Refactor while let on iterator lint to its module; rename for loop explicit counter to explicit counter loop
This commit is contained in:
nahuakang
Yoshitomo Nakanishi
parent
455d0476b1
commit
d0b657c0b7
3 changed files with 179 additions and 166 deletions
|
|
@ -1,5 +1,5 @@
|
|||
mod explicit_counter_loop;
|
||||
mod for_loop_arg;
|
||||
mod for_loop_explicit_counter;
|
||||
mod for_loop_over_map_kv;
|
||||
mod for_loop_range;
|
||||
mod for_mut_range_bound;
|
||||
|
|
@ -11,27 +11,20 @@ mod needless_collect;
|
|||
mod never_loop;
|
||||
mod same_item_push;
|
||||
mod utils;
|
||||
mod while_let_on_iterator;
|
||||
|
||||
use crate::utils::sugg::Sugg;
|
||||
use crate::utils::usage::mutated_variables;
|
||||
use crate::utils::{
|
||||
get_enclosing_block, get_trait_def_id, higher, implements_trait, is_in_panic_handler, is_no_std_crate,
|
||||
is_refutable, last_path_segment, match_trait_method, path_to_local, path_to_local_id, paths,
|
||||
snippet_with_applicability, span_lint_and_help, span_lint_and_sugg, sugg,
|
||||
higher, is_in_panic_handler, is_no_std_crate, snippet_with_applicability, span_lint_and_help, span_lint_and_sugg,
|
||||
sugg,
|
||||
};
|
||||
use if_chain::if_chain;
|
||||
use rustc_errors::Applicability;
|
||||
use rustc_hir::intravisit::{walk_block, walk_expr, NestedVisitorMap, Visitor};
|
||||
use rustc_hir::{Block, Expr, ExprKind, HirId, LoopSource, MatchSource, Node, Pat, PatKind, StmtKind};
|
||||
use rustc_hir::{Block, Expr, ExprKind, LoopSource, MatchSource, Pat, StmtKind};
|
||||
use rustc_lint::{LateContext, LateLintPass, LintContext};
|
||||
use rustc_middle::hir::map::Map;
|
||||
use rustc_middle::lint::in_external_macro;
|
||||
use rustc_session::{declare_lint_pass, declare_tool_lint};
|
||||
use rustc_span::source_map::Span;
|
||||
use rustc_span::symbol::sym;
|
||||
use utils::{
|
||||
get_span_of_entire_for_loop, make_iterator_snippet, IncrementVisitor, InitializeVisitor, LoopNestVisitor, Nesting,
|
||||
};
|
||||
use utils::{get_span_of_entire_for_loop, make_iterator_snippet, IncrementVisitor, InitializeVisitor};
|
||||
|
||||
declare_clippy_lint! {
|
||||
/// **What it does:** Checks for for-loops that manually copy items between
|
||||
|
|
@ -625,54 +618,8 @@ impl<'tcx> LateLintPass<'tcx> for Loops {
|
|||
}
|
||||
}
|
||||
}
|
||||
if let ExprKind::Match(ref match_expr, ref arms, MatchSource::WhileLetDesugar) = expr.kind {
|
||||
let pat = &arms[0].pat.kind;
|
||||
if let (
|
||||
&PatKind::TupleStruct(ref qpath, ref pat_args, _),
|
||||
&ExprKind::MethodCall(ref method_path, _, ref method_args, _),
|
||||
) = (pat, &match_expr.kind)
|
||||
{
|
||||
let iter_expr = &method_args[0];
|
||||
|
||||
// Don't lint when the iterator is recreated on every iteration
|
||||
if_chain! {
|
||||
if let ExprKind::MethodCall(..) | ExprKind::Call(..) = iter_expr.kind;
|
||||
if let Some(iter_def_id) = get_trait_def_id(cx, &paths::ITERATOR);
|
||||
