From 1babece1e8888151b1b248367eb1017450dc107c Mon Sep 17 00:00:00 2001
From: Ezra Shaw <ezrasure@outlook.com>
Date: Fri, 13 Jan 2023 14:14:26 +1300
Subject: [PATCH] suggest fix for attempted integer identifier in patterns
---
.../locales/en-US/mir_build.ftl | 2 ++
compiler/rustc_mir_build/src/errors.rs | 15 ++++++++
.../src/thir/pattern/check_match.rs | 20 ++++++++---
.../ui/consts/const-match-check.eval1.stderr | 4 +++
.../ui/consts/const-match-check.eval2.stderr | 4 +++
.../consts/const-match-check.matchck.stderr | 16 +++++++++
tests/ui/pattern/issue-106552.rs | 7 ++++
tests/ui/pattern/issue-106552.stderr | 35 +++++++++++++++++++
8 files changed, 99 insertions(+), 4 deletions(-)
create mode 100644 tests/ui/pattern/issue-106552.rs
create mode 100644 tests/ui/pattern/issue-106552.stderr
diff --git a/compiler/rustc_error_messages/locales/en-US/mir_build.ftl b/compiler/rustc_error_messages/locales/en-US/mir_build.ftl
index a082c0b61fa..224855fff8b 100644
--- a/compiler/rustc_error_messages/locales/en-US/mir_build.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/mir_build.ftl
@@ -364,3 +364,5 @@ mir_build_suggest_let_else = you might want to use `let else` to handle the {$co
[one] variant that isn't
*[other] variants that aren't
} matched
+
+mir_build_suggest_attempted_int_lit = alternatively, you could prepend the pattern with an underscore to define a new named variable; identifiers cannot begin with digits
diff --git a/compiler/rustc_mir_build/src/errors.rs b/compiler/rustc_mir_build/src/errors.rs
index 06523b0a1de..7f81aef1c73 100644
--- a/compiler/rustc_mir_build/src/errors.rs
+++ b/compiler/rustc_mir_build/src/errors.rs
@@ -770,6 +770,8 @@ pub(crate) struct PatternNotCovered<'s, 'tcx> {
#[subdiagnostic]
pub let_suggestion: Option<SuggestLet>,
#[subdiagnostic]
+ pub misc_suggestion: Option<MiscPatternSuggestion>,
+ #[subdiagnostic]
pub res_defined_here: Option<ResDefinedHere>,
}
@@ -848,3 +850,16 @@ pub enum SuggestLet {
count: usize,
},
}
+
+#[derive(Subdiagnostic)]
+pub enum MiscPatternSuggestion {
+ #[suggestion(
+ mir_build_suggest_attempted_int_lit,
+ code = "_",
+ applicability = "maybe-incorrect"
+ )]
+ AttemptedIntegerLiteral {
+ #[primary_span]
+ start_span: Span,
+ },
+}
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
index e13c0662ef8..34e637f5948 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
@@ -6,8 +6,9 @@ use super::{PatCtxt, PatternError};
use crate::errors::*;
+use hir::{ExprKind, PatKind};
use rustc_arena::TypedArena;
-use rustc_ast::Mutability;
+use rustc_ast::{LitKind, Mutability};
use rustc_errors::{
struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, MultiSpan,
};
@@ -389,7 +390,7 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
return;
}
- let (inform, interpreted_as_const, res_defined_here,let_suggestion) =
+ let (inform, interpreted_as_const, res_defined_here,let_suggestion, misc_suggestion) =
if let hir::PatKind::Path(hir::QPath::Resolved(
None,
hir::Path {
@@ -413,6 +414,7 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
}
},
None,
+ None,
)
} else if let Some(span) = sp && self.tcx.sess.source_map().is_span_accessible(span) {
let mut bindings = vec![];
@@ -426,10 +428,19 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
let end_span = semi_span.shrink_to_lo();
let count = witnesses.len();
+ // If the pattern to match is an integer literal:
+ let int_suggestion = if
+ let PatKind::Lit(expr) = &pat.kind
+ && bindings.is_empty()
+ && let ExprKind::Lit(Spanned { node: LitKind::Int(_, _), span }) = expr.kind {
+ // Then give a suggestion, the user might've meant to create a binding instead.
