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Commit f59e084

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J-ZhengLiJ-ZhengLi
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add new functionalities back
1 parent 6bbbdf1 commit f59e084

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3 files changed

+76
-17
lines changed

3 files changed

+76
-17
lines changed

‎clippy_lints/src/question_mark.rs‎

Lines changed: 57 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -2,11 +2,13 @@ use clippy_utils::diagnostics::span_lint_and_sugg;
22
use clippy_utils::higher;
33
use clippy_utils::source::snippet_with_applicability;
44
use clippy_utils::ty::is_type_diagnostic_item;
5-
use clippy_utils::{eq_expr_value, is_lang_ctor, path_to_local, path_to_local_id, peel_blocks, peel_blocks_with_stmt};
5+
use clippy_utils::{
6+
eq_expr_value, is_else_clause, is_lang_ctor, path_to_local, path_to_local_id, peel_blocks, peel_blocks_with_stmt,
7+
};
68
use if_chain::if_chain;
79
use rustc_errors::Applicability;
810
use rustc_hir::LangItem::{OptionNone, OptionSome, ResultErr, ResultOk};
9-
use rustc_hir::{BindingAnnotation, Expr, ExprKind, PatKind, QPath};
11+
use rustc_hir::{BindingAnnotation, Expr, ExprKind, PatKind, PathSegment, QPath};
1012
use rustc_lint::{LateContext, LateLintPass};
1113
use rustc_session::{declare_lint_pass, declare_tool_lint};
1214
use rustc_span::{sym, symbol::Symbol};
@@ -73,6 +75,7 @@ enum IfBlockType<'hir> {
7375
fn check_is_none_or_err_and_early_return(cx: &LateContext<'_>, expr: &Expr<'_>) {
7476
if_chain! {
7577
if let Some(higher::If { cond, then, r#else }) = higher::If::hir(expr);
78+
if !is_else_clause(cx.tcx, expr);
7679
if let ExprKind::MethodCall(segment, args, _) = &cond.kind;
7780
if let Some(subject) = args.get(0);
7881
let if_block = IfBlockType::IfIs(subject, segment.ident.name, then, r#else);
@@ -103,6 +106,7 @@ fn move_by_default(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
103106
fn check_if_let_some_or_err_and_early_return(cx: &LateContext<'_>, expr: &Expr<'_>) {
104107
if_chain! {
105108
if let Some(higher::IfLet { let_pat, let_expr, if_then, if_else }) = higher::IfLet::hir(cx, expr);
109+
if !is_else_clause(cx.tcx, expr);
106110
if let PatKind::TupleStruct(ref path1, fields, None) = let_pat.kind;
107111
if let PatKind::Binding(annot, bind_id, ident, _) = fields[0].kind;
108112
let if_block = IfBlockType::IfLet(path1, ident.name, let_expr, if_then, if_else);
@@ -112,7 +116,12 @@ fn check_if_let_some_or_err_and_early_return(cx: &LateContext<'_>, expr: &Expr<'
112116
let mut applicability = Applicability::MachineApplicable;
113117
let receiver_str = snippet_with_applicability(cx, let_expr.span, "..", &mut applicability);
114118
let by_ref = matches!(annot, BindingAnnotation::Ref | BindingAnnotation::RefMut);
115-
let replacement = format!("{}{}?", receiver_str, if by_ref { ".as_ref()" } else { "" },);
119+
let replacement = format!(
120+
"{}{}?{}",
121+
receiver_str,
122+
if by_ref { ".as_ref()" } else { "" },
123+
if requires_semi(if_then, if_else) { ";" } else { "" }
124+
);
116125
offer_suggestion(cx, expr, replacement, applicability);
117126
}
118127
}
@@ -125,14 +134,14 @@ fn is_early_return(smbl: Symbol, cx: &LateContext<'_>, if_block: &IfBlockType<'_
125134
// If the block could be identified as `if x.is_none()/is_err()`,
126135
// we then only need to check the if_then return to see if it is none/err.
127136
is_type_diagnostic_item(cx, caller_ty, smbl)
128-
&& expr_return_none_or_err(smbl, cx, if_then, caller)
137+
&& expr_return_none_or_err(smbl, cx, if_then, caller, None)
129138
&& match smbl {
130139
sym::Option => call_sym == sym!(is_none),
131140
sym::Result => call_sym == sym!(is_err),
132141
_ => false,
133142
}
134143
},
135-
IfBlockType::IfLet(qpath, _, let_expr, if_then, if_else) => {
144+
IfBlockType::IfLet(qpath, let_pat_sym, let_expr, if_then, if_else) => {
136145
let let_expr_ty = cx.typeck_results().expr_ty(let_expr);
137146
is_type_diagnostic_item(cx, let_expr_ty, smbl)
138147
&& match smbl {
@@ -144,7 +153,8 @@ fn is_early_return(smbl: Symbol, cx: &LateContext<'_>, if_block: &IfBlockType<'_
144153
} else {
145154
return false;
146155
};
147-
expr_return_none_or_err(smbl, cx, else_expr, let_expr) && is_lang_ctor(cx, qpath, OptionSome)
156+
expr_return_none_or_err(smbl, cx, else_expr, let_expr, None)
157+
&& is_lang_ctor(cx, qpath, OptionSome)
148158
},
149159
sym::Result => {
150160
if is_lang_ctor(cx, qpath, ResultOk) {
@@ -153,9 +163,9 @@ fn is_early_return(smbl: Symbol, cx: &LateContext<'_>, if_block: &IfBlockType<'_
153163
} else {
154164
return false;
155165
};
156-
expr_return_none_or_err(smbl, cx, else_expr, let_expr)
166+
expr_return_none_or_err(smbl, cx, else_expr, let_expr, Some(let_pat_sym))
157167
} else if is_lang_ctor(cx, qpath, ResultErr) {
158-
expr_return_none_or_err(smbl, cx, if_then, let_expr)
168+
expr_return_none_or_err(smbl, cx, if_then, let_expr, Some(let_pat_sym))
159169
} else {
160170
false
161171
}
@@ -166,18 +176,55 @@ fn is_early_return(smbl: Symbol, cx: &LateContext<'_>, if_block: &IfBlockType<'_
166176
}
167177
}
168178

