mathieu/granite-rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Auto merge of #99309 - RalfJung:no-large-copies, r=oli-obk

Browse source 
interpret: make some large types not Copy

Also remove some unused trait impls (mostly HashStable).

This didn't find any unnecessary copies that I managed to avoid, but it might still be better to require explicit clone for these types? Not sure.

r? `@oli-obk`
This commit is contained in:
bors 2022-07-19 16:33:45 +00:00
commit 29c5a028b0
9 changed files with 54 additions and 82 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

44
compiler/rustc_const_eval/src/interpret/eval_context.rs
View file

@ -2,10 +2,8 @@ use std::cell::Cell;
use std::fmt;
use std::mem;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_hir::{self as hir, def_id::DefId, definitions::DefPathData};
use rustc_index::vec::IndexVec;
use rustc_macros::HashStable;
use rustc_middle::mir;
use rustc_middle::mir::interpret::{InterpError, InvalidProgramInfo};
use rustc_middle::ty::layout::{
@ -16,7 +14,6 @@ use rustc_middle::ty::{
self, query::TyCtxtAt, subst::SubstsRef, ParamEnv, Ty, TyCtxt, TypeFoldable,
};
use rustc_mir_dataflow::storage::always_storage_live_locals;
use rustc_query_system::ich::StableHashingContext;
use rustc_session::Limit;
use rustc_span::{Pos, Span};
use rustc_target::abi::{call::FnAbi, Align, HasDataLayout, Size, TargetDataLayout};
@ -142,7 +139,7 @@ pub struct FrameInfo<'tcx> {
}
/// Unwind information.
#[derive(Clone, Copy, Eq, PartialEq, Debug, HashStable)]
#[derive(Clone, Copy, Eq, PartialEq, Debug)]
pub enum StackPopUnwind {
/// The cleanup block.
Cleanup(mir::BasicBlock),
@ -152,7 +149,7 @@ pub enum StackPopUnwind {
NotAllowed,
}
#[derive(Clone, Copy, Eq, PartialEq, Debug, HashStable)] // Miri debug-prints these
#[derive(Clone, Copy, Eq, PartialEq, Debug)] // Miri debug-prints these
pub enum StackPopCleanup {
/// Jump to the next block in the caller, or cause UB if None (that's a function
/// that may never return). Also store layout of return place so
@ -168,16 +165,15 @@ pub enum StackPopCleanup {
}
/// State of a local variable including a memoized layout
#[derