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Auto merge of #8042 - camsteffen:peel-blocks, r=xFrednet

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Peel blocks and statements utils

changelog: none

* Rename `remove_blocks` to `peel_blocks`
* Add `peel_blocks_and_stmts`
* Various refactors to use the above utils
* The utils also now check `block.rules`
This commit is contained in:
bors 2021-12-06 18:34:27 +00:00
commit 48d939f516
24 changed files with 197 additions and 319 deletions
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12
clippy_lints/src/assertions_on_constants.rs
View File

@ -2,7 +2,7 @@
use clippy_utils::diagnostics::span_lint_and_help;
use clippy_utils::higher;
use clippy_utils::source::snippet_opt;
use clippy_utils::{is_direct_expn_of, is_expn_of, match_panic_call};
use clippy_utils::{is_direct_expn_of, is_expn_of, match_panic_call, peel_blocks};
use if_chain::if_chain;
use rustc_hir::{Expr, ExprKind, UnOp};
use rustc_lint::{LateContext, LateLintPass};
@ -122,15 +122,7 @@ fn match_assert_with_message<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>)
if let ExprKind::Unary(UnOp::Not, expr) = cond.kind;
// bind the first argument of the `assert!` macro
if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), expr);
// block
if let ExprKind::Block(block, _) = then.kind;
if block.stmts.is_empty();
if let Some(block_expr) = &block.expr;
// inner block is optional. unwrap it if it exists, or use the expression as is otherwise.
if let Some(begin_panic_call) = match block_expr.kind {
ExprKind::Block(inner_block, _) => &inner_block.expr,
_ => &block.expr,
};
let begin_panic_call = peel_blocks(then);
// function call
if let Some(arg) = match_panic_call(cx, begin_panic_call);
// bind the second argument of the `assert!` macro if it exists

4
clippy_lints/src/bytecount.rs
View File

@ -2,7 +2,7 @@
use clippy_utils::source::snippet_with_applicability;
use clippy_utils::ty::match_type;
use clippy_utils::visitors::is_local_used;
use clippy_utils::{path_to_local_id, paths, peel_ref_operators, remove_blocks, strip_pat_refs};
use clippy_utils::{path_to_local_id, paths, peel_blocks, peel_ref_operators, strip_pat_refs};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{BinOpKind, Expr, ExprKind, PatKind};
@ -55,7 +55,7 @@ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
cx.typeck_results().expr_ty(filter_recv).peel_refs(),
&paths::SLICE_ITER);
let operand_is_arg = |expr| {
let expr = peel_ref_operators(cx, remove_blocks(expr));
let expr = peel_ref_operators(cx, peel_blocks(expr));
path_to_local_id(expr, arg_id)
};
let needle = if operand_is_arg(l) {

20
clippy_lints/src/collapsible_match.rs
View File

@ -1,10 +1,10 @@
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::higher::IfLetOrMatch;
use clippy_utils::visitors::is_local_used;
use clippy_utils::{is_lang_ctor, is_unit_expr, path_to_local, peel_ref_operators, SpanlessEq};
use clippy_utils::{is_lang_ctor, is_unit_expr, path_to_local, peel_blocks_with_stmt, peel_ref_operators, SpanlessEq};
use if_chain::if_chain;
use rustc_hir::LangItem::OptionNone;
use rustc_hir::{Arm, Expr, ExprKind, Guard, HirId, Pat, PatKind, StmtKind};
use rustc_hir::{Arm, Expr, Guard, HirId, Pat, PatKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::{MultiSpan, Span};
@ -75,7 +75,7 @@ fn check_arm<'tcx>(
outer_guard: Option<&'tcx Guard<'tcx>>,
outer_else_body: Option<&'tcx Expr<'tcx>>,
) {
let inner_expr = strip_singleton_blocks(outer_then_body);
let inner_expr = peel_blocks_with_stmt(outer_then_body);
if_chain! {
if let Some(inner) = IfLetOrMatch::parse(cx, inner_expr);
if let Some((inner_scrutinee, inner_then_pat, inner_else_body)) = match inner {
@ -138,20 +138,6 @@ fn check_arm<'tcx>(
}
}
fn strip_singleton_blocks<'hir>(mut expr: &'hir Expr<'hir>) -> &'hir Expr<'hir> {
while let ExprKind::Block(block, _) = expr.kind {
match (block.stmts, block.expr) {
([stmt], None) => match stmt.kind {
StmtKind::Expr(e) | StmtKind::Semi(e) => expr = e,
_ => break,
},
([], Some(e)) => expr = e,
_ => break,
}
}
expr
}
/// A "wild-like" arm has a wild (`_`) or `None` pattern and no guard. Such arms can be "collapsed"
/// into a single wild arm without any significant loss in semantics or readability.
fn arm_is_wild_like(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool {

4
clippy_lints/src/derivable_impls.rs
View File

@ -1,5 +1,5 @@
use clippy_utils::diagnostics::span_lint_and_help;
use clippy_utils::{is_automatically_derived, is_default_equivalent, remove_blocks};
use clippy_utils::{is_automatically_derived, is_default_equivalent, peel_blocks};
use rustc_hir::{
def::{DefKind, Res},
Body, Expr, ExprKind, GenericArg, Impl, ImplItemKind, Item, ItemKind, Node, PathSegment, QPath, TyKind,
@ -95,7 +95,7 @@ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
}
}
}
let should_emit = match remove_blocks(func_expr).kind {
let should_emit = match peel_blocks(func_expr).kind {
ExprKind::Tup(fields) => fields.iter().all(|e| is_default_equivalent(cx, e)),
ExprKind::Call(callee, args)
if is_path_self(callee) => args.iter().all(|e| is_default_equivalent(cx, e)),