169-
fn expr_return_none_or_err(smbl: Symbol, cx: &LateContext<'_>, expr: &Expr<'_>, cond_expr: &Expr<'_>) -> bool {
179+
fn expr_return_none_or_err(
180+
smbl: Symbol,
181+
cx: &LateContext<'_>,
182+
expr: &Expr<'_>,
183+
cond_expr: &Expr<'_>,
184+
err_sym: Option<Symbol>,
185+
) -> bool {
170186
match peel_blocks_with_stmt(expr).kind {
171-
ExprKind::Ret(Some(ret_expr)) => expr_return_none_or_err(smbl, cx, ret_expr, cond_expr),
187+
ExprKind::Ret(Some(ret_expr)) => expr_return_none_or_err(smbl, cx, ret_expr, cond_expr, err_sym),
172188
ExprKind::Path(ref qpath) => match smbl {
173189
sym::Option => is_lang_ctor(cx, qpath, OptionNone),
174190
sym::Result => path_to_local(expr).is_some() && path_to_local(expr) == path_to_local(cond_expr),
175191
_ => false,
176192
},
193+
ExprKind::Call(call_expr, args_expr) => {
194+
if_chain! {
195+
if smbl == sym::Result;
196+
if let ExprKind::Path(QPath::Resolved(_, path)) = &call_expr.kind;
197+
if let Some(segment) = path.segments.first();
198+
if let Some(err_sym) = err_sym;
199+
if let Some(arg) = args_expr.first();
200+
if let ExprKind::Path(QPath::Resolved(_, arg_path)) = &arg.kind;
201+
if let Some(PathSegment { ident, .. }) = arg_path.segments.first();
202+
then {
203+
return segment.ident.name == sym::Err && err_sym == ident.name;
204+
}
205+
}
206+
false
207+
},
177208
_ => false,
178209
}
179210
}
180211

212+
/// Check whether the fixed code needs semicolon after `?`
213+
///
214+
/// It will need a semicolon if all block(s) has one.
215+
fn requires_semi(if_then: &Expr<'_>, if_else: Option<&Expr<'_>>) -> bool {
216+
let if_then_kind = &peel_blocks_with_stmt(if_then).kind;
217+
let if_then_is_ret_stmt = matches!(if_then_kind, ExprKind::Ret(..));
218+
219+
if if_else.is_none() {
220+
return if_then_is_ret_stmt;
221+
}
222+
if let ExprKind::Ret(_) = peel_blocks_with_stmt(if_else.unwrap()).kind {
223+
return if_then_is_ret_stmt;
224+
}
225+
false
226+
}
227+
181228
fn offer_suggestion(cx: &LateContext<'_>, expr: &Expr<'_>, suggestion: String, applicability: Applicability) {
182229
if !suggestion.is_empty() {
183230
span_lint_and_sugg(

‎tests/ui/question_mark.fixed‎

Lines changed: 2 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -158,16 +158,12 @@ fn f() -> NotOption {
158158
fn do_something() {}
159159

160160
fn err_immediate_return() -> Result<i32, i32> {
161-
if let Err(err) = func_returning_result() {
162-
return Err(err);
163-
}
161+
func_returning_result()?;
164162
Ok(1)
165163
}
166164

167165
fn err_immediate_return_and_do_something() -> Result<i32, i32> {
168-
if let Err(err) = func_returning_result() {
169-
return Err(err);
170-
}
166+
func_returning_result()?;
171167
do_something();
172168
Ok(1)
173169
}

‎tests/ui/question_mark.stderr‎

Lines changed: 17 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -114,5 +114,21 @@ LL | | return x;
114114
LL | | }
115115
| |_____^ help: replace it with: `x?;`
116116

117-
error: aborting due to 13 previous errors
117+
error: this block may be rewritten with the `?` operator
118+
--> $DIR/question_mark.rs:193:5
119+
|
120+
LL | / if let Err(err) = func_returning_result() {
121+
LL | | return Err(err);
122+
LL | | }
123+
| |_____^ help: replace it with: `func_returning_result()?;`
124+
125+
error: this block may be rewritten with the `?` operator
126+
--> $DIR/question_mark.rs:200:5
127+
|
128+
LL | / if let Err(err) = func_returning_result() {
129+
LL | | return Err(err);
130+
LL | | }
131+
| |_____^ help: replace it with: `func_returning_result()?;`
132+
133+
error: aborting due to 15 previous errors
118134

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