From 952df48948438a67a8130137a120e515897cde87 Mon Sep 17 00:00:00 2001
From: yukang <moorekang@gmail.com>
Date: Wed, 9 Nov 2022 16:43:37 +0800
Subject: [PATCH 1/3] Fix #104086, Tighten the 'introduce new binding'
suggestion
---
.../rustc_resolve/src/late/diagnostics.rs | 25 ++++--
.../suggestions/issue-104086-suggest-let.rs | 10 +++
.../issue-104086-suggest-let.stderr | 81 +++++++++++++++++++
3 files changed, 109 insertions(+), 7 deletions(-)
create mode 100644 src/test/ui/suggestions/issue-104086-suggest-let.rs
create mode 100644 src/test/ui/suggestions/issue-104086-suggest-let.stderr
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index a1338dcd4771b..45c11fc9eb00d 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -1810,18 +1810,27 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
false
}
- fn let_binding_suggestion(&self, err: &mut Diagnostic, ident_span: Span) -> bool {
+ fn let_binding_suggestion(&mut self, err: &mut Diagnostic, ident_span: Span) -> bool {
// try to give a suggestion for this pattern: `name = 1`, which is common in other languages
let mut added_suggestion = false;
- if let Some(Expr { kind: ExprKind::Assign(lhs, _rhs, _), .. }) = self.diagnostic_metadata.in_assignment &&
- let ast::ExprKind::Path(None, _) = lhs.kind {
+ if let Some(Expr { kind: ExprKind::Assign(lhs, rhs, _), .. }) =
+ self.diagnostic_metadata.in_assignment
+ {
+ let is_rhs_assign = match rhs.kind {
+ ExprKind::Assign(..) => true,
+ _ => false,
+ };
+
+ if let ast::ExprKind::Path(None, _) = lhs.kind && !is_rhs_assign {
let sm = self.r.session.source_map();
let line_span = sm.span_extend_to_line(ident_span);
let ident_name = sm.span_to_snippet(ident_span).unwrap();
- // HACK(chenyukang): make sure ident_name is at the starting of the line to protect against macros
- if sm
- .span_to_snippet(line_span)
- .map_or(false, |s| s.trim().starts_with(&ident_name))
+ // HACK(chenyukang): make sure ident_name is at the starting of the line to protect against macros,
+ // and avoid some special cases like `x = x = x`
+ if let Ok(line) = sm.span_to_snippet(line_span) &&
+ let stripped = line.split_whitespace().collect::<String>() &&
+ stripped.trim().starts_with(&ident_name) &&
+ stripped.matches(&format!("{}=", &ident_name)).count() == 1
{
err.span_suggestion_verbose(
ident_span.shrink_to_lo(),
@@ -1832,6 +1841,8 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
added_suggestion = true;
}
}
+ self.diagnostic_metadata.in_assignment = None;
+ }
added_suggestion
}
diff --git a/src/test/ui/suggestions/issue-104086-suggest-let.rs b/src/test/ui/suggestions/issue-104086-suggest-let.rs
new file mode 100644
index 0000000000000..e23109a3be69c
--- /dev/null
+++ b/src/test/ui/suggestions/issue-104086-suggest-let.rs
@@ -0,0 +1,10 @@
+// error-pattern: not found in this scope
+
+fn main() {
+ x = x = x;
+ x = y = y = y;
+ x = y = y;
+ x = x = y;
+ x = x; // will suggest add `let`
+ x = y // will suggest add `let`
+}
diff --git a/src/test/ui/suggestions/issue-104086-suggest-let.stderr b/src/test/ui/suggestions/issue-104086-suggest-let.stderr
new file mode 100644
index 0000000000000..2af9c142ec69e
--- /dev/null
+++ b/src/test/ui/suggestions/issue-104086-suggest-let.stderr
@@ -0,0 +1,81 @@
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:4:5
+ |
+LL | x = x = x;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:4:9
+ |
+LL | x = x = x;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:4:13
+ |
+LL | x = x = x;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:5:5
+ |
+LL | x = y = y = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `y` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:5:9
+ |
+LL | x = y = y = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `y` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:5:13
+ |
+LL | x = y = y = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `y` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:5:17
+ |
+LL | x = y = y = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:6:5
+ |
+LL | x = y = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `y` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:6:9
+ |
+LL | x = y = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `y` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:6:13
+ |
+LL | x = y = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:7:5
+ |
+LL | x = x = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:7:9
+ |
+LL | x = x = y;
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `y` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:7:13
+ |
+LL | x = x = y;
+ | ^ not found in this scope
+
+error: aborting due to 13 previous errors
+
+For more information about this error, try `rustc --explain E0425`.
