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Auto merge of #3921 - euclio:single-char-names-multispan, r=flip1995

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use a multispan for MANY_SINGLE_CHAR_NAMES
This commit is contained in:
bors 2019-04-08 08:42:13 +00:00
commit 4fdd113bed
5 changed files with 142 additions and 45 deletions
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87
clippy_lints/src/non_expressive_names.rs
View file

@ -88,7 +88,33 @@ struct SimilarNamesLocalVisitor<'a, 'tcx: 'a> {
names: Vec<ExistingName>,
cx: &'a EarlyContext<'tcx>,
lint: &'a NonExpressiveNames,
single_char_names: Vec<char>,
/// A stack of scopes containing the single-character bindings in each scope.
single_char_names: Vec<Vec<Ident>>,
}
impl<'a, 'tcx: 'a> SimilarNamesLocalVisitor<'a, 'tcx> {
fn check_single_char_names(&self) {
let num_single_char_names = self.single_char_names.iter().flatten().count();
let threshold = self.lint.single_char_binding_names_threshold;
if num_single_char_names as u64 >= threshold {
let span = self
.single_char_names
.iter()
.flatten()
.map(|ident| ident.span)
.collect::<Vec<_>>();
span_lint(
self.cx,
MANY_SINGLE_CHAR_NAMES,
span,
&format!(
"{} bindings with single-character names in scope",
num_single_char_names
),
);
}
}
}
// this list contains lists of names that are allowed to be similar
@ -109,7 +135,7 @@ struct SimilarNamesNameVisitor<'a: 'b, 'tcx: 'a, 'b>(&'b mut SimilarNamesLocalVi
impl<'a, 'tcx: 'a, 'b> Visitor<'tcx> for SimilarNamesNameVisitor<'a, 'tcx, 'b> {
fn visit_pat(&mut self, pat: &'tcx Pat) {
match pat.node {
PatKind::Ident(_, ident, _) => self.check_name(ident.span, ident.name),
PatKind::Ident(_, ident, _) => self.check_ident(ident),
PatKind::Struct(_, ref fields, _) => {
for field in fields {
if !field.node.is_shorthand {
@ -140,27 +166,24 @@ fn whitelisted(interned_name: &str, list: &[&str]) -> bool {
}
impl<'a, 'tcx, 'b> SimilarNamesNameVisitor<'a, 'tcx, 'b> {
fn check_short_name(&mut self, c: char, span: Span) {
// make sure we ignore shadowing
if self.0.single_char_names.contains(&c) {
fn check_short_ident(&mut self, ident: Ident) {
// Ignore shadowing
if self
.0
.single_char_names
.iter()
.flatten()
.any(|id| id.name == ident.name)
{
return;
}
self.0.single_char_names.push(c);
if self.0.single_char_names.len() as u64 >= self.0.lint.single_char_binding_names_threshold {
span_lint(
self.0.cx,
MANY_SINGLE_CHAR_NAMES,
span,
&format!(
"{}th binding whose name is just one char",
self.0.single_char_names.len()
),
);
} else if let Some(scope) = &mut self.0.single_char_names.last_mut() {
scope.push(ident);
}
}
#[allow(clippy::too_many_lines)]