12
clippy_lints/src/floating_point_arithmetic.rs
View File

@ -4,7 +4,7 @@
};
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::higher;
use clippy_utils::{eq_expr_value, get_parent_expr, in_constant, numeric_literal, sugg};
use clippy_utils::{eq_expr_value, get_parent_expr, in_constant, numeric_literal, peel_blocks, sugg};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{BinOpKind, Expr, ExprKind, PathSegment, UnOp};
@ -546,13 +546,9 @@ fn are_negated<'a>(cx: &LateContext<'_>, expr1: &'a Expr<'a>, expr2: &'a Expr<'a
fn check_custom_abs(cx: &LateContext<'_>, expr: &Expr<'_>) {
if_chain! {
if let Some(higher::If { cond, then, r#else }) = higher::If::hir(expr);
if let ExprKind::Block(block, _) = then.kind;
if block.stmts.is_empty();
if let Some(if_body_expr) = block.expr;
if let Some(ExprKind::Block(else_block, _)) = r#else.map(|el| &el.kind);
if else_block.stmts.is_empty();
if let Some(else_body_expr) = else_block.expr;
if let Some(higher::If { cond, then, r#else: Some(r#else) }) = higher::If::hir(expr);
let if_body_expr = peel_blocks(then);
let else_body_expr = peel_blocks(r#else);
if let Some((if_expr_positive, body)) = are_negated(cx, if_body_expr, else_body_expr);
then {
let positive_abs_sugg = (

7
clippy_lints/src/if_then_some_else_none.rs
View File

@ -1,6 +1,6 @@
use clippy_utils::diagnostics::span_lint_and_help;
use clippy_utils::source::snippet_with_macro_callsite;
use clippy_utils::{contains_return, higher, is_else_clause, is_lang_ctor, meets_msrv, msrvs};
use clippy_utils::{contains_return, higher, is_else_clause, is_lang_ctor, meets_msrv, msrvs, peel_blocks};
use if_chain::if_chain;
use rustc_hir::LangItem::{OptionNone, OptionSome};
use rustc_hir::{Expr, ExprKind, Stmt, StmtKind};
@ -77,10 +77,7 @@ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'tcx Expr<'_>) {
if let ExprKind::Call(then_call, [then_arg]) = then_expr.kind;
if let ExprKind::Path(ref then_call_qpath) = then_call.kind;
if is_lang_ctor(cx, then_call_qpath, OptionSome);
if let ExprKind::Block(els_block, _) = els.kind;
if els_block.stmts.is_empty();
if let Some(els_expr) = els_block.expr;
if let ExprKind::Path(ref qpath) = els_expr.kind;
if let ExprKind::Path(ref qpath) = peel_blocks(els).kind;
if is_lang_ctor(cx, qpath, OptionNone);
if !stmts_contains_early_return(then_block.stmts);
then {

16
clippy_lints/src/implicit_saturating_sub.rs
View File

@ -1,10 +1,9 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::higher;
use clippy_utils::SpanlessEq;
use clippy_utils::{higher, peel_blocks_with_stmt, SpanlessEq};
use if_chain::if_chain;
use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
use rustc_hir::{lang_items::LangItem, BinOpKind, Expr, ExprKind, QPath, StmtKind};
use rustc_hir::{lang_items::LangItem, BinOpKind, Expr, ExprKind, QPath};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
@ -52,13 +51,8 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
// Ensure that the binary operator is >, != and <
if BinOpKind::Ne == cond_op.node || BinOpKind::Gt == cond_op.node || BinOpKind::Lt == cond_op.node;
// Check if the true condition block has only one statement
if let ExprKind::Block(block, _) = then.kind;
if block.stmts.len() == 1 && block.expr.is_none();
// Check if assign operation is done
if let StmtKind::Semi(e) = block.stmts[0].kind;
if let Some(target) = subtracts_one(cx, e);
if let Some(target) = subtracts_one(cx, then);
// Extracting out the variable name
if let ExprKind::Path(QPath::Resolved(_, ares_path)) = target.kind;
@ -138,8 +132,8 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
}
}
fn subtracts_one<'a>(cx: &LateContext<'_>, expr: &Expr<'a>) -> Option<&'a Expr<'a>> {
match expr.kind {
fn subtracts_one<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<&'a Expr<'a>> {
match peel_blocks_with_stmt(expr).kind {
ExprKind::AssignOp(ref op1, target, value) => {
if_chain! {
if BinOpKind::Sub == op1.node;