+ Some(MiscPatternSuggestion::AttemptedIntegerLiteral { start_span: span.shrink_to_lo() })
+ } else { None };
+
let let_suggestion = if bindings.is_empty() {SuggestLet::If{start_span, semi_span, count}} else{ SuggestLet::Else{end_span, count }};
- (sp.map(|_|Inform), None, None, Some(let_suggestion))
+ (sp.map(|_|Inform), None, None, Some(let_suggestion), int_suggestion)
} else{
- (sp.map(|_|Inform), None, None, None)
+ (sp.map(|_|Inform), None, None, None, None)
};
let adt_defined_here = try {
@@ -453,6 +464,7 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
_p: (),
pattern_ty,
let_suggestion,
+ misc_suggestion,
res_defined_here,
adt_defined_here,
});
diff --git a/tests/ui/consts/const-match-check.eval1.stderr b/tests/ui/consts/const-match-check.eval1.stderr
index 1caf1617e21..08fcd1deab1 100644
--- a/tests/ui/consts/const-match-check.eval1.stderr
+++ b/tests/ui/consts/const-match-check.eval1.stderr
@@ -11,6 +11,10 @@ help: you might want to use `if let` to ignore the variants that aren't matched
|
LL | A = { if let 0 = 0 { todo!() } 0 },
| ++ ~~~~~~~~~~~
+help: alternatively, you could prepend the pattern with an underscore to define a new named variable; identifiers cannot begin with digits
+ |
+LL | A = { let _0 = 0; 0 },
+ | +
error: aborting due to previous error
diff --git a/tests/ui/consts/const-match-check.eval2.stderr b/tests/ui/consts/const-match-check.eval2.stderr
index f038ba1c8ed..5d86ca4bfd1 100644
--- a/tests/ui/consts/const-match-check.eval2.stderr
+++ b/tests/ui/consts/const-match-check.eval2.stderr
@@ -11,6 +11,10 @@ help: you might want to use `if let` to ignore the variants that aren't matched
|
LL | let x: [i32; { if let 0 = 0 { todo!() } 0 }] = [];
| ++ ~~~~~~~~~~~
+help: alternatively, you could prepend the pattern with an underscore to define a new named variable; identifiers cannot begin with digits
+ |
+LL | let x: [i32; { let _0 = 0; 0 }] = [];
+ | +
error: aborting due to previous error
diff --git a/tests/ui/consts/const-match-check.matchck.stderr b/tests/ui/consts/const-match-check.matchck.stderr
index b1921f8a41e..c8f66bb0fc0 100644
--- a/tests/ui/consts/const-match-check.matchck.stderr
+++ b/tests/ui/consts/const-match-check.matchck.stderr
@@ -11,6 +11,10 @@ help: you might want to use `if let` to ignore the variants that aren't matched
|
LL | const X: i32 = { if let 0 = 0 { todo!() } 0 };
| ++ ~~~~~~~~~~~
+help: alternatively, you could prepend the pattern with an underscore to define a new named variable; identifiers cannot begin with digits
+ |
+LL | const X: i32 = { let _0 = 0; 0 };
+ | +
error[E0005]: refutable pattern in local binding
--> $DIR/const-match-check.rs:8:23
@@ -25,6 +29,10 @@ help: you might want to use `if let` to ignore the variants that aren't matched
|
LL | static Y: i32 = { if let 0 = 0 { todo!() } 0 };
| ++ ~~~~~~~~~~~
+help: alternatively, you could prepend the pattern with an underscore to define a new named variable; identifiers cannot begin with digits
+ |
+LL | static Y: i32 = { let _0 = 0; 0 };
+ | +
error[E0005]: refutable pattern in local binding
--> $DIR/const-match-check.rs:13:26
@@ -39,6 +47,10 @@ help: you might want to use `if let` to ignore the variants that aren't matched
|
LL | const X: i32 = { if let 0 = 0 { todo!() } 0 };
| ++ ~~~~~~~~~~~
+help: alternatively, you could prepend the pattern with an underscore to define a new named variable; identifiers cannot begin with digits
+ |
+LL | const X: i32 = { let _0 = 0; 0 };
+ | +
error[E0005]: refutable pattern in local binding
--> $DIR/const-match-check.rs:19:26
@@ -53,6 +65,10 @@ help: you might want to use `if let` to ignore the variants that aren't matched
|
LL | const X: i32 = { if let 0 = 0 { todo!() } 0 };
| ++ ~~~~~~~~~~~
+help: alternatively, you could prepend the pattern with an underscore to define a new named variable; identifiers cannot begin with digits
+ |
+LL | const X: i32 = { let _0 = 0; 0 };
+ | +
error: aborting due to 4 previous errors
diff --git a/tests/ui/pattern/issue-106552.rs b/tests/ui/pattern/issue-106552.rs
new file mode 100644
index 00000000000..aa2c141e05e
--- /dev/null
+++ b/tests/ui/pattern/issue-106552.rs
@@ -0,0 +1,7 @@
+fn main() {
+ let 5 = 6;
+ //~^ error refutable pattern in local binding [E0005]
+
+ let x @ 5 = 6;
+ //~^ error refutable pattern in local binding [E0005]
+}
diff --git a/tests/ui/pattern/issue-106552.stderr b/tests/ui/pattern/issue-106552.stderr
new file mode 100644
index 00000000000..ed5d40c0968
--- /dev/null
+++ b/tests/ui/pattern/issue-106552.stderr
@@ -0,0 +1,35 @@
+error[E0005]: refutable pattern in local binding
+ --> $DIR/issue-106552.rs:2:9
+ |
+LL | let 5 = 6;
+ | ^ patterns `i32::MIN..=4_i32` and `6_i32..=i32::MAX` not covered
+ |
+ = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
+ = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
+ = note: the matched value is of type `i32`
+help: you might want to use `if let` to ignore the variants that aren't matched
+ |
+LL | if let 5 = 6 { todo!() }
+ | ++ ~~~~~~~~~~~
+help: alternatively, you could prepend the pattern with an underscore to define a new named variable; identifiers cannot begin with digits
+ |
+LL | let _5 = 6;
+ | +
+
+error[E0005]: refutable pattern in local binding
+ --> $DIR/issue-106552.rs:5:9
+ |
+LL | let x @ 5 = 6;
+ | ^^^^^ patterns `i32::MIN..=4_i32` and `6_i32..=i32::MAX` not covered
+ |
+ = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
+ = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
+ = note: the matched value is of type `i32`
+help: you might want to use `let else` to handle the variants that aren't matched
+ |
+LL | let x @ 5 = 6 else { todo!() };
+ | ++++++++++++++++
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0005`.