Additionally suggest the semantic equal variant

This commit is contained in:
flip1995 2018-01-30 17:45:35 +01:00
parent b7cb0752ff
commit bd421cb5a5
3 changed files with 96 additions and 20 deletions

View File

@ -1,4 +1,5 @@
use rustc::hir;
use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
use rustc::lint::*;
use syntax::ast;
use utils::{get_trait_def_id, implements_trait, snippet_opt, span_lint_and_then, SpanlessEq};
@ -98,13 +99,19 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssignOps {
{
let a = &sugg::Sugg::hir(cx, assignee, "..");
let r = &sugg::Sugg::hir(cx, rhs, "..");
let long = format!("{} = {}", snip_a, sugg::make_binop(higher::binop(op.node), a, r));
db.span_suggestion(
expr.span,
&format!("Did you mean {} = {} {} {} or {} = {}? Consider replacing it with",
&format!("Did you mean {} = {} {} {} or {}? Consider replacing it with",
snip_a, snip_a, op.node.as_str(), snip_r,
snip_a, sugg::make_binop(higher::binop(op.node), a, r)),
long),
format!("{} {}= {}", snip_a, op.node.as_str(), snip_r)
);
db.span_suggestion(
expr.span,
"or",
long
);
},
);
};
@ -193,23 +200,34 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssignOps {
);
}
};
// a = a op b
if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, l) {
lint(assignee, r);
}
// a = b commutative_op a
if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, r) {
match op.node {
hir::BiAdd |
hir::BiMul |
hir::BiAnd |
hir::BiOr |
hir::BiBitXor |
hir::BiBitAnd |
hir::BiBitOr => {
lint(assignee, l);
},
_ => {},
let mut visitor = ExprVisitor {
assignee: assignee,
counter: 0,
cx: cx
};
walk_expr(&mut visitor, e);
if visitor.counter == 1 {
// a = a op b
if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, l) {
lint(assignee, r);
}
// a = b commutative_op a
if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, r) {
match op.node {
hir::BiAdd |
hir::BiMul |
hir::BiAnd |
hir::BiOr |
hir::BiBitXor |
hir::BiBitAnd |
hir::BiBitOr => {
lint(assignee, l);
},
_ => {},
}
}
}
}
@ -226,3 +244,22 @@ fn is_commutative(op: hir::BinOp_) -> bool {
BiSub | BiDiv | BiRem | BiShl | BiShr | BiLt | BiLe | BiGe | BiGt => false,
}
}
struct ExprVisitor<'a, 'tcx: 'a> {
assignee: &'a hir::Expr,
counter: u8,
cx: &'a LateContext<'a, 'tcx>,
}
impl<'a, 'tcx: 'a> Visitor<'tcx> for ExprVisitor<'a, 'tcx> {
fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
if SpanlessEq::new(self.cx).ignore_fn().eq_expr(self.assignee, &expr) {
self.counter += 1;
}
walk_expr(self, expr);
}
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
NestedVisitorMap::None
}
}

View File

@ -2,7 +2,7 @@
#[allow(unused_assignments)]
#[warn(misrefactored_assign_op)]
#[warn(misrefactored_assign_op, assign_op_pattern)]
fn main() {
let mut a = 5;
a += a + 1;
@ -14,6 +14,9 @@ fn main() {
a %= a % 5;
a &= a & 1;
a *= a * a;
a = a * a * a;
a = a * 42 * a;
a = a * 2 + a;
a -= 1 - a;
a /= 5 / a;
a %= 42 % a;

View File

@ -9,6 +9,10 @@ help: Did you mean a = a + 1 or a = a + a + 1? Consider replacing it with
|
8 | a += 1;
| ^^^^^^
help: or
|
8 | a = a + a + 1;
| ^^^^^^^^^^^^^
error: variable appears on both sides of an assignment operation
--> $DIR/assign_ops2.rs:9:5
@ -19,6 +23,10 @@ help: Did you mean a = a + 1 or a = a + 1 + a? Consider replacing it with
|
9 | a += 1;
| ^^^^^^
help: or
|
9 | a = a + 1 + a;
| ^^^^^^^^^^^^^
error: variable appears on both sides of an assignment operation
--> $DIR/assign_ops2.rs:10:5
@ -29,6 +37,10 @@ help: Did you mean a = a - 1 or a = a - (a - 1)? Consider replacing it with
|
10 | a -= 1;
| ^^^^^^
help: or
|
10 | a = a - (a - 1);
| ^^^^^^^^^^^^^^^
error: variable appears on both sides of an assignment operation
--> $DIR/assign_ops2.rs:11:5
@ -39,6 +51,10 @@ help: Did you mean a = a * 99 or a = a * a * 99? Consider replacing it with
|
11 | a *= 99;
| ^^^^^^^
help: or
|
11 | a = a * a * 99;
| ^^^^^^^^^^^^^^
error: variable appears on both sides of an assignment operation
--> $DIR/assign_ops2.rs:12:5
@ -49,6 +65,10 @@ help: Did you mean a = a * 42 or a = a * 42 * a? Consider replacing it with
|
12 | a *= 42;
| ^^^^^^^
help: or
|
12 | a = a * 42 * a;
| ^^^^^^^^^^^^^^
error: variable appears on both sides of an assignment operation
--> $DIR/assign_ops2.rs:13:5
@ -59,6 +79,10 @@ help: Did you mean a = a / 2 or a = a / (a / 2)? Consider replacing it with
|
13 | a /= 2;
| ^^^^^^
help: or
|
13 | a = a / (a / 2);
| ^^^^^^^^^^^^^^^
error: variable appears on both sides of an assignment operation
--> $DIR/assign_ops2.rs:14:5
@ -69,6 +93,10 @@ help: Did you mean a = a % 5 or a = a % (a % 5)? Consider replacing it with
|
14 | a %= 5;
| ^^^^^^
help: or
|
14 | a = a % (a % 5);
| ^^^^^^^^^^^^^^^
error: variable appears on both sides of an assignment operation
--> $DIR/assign_ops2.rs:15:5
@ -79,6 +107,10 @@ help: Did you mean a = a & 1 or a = a & a & 1? Consider replacing it with
|
15 | a &= 1;
| ^^^^^^
help: or
|
15 | a = a & a & 1;
| ^^^^^^^^^^^^^
error: variable appears on both sides of an assignment operation
--> $DIR/assign_ops2.rs:16:5
@ -89,6 +121,10 @@ help: Did you mean a = a * a or a = a * a * a? Consider replacing it with
|
16 | a *= a;
| ^^^^^^
help: or
|
16 | a = a * a * a;
| ^^^^^^^^^^^^^
error: aborting due to 9 previous errors