mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge lint with single_char_pattern

Browse Source
This commit is contained in:
Christoph Walcher 2020-08-14 12:52:19 +02:00
parent 72d2c2eab4
commit ae56e988a2
No known key found for this signature in database
GPG Key ID: A193164A4D05EE44
7 changed files with 108 additions and 83 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
clippy_lints/src/lib.rs
View File

@ -287,7 +287,6 @@ mod repeat_once;
mod returns;
mod serde_api;
mod shadow;
mod single_char_push_str;
mod single_component_path_imports;
mod slow_vector_initialization;
mod stable_sort_primitive;
@ -678,6 +677,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
&methods::SEARCH_IS_SOME,
&methods::SHOULD_IMPLEMENT_TRAIT,
&methods::SINGLE_CHAR_PATTERN,
&methods::SINGLE_CHAR_PUSH_STR,
&methods::SKIP_WHILE_NEXT,
&methods::STRING_EXTEND_CHARS,
&methods::SUSPICIOUS_MAP,
@ -776,7 +776,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
&shadow::SHADOW_REUSE,
&shadow::SHADOW_SAME,
&shadow::SHADOW_UNRELATED,
&single_char_push_str::SINGLE_CHAR_PUSH_STR,
&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS,
&slow_vector_initialization::SLOW_VECTOR_INITIALIZATION,
&stable_sort_primitive::STABLE_SORT_PRIMITIVE,
@ -934,7 +933,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
store.register_late_pass(move || box escape::BoxedLocal{too_large_for_stack});
store.register_late_pass(|| box panic_unimplemented::PanicUnimplemented);
store.register_late_pass(|| box strings::StringLitAsBytes);
store.register_late_pass(|| box single_char_push_str::SingleCharPushStrPass);
store.register_late_pass(|| box derive::Derive);
store.register_late_pass(|| box types::CharLitAsU8);
store.register_late_pass(|| box vec::UselessVec);
@ -1352,6 +1350,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&methods::SEARCH_IS_SOME),
LintId::of(&methods::SHOULD_IMPLEMENT_TRAIT),
LintId::of(&methods::SINGLE_CHAR_PATTERN),
LintId::of(&methods::SINGLE_CHAR_PUSH_STR),
LintId::of(&methods::SKIP_WHILE_NEXT),
LintId::of(&methods::STRING_EXTEND_CHARS),
LintId::of(&methods::SUSPICIOUS_MAP),
@ -1419,7 +1418,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&returns::NEEDLESS_RETURN),
LintId::of(&returns::UNUSED_UNIT),
LintId::of(&serde_api::SERDE_API_MISUSE),
LintId::of(&single_char_push_str::SINGLE_CHAR_PUSH_STR),
LintId::of(&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS),
LintId::of(&slow_vector_initialization::SLOW_VECTOR_INITIALIZATION),
LintId::of(&stable_sort_primitive::STABLE_SORT_PRIMITIVE),
@ -1536,6 +1534,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&methods::OPTION_MAP_OR_NONE),
LintId::of(&methods::RESULT_MAP_OR_INTO_OPTION),
LintId::of(&methods::SHOULD_IMPLEMENT_TRAIT),
LintId::of(&methods::SINGLE_CHAR_PUSH_STR),
LintId::of(&methods::STRING_EXTEND_CHARS),
LintId::of(&methods::UNNECESSARY_FOLD),
LintId::of(&methods::WRONG_SELF_CONVENTION),
@ -1560,7 +1559,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&regex::TRIVIAL_REGEX),
LintId::of(&returns::NEEDLESS_RETURN),
LintId::of(&returns::UNUSED_UNIT),
LintId::of(&single_char_push_str::SINGLE_CHAR_PUSH_STR),
LintId::of(&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS),
LintId::of(&strings::STRING_LIT_AS_BYTES),
LintId::of(&tabs_in_doc_comments::TABS_IN_DOC_COMMENTS),