if implements_trait(cx, cx.typeck_results().expr_ty(iter_expr), iter_def_id, &[]);
|
||||
then {
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
let lhs_constructor = last_path_segment(qpath);
|
||||
if method_path.ident.name == sym::next
|
||||
&& match_trait_method(cx, match_expr, &paths::ITERATOR)
|
||||
&& lhs_constructor.ident.name == sym::Some
|
||||
&& (pat_args.is_empty()
|
||||
|| !is_refutable(cx, &pat_args[0])
|
||||
&& !is_used_inside(cx, iter_expr, &arms[0].body)
|
||||
&& !is_iterator_used_after_while_let(cx, iter_expr)
|
||||
&& !is_nested(cx, expr, &method_args[0]))
|
||||
{
|
||||
let mut applicability = Applicability::MachineApplicable;
|
||||
let iterator = snippet_with_applicability(cx, method_args[0].span, "_", &mut applicability);
|
||||
let loop_var = if pat_args.is_empty() {
|
||||
"_".to_string()
|
||||
} else {
|
||||
snippet_with_applicability(cx, pat_args[0].span, "_", &mut applicability).into_owned()
|
||||
};
|
||||
span_lint_and_sugg(
|
||||
cx,
|
||||
WHILE_LET_ON_ITERATOR,
|
||||
expr.span.with_hi(match_expr.span.hi()),
|
||||
"this loop could be written as a `for` loop",
|
||||
"try",
|
||||
format!("for {} in {}", loop_var, iterator),
|
||||
applicability,
|
||||
);
|
||||
}
|
||||
}
|
||||
}
|
||||
while_let_on_iterator::check_while_let_on_iterator(cx, expr);
|
||||
|
||||
if let Some((cond, body)) = higher::while_loop(&expr) {
|
||||
infinite_loop::check_infinite_loop(cx, cond, body);
|
||||
|
|
@ -693,7 +640,7 @@ fn check_for_loop<'tcx>(
|
|||
let is_manual_memcpy_triggered = manual_memcpy::detect_manual_memcpy(cx, pat, arg, body, expr);
|
||||
if !is_manual_memcpy_triggered {
|
||||
for_loop_range::check_for_loop_range(cx, pat, arg, body, expr);
|
||||
for_loop_explicit_counter::check_for_loop_explicit_counter(cx, pat, arg, body, expr);
|
||||
explicit_counter_loop::check_for_loop_explicit_counter(cx, pat, arg, body, expr);
|
||||
}
|
||||
for_loop_arg::check_for_loop_arg(cx, pat, arg, expr);
|
||||
for_loop_over_map_kv::check_for_loop_over_map_kv(cx, pat, arg, body, expr);
|
||||
|
|
@ -773,61 +720,6 @@ impl std::ops::Sub<&MinifyingSugg<'static>> for MinifyingSugg<'static> {
|
|||
}
|
||||
}
|
||||
|
||||
fn is_used_inside<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, container: &'tcx Expr<'_>) -> bool {
|
||||
let def_id = match path_to_local(expr) {
|
||||
Some(id) => id,
|
||||
None => return false,
|
||||
};
|
||||
if let Some(used_mutably) = mutated_variables(container, cx) {
|
||||
if used_mutably.contains(&def_id) {
|
||||
return true;
|
||||
}
|
||||
}
|
||||
false
|
||||
}
|
||||
|
||||
fn is_iterator_used_after_while_let<'tcx>(cx: &LateContext<'tcx>, iter_expr: &'tcx Expr<'_>) -> bool {
|
||||
let def_id = match path_to_local(iter_expr) {
|
||||
Some(id) => id,
|
||||
None => return false,
|
||||
};
|
||||
let mut visitor = VarUsedAfterLoopVisitor {
|
||||
def_id,
|
||||
iter_expr_id: iter_expr.hir_id,
|
||||
past_while_let: false,
|
||||