From 5689f9c679838a921be5a0ac64e0cd13637efc35 Mon Sep 17 00:00:00 2001
From: yukang <moorekang@gmail.com>
Date: Wed, 9 Nov 2022 17:10:33 +0800
Subject: [PATCH 2/3] fix tests and code cleanup
---
.../rustc_resolve/src/late/diagnostics.rs | 6 +-
.../suggestions/issue-104086-suggest-let.rs | 24 ++++++-
.../issue-104086-suggest-let.stderr | 62 ++++++++++++++-----
3 files changed, 71 insertions(+), 21 deletions(-)
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 45c11fc9eb00d..9e47f4bc6c1c5 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -1816,11 +1816,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
if let Some(Expr { kind: ExprKind::Assign(lhs, rhs, _), .. }) =
self.diagnostic_metadata.in_assignment
{
- let is_rhs_assign = match rhs.kind {
- ExprKind::Assign(..) => true,
- _ => false,
- };
-
+ let is_rhs_assign = matches!(rhs.kind, ExprKind::Assign(..));
if let ast::ExprKind::Path(None, _) = lhs.kind && !is_rhs_assign {
let sm = self.r.session.source_map();
let line_span = sm.span_extend_to_line(ident_span);
diff --git a/src/test/ui/suggestions/issue-104086-suggest-let.rs b/src/test/ui/suggestions/issue-104086-suggest-let.rs
index e23109a3be69c..d22ad27d0e031 100644
--- a/src/test/ui/suggestions/issue-104086-suggest-let.rs
+++ b/src/test/ui/suggestions/issue-104086-suggest-let.rs
@@ -1,10 +1,30 @@
-// error-pattern: not found in this scope
-
fn main() {
x = x = x;
+ //~^ ERROR cannot find value `x` in this scope
+ //~| ERROR cannot find value `x` in this scope
+ //~| ERROR cannot find value `x` in this scope
+
x = y = y = y;
+ //~^ ERROR cannot find value `y` in this scope
+ //~| ERROR cannot find value `y` in this scope
+ //~| ERROR cannot find value `y` in this scope
+ //~| ERROR cannot find value `x` in this scope
+
x = y = y;
+ //~^ ERROR cannot find value `x` in this scope
+ //~| ERROR cannot find value `y` in this scope
+ //~| ERROR cannot find value `y` in this scope
+
x = x = y;
+ //~^ ERROR cannot find value `x` in this scope
+ //~| ERROR cannot find value `x` in this scope
+ //~| ERROR cannot find value `y` in this scope
+
x = x; // will suggest add `let`
+ //~^ ERROR cannot find value `x` in this scope
+ //~| ERROR cannot find value `x` in this scope
+
x = y // will suggest add `let`
+ //~^ ERROR cannot find value `x` in this scope
+ //~| ERROR cannot find value `y` in this scope
}
diff --git a/src/test/ui/suggestions/issue-104086-suggest-let.stderr b/src/test/ui/suggestions/issue-104086-suggest-let.stderr
index 2af9c142ec69e..d37a18f005fda 100644
--- a/src/test/ui/suggestions/issue-104086-suggest-let.stderr
+++ b/src/test/ui/suggestions/issue-104086-suggest-let.stderr
@@ -1,81 +1,115 @@
error[E0425]: cannot find value `x` in this scope
- --> $DIR/issue-104086-suggest-let.rs:4:5
+ --> $DIR/issue-104086-suggest-let.rs:2:5
|
LL | x = x = x;
| ^ not found in this scope
error[E0425]: cannot find value `x` in this scope
- --> $DIR/issue-104086-suggest-let.rs:4:9
+ --> $DIR/issue-104086-suggest-let.rs:2:9
|
LL | x = x = x;
| ^ not found in this scope
error[E0425]: cannot find value `x` in this scope
- --> $DIR/issue-104086-suggest-let.rs:4:13
+ --> $DIR/issue-104086-suggest-let.rs:2:13
|
LL | x = x = x;
| ^ not found in this scope
error[E0425]: cannot find value `x` in this scope
- --> $DIR/issue-104086-suggest-let.rs:5:5
+ --> $DIR/issue-104086-suggest-let.rs:7:5
|
LL | x = y = y = y;
| ^ not found in this scope
error[E0425]: cannot find value `y` in this scope
