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Split out match_bool

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This commit is contained in:
Jason Newcomb 2022-02-06 14:25:53 -05:00
parent f23dc16e1d
commit f3dd909e0f
2 changed files with 80 additions and 69 deletions
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75
clippy_lints/src/matches/match_bool.rs Normal file
View File

@ -0,0 +1,75 @@
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::is_unit_expr;
use clippy_utils::source::{expr_block, snippet};
use clippy_utils::sugg::Sugg;
use rustc_ast::LitKind;
use rustc_errors::Applicability;
use rustc_hir::{Arm, Expr, ExprKind, PatKind};
use rustc_lint::LateContext;
use rustc_middle::ty;
use super::MATCH_BOOL;
pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
// Type of expression is `bool`.
if *cx.typeck_results().expr_ty(ex).kind() == ty::Bool {
span_lint_and_then(
cx,
MATCH_BOOL,
expr.span,
"you seem to be trying to match on a boolean expression",
move |diag| {
if arms.len() == 2 {
// no guards
let exprs = if let PatKind::Lit(arm_bool) = arms[0].pat.kind {
if let ExprKind::Lit(ref lit) = arm_bool.kind {
match lit.node {
LitKind::Bool(true) => Some((&*arms[0].body, &*arms[1].body)),
LitKind::Bool(false) => Some((&*arms[1].body, &*arms[0].body)),
_ => None,
}
} else {
None
}
} else {
None
};
if let Some((true_expr, false_expr)) = exprs {
let sugg = match (is_unit_expr(true_expr), is_unit_expr(false_expr)) {
(false, false) => Some(format!(
"if {} {} else {}",
snippet(cx, ex.span, "b"),
expr_block(cx, true_expr, None, "..", Some(expr.span)),
expr_block(cx, false_expr, None, "..", Some(expr.span))
)),
(false, true) => Some(format!(
"if {} {}",
snippet(cx, ex.span, "b"),
expr_block(cx, true_expr, None, "..", Some(expr.span))
)),
(true, false) => {
let test = Sugg::hir(cx, ex, "..");
Some(format!(
"if {} {}",
!test,
expr_block(cx, false_expr, None, "..", Some(expr.span))
))
},
(true, true) => None,
};
if let Some(sugg) = sugg {
diag.span_suggestion(
expr.span,
"consider using an `if`/`else` expression",
sugg,
Applicability::HasPlaceholders,
);
}
}
}
},
);
}
}

74
clippy_lints/src/matches/mod.rs
View File

@ -4,17 +4,16 @@
};
use clippy_utils::macros::{is_panic, root_macro_call};
use clippy_utils::peel_blocks_with_stmt;
use clippy_utils::source::{expr_block, indent_of, snippet, snippet_block, snippet_opt, snippet_with_applicability};
use clippy_utils::source::{indent_of, snippet, snippet_block, snippet_opt, snippet_with_applicability};
use clippy_utils::sugg::Sugg;
use clippy_utils::ty::is_type_diagnostic_item;
use clippy_utils::visitors::is_local_used;
use clippy_utils::{
get_parent_expr, is_lang_ctor, is_refutable, is_unit_expr, is_wild, meets_msrv, msrvs, path_to_local_id,
peel_blocks, peel_hir_pat_refs, recurse_or_patterns, strip_pat_refs,
get_parent_expr, is_lang_ctor, is_refutable, is_wild, meets_msrv, msrvs, path_to_local_id, peel_blocks,
peel_hir_pat_refs, recurse_or_patterns, strip_pat_refs,
};
use core::iter::once;
use if_chain::if_chain;
use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
use rustc_hir::def::{CtorKind, DefKind, Res};
use rustc_hir::LangItem::{OptionNone, OptionSome};
@ -29,6 +28,7 @@
use rustc_span::{sym, symbol::kw, Span};
use std::cmp::Ordering;
mod match_bool;
mod match_like_matches;
mod match_same_arms;
mod redundant_pattern_match;
@ -631,7 +631,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if let ExprKind::Match(ex, arms, MatchSource::Normal) = expr.kind {
single_match::check(cx, ex, arms, expr);
check_match_bool(cx, ex, arms, expr);
match_bool::check(cx, ex, arms, expr);
check_overlapping_arms(cx, ex, arms);
check_wild_err_arm(cx, ex, arms);
check_wild_enum_match(cx, ex, arms);
@ -710,70 +710,6 @@ fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
extract_msrv_attr!(LateContext);
}
fn check_match_bool(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
// Type of expression is `bool`.
if *cx.typeck_results().expr_ty(ex).kind() == ty::Bool {
span_lint_and_then(
cx,
MATCH_BOOL,
expr.span,
"you seem to be trying to match on a boolean expression",
move |diag| {
if arms.len() == 2 {
// no guards
let exprs = if let PatKind::Lit(arm_bool) = arms[0].pat.kind {
if let ExprKind::Lit(ref lit) = arm_bool.kind {
match lit.node {
LitKind::Bool(true) => Some((&*arms[0].body, &*arms[1].body)),
LitKind::Bool(false) => Some((&*arms[1].body, &*arms[0].body)),
_ => None,
}
} else {
None
}
} else {
None
};
if let Some((true_expr, false_expr)) = exprs {
let sugg = match (is_unit_expr(true_expr), is_unit_expr(false_expr)) {
(false, false) => Some(format!(
"if {} {} else {}",
snippet(cx, ex.span, "b"),
expr_block(cx, true_expr, None, "..", Some(expr.span)),
expr_block(cx, false_expr, None, "..", Some(expr.span))
)),
(false, true) => Some(format!(
"if {} {}",
snippet(cx, ex.span, "b"),
expr_block(cx, true_expr, None, "..", Some(expr.span))
)),
(true, false) => {
let test = Sugg::hir(cx, ex, "..");
Some(format!(
"if {} {}",
!test,
expr_block(cx, false_expr, None, "..", Some(expr.span))
))
},
(true, true) => None,
};
if let Some(sugg) = sugg {
diag.span_suggestion(
expr.span,
"consider using an `if`/`else` expression",
sugg,
Applicability::HasPlaceholders,
);
}
}
}
},
);
}
}
fn check_overlapping_arms<'tcx>(cx: &LateContext<'tcx>, ex: &'tcx Expr<'_>, arms: &'tcx [Arm<'_>]) {
if arms.len() >= 2 && cx.typeck_results().expr_ty(ex).is_integral() {
let ranges = all_ranges(cx, arms, cx.typeck_results().expr_ty(ex));