112
clippy_lints/src/loops/manual_flatten.rs
View File

@ -3,11 +3,11 @@
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::higher;
use clippy_utils::visitors::is_local_used;
use clippy_utils::{is_lang_ctor, path_to_local_id};
use clippy_utils::{is_lang_ctor, path_to_local_id, peel_blocks_with_stmt};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::LangItem::{OptionSome, ResultOk};
use rustc_hir::{Expr, ExprKind, Pat, PatKind, StmtKind};
use rustc_hir::{Expr, Pat, PatKind};
use rustc_lint::LateContext;
use rustc_middle::ty;
use rustc_span::source_map::Span;
@ -21,71 +21,55 @@ pub(super) fn check<'tcx>(
body: &'tcx Expr<'_>,
span: Span,
) {
if let ExprKind::Block(block, _) = body.kind {
// Ensure the `if let` statement is the only expression or statement in the for-loop
let inner_expr = if block.stmts.len() == 1 && block.expr.is_none() {
let match_stmt = &block.stmts[0];
if let StmtKind::Semi(inner_expr) = match_stmt.kind {
Some(inner_expr)
} else {
None
}
} else if block.stmts.is_empty() {
block.expr
} else {
None
};
let inner_expr = peel_blocks_with_stmt(body);
if_chain! {
if let Some(higher::IfLet { let_pat, let_expr, if_then, if_else: None })
= higher::IfLet::hir(cx, inner_expr);
// Ensure match_expr in `if let` statement is the same as the pat from the for-loop
if let PatKind::Binding(_, pat_hir_id, _, _) = pat.kind;
if path_to_local_id(let_expr, pat_hir_id);
// Ensure the `if let` statement is for the `Some` variant of `Option` or the `Ok` variant of `Result`
if let PatKind::TupleStruct(ref qpath, _, _) = let_pat.kind;
let some_ctor = is_lang_ctor(cx, qpath, OptionSome);
let ok_ctor = is_lang_ctor(cx, qpath, ResultOk);
if some_ctor || ok_ctor;
// Ensure expr in `if let` is not used afterwards
if !is_local_used(cx, if_then, pat_hir_id);
then {
let if_let_type = if some_ctor { "Some" } else { "Ok" };
// Prepare the error message
let msg = format!("unnecessary `if let` since only the `{}` variant of the iterator element is used", if_let_type);
if_chain! {
if let Some(inner_expr) = inner_expr;
if let Some(higher::IfLet { let_pat, let_expr, if_then, if_else: None })
= higher::IfLet::hir(cx, inner_expr);
// Ensure match_expr in `if let` statement is the same as the pat from the for-loop
if let PatKind::Binding(_, pat_hir_id, _, _) = pat.kind;
if path_to_local_id(let_expr, pat_hir_id);
// Ensure the `if let` statement is for the `Some` variant of `Option` or the `Ok` variant of `Result`
if let PatKind::TupleStruct(ref qpath, _, _) = let_pat.kind;
let some_ctor = is_lang_ctor(cx, qpath, OptionSome);
let ok_ctor = is_lang_ctor(cx, qpath, ResultOk);
if some_ctor || ok_ctor;
// Ensure epxr in `if let` is not used afterwards
if !is_local_used(cx, if_then, pat_hir_id);
then {
let if_let_type = if some_ctor { "Some" } else { "Ok" };
// Prepare the error message
let msg = format!("unnecessary `if let` since only the `{}` variant of the iterator element is used", if_let_type);
// Prepare the help message
let mut applicability = Applicability::MaybeIncorrect;
let arg_snippet = make_iterator_snippet(cx, arg, &mut applicability);
let copied = match cx.typeck_results().expr_ty(let_expr).kind() {
ty::Ref(_, inner, _) => match inner.kind() {
ty::Ref(..) => ".copied()",
_ => ""
}
// Prepare the help message
let mut applicability = Applicability::MaybeIncorrect;
let arg_snippet = make_iterator_snippet(cx, arg, &mut applicability);
let copied = match cx.typeck_results().expr_ty(let_expr).kind() {
ty::Ref(_, inner, _) => match inner.kind() {
ty::Ref(..) => ".copied()",
_ => ""
};
}
_ => ""
};
span_lint_and_then(
cx,
MANUAL_FLATTEN,
span,
&msg,
|diag| {
let sugg = format!("{}{}.flatten()", arg_snippet, copied);
diag.span_suggestion(
arg.span,
"try",
sugg,
Applicability::MaybeIncorrect,
);
diag.span_help(
inner_expr.span,
"...and remove the `if let` statement in the for loop",
);
}
);
}
span_lint_and_then(
cx,
MANUAL_FLATTEN,
span,
&msg,
|diag| {
let sugg = format!("{}{}.flatten()", arg_snippet, copied);
diag.span_suggestion(
arg.span,
"try",
sugg,
Applicability::MaybeIncorrect,
);
diag.span_help(
inner_expr.span,
"...and remove the `if let` statement in the for loop",
);
}
);
}
}
}

4
clippy_lints/src/loops/never_loop.rs
View File

@ -92,9 +92,7 @@ fn combine_branches(b1: NeverLoopResult, b2: NeverLoopResult) -> NeverLoopResult
}
fn never_loop_block(block: &Block<'_>, main_loop_id: HirId) -> NeverLoopResult {
let stmts = block.stmts.iter().map(stmt_to_expr);
let expr = once(block.expr);
let mut iter = stmts.chain(expr).flatten();
let mut iter = block.stmts.iter().filter_map(stmt_to_expr).chain(block.expr);
never_loop_expr_seq(&mut iter, main_loop_id)
}

15
clippy_lints/src/manual_map.rs
View File

@ -5,7 +5,7 @@
use clippy_utils::ty::{is_type_diagnostic_item, peel_mid_ty_refs_is_mutable, type_is_unsafe_function};
use clippy_utils::{
can_move_expr_to_closure, in_constant, is_else_clause, is_lang_ctor, is_lint_allowed, path_to_local_id,
peel_hir_expr_refs, peel_hir_expr_while, CaptureKind,
peel_blocks, peel_hir_expr_refs, peel_hir_expr_while, CaptureKind,
};
use rustc_ast::util::parser::PREC_POSTFIX;
use rustc_errors::Applicability;
@ -307,16 +307,5 @@ fn get_some_expr(
// Checks for the `None` value.
fn is_none_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
match expr.kind {
ExprKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
ExprKind::Block(
Block {
stmts: [],
expr: Some(expr),
..
},
_,
) => is_none_expr(cx, expr),
_ => false,
}
matches!(peel_blocks(expr).kind, ExprKind::Path(ref qpath) if is_lang_ctor(cx, qpath, OptionNone))
}