- --> $DIR/issue-104086-suggest-let.rs:5:9
+ --> $DIR/issue-104086-suggest-let.rs:7:9
|
LL | x = y = y = y;
| ^ not found in this scope
error[E0425]: cannot find value `y` in this scope
- --> $DIR/issue-104086-suggest-let.rs:5:13
+ --> $DIR/issue-104086-suggest-let.rs:7:13
|
LL | x = y = y = y;
| ^ not found in this scope
error[E0425]: cannot find value `y` in this scope
- --> $DIR/issue-104086-suggest-let.rs:5:17
+ --> $DIR/issue-104086-suggest-let.rs:7:17
|
LL | x = y = y = y;
| ^ not found in this scope
error[E0425]: cannot find value `x` in this scope
- --> $DIR/issue-104086-suggest-let.rs:6:5
+ --> $DIR/issue-104086-suggest-let.rs:13:5
|
LL | x = y = y;
| ^ not found in this scope
error[E0425]: cannot find value `y` in this scope
- --> $DIR/issue-104086-suggest-let.rs:6:9
+ --> $DIR/issue-104086-suggest-let.rs:13:9
|
LL | x = y = y;
| ^ not found in this scope
error[E0425]: cannot find value `y` in this scope
- --> $DIR/issue-104086-suggest-let.rs:6:13
+ --> $DIR/issue-104086-suggest-let.rs:13:13
|
LL | x = y = y;
| ^ not found in this scope
error[E0425]: cannot find value `x` in this scope
- --> $DIR/issue-104086-suggest-let.rs:7:5
+ --> $DIR/issue-104086-suggest-let.rs:18:5
|
LL | x = x = y;
| ^ not found in this scope
error[E0425]: cannot find value `x` in this scope
- --> $DIR/issue-104086-suggest-let.rs:7:9
+ --> $DIR/issue-104086-suggest-let.rs:18:9
|
LL | x = x = y;
| ^ not found in this scope
error[E0425]: cannot find value `y` in this scope
- --> $DIR/issue-104086-suggest-let.rs:7:13
+ --> $DIR/issue-104086-suggest-let.rs:18:13
|
LL | x = x = y;
| ^ not found in this scope
-error: aborting due to 13 previous errors
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:23:5
+ |
+LL | x = x; // will suggest add `let`
+ | ^
+ |
+help: you might have meant to introduce a new binding
+ |
+LL | let x = x; // will suggest add `let`
+ | +++
+
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:23:9
+ |
+LL | x = x; // will suggest add `let`
+ | ^ not found in this scope
+
+error[E0425]: cannot find value `x` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:27:5
+ |
+LL | x = y // will suggest add `let`
+ | ^
+ |
+help: you might have meant to introduce a new binding
+ |
+LL | let x = y // will suggest add `let`
+ | +++
+
+error[E0425]: cannot find value `y` in this scope
+ --> $DIR/issue-104086-suggest-let.rs:27:9
+ |
+LL | x = y // will suggest add `let`
+ | ^ not found in this scope
+
+error: aborting due to 17 previous errors
For more information about this error, try `rustc --explain E0425`.
From c69872bb6c0657241a5b3cf8944861dbd3ff7468 Mon Sep 17 00:00:00 2001
From: yukang <moorekang@gmail.com>
Date: Wed, 9 Nov 2022 22:00:22 +0800
Subject: [PATCH 3/3] add 'is_assign_rhs' to avoid weird suggesting 'let'
---
compiler/rustc_resolve/src/late.rs | 14 +++++++---
.../rustc_resolve/src/late/diagnostics.rs | 28 +++++--------------
.../issue-104086-suggest-let.stderr | 28 ++++++++++++++++---
3 files changed, 41 insertions(+), 29 deletions(-)
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 6d2ee25df320d..ede67813883d6 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -527,6 +527,7 @@ struct DiagnosticMetadata<'ast> {
/// Used to detect possible new binding written without `let` and to provide structured suggestion.
in_assignment: Option<&'ast Expr>,
+ is_assign_rhs: bool,
/// If we are currently in a trait object definition. Used to point at the bounds when
/// encountering a struct or enum.