89
clippy_lints/src/methods/mod.rs
View File

@ -1306,6 +1306,29 @@ declare_clippy_lint! {
"using `.iter().next()` on a sliced array, which can be shortened to just `.get()`"
}
declare_clippy_lint! {
/// **What it does:** Warns when using push_str with a single-character string literal,
/// and push with a char would work fine.
///
/// **Why is this bad?** it's less clear that we are pushing a single character
///
/// **Known problems:** None
///
/// **Example:**
/// ```
/// let mut string = String::new();
/// string.push_str("R");
/// ```
/// Could be written as
/// ```
/// let mut string = String::new();
/// string.push('R');
/// ```
pub SINGLE_CHAR_PUSH_STR,
style,
"`push_str()` used with a single-character string literal as parameter"
}
declare_lint_pass!(Methods => [
UNWRAP_USED,
EXPECT_USED,
@ -1327,6 +1350,7 @@ declare_lint_pass!(Methods => [
INEFFICIENT_TO_STRING,
NEW_RET_NO_SELF,
SINGLE_CHAR_PATTERN,
SINGLE_CHAR_PUSH_STR,
SEARCH_IS_SOME,
TEMPORARY_CSTRING_AS_PTR,
FILTER_NEXT,
@ -1441,6 +1465,12 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
inefficient_to_string::lint(cx, expr, &args[0], self_ty);
}
if let Some(fn_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id) {
if match_def_path(cx, fn_def_id, &paths::PUSH_STR) {
lint_single_char_push_string(cx, expr, args);
}
}
match self_ty.kind {
ty::Ref(_, ty, _) if ty.kind == ty::Str => {
for &(method, pos) in &PATTERN_METHODS {
@ -3124,15 +3154,18 @@ fn lint_chars_last_cmp_with_unwrap<'tcx>(cx: &LateContext<'tcx>, info: &BinaryEx
}
}
/// lint for length-1 `str`s for methods in `PATTERN_METHODS`
fn lint_single_char_pattern<'tcx>(cx: &LateContext<'tcx>, _expr: &'tcx hir::Expr<'_>, arg: &'tcx hir::Expr<'_>) {
fn get_hint_if_single_char_arg<'tcx>(
cx: &LateContext<'tcx>,
arg: &'tcx hir::Expr<'_>,
applicability: &mut Applicability,
) -> Option<String> {
if_chain! {
if let hir::ExprKind::Lit(lit) = &arg.kind;
if let ast::LitKind::Str(r, style) = lit.node;
if r.as_str().len() == 1;
let string = r.as_str();
if string.len() == 1;
then {
let mut applicability = Applicability::MachineApplicable;
let snip = snippet_with_applicability(cx, arg.span, "..", &mut applicability);
let snip = snippet_with_applicability(cx, arg.span, &string, applicability);
let ch = if let ast::StrStyle::Raw(nhash) = style {
let nhash = nhash as usize;
// for raw string: r##"a"##
@ -3142,19 +3175,47 @@ fn lint_single_char_pattern<'tcx>(cx: &LateContext<'tcx>, _expr: &'tcx hir::Expr
&snip[1..(snip.len() - 1)]
};
let hint = format!("'{}'", if ch == "'" { "\\'" } else { ch });
span_lint_and_sugg(
cx,
SINGLE_CHAR_PATTERN,
arg.span,
"single-character string constant used as pattern",
"try using a `char` instead",
hint,
applicability,
);
Some(hint)
} else {
None
}
}
}
/// lint for length-1 `str`s for methods in `PATTERN_METHODS`
fn lint_single_char_pattern<'tcx>(cx: &LateContext<'tcx>, _expr: &'tcx hir::Expr<'_>, arg: &'tcx hir::Expr<'_>) {
let mut applicability = Applicability::MachineApplicable;
if let Some(hint) = get_hint_if_single_char_arg(cx, arg, &mut applicability) {
span_lint_and_sugg(
cx,
SINGLE_CHAR_PATTERN,
arg.span,
"single-character string constant used as pattern",
"try using a `char` instead",
hint,
applicability,
);
}
}
/// lint for length-1 `str`s as argument for `push_str`
fn lint_single_char_push_string<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, args: &'tcx [hir::Expr<'_>]) {
let mut applicability = Applicability::MachineApplicable;
if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[1], &mut applicability) {
let base_string_snippet = snippet_with_applicability(cx, args[0].span, "_", &mut applicability);
let sugg = format!("{}.push({})", base_string_snippet, extension_string);
span_lint_and_sugg(
cx,
SINGLE_CHAR_PUSH_STR,
expr.span,
"calling `push_str()` using a single-character string literal",
"consider using `push` with a character literal",
sugg,
applicability,
);
}
}
/// Checks for the `USELESS_ASREF` lint.
fn lint_asref(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_ref_args: &[hir::Expr<'_>]) {
// when we get here, we've already checked that the call name is "as_ref" or "as_mut"

