Auto merge of #94695 - matthiaskrgr:rollup-5pi3acz, r=matthiaskrgr

Rollup of 4 pull requests

Successful merges:

 - #94553 (add tests for #94502)
 - #94614 (Remove ordering traits from `rustc_span::hygiene::LocalExpnId`)
 - #94685 (interpret: move saturating_add/sub into (pub) helper method)
 - #94688 (Erase regions when checking for missing Copy predicates)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
This commit is contained in:
bors 2022-03-07 13:02:31 +00:00
commit d137c3a7bd
7 changed files with 138 additions and 41 deletions

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@ -448,8 +448,16 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
self.mir_hir_id(),
rustc_infer::traits::ObligationCauseCode::MiscObligation,
);
fulfill_cx.register_bound(&infcx, self.param_env, ty, copy_did, cause);
let errors = fulfill_cx.select_where_possible(&infcx);
fulfill_cx.register_bound(
&infcx,
self.param_env,
// Erase any region vids from the type, which may not be resolved
infcx.tcx.erase_regions(ty),
copy_did,
cause,
);
// Select all, including ambiguous predicates
let errors = fulfill_cx.select_all_or_error(&infcx);
// Only emit suggestion if all required predicates are on generic
errors

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@ -219,48 +219,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
sym::saturating_add | sym::saturating_sub => {
let l = self.read_immediate(&args[0])?;
let r = self.read_immediate(&args[1])?;
let is_add = intrinsic_name == sym::saturating_add;
let (val, overflowed, _ty) = self.overflowing_binary_op(
if is_add { BinOp::Add } else { BinOp::Sub },
let val = self.saturating_arith(
if intrinsic_name == sym::saturating_add { BinOp::Add } else { BinOp::Sub },
&l,
&r,
)?;
let val = if overflowed {
let size = l.layout.size;
let num_bits = size.bits();
if l.layout.abi.is_signed() {
// For signed ints the saturated value depends on the sign of the first
// term since the sign of the second term can be inferred from this and
// the fact that the operation has overflowed (if either is 0 no
// overflow can occur)
let first_term: u128 = l.to_scalar()?.to_bits(l.layout.size)?;
let first_term_positive = first_term & (1 << (num_bits - 1)) == 0;
if first_term_positive {
// Negative overflow not possible since the positive first term
// can only increase an (in range) negative term for addition
// or corresponding negated positive term for subtraction
Scalar::from_uint(
(1u128 << (num_bits - 1)) - 1, // max positive
Size::from_bits(num_bits),
)
} else {
// Positive overflow not possible for similar reason
// max negative
Scalar::from_uint(1u128 << (num_bits - 1), Size::from_bits(num_bits))
}
} else {
// unsigned
if is_add {
// max unsigned
Scalar::from_uint(size.unsigned_int_max(), Size::from_bits(num_bits))
} else {
// underflow to 0
Scalar::from_uint(0u128, Size::from_bits(num_bits))
}
}
} else {
val
};
self.write_scalar(val, dest)?;
}
sym::discriminant_value => {
@ -508,6 +471,49 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
self.binop_ignore_overflow(BinOp::Div, &a, &b, dest)
}
pub fn saturating_arith(
&self,
mir_op: BinOp,
l: &ImmTy<'tcx, M::PointerTag>,
r: &ImmTy<'tcx, M::PointerTag>,
) -> InterpResult<'tcx, Scalar<M::PointerTag>> {
assert!(matches!(mir_op, BinOp::Add | BinOp::Sub));
let (val, overflowed, _ty) = self.overflowing_binary_op(mir_op, l, r)?;
Ok(if overflowed {
let size = l.layout.size;
let num_bits = size.bits();
if l.layout.abi.is_signed() {
// For signed ints the saturated value depends on the sign of the first
// term since the sign of the second term can be inferred from this and
// the fact that the operation has overflowed (if either is 0 no
// overflow can occur)
let first_term: u128 = l.to_scalar()?.to_bits(l.layout.size)?;
let first_term_positive = first_term & (1 << (num_bits - 1)) == 0;
if first_term_positive {
// Negative overflow not possible since the positive first term
// can only increase an (in range) negative term for addition
// or corresponding negated positive term for subtraction
Scalar::from_int(size.signed_int_max(), size)
} else {
// Positive overflow not possible for similar reason
// max negative
Scalar::from_int(size.signed_int_min(), size)
}
} else {
// unsigned
if matches!(mir_op, BinOp::Add) {
// max unsigned
Scalar::from_uint(size.unsigned_int_max(), size)
} else {
// underflow to 0
Scalar::from_uint(0u128, size)
}
}
} else {
val
})
}
/// Offsets a pointer by some multiple of its type, returning an error if the pointer leaves its
/// allocation. For integer pointers, we consider each of them their own tiny allocation of size
/// 0, so offset-by-0 (and only 0) is okay -- except that null cannot be offset by _any_ value.

