod_str}"),
+ fallback_label: if path_str == "async" && expected.starts_with("struct") {
"`async` blocks are only allowed in Rust 2018 or later".to_string()
} else {
- format!("not found in {}", mod_str)
+ format!("not found in {mod_str}")
},
- item_span,
- false,
- )
+ span: item_span,
+ could_be_expr: false,
+ suggestion,
+ }
};
let code = source.error_code(res.is_some());
- let mut err = self.r.session.struct_span_err_with_code(base_span, &base_msg, code);
+ let mut err =
+ self.r.session.struct_span_err_with_code(base_error.span, &base_error.msg, code);
+
+ if let Some(sugg) = base_error.suggestion {
+ err.span_suggestion_verbose(sugg.0, sugg.1, sugg.2, Applicability::MaybeIncorrect);
+ }
if let Some(span) = self.diagnostic_metadata.current_block_could_be_bare_struct_literal {
err.multipart_suggestion(
@@ -269,7 +309,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
}
}
- self.detect_assoct_type_constraint_meant_as_path(base_span, &mut err);
+ self.detect_assoct_type_constraint_meant_as_path(base_error.span, &mut err);
// Emit special messages for unresolved `Self` and `self`.
if is_self_type(path, ns) {
@@ -471,7 +511,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
source,
res,
&path_str,
- &fallback_label,
+ &base_error.fallback_label,
) {
// We do this to avoid losing a secondary span when we override the main error span.
self.r.add_typo_suggestion(&mut err, typo_sugg, ident_span);
@@ -479,8 +519,9 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
}
}
- let is_macro = base_span.from_expansion() && base_span.desugaring_kind().is_none();
- if !self.type_ascription_suggestion(&mut err, base_span) {
+ let is_macro =
+ base_error.span.from_expansion() && base_error.span.desugaring_kind().is_none();
+ if !self.type_ascription_suggestion(&mut err, base_error.span) {
let mut fallback = false;
if let (
PathSource::Trait(AliasPossibility::Maybe),
@@ -493,7 +534,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
let spans: Vec<Span> = bounds
.iter()
.map(|bound| bound.span())
- .filter(|&sp| sp != base_span)
+ .filter(|&sp| sp != base_error.span)
.collect();
let start_span = bounds.iter().map(|bound| bound.span()).next().unwrap();
@@ -515,7 +556,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
multi_span.push_span_label(sp, msg);
}
multi_span.push_span_label(
- base_span,
+ base_error.span,
"expected this type to be a trait...".to_string(),
);
err.span_help(
@@ -525,14 +566,14 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
);
if bounds.iter().all(|bound| match bound {
ast::GenericBound::Outlives(_) => true,
- ast::GenericBound::Trait(tr, _) => tr.span == base_span,
+ ast::GenericBound::Trait(tr, _) => tr.span == base_error.span,
}) {
let mut sugg = vec![];
- if base_span != start_span {
- sugg.push((start_span.until(base_span), String::new()));
+ if base_error.span != start_span {
+ sugg.push((start_span.until(base_error.span), String::new()));
}
- if base_span != end_span {
- sugg.push((base_span.shrink_to_hi().to(end_span), String::new()));
+ if base_error.span != end_span {
+ sugg.push((base_error.span.shrink_to_hi().to(end_span), String::new()));
}
err.multipart_suggestion(
@@ -550,7 +591,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
fallback = true;
match self.diagnostic_metadata.current_let_binding {
Some((pat_sp, Some(ty_sp), None))
- if ty_sp.contains(base_span) && could_be_expr =>
+ if ty_sp.contains(base_error.span) && base_error.could_be_expr =>
{
err.span_suggestion_short(
pat_sp.between(ty_sp),
@@ -568,7 +609,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
}
if fallback {
// Fallback label.
- err.span_label(base_span, fallback_label);
+ err.span_label(base_error.span, base_error.fallback_label);
}
}
if let Some(err_code) = &err.code {
diff --git a/src/test/ui/resolve/issue-2356.stderr b/src/test/ui/resolve/issue-2356.stderr
index d1872673885..b8d528efc15 100644
--- a/src/test/ui/resolve/issue-2356.stderr
+++ b/src/test/ui/resolve/issue-2356.stderr
@@ -48,6 +48,11 @@ error[E0425]: cannot find function `static_method` in this scope
|
LL | static_method();
| ^^^^^^^^^^^^^ not found in this scope
+ |
+help: consider using the associated function
+ |
+LL | Self::static_method();
+ | ~~~~~~~~~~~~~~~~~~~
error[E0425]: cannot find function `purr` in this scope
--> $DIR/issue-2356.rs:54:9
@@ -85,6 +90,11 @@ error[E0425]: cannot find function `grow_older` in this scope
|
LL | grow_older();
| ^^^^^^^^^^ not found in this scope
+ |
+help: consider using the associated function
+ |
+LL | Self::grow_older();
+ | ~~~~~~~~~~~~~~~~
error[E0425]: cannot find function `shave` in this scope
--> $DIR/issue-2356.rs:74:5
diff --git a/src/test/ui/suggestions/assoc_fn_without_self.rs b/src/test/ui/suggestions/assoc_fn_without_self.rs
new file mode 100644
index 00000000000..778d9847773
--- /dev/null
+++ b/src/test/ui/suggestions/assoc_fn_without_self.rs
@@ -0,0 +1,20 @@
+fn main() {}
+
+struct S;
+
+impl S {
+ fn foo() {}
+
+ fn bar(&self) {}
+
+ fn baz(a: u8, b: u8) {}
+
+ fn b() {
+ fn c() {
+ foo(); //~ ERROR cannot find function `foo` in this scope
+ }
+ foo(); //~ ERROR cannot find function `foo` in this scope
+ bar(); //~ ERROR cannot find function `bar` in this scope
+ baz(2, 3); //~ ERROR cannot find function `baz` in this scope
+ }
+}
diff --git a/src/test/ui/suggestions/assoc_fn_without_self.stderr b/src/test/ui/suggestions/assoc_fn_without_self.stderr
new file mode 100644
index 00000000000..4a0e62e7309
--- /dev/null
+++ b/src/test/ui/suggestions/assoc_fn_without_self.stderr
@@ -0,0 +1,37 @@
+error[E0425]: cannot find function `foo` in this scope
+ --> $DIR/assoc_fn_without_self.rs:14:13
+ |
+LL | foo();
+ | ^^^ not found in this scope
+
+error[E0425]: cannot find function `foo` in this scope
+ --> $DIR/assoc_fn_without_self.rs:16:9
+ |
+LL | foo();
+ | ^^^ not found in this scope
+ |
+help: consider using the associated function
+ |
+LL | Self::foo();
+ | ~~~~~~~~~
+
+error[E0425]: cannot find function `bar` in this scope
+ --> $DIR/assoc_fn_without_self.rs:17:9
+ |
+LL | bar();
+ | ^^^ not found in this scope
+
+error[E0425]: cannot find function `baz` in this scope
+ --> $DIR/assoc_fn_without_self.rs:18:9
+ |
+LL | baz(2, 3);
+ | ^^^ not found in this scope
+ |
+help: consider using the associated function
+ |
+LL | Self::baz(2, 3);
+ | ~~~~~~~~~
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0425`.