var_used_after_while_let: false,
|
||||
};
|
||||
if let Some(enclosing_block) = get_enclosing_block(cx, def_id) {
|
||||
walk_block(&mut visitor, enclosing_block);
|
||||
}
|
||||
visitor.var_used_after_while_let
|
||||
}
|
||||
|
||||
struct VarUsedAfterLoopVisitor {
|
||||
def_id: HirId,
|
||||
iter_expr_id: HirId,
|
||||
past_while_let: bool,
|
||||
var_used_after_while_let: bool,
|
||||
}
|
||||
|
||||
impl<'tcx> Visitor<'tcx> for VarUsedAfterLoopVisitor {
|
||||
type Map = Map<'tcx>;
|
||||
|
||||
fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
|
||||
if self.past_while_let {
|
||||
if path_to_local_id(expr, self.def_id) {
|
||||
self.var_used_after_while_let = true;
|
||||
}
|
||||
} else if self.iter_expr_id == expr.hir_id {
|
||||
self.past_while_let = true;
|
||||
}
|
||||
walk_expr(self, expr);
|
||||
}
|
||||
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
|
||||
NestedVisitorMap::None
|
||||
}
|
||||
}
|
||||
|
||||
/// If a block begins with a statement (possibly a `let` binding) and has an
|
||||
/// expression, return it.
|
||||
fn extract_expr_from_first_stmt<'tcx>(block: &Block<'tcx>) -> Option<&'tcx Expr<'tcx>> {
|
||||
|
|
@ -863,53 +755,3 @@ fn is_simple_break_expr(expr: &Expr<'_>) -> bool {
|
|||
_ => false,
|
||||
}
|
||||
}
|
||||
|
||||
fn is_nested(cx: &LateContext<'_>, match_expr: &Expr<'_>, iter_expr: &Expr<'_>) -> bool {
|
||||
if_chain! {
|
||||
if let Some(loop_block) = get_enclosing_block(cx, match_expr.hir_id);
|
||||
let parent_node = cx.tcx.hir().get_parent_node(loop_block.hir_id);
|
||||
if let Some(Node::Expr(loop_expr)) = cx.tcx.hir().find(parent_node);
|
||||
then {
|
||||
return is_loop_nested(cx, loop_expr, iter_expr)
|
||||
}
|
||||
}
|
||||
false
|
||||
}
|
||||
|
||||
fn is_loop_nested(cx: &LateContext<'_>, loop_expr: &Expr<'_>, iter_expr: &Expr<'_>) -> bool {
|
||||
let mut id = loop_expr.hir_id;
|
||||
let iter_id = if let Some(id) = path_to_local(iter_expr) {
|
||||
id
|
||||
} else {
|
||||
return true;
|
||||
};
|
||||
loop {
|
||||
let parent = cx.tcx.hir().get_parent_node(id);
|
||||
if parent == id {
|
||||
return false;
|
||||
}
|
||||
match cx.tcx.hir().find(parent) {
|
||||
Some(Node::Expr(expr)) => {
|
||||
if let ExprKind::Loop(..) = expr.kind {
|
||||
return true;
|
||||
};
|
||||
},
|
||||
Some(Node::Block(block)) => {
|
||||
let mut block_visitor = LoopNestVisitor {
|
||||
hir_id: id,
|
||||
iterator: iter_id,
|
||||
nesting: Nesting::Unknown,
|
||||
};
|
||||
walk_block(&mut block_visitor, block);
|
||||
if block_visitor.nesting == Nesting::RuledOut {
|
||||
return false;
|
||||
}
|
||||
},
|
||||
Some(Node::Stmt(_)) => (),
|
||||
_ => {
|
||||
return false;
|
||||
},
|
||||
}
|
||||
id = parent;
|
||||
}
|
||||
}
|
||||
|
|
|
|||
171
clippy_lints/src/loops/while_let_on_iterator.rs
Normal file
171
clippy_lints/src/loops/while_let_on_iterator.rs
Normal file
|
|
@ -0,0 +1,171 @@
|
|||
use super::utils::{LoopNestVisitor, Nesting};
|
||||