5
clippy_lints/src/map_clone.rs
View File

@ -1,8 +1,7 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::is_trait_method;
use clippy_utils::remove_blocks;
use clippy_utils::source::snippet_with_applicability;
use clippy_utils::ty::{is_copy, is_type_diagnostic_item};
use clippy_utils::{is_trait_method, peel_blocks};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
@ -60,7 +59,7 @@ fn check_expr(&mut self, cx: &LateContext<'_>, e: &hir::Expr<'_>) {
if let hir::ExprKind::Closure(_, _, body_id, _, _) = args[1].kind;
then {
let closure_body = cx.tcx.hir().body(body_id);
let closure_expr = remove_blocks(&closure_body.value);
let closure_expr = peel_blocks(&closure_body.value);
match closure_body.params[0].pat.kind {
hir::PatKind::Ref(inner, hir::Mutability::Not) => if let hir::PatKind::Binding(
hir::BindingAnnotation::Unannotated, .., name, None

10
clippy_lints/src/matches.rs
View File

@ -9,7 +9,7 @@
use clippy_utils::visitors::is_local_used;
use clippy_utils::{
get_parent_expr, is_expn_of, is_lang_ctor, is_lint_allowed, is_refutable, is_unit_expr, is_wild, meets_msrv, msrvs,
path_to_local, path_to_local_id, peel_hir_pat_refs, peel_n_hir_expr_refs, recurse_or_patterns, remove_blocks,
path_to_local, path_to_local_id, peel_blocks, peel_hir_pat_refs, peel_n_hir_expr_refs, recurse_or_patterns,
strip_pat_refs,
};
use clippy_utils::{paths, search_same, SpanlessEq, SpanlessHash};
@ -659,7 +659,7 @@ fn check_local(&mut self, cx: &LateContext<'tcx>, local: &'tcx Local<'_>) {
QPath::Resolved(None, variant_name), args, _) = arms[0].pat.kind;
if args.len() == 1;
if let PatKind::Binding(_, arg, ..) = strip_pat_refs(&args[0]).kind;
let body = remove_blocks(arms[0].body);
let body = peel_blocks(arms[0].body);
if path_to_local_id(body, arg);
then {
@ -724,7 +724,7 @@ fn check_single_match(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], exp
return;
}
let els = arms[1].body;
let els = if is_unit_expr(remove_blocks(els)) {
let els = if is_unit_expr(peel_blocks(els)) {
None
} else if let ExprKind::Block(Block { stmts, expr: block_expr, .. }, _) = els.kind {
if stmts.len() == 1 && block_expr.is_none() || stmts.is_empty() && block_expr.is_some() {
@ -1482,7 +1482,7 @@ fn check_match_single_binding<'a>(cx: &LateContext<'a>, ex: &Expr<'a>, arms: &[A
let matched_vars = ex.span;
let bind_names = arms[0].pat.span;
let match_body = remove_blocks(arms[0].body);
let match_body = peel_blocks(arms[0].body);
let mut snippet_body = if match_body.span.from_expansion() {
Sugg::hir_with_macro_callsite(cx, match_body, "..").to_string()
} else {
@ -1679,7 +1679,7 @@ fn is_ref_some_arm(cx: &LateContext<'_>, arm: &Arm<'_>) -> Option<BindingAnnotat
if is_lang_ctor(cx, qpath, OptionSome);
if let PatKind::Binding(rb, .., ident, _) = first_pat.kind;
if rb == BindingAnnotation::Ref || rb == BindingAnnotation::RefMut;
if let ExprKind::Call(e, args) = remove_blocks(arm.body).kind;
if let ExprKind::Call(e, args) = peel_blocks(arm.body).kind;
if let ExprKind::Path(ref some_path) = e.kind;
if is_lang_ctor(cx, some_path, OptionSome) && args.len() == 1;
if let ExprKind::Path(QPath::Resolved(_, path2)) = args[0].kind;

4
clippy_lints/src/methods/bind_instead_of_map.rs
View File

@ -1,7 +1,7 @@
use super::{contains_return, BIND_INSTEAD_OF_MAP};
use clippy_utils::diagnostics::{multispan_sugg_with_applicability, span_lint_and_sugg, span_lint_and_then};
use clippy_utils::source::{snippet, snippet_with_macro_callsite};
use clippy_utils::{remove_blocks, visitors::find_all_ret_expressions};
use clippy_utils::{peel_blocks, visitors::find_all_ret_expressions};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
@ -152,7 +152,7 @@ fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, arg:
match arg.kind {
hir::ExprKind::Closure(_, _, body_id, closure_args_span, _) => {
let closure_body = cx.tcx.hir().body(body_id);
let closure_expr = remove_blocks(&closure_body.value);
let closure_expr = peel_blocks(&closure_body.value);
if Self::lint_closure_autofixable(cx, expr, recv, closure_expr, closure_args_span) {
true

4
clippy_lints/src/methods/filter_map.rs
View File

@ -1,7 +1,7 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::source::{indent_of, reindent_multiline, snippet};
use clippy_utils::ty::is_type_diagnostic_item;
use clippy_utils::{is_trait_method, path_to_local_id, remove_blocks, SpanlessEq};
use clippy_utils::{is_trait_method, path_to_local_id, peel_blocks, SpanlessEq};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
@ -25,7 +25,7 @@ fn is_method<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, method_name: Sy
},
hir::ExprKind::Closure(_, _, c, _, _) => {
let body = cx.tcx.hir().body(*c);
let closure_expr = remove_blocks(&body.value);
let closure_expr = peel_blocks(&body.value);
let arg_id = body.params[0].pat.hir_id;
match closure_expr.kind {
hir::ExprKind::MethodCall(hir::PathSegment { ident, .. }, _, args, _) => {