fn check_name(&mut self, span: Span, name: Name) {
let interned_name = name.as_str();
fn check_ident(&mut self, ident: Ident) {
let interned_name = ident.name.as_str();
if interned_name.chars().any(char::is_uppercase) {
return;
}
@ -168,7 +191,7 @@ impl<'a, 'tcx, 'b> SimilarNamesNameVisitor<'a, 'tcx, 'b> {
span_lint(
self.0.cx,
JUST_UNDERSCORES_AND_DIGITS,
span,
ident.span,
"consider choosing a more descriptive name",
);
return;
@ -176,8 +199,7 @@ impl<'a, 'tcx, 'b> SimilarNamesNameVisitor<'a, 'tcx, 'b> {
let count = interned_name.chars().count();
if count < 3 {
if count == 1 {
let c = interned_name.chars().next().expect("already checked");
self.check_short_name(c, span);
self.check_short_ident(ident);
}
return;
}
@ -247,13 +269,13 @@ impl<'a, 'tcx, 'b> SimilarNamesNameVisitor<'a, 'tcx, 'b> {
span_lint_and_then(
self.0.cx,
SIMILAR_NAMES,
span,
ident.span,
"binding's name is too similar to existing binding",
|diag| {
diag.span_note(existing_name.span, "existing binding defined here");
if let Some(split) = split_at {
diag.span_help(
span,
ident.span,
&format!(
"separate the discriminating character by an \
underscore like: `{}_{}`",
@ -269,7 +291,7 @@ impl<'a, 'tcx, 'b> SimilarNamesNameVisitor<'a, 'tcx, 'b> {
self.0.names.push(ExistingName {
whitelist: get_whitelist(&interned_name).unwrap_or(&[]),
interned: interned_name,
span,
span: ident.span,
len: count,
});
}
@ -297,15 +319,25 @@ impl<'a, 'tcx> Visitor<'tcx> for SimilarNamesLocalVisitor<'a, 'tcx> {
SimilarNamesNameVisitor(self).visit_pat(&*local.pat);
}
fn visit_block(&mut self, blk: &'tcx Block) {
self.single_char_names.push(vec![]);
self.apply(|this| walk_block(this, blk));
self.check_single_char_names();
self.single_char_names.pop();
}
fn visit_arm(&mut self, arm: &'tcx Arm) {
self.single_char_names.push(vec![]);
self.apply(|this| {
// just go through the first pattern, as either all patterns
// bind the same bindings or rustc would have errored much earlier
SimilarNamesNameVisitor(this).visit_pat(&arm.pats[0]);
this.apply(|this| walk_expr(this, &arm.body));
});
self.check_single_char_names();
self.single_char_names.pop();
}
fn visit_item(&mut self, _: &Item) {
// do not recurse into inner items
@ -335,14 +367,17 @@ fn do_check(lint: &mut NonExpressiveNames, cx: &EarlyContext<'_>, attrs: &[Attri
names: Vec::new(),
cx,
lint,
single_char_names: Vec::new(),
single_char_names: vec![vec![]],
};
// initialize with function arguments
for arg in &decl.inputs {
SimilarNamesNameVisitor(&mut visitor).visit_pat(&arg.pat);
}
// walk all other bindings
walk_block(&mut visitor, blk);
visitor.check_single_char_names();
}
}