use super::WHILE_LET_ON_ITERATOR;
|
||||
use crate::utils::usage::mutated_variables;
|
||||
use crate::utils::{
|
||||
get_enclosing_block, get_trait_def_id, implements_trait, is_refutable, last_path_segment, match_trait_method,
|
||||
path_to_local, path_to_local_id, paths, snippet_with_applicability, span_lint_and_sugg,
|
||||
};
|
||||
use if_chain::if_chain;
|
||||
use rustc_errors::Applicability;
|
||||
use rustc_hir::intravisit::{walk_block, walk_expr, NestedVisitorMap, Visitor};
|
||||
use rustc_hir::{Expr, ExprKind, HirId, MatchSource, Node, PatKind};
|
||||
use rustc_lint::LateContext;
|
||||
use rustc_middle::hir::map::Map;
|
||||
|
||||
use rustc_span::symbol::sym;
|
||||
|
||||
pub(super) fn check_while_let_on_iterator(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
|
||||
if let ExprKind::Match(ref match_expr, ref arms, MatchSource::WhileLetDesugar) = expr.kind {
|
||||
let pat = &arms[0].pat.kind;
|
||||
if let (
|
||||
&PatKind::TupleStruct(ref qpath, ref pat_args, _),
|
||||
&ExprKind::MethodCall(ref method_path, _, ref method_args, _),
|
||||
) = (pat, &match_expr.kind)
|
||||
{
|
||||
let iter_expr = &method_args[0];
|
||||
|
||||
// Don't lint when the iterator is recreated on every iteration
|
||||
if_chain! {
|
||||
if let ExprKind::MethodCall(..) | ExprKind::Call(..) = iter_expr.kind;
|
||||
if let Some(iter_def_id) = get_trait_def_id(cx, &paths::ITERATOR);
|
||||
if implements_trait(cx, cx.typeck_results().expr_ty(iter_expr), iter_def_id, &[]);
|
||||
then {
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
let lhs_constructor = last_path_segment(qpath);
|
||||
if method_path.ident.name == sym::next
|
||||
&& match_trait_method(cx, match_expr, &paths::ITERATOR)
|
||||
&& lhs_constructor.ident.name == sym::Some
|
||||
&& (pat_args.is_empty()
|
||||
|| !is_refutable(cx, &pat_args[0])
|
||||
&& !is_used_inside(cx, iter_expr, &arms[0].body)
|
||||
&& !is_iterator_used_after_while_let(cx, iter_expr)
|
||||
&& !is_nested(cx, expr, &method_args[0]))
|
||||
{
|
||||
let mut applicability = Applicability::MachineApplicable;
|
||||
let iterator = snippet_with_applicability(cx, method_args[0].span, "_", &mut applicability);
|
||||
let loop_var = if pat_args.is_empty() {
|
||||
"_".to_string()
|
||||
} else {
|
||||
snippet_with_applicability(cx, pat_args[0].span, "_", &mut applicability).into_owned()
|
||||
};
|
||||
span_lint_and_sugg(
|
||||
cx,
|
||||
WHILE_LET_ON_ITERATOR,
|
||||
expr.span.with_hi(match_expr.span.hi()),
|
||||
"this loop could be written as a `for` loop",
|
||||
"try",
|
||||
format!("for {} in {}", loop_var, iterator),
|
||||
applicability,
|
||||
);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn is_used_inside<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, container: &'tcx Expr<'_>) -> bool {
|
||||
let def_id = match path_to_local(expr) {
|
||||
Some(id) => id,
|
||||
None => return false,
|
||||
};
|
||||