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@ -85,10 +85,17 @@ rustc_index::newtype_index! {
/// A unique ID associated with a macro invocation and expansion.
pub struct LocalExpnId {
ENCODABLE = custom
ORD_IMPL = custom
DEBUG_FORMAT = "expn{}"
}
}
// To ensure correctness of incremental compilation,
// `LocalExpnId` must not implement `Ord` or `PartialOrd`.
// See https://github.com/rust-lang/rust/issues/90317.
impl !Ord for LocalExpnId {}
impl !PartialOrd for LocalExpnId {}
/// Assert that the provided `HashStableContext` is configured with the 'default'
/// `HashingControls`. We should always have bailed out before getting to here
/// with a non-default mode. With this check in place, we can avoid the need

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@ -0,0 +1,17 @@
pub struct DataStruct();
pub struct HelperStruct<'n> {
pub helpers: [Vec<&'n i64>; 2],
pub is_empty: bool,
}
impl DataStruct {
pub fn f(&self) -> HelperStruct {
let helpers = [vec![], vec![]];
HelperStruct { helpers, is_empty: helpers[0].is_empty() }
//~^ ERROR borrow of moved value
}
}
fn main() {}

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@ -0,0 +1,14 @@
error[E0382]: borrow of moved value: `helpers`
--> $DIR/copy-suggestion-region-vid.rs:12:43
|
LL | let helpers = [vec![], vec![]];
| ------- move occurs because `helpers` has type `[Vec<&i64>; 2]`, which does not implement the `Copy` trait
LL |
LL | HelperStruct { helpers, is_empty: helpers[0].is_empty() }
| ------- ^^^^^^^^^^^^^^^^^^^^^ value borrowed here after move
| |
| value moved here
error: aborting due to previous error
For more information about this error, try `rustc --explain E0382`.

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@ -0,0 +1,28 @@
// check-pass
// mir borrowck previously incorrectly set `tainted_by_errors`
// when buffering lints, which resulted in ICE later on,
// see #94502.
// Errors with `nll` which is already tested in enough other tests,
// so we ignore it here.
//
// ignore-compare-mode-nll
struct Repro;
impl Repro {
fn get(&self) -> &i32 {
&3
}
fn insert(&mut self, _: i32) {}
}
fn main() {
let x = &0;
let mut conflict = Repro;
let prev = conflict.get();
conflict.insert(*prev + *x);
//~^ WARN cannot borrow `conflict` as mutable because it is also borrowed as immutable
//~| WARN this borrowing pattern was not meant to be accepted
}

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@ -0,0 +1,17 @@
warning: cannot borrow `conflict` as mutable because it is also borrowed as immutable
--> $DIR/lint-no-err.rs:25:5
|
LL | let prev = conflict.get();
| -------------- immutable borrow occurs here
LL | conflict.insert(*prev + *x);
| ^^^^^^^^^^^^^^^^-----^^^^^^
| | |
| | immutable borrow later used here
| mutable borrow occurs here
|
= note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
= warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
= note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
warning: 1 warning emitted