4
clippy_lints/src/methods/option_as_ref_deref.rs
View File

@ -1,7 +1,7 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::source::snippet;
use clippy_utils::ty::is_type_diagnostic_item;
use clippy_utils::{match_def_path, meets_msrv, msrvs, path_to_local_id, paths, remove_blocks};
use clippy_utils::{match_def_path, meets_msrv, msrvs, path_to_local_id, paths, peel_blocks};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
@ -53,7 +53,7 @@ pub(super) fn check<'tcx>(
}),
hir::ExprKind::Closure(_, _, body_id, _, _) => {
let closure_body = cx.tcx.hir().body(body_id);
let closure_expr = remove_blocks(&closure_body.value);
let closure_expr = peel_blocks(&closure_body.value);
match &closure_expr.kind {
hir::ExprKind::MethodCall(_, _, args, _) => {

4
clippy_lints/src/methods/unnecessary_fold.rs
View File

@ -1,6 +1,6 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::source::snippet_with_applicability;
use clippy_utils::{is_trait_method, path_to_local_id, remove_blocks, strip_pat_refs};
use clippy_utils::{is_trait_method, path_to_local_id, peel_blocks, strip_pat_refs};
use if_chain::if_chain;
use rustc_ast::ast;
use rustc_errors::Applicability;
@ -31,7 +31,7 @@ fn check_fold_with_op(
// Extract the body of the closure passed to fold
if let hir::ExprKind::Closure(_, _, body_id, _, _) = acc.kind;
let closure_body = cx.tcx.hir().body(body_id);
let closure_expr = remove_blocks(&closure_body.value);
let closure_expr = peel_blocks(&closure_body.value);
// Check if the closure body is of the form `acc <op> some_expr(x)`
if let hir::ExprKind::Binary(ref bin_op, left_expr, right_expr) = closure_expr.kind;

63
clippy_lints/src/needless_bool.rs
View File

@ -6,10 +6,10 @@
use clippy_utils::higher;
use clippy_utils::source::snippet_with_applicability;
use clippy_utils::sugg::Sugg;
use clippy_utils::{get_parent_node, is_else_clause, is_expn_of};
use clippy_utils::{get_parent_node, is_else_clause, is_expn_of, peel_blocks, peel_blocks_with_stmt};
use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
use rustc_hir::{BinOpKind, Block, Expr, ExprKind, HirId, Node, StmtKind, UnOp};
use rustc_hir::{BinOpKind, Block, Expr, ExprKind, HirId, Node, UnOp};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Spanned;
@ -143,8 +143,8 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
applicability,
);
};
if let ExprKind::Block(then, _) = then.kind {
match (fetch_bool_block(then), fetch_bool_expr(r#else)) {
if let Some((a, b)) = fetch_bool_block(then).and_then(|a| Some((a, fetch_bool_block(r#else)?))) {
match (a, b) {
(RetBool(true), RetBool(true)) | (Bool(true), Bool(true)) => {
span_lint(
cx,
@ -167,8 +167,6 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
(Bool(false), Bool(true)) => reduce(false, true),
_ => (),
}
} else {
panic!("IfExpr `then` node is not an `ExprKind::Block`");
}
}
}
@ -271,8 +269,6 @@ fn check_comparison<'a, 'tcx>(
right_false: Option<(impl FnOnce(Sugg<'a>) -> Sugg<'a>, &str)>,
no_literal: Option<(impl FnOnce(Sugg<'a>, Sugg<'a>) -> Sugg<'a>, &str)>,
) {
use self::Expression::{Bool, Other};
if let ExprKind::Binary(op, left_side, right_side) = e.kind {
let (l_ty, r_ty) = (
cx.typeck_results().expr_ty(left_side),
@ -304,19 +300,19 @@ fn check_comparison<'a, 'tcx>(
}
match (fetch_bool_expr(left_side), fetch_bool_expr(right_side)) {
(Bool(true), Other) => left_true.map_or((), |(h, m)| {
(Some(true), None) => left_true.map_or((), |(h, m)| {
suggest_bool_comparison(cx, e, right_side, applicability, m, h);
}),
(Other, Bool(true)) => right_true.map_or((), |(h, m)| {
(None, Some(true)) => right_true.map_or((), |(h, m)| {
suggest_bool_comparison(cx, e, left_side, applicability, m, h);
}),
(Bool(false), Other) => left_false.map_or((), |(h, m)| {
(Some(false), None) => left_false.map_or((), |(h, m)| {
suggest_bool_comparison(cx, e, right_side, applicability, m, h);
}),
(Other, Bool(false)) => right_false.map_or((), |(h, m)| {
(None, Some(false)) => right_false.map_or((), |(h, m)| {
suggest_bool_comparison(cx, e, left_side, applicability, m, h);
}),
(Other, Other) => no_literal.map_or((), |(h, m)| {
(None, None) => no_literal.map_or((), |(h, m)| {
let left_side = Sugg::hir_with_applicability(cx, left_side, "..", &mut applicability);
let right_side = Sugg::hir_with_applicability(cx, right_side, "..", &mut applicability);
span_lint_and_sugg(
@ -365,41 +361,20 @@ fn suggest_bool_comparison<'a, 'tcx>(
enum Expression {
Bool(bool),
RetBool(bool),
Other,
}
fn fetch_bool_block(block: &Block<'_>) -> Expression {
match (&*block.stmts, block.expr.as_ref()) {
(&[], Some(e)) => fetch_bool_expr(&**e),
(&[ref e], None) => {
if let StmtKind::Semi(e) = e.kind {
if let ExprKind::Ret(_) = e.kind {
fetch_bool_expr(e)
} else {
Expression::Other
}
} else {
Expression::Other
}
},
_ => Expression::Other,
fn fetch_bool_block(expr: &Expr<'_>) -> Option<Expression> {
match peel_blocks_with_stmt(expr).kind {
ExprKind::Ret(Some(ret)) => Some(Expression::RetBool(fetch_bool_expr(ret)?)),
_ => Some(Expression::Bool(fetch_bool_expr(expr)?)),
}
}
fn fetch_bool_expr(expr: &Expr<'_>) -> Expression {
match expr.kind {
ExprKind::Block(block, _) => fetch_bool_block(block),
ExprKind::Lit(ref lit_ptr) => {
if let LitKind::Bool(value) = lit_ptr.node {
Expression::Bool(value)
} else {
Expression::Other
}
},
ExprKind::Ret(Some(expr)) => match fetch_bool_expr(expr) {
Expression::Bool(value) => Expression::RetBool(value),
_ => Expression::Other,
},
_ => Expression::Other,
fn fetch_bool_expr(expr: &Expr<'_>) -> Option<bool> {
if let ExprKind::Lit(ref lit_ptr) = peel_blocks(expr).kind {
if let LitKind::Bool(value) = lit_ptr.node {
return Some(value);
}
}
None
}