62
clippy_lints/src/single_char_push_str.rs
View File

@ -1,62 +0,0 @@
use crate::utils::{match_def_path, paths, snippet_with_applicability, span_lint_and_sugg};
use if_chain::if_chain;
use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
/// **What it does:** Warns when using push_str with a single-character string literal,
/// and push with a char would work fine.
///
/// **Why is this bad?** This is in all probability not the intended outcome. At
/// the least it hurts readability of the code.
///
/// **Known problems:** None
///
/// **Example:**
/// ```
/// let mut string = String::new();
/// string.push_str("R");
/// ```
/// Could be written as
/// ```
/// let mut string = String::new();
/// string.push('R');
/// ```
pub SINGLE_CHAR_PUSH_STR,
style,
"`push_str()` used with a single-character string literal as parameter"
}
declare_lint_pass!(SingleCharPushStrPass => [SINGLE_CHAR_PUSH_STR]);
impl<'tcx> LateLintPass<'tcx> for SingleCharPushStrPass {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if_chain! {
if let ExprKind::MethodCall(_, _, ref args, _) = expr.kind;
if let [base_string, extension_string] = args;
if let Some(fn_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
if match_def_path(cx, fn_def_id, &paths::PUSH_STR);
if let ExprKind::Lit(ref lit) = extension_string.kind;
if let LitKind::Str(symbol,_) = lit.node;
let extension_string_val = symbol.as_str().to_string();
if extension_string_val.len() == 1;
then {
let mut applicability = Applicability::MachineApplicable;
let base_string_snippet = snippet_with_applicability(cx, base_string.span, "_", &mut applicability);
let sugg = format!("{}.push({:?})", base_string_snippet, extension_string_val.chars().next().unwrap());
span_lint_and_sugg(
cx,
SINGLE_CHAR_PUSH_STR,
expr.span,
"calling `push_str()` using a single-character string literal",
"consider using `push` with a character literal",
sugg,
applicability
);
}
}
}
}

2
src/lintlist/mod.rs
View File

@ -2017,7 +2017,7 @@ pub static ref ALL_LINTS: Vec<Lint> = vec![
group: "style",
desc: "`push_str()` used with a single-character string literal as parameter",
deprecation: None,
module: "single_char_push_str",
module: "methods",
},
Lint {
name: "single_component_path_imports",

5
tests/ui/single_char_push_str.fixed
View File

@ -7,4 +7,9 @@ fn main() {
string.push('\'');
string.push('u');
string.push_str("st");
string.push_str("");
string.push('\x52');
string.push('\u{0052}');
string.push('a');
}

5
tests/ui/single_char_push_str.rs
View File

@ -7,4 +7,9 @@ fn main() {
string.push_str("'");
string.push('u');
string.push_str("st");
string.push_str("");
string.push_str("\x52");
string.push_str("\u{0052}");
string.push_str(r##"a"##);
}

20
tests/ui/single_char_push_str.stderr
View File

@ -12,5 +12,23 @@ error: calling `push_str()` using a single-character string literal
LL | string.push_str("'");
| ^^^^^^^^^^^^^^^^^^^^ help: consider using `push` with a character literal: `string.push('/'')`
error: aborting due to 2 previous errors
error: calling `push_str()` using a single-character string literal
--> $DIR/single_char_push_str.rs:12:5
|
LL | string.push_str("/x52");
| ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `push` with a character literal: `string.push('/x52')`
error: calling `push_str()` using a single-character string literal
--> $DIR/single_char_push_str.rs:13:5
|
LL | string.push_str("/u{0052}");
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `push` with a character literal: `string.push('/u{0052}')`
error: calling `push_str()` using a single-character string literal
--> $DIR/single_char_push_str.rs:14:5
|
LL | string.push_str(r##"a"##);
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `push` with a character literal: `string.push('a')`
error: aborting due to 5 previous errors