@@ -3963,10 +3964,15 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
self.resolve_expr(elem, Some(expr));
self.visit_expr(idx);
}
- ExprKind::Assign(..) => {
- let old = self.diagnostic_metadata.in_assignment.replace(expr);
- visit::walk_expr(self, expr);
- self.diagnostic_metadata.in_assignment = old;
+ ExprKind::Assign(ref lhs, ref rhs, _) => {
+ if !self.diagnostic_metadata.is_assign_rhs {
+ self.diagnostic_metadata.in_assignment = Some(expr);
+ }
+ self.visit_expr(lhs);
+ self.diagnostic_metadata.is_assign_rhs = true;
+ self.diagnostic_metadata.in_assignment = None;
+ self.visit_expr(rhs);
+ self.diagnostic_metadata.is_assign_rhs = false;
}
_ => {
visit::walk_expr(self, expr);
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 9e47f4bc6c1c5..ec1ac015daf21 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -1810,36 +1810,22 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
false
}
+ // try to give a suggestion for this pattern: `name = blah`, which is common in other languages
+ // suggest `let name = blah` to introduce a new binding
fn let_binding_suggestion(&mut self, err: &mut Diagnostic, ident_span: Span) -> bool {
- // try to give a suggestion for this pattern: `name = 1`, which is common in other languages
- let mut added_suggestion = false;
- if let Some(Expr { kind: ExprKind::Assign(lhs, rhs, _), .. }) =
- self.diagnostic_metadata.in_assignment
- {
- let is_rhs_assign = matches!(rhs.kind, ExprKind::Assign(..));
- if let ast::ExprKind::Path(None, _) = lhs.kind && !is_rhs_assign {
- let sm = self.r.session.source_map();
- let line_span = sm.span_extend_to_line(ident_span);
- let ident_name = sm.span_to_snippet(ident_span).unwrap();
- // HACK(chenyukang): make sure ident_name is at the starting of the line to protect against macros,
- // and avoid some special cases like `x = x = x`
- if let Ok(line) = sm.span_to_snippet(line_span) &&
- let stripped = line.split_whitespace().collect::<String>() &&
- stripped.trim().starts_with(&ident_name) &&
- stripped.matches(&format!("{}=", &ident_name)).count() == 1
- {
+ if let Some(Expr { kind: ExprKind::Assign(lhs, .. ), .. }) = self.diagnostic_metadata.in_assignment &&
+ let ast::ExprKind::Path(None, _) = lhs.kind {
+ if !ident_span.from_expansion() {
err.span_suggestion_verbose(
ident_span.shrink_to_lo(),
"you might have meant to introduce a new binding",
"let ".to_string(),
Applicability::MaybeIncorrect,
);
- added_suggestion = true;
+ return true;
}
}
- self.diagnostic_metadata.in_assignment = None;
- }
- added_suggestion
+ false
}
fn find_module(&mut self, def_id: DefId) -> Option<(Module<'a>, ImportSuggestion)> {
diff --git a/src/test/ui/suggestions/issue-104086-suggest-let.stderr b/src/test/ui/suggestions/issue-104086-suggest-let.stderr
index d37a18f005fda..fb4ea3121ac67 100644
--- a/src/test/ui/suggestions/issue-104086-suggest-let.stderr
+++ b/src/test/ui/suggestions/issue-104086-suggest-let.stderr
@@ -2,7 +2,12 @@ error[E0425]: cannot find value `x` in this scope
--> $DIR/issue-104086-suggest-let.rs:2:5
|
LL | x = x = x;
- | ^ not found in this scope
+ | ^
+ |
+help: you might have meant to introduce a new binding
+ |
+LL | let x = x = x;
+ | +++
error[E0425]: cannot find value `x` in this scope
--> $DIR/issue-104086-suggest-let.rs:2:9
@@ -20,7 +25,12 @@ error[E0425]: cannot find value `x` in this scope
--> $DIR/issue-104086-suggest-let.rs:7:5
|
LL | x = y = y = y;
- | ^ not found in this scope
+ | ^
+ |
+help: you might have meant to introduce a new binding
+ |
+LL | let x = y = y = y;
+ | +++
error[E0425]: cannot find value `y` in this scope
--> $DIR/issue-104086-suggest-let.rs:7:9
@@ -44,7 +54,12 @@ error[E0425]: cannot find value `x` in this scope
--> $DIR/issue-104086-suggest-let.rs:13:5
|
LL | x = y = y;
- | ^ not found in this scope
+ | ^
+ |
+help: you might have meant to introduce a new binding
+ |
+LL | let x = y = y;
+ | +++
error[E0425]: cannot find value `y` in this scope
--> $DIR/issue-104086-suggest-let.rs:13:9
@@ -62,7 +77,12 @@ error[E0425]: cannot find value `x` in this scope
--> $DIR/issue-104086-suggest-let.rs:18:5
|
LL | x = x = y;
- | ^ not found in this scope
+ | ^
+ |
+help: you might have meant to introduce a new binding
+ |
+LL | let x = x = y;
+ | +++
error[E0425]: cannot find value `x` in this scope
--> $DIR/issue-104086-suggest-let.rs:18:9