6
clippy_lints/src/no_effect.rs
View File

@ -1,5 +1,6 @@
use clippy_utils::diagnostics::{span_lint_hir, span_lint_hir_and_then};
use clippy_utils::is_lint_allowed;
use clippy_utils::peel_blocks;
use clippy_utils::source::snippet_opt;
use clippy_utils::ty::has_drop;
use rustc_errors::Applicability;
@ -114,7 +115,7 @@ fn has_no_effect(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
if expr.span.from_expansion() {
return false;
}
match expr.kind {
match peel_blocks(expr).kind {
ExprKind::Lit(..) | ExprKind::Closure(..) => true,
ExprKind::Path(..) => !has_drop(cx, cx.typeck_results().expr_ty(expr)),
ExprKind::Index(a, b) | ExprKind::Binary(_, a, b) => has_no_effect(cx, a) && has_no_effect(cx, b),
@ -150,9 +151,6 @@ fn has_no_effect(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
false
}
},
ExprKind::Block(block, _) => {
block.stmts.is_empty() && block.expr.as_ref().map_or(false, |expr| has_no_effect(cx, expr))
},
_ => false,
}
}

33
clippy_lints/src/option_if_let_else.rs
View File

@ -1,15 +1,14 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::higher;
use clippy_utils::sugg::Sugg;
use clippy_utils::ty::is_type_diagnostic_item;
use clippy_utils::{
can_move_expr_to_closure, eager_or_lazy, in_constant, is_else_clause, is_lang_ctor, peel_hir_expr_while,
CaptureKind,
can_move_expr_to_closure, eager_or_lazy, higher, in_constant, is_else_clause, is_lang_ctor, peel_blocks,
peel_hir_expr_while, CaptureKind,
};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::LangItem::OptionSome;
use rustc_hir::{def::Res, BindingAnnotation, Block, Expr, ExprKind, Mutability, PatKind, Path, QPath, UnOp};
use rustc_hir::{def::Res, BindingAnnotation, Expr, ExprKind, Mutability, PatKind, Path, QPath, UnOp};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::sym;
@ -86,28 +85,6 @@ struct OptionIfLetElseOccurence {
none_expr: String,
}
/// Extracts the body of a given arm. If the arm contains only an expression,
/// then it returns the expression. Otherwise, it returns the entire block
fn extract_body_from_expr<'a>(expr: &'a Expr<'a>) -> Option<&'a Expr<'a>> {
if let ExprKind::Block(
Block {
stmts: block_stmts,
expr: Some(block_expr),
..
},
_,
) = expr.kind
{
if let [] = block_stmts {
Some(block_expr)
} else {
Some(expr)
}
} else {
None
}
}
fn format_option_in_sugg(cx: &LateContext<'_>, cond_expr: &Expr<'_>, as_ref: bool, as_mut: bool) -> String {
format!(
"{}{}",
@ -145,8 +122,8 @@ fn detect_option_if_let_else<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>) ->
then {
let capture_mut = if bind_annotation == &BindingAnnotation::Mutable { "mut " } else { "" };
let some_body = extract_body_from_expr(if_then)?;
let none_body = extract_body_from_expr(if_else)?;
let some_body = peel_blocks(if_then);
let none_body = peel_blocks(if_else);
let method_sugg = if eager_or_lazy::switch_to_eager_eval(cx, none_body) { "map_or" } else { "map_or_else" };
let capture_name = id.name.to_ident_string();
let (as_ref, as_mut) = match &let_expr.kind {

