Rename negate to sign and make it strong types then make art1 &str

This commit is contained in:
rail 2020-04-27 18:57:36 +12:00
parent 7dd0f3459f
commit 3f1e51b3f4

View file

@ -786,20 +786,29 @@ fn same_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, var: HirId) -
}
}
#[derive(Clone, Copy)]
enum OffsetSign {
Positive,
Negative,
}
struct Offset {
value: String,
negate: bool,
sign: OffsetSign,
}
impl Offset {
fn negative(s: String) -> Self {
Self { value: s, negate: true }
fn negative(value: String) -> Self {
Self {
value,
sign: OffsetSign::Negative,
}
}
fn positive(s: String) -> Self {
fn positive(value: String) -> Self {
Self {
value: s,
negate: false,
value,
sign: OffsetSign::Positive,
}
}
}
@ -949,31 +958,23 @@ fn detect_manual_memcpy<'a, 'tcx>(
{
// the var must be a single name
if let PatKind::Binding(_, canonical_id, _, _) = pat.kind {
let print_sum = |arg1: &Offset, arg2: &Offset| -> String {
match (&arg1.value[..], arg1.negate, &arg2.value[..], arg2.negate) {
("0", _, "0", _) => "0".into(),
("0", _, x, false) | (x, false, "0", _) => x.into(),
("0", _, x, true) => format!("-{}", x),
(x, false, y, false) => format!("({} + {})", x, y),
(x, false, y, true) => {
let print_sum = |arg1: &str, arg2: &Offset| -> String {
match (arg1, &arg2.value[..], arg2.sign) {
("0", "0", _) => "0".into(),
("0", x, OffsetSign::Positive) | (x, "0", _) => x.into(),
("0", x, OffsetSign::Negative) => format!("-{}", x),
(x, y, OffsetSign::Positive) => format!("({} + {})", x, y),
(x, y, OffsetSign::Negative) => {
if x == y {
"0".into()
} else {
format!("({} - {})", x, y)
}
},
(x, true, y, false) => {
if x == y {
"0".into()
} else {
format!("({} - {})", y, x)
}
},
(x, true, y, true) => format!("-({} + {})", x, y),
}
};
let print_offset = |start_str: &Offset, inline_offset: &Offset| -> String {
let print_offset = |start_str: &str, inline_offset: &Offset| -> String {
let offset = print_sum(start_str, inline_offset);
if offset.as_str() == "0" {
"".into()
@ -990,10 +991,9 @@ fn detect_manual_memcpy<'a, 'tcx>(
if let Some(arg) = len_args.get(0);
if snippet(cx, arg.span, "??") == var_name;
then {
if offset.negate {
format!("({} - {})", snippet(cx, end.span, "<src>.len()"), offset.value)
} else {
String::new()
match offset.sign {
OffsetSign::Negative => format!("({} - {})", snippet(cx, end.span, "<src>.len()"), offset.value),
OffsetSign::Positive => "".into(),
}
} else {
let end_str = match limits {
@ -1004,7 +1004,7 @@ fn detect_manual_memcpy<'a, 'tcx>(
ast::RangeLimits::HalfOpen => format!("{}", snippet(cx, end.span, "..")),
};
print_sum(&Offset::positive(end_str), &offset)
print_sum(&end_str, &offset)
}
}
};
@ -1016,7 +1016,7 @@ fn detect_manual_memcpy<'a, 'tcx>(
let big_sugg = manual_copies
.into_iter()
.map(|(dst_var, src_var)| {
let start_str = Offset::positive(snippet(cx, start.span, "").to_string());
let start_str = snippet(cx, start.span, "").to_string();
let dst_offset = print_offset(&start_str, &dst_var.offset);
let dst_limit = print_limit(end, dst_var.offset, &dst_var.var_name);
let src_offset = print_offset(&start_str, &src_var.offset);