4
clippy_lints/src/utils/diagnostics.rs
View file

@ -5,7 +5,7 @@ use rustc::lint::{LateContext, Lint, LintContext};
use rustc_errors::{Applicability, CodeSuggestion, Substitution, SubstitutionPart, SuggestionStyle};
use std::env;
use syntax::errors::DiagnosticBuilder;
use syntax::source_map::Span;
use syntax::source_map::{MultiSpan, Span};
/// Wrapper around `DiagnosticBuilder` that adds a link to Clippy documentation for the emitted lint
struct DiagnosticWrapper<'a>(DiagnosticBuilder<'a>);
@ -48,7 +48,7 @@ impl<'a> DiagnosticWrapper<'a> {
/// 17 | std::mem::forget(seven);
/// | ^^^^^^^^^^^^^^^^^^^^^^^
/// ```
pub fn span_lint<'a, T: LintContext<'a>>(cx: &T, lint: &'static Lint, sp: Span, msg: &str) {
pub fn span_lint<'a, T: LintContext<'a>>(cx: &T, lint: &'static Lint, sp: impl Into<MultiSpan>, msg: &str) {
DiagnosticWrapper(cx.struct_span_lint(lint, sp, msg)).docs_link(lint);
}

39
tests/ui/non_expressive_names.rs
View file

@ -49,6 +49,45 @@ fn bla() {
}
}
fn bindings(a: i32, b: i32, c: i32, d: i32, e: i32, f: i32, g: i32, h: i32) {}
fn bindings2() {
let (a, b, c, d, e, f, g, h) = unimplemented!();
}
fn shadowing() {
let a = 0i32;
let a = 0i32;
let a = 0i32;
let a = 0i32;
let a = 0i32;
let a = 0i32;
{
let a = 0i32;
}
}
fn patterns() {
enum Z {
A(i32),
B(i32),
C(i32),
D(i32),
E(i32),
F(i32),
}
// These should not trigger a warning, since the pattern bindings are a new scope.
match Z::A(0) {
Z::A(a) => {},
Z::B(b) => {},
Z::C(c) => {},
Z::D(d) => {},
Z::E(e) => {},
Z::F(f) => {},
}
}
fn underscores_and_numbers() {
let _1 = 1; //~ERROR Consider a more descriptive name
let ____1 = 1; //~ERROR Consider a more descriptive name

57
tests/ui/non_expressive_names.stderr
View file

@ -1,31 +1,54 @@
error: 5th binding whose name is just one char
--> $DIR/non_expressive_names.rs:35:17
error: 5 bindings with single-character names in scope
--> $DIR/non_expressive_names.rs:27:9
|
LL | let a: i32;
| ^
LL | let (b, c, d): (i32, i64, i16);
| ^ ^ ^
...
LL | let e: i32;
| ^
|
= note: `-D clippy::many-single-char-names` implied by `-D warnings`
error: 5th binding whose name is just one char
--> $DIR/non_expressive_names.rs:38:17
error: 6 bindings with single-character names in scope
--> $DIR/non_expressive_names.rs:27:9
|
LL | let a: i32;
| ^
LL | let (b, c, d): (i32, i64, i16);
| ^ ^ ^
...
LL | let e: i32;
| ^
error: 6th binding whose name is just one char
--> $DIR/non_expressive_names.rs:39:17
|
LL | let f: i32;
| ^
error: 5th binding whose name is just one char
--> $DIR/non_expressive_names.rs:43:13
error: 5 bindings with single-character names in scope
--> $DIR/non_expressive_names.rs:27:9
|
LL | let a: i32;
| ^
LL | let (b, c, d): (i32, i64, i16);
| ^ ^ ^
...
LL | e => panic!(),
| ^
error: 8 bindings with single-character names in scope
--> $DIR/non_expressive_names.rs:52:13
|
LL | fn bindings(a: i32, b: i32, c: i32, d: i32, e: i32, f: i32, g: i32, h: i32) {}
| ^ ^ ^ ^ ^ ^ ^ ^
error: 8 bindings with single-character names in scope
--> $DIR/non_expressive_names.rs:55:10
|
LL | let (a, b, c, d, e, f, g, h) = unimplemented!();
| ^ ^ ^ ^ ^ ^ ^ ^
error: consider choosing a more descriptive name
--> $DIR/non_expressive_names.rs:53:9
--> $DIR/non_expressive_names.rs:92:9
|
LL | let _1 = 1; //~ERROR Consider a more descriptive name
| ^^
@ -33,34 +56,34 @@ LL | let _1 = 1; //~ERROR Consider a more descriptive name
= note: `-D clippy::just-underscores-and-digits` implied by `-D warnings`
error: consider choosing a more descriptive name
--> $DIR/non_expressive_names.rs:54:9
--> $DIR/non_expressive_names.rs:93:9
|
LL | let ____1 = 1; //~ERROR Consider a more descriptive name
| ^^^^^
error: consider choosing a more descriptive name
--> $DIR/non_expressive_names.rs:55:9
--> $DIR/non_expressive_names.rs:94:9
|
LL | let __1___2 = 12; //~ERROR Consider a more descriptive name
| ^^^^^^^
error: consider choosing a more descriptive name
--> $DIR/non_expressive_names.rs:75:13
--> $DIR/non_expressive_names.rs:114:13
|
LL | let _1 = 1;
| ^^
error: consider choosing a more descriptive name
--> $DIR/non_expressive_names.rs:76:13
--> $DIR/non_expressive_names.rs:115:13
|
LL | let ____1 = 1;
| ^^^^^
error: consider choosing a more descriptive name
--> $DIR/non_expressive_names.rs:77:13
--> $DIR/non_expressive_names.rs:116:13
|
LL | let __1___2 = 12;
| ^^^^^^^
error: aborting due to 10 previous errors
error: aborting due to 11 previous errors

0
tests/ui/non_expressive_names.stdout Normal file
View file