63
clippy_lints/src/question_mark.rs
View File

@ -1,14 +1,13 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::higher;
use clippy_utils::is_lang_ctor;
use clippy_utils::source::snippet_with_applicability;
use clippy_utils::sugg::Sugg;
use clippy_utils::ty::is_type_diagnostic_item;
use clippy_utils::{eq_expr_value, path_to_local, path_to_local_id};
use clippy_utils::{eq_expr_value, is_lang_ctor, path_to_local, path_to_local_id, peel_blocks, peel_blocks_with_stmt};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::LangItem::{OptionNone, OptionSome, ResultOk};
use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, PatKind, StmtKind};
use rustc_hir::{BindingAnnotation, Expr, ExprKind, PatKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::sym;
@ -68,14 +67,8 @@ fn check_is_none_or_err_and_early_return(cx: &LateContext<'_>, expr: &Expr<'_>)
let receiver_str = &Sugg::hir_with_applicability(cx, subject, "..", &mut applicability);
let mut replacement: Option<String> = None;
if let Some(else_inner) = r#else {
if_chain! {
if let ExprKind::Block(block, None) = &else_inner.kind;
if block.stmts.is_empty();
if let Some(block_expr) = &block.expr;
if eq_expr_value(cx, subject, block_expr);
then {
replacement = Some(format!("Some({}?)", receiver_str));
}
if eq_expr_value(cx, subject, peel_blocks(else_inner)) {
replacement = Some(format!("Some({}?)", receiver_str));
}
} else if Self::moves_by_default(cx, subject)
&& !matches!(subject.kind, ExprKind::Call(..) | ExprKind::MethodCall(..))
@ -110,10 +103,7 @@ fn check_if_let_some_or_err_and_early_return(cx: &LateContext<'_>, expr: &Expr<'
if let PatKind::Binding(annot, bind_id, _, _) = fields[0].kind;
let by_ref = matches!(annot, BindingAnnotation::Ref | BindingAnnotation::RefMut);
if let ExprKind::Block(block, None) = if_then.kind;
if block.stmts.is_empty();
if let Some(trailing_expr) = &block.expr;
if path_to_local_id(trailing_expr, bind_id);
if path_to_local_id(peel_blocks(if_then), bind_id);
then {
let mut applicability = Applicability::MachineApplicable;
let receiver_str = snippet_with_applicability(cx, let_expr.span, "..", &mut applicability);
@ -159,14 +149,7 @@ fn is_result(cx: &LateContext<'_>, expression: &Expr<'_>) -> bool {
}
fn expression_returns_none(cx: &LateContext<'_>, expression: &Expr<'_>) -> bool {
match expression.kind {
ExprKind::Block(block, _) => {
if let Some(return_expression) = Self::return_expression(block) {
return Self::expression_returns_none(cx, return_expression);
}
false
},
match peel_blocks_with_stmt(expression).kind {
ExprKind::Ret(Some(expr)) => Self::expression_returns_none(cx, expr),
ExprKind::Path(ref qpath) => is_lang_ctor(cx, qpath, OptionNone),
_ => false,
@ -174,44 +157,12 @@ fn expression_returns_none(cx: &LateContext<'_>, expression: &Expr<'_>) -> bool
}
fn expression_returns_unmodified_err(cx: &LateContext<'_>, expr: &Expr<'_>, cond_expr: &Expr<'_>) -> bool {
match expr.kind {
ExprKind::Block(block, _) => {
if let Some(return_expression) = Self::return_expression(block) {
return Self::expression_returns_unmodified_err(cx, return_expression, cond_expr);
}
false
},
match peel_blocks_with_stmt(expr).kind {
ExprKind::Ret(Some(ret_expr)) => Self::expression_returns_unmodified_err(cx, ret_expr, cond_expr),
ExprKind::Path(_) => path_to_local(expr) == path_to_local(cond_expr),
_ => false,
}
}
fn return_expression<'tcx>(block: &Block<'tcx>) -> Option<&'tcx Expr<'tcx>> {
// Check if last expression is a return statement. Then, return the expression
if_chain! {
if block.stmts.len() == 1;
if let Some(expr) = block.stmts.iter().last();
if let StmtKind::Semi(expr) = expr.kind;
if let ExprKind::Ret(Some(ret_expr)) = expr.kind;
then {
return Some(ret_expr);
}
}
// Check for `return` without a semicolon.
if_chain! {
if block.stmts.is_empty();
if let Some(ExprKind::Ret(Some(ret_expr))) = block.expr.as_ref().map(|e| &e.kind);
then {
return Some(ret_expr);
}
}
None
}
}
impl<'tcx> LateLintPass<'tcx> for QuestionMark {

7
clippy_lints/src/strings.rs
View File

@ -1,8 +1,8 @@
use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg};
use clippy_utils::source::{snippet, snippet_with_applicability};
use clippy_utils::ty::is_type_diagnostic_item;
use clippy_utils::SpanlessEq;
use clippy_utils::{get_parent_expr, is_lint_allowed, match_function_call, method_calls, paths};
use clippy_utils::{peel_blocks, SpanlessEq};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, LangItem, QPath};
@ -201,7 +201,7 @@ fn is_string(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
}
fn is_add(cx: &LateContext<'_>, src: &Expr<'_>, target: &Expr<'_>) -> bool {
match src.kind {
match peel_blocks(src).kind {
ExprKind::Binary(
Spanned {
node: BinOpKind::Add, ..
@ -209,9 +209,6 @@ fn is_add(cx: &LateContext<'_>, src: &Expr<'_>, target: &Expr<'_>) -> bool {
left,
_,
) => SpanlessEq::new(cx).eq_expr(target, left),
ExprKind::Block(block, _) => {
block.stmts.is_empty() && block.expr.as_ref().map_or(false, |expr| is_add(cx, expr, target))
},
_ => false,
}
}

10
clippy_lints/src/utils/internal_lints.rs
View File

@ -1,11 +1,10 @@
use clippy_utils::consts::{constant_simple, Constant};
use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
use clippy_utils::higher;
use clippy_utils::source::snippet;
use clippy_utils::ty::match_type;
use clippy_utils::{
is_else_clause, is_expn_of, is_expr_path_def_path, is_lint_allowed, match_def_path, method_calls, path_to_res,
paths, SpanlessEq,
higher, is_else_clause, is_expn_of, is_expr_path_def_path, is_lint_allowed, match_def_path, method_calls,
path_to_res, paths, peel_blocks_with_stmt, SpanlessEq,
};
use if_chain::if_chain;
use rustc_ast as ast;
@ -662,10 +661,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
if and_then_args.len() == 5;
if let ExprKind::Closure(_, _, body_id, _, _) = &and_then_args[4].kind;
let body = cx.tcx.hir().body(*body_id);
if let ExprKind::Block(block, _) = &body.value.kind;
let stmts = &block.stmts;
if stmts.len() == 1 && block.expr.is_none();
if let StmtKind::Semi(only_expr) = &stmts[0].kind;
let only_expr = peel_blocks_with_stmt(&body.value);
if let ExprKind::MethodCall(ps, _, span_call_args, _) = &only_expr.kind;
then {
let and_then_snippets = get_and_then_snippets(cx, and_then_args);

11
clippy_lints/src/utils/internal_lints/metadata_collector.rs
View File

@ -8,6 +8,11 @@
//! during any comparison or mapping. (Please take care of this, it's not fun to spend time on such
//! a simple mistake)
use crate::utils::internal_lints::{extract_clippy_version_value, is_lint_ref_type};
use clippy_utils::diagnostics::span_lint;
use clippy_utils::ty::{match_type, walk_ptrs_ty_depth};
use clippy_utils::{last_path_segment, match_def_path, match_function_call, match_path, paths};
use if_chain::if_chain;
use rustc_ast as ast;
use rustc_data_structures::fx::FxHashMap;
@ -25,12 +30,6 @@
use std::io::prelude::*;
use std::path::Path;
use crate::utils::internal_lints::{extract_clippy_version_value, is_lint_ref_type};
use clippy_utils::{
diagnostics::span_lint, last_path_segment, match_def_path, match_function_call, match_path, paths, ty::match_type,
ty::walk_ptrs_ty_depth,
};
/// This is the output file of the lint collector.
const OUTPUT_FILE: &str = "../util/gh-pages/lints.json";
/// These lints are excluded from the export.

86
clippy_utils/src/lib.rs
View File

@ -73,10 +73,10 @@
use rustc_hir::itemlikevisit::ItemLikeVisitor;
use rustc_hir::LangItem::{OptionNone, ResultErr, ResultOk};
use rustc_hir::{
def, Arm, BindingAnnotation, Block, Body, Constness, Destination, Expr, ExprKind, FnDecl, ForeignItem, GenericArgs,
HirId, Impl, ImplItem, ImplItemKind, IsAsync, Item, ItemKind, LangItem, Local, MatchSource, Mutability, Node,
Param, Pat, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitItem, TraitItemKind, TraitRef, TyKind,
UnOp,
def, Arm, BindingAnnotation, Block, BlockCheckMode, Body, Constness, Destination, Expr, ExprKind, FnDecl,
ForeignItem, GenericArgs, HirId, Impl, ImplItem, ImplItemKind, IsAsync, Item, ItemKind, LangItem, Local,
MatchSource, Mutability, Node, Param, Pat, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitItem,
TraitItemKind, TraitRef, TyKind, UnOp,
};
use rustc_lint::{LateContext, Level, Lint, LintContext};
use rustc_middle::hir::exports::Export;
@ -1224,6 +1224,70 @@ pub fn get_parent_as_impl(tcx: TyCtxt<'_>, id: HirId) -> Option<&Impl<'_>> {
}
}
/// Removes blocks around an expression, only if the block contains just one expression
/// and no statements. Unsafe blocks are not removed.
///
/// Examples:
/// * `{}` -> `{}`
/// * `{ x }` -> `x`
/// * `{{ x }}` -> `x`
/// * `{ x; }` -> `{ x; }`
/// * `{ x; y }` -> `{ x; y }`
/// * `{ unsafe { x } }` -> `unsafe { x }`
pub fn peel_blocks<'a>(mut expr: &'a Expr<'a>) -> &'a Expr<'a> {
while let ExprKind::Block(
Block {
stmts: [],
expr: Some(inner),
rules: BlockCheckMode::DefaultBlock,
..
},
_,
) = expr.kind
{
expr = inner;
}
expr
}
/// Removes blocks around an expression, only if the block contains just one expression
/// or just one expression statement with a semicolon. Unsafe blocks are not removed.
///
/// Examples:
/// * `{}` -> `{}`
/// * `{ x }` -> `x`
/// * `{ x; }` -> `x`
/// * `{{ x; }}` -> `x`
/// * `{ x; y }` -> `{ x; y }`
/// * `{ unsafe { x } }` -> `unsafe { x }`
pub fn peel_blocks_with_stmt<'a>(mut expr: &'a Expr<'a>) -> &'a Expr<'a> {
while let ExprKind::Block(
Block {
stmts: [],
expr: Some(inner),
rules: BlockCheckMode::DefaultBlock,
..
}
| Block {
stmts:
[
Stmt {
kind: StmtKind::Expr(inner) | StmtKind::Semi(inner),
..
},
],
expr: None,
rules: BlockCheckMode::DefaultBlock,
..
},
_,
) = expr.kind
{
expr = inner;
}
expr
}
/// Checks if the given expression is the else clause of either an `if` or `if let` expression.
pub fn is_else_clause(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool {
let mut iter = tcx.hir().parent_iter(expr.hir_id);
@ -1405,20 +1469,6 @@ pub fn is_automatically_derived(attrs: &[ast::Attribute]) -> bool {
has_attr(attrs, sym::automatically_derived)
}
/// Remove blocks around an expression.
///
/// Ie. `x`, `{ x }` and `{{{{ x }}}}` all give `x`. `{ x; y }` and `{}` return
/// themselves.
pub fn remove_blocks<'tcx>(mut expr: &'tcx Expr<'tcx>) -> &'tcx Expr<'tcx> {
while let ExprKind::Block(block, ..) = expr.kind {
match (block.stmts.is_empty(), block.expr.as_ref()) {
(true, Some(e)) => expr = e,
_ => break,
}
}
expr
}
pub fn is_self(slf: &Param<'_>) -> bool {
if let PatKind::Binding(.., name, _) = slf.pat.kind {
name.name == kw::SelfLower