if let Some(used_mutably) = mutated_variables(container, cx) {
|
||||
if used_mutably.contains(&def_id) {
|
||||
return true;
|
||||
}
|
||||
}
|
||||
false
|
||||
}
|
||||
|
||||
fn is_iterator_used_after_while_let<'tcx>(cx: &LateContext<'tcx>, iter_expr: &'tcx Expr<'_>) -> bool {
|
||||
let def_id = match path_to_local(iter_expr) {
|
||||
Some(id) => id,
|
||||
None => return false,
|
||||
};
|
||||
let mut visitor = VarUsedAfterLoopVisitor {
|
||||
def_id,
|
||||
iter_expr_id: iter_expr.hir_id,
|
||||
past_while_let: false,
|
||||
var_used_after_while_let: false,
|
||||
};
|
||||
if let Some(enclosing_block) = get_enclosing_block(cx, def_id) {
|
||||
walk_block(&mut visitor, enclosing_block);
|
||||
}
|
||||
visitor.var_used_after_while_let
|
||||
}
|
||||
|
||||
fn is_nested(cx: &LateContext<'_>, match_expr: &Expr<'_>, iter_expr: &Expr<'_>) -> bool {
|
||||
if_chain! {
|
||||
if let Some(loop_block) = get_enclosing_block(cx, match_expr.hir_id);
|
||||
let parent_node = cx.tcx.hir().get_parent_node(loop_block.hir_id);
|
||||
if let Some(Node::Expr(loop_expr)) = cx.tcx.hir().find(parent_node);
|
||||
then {
|
||||
return is_loop_nested(cx, loop_expr, iter_expr)
|
||||
}
|
||||
}
|
||||
false
|
||||
}
|
||||
|
||||
fn is_loop_nested(cx: &LateContext<'_>, loop_expr: &Expr<'_>, iter_expr: &Expr<'_>) -> bool {
|
||||
let mut id = loop_expr.hir_id;
|
||||
let iter_id = if let Some(id) = path_to_local(iter_expr) {
|
||||
id
|
||||
} else {
|
||||
return true;
|
||||
};
|
||||
loop {
|
||||
let parent = cx.tcx.hir().get_parent_node(id);
|
||||
if parent == id {
|
||||
return false;
|
||||
}
|
||||
match cx.tcx.hir().find(parent) {
|
||||
Some(Node::Expr(expr)) => {
|
||||
if let ExprKind::Loop(..) = expr.kind {
|
||||
return true;
|
||||
};
|
||||
},
|
||||
Some(Node::Block(block)) => {
|
||||
let mut block_visitor = LoopNestVisitor {
|
||||
hir_id: id,
|
||||
iterator: iter_id,
|
||||
nesting: Nesting::Unknown,
|
||||
};
|
||||
walk_block(&mut block_visitor, block);
|
||||
if block_visitor.nesting == Nesting::RuledOut {
|
||||
return false;
|
||||
}
|
||||
},
|
||||
Some(Node::Stmt(_)) => (),
|
||||
_ => {
|
||||
return false;
|
||||
},
|
||||
}
|
||||
id = parent;
|
||||
}
|
||||
}
|
||||
|
||||
struct VarUsedAfterLoopVisitor {
|
||||
def_id: HirId,
|
||||
iter_expr_id: HirId,
|
||||
past_while_let: bool,
|
||||
var_used_after_while_let: bool,
|
||||
}
|
||||
|
||||
impl<'tcx> Visitor<'tcx> for VarUsedAfterLoopVisitor {
|
||||
type Map = Map<'tcx>;
|
||||
|
||||
fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
|
||||
if self.past_while_let {
|
||||
if path_to_local_id(expr, self.def_id) {
|
||||
self.var_used_after_while_let = true;
|
||||
}
|
||||
} else if self.iter_expr_id == expr.hir_id {
|
||||
self.past_while_let = true;
|
||||
}
|
||||
walk_expr(self, expr);
|
||||
}
|
||||
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
|
||||
NestedVisitorMap::None
|
||||
}
|
||||
}
|
||||
Loading…
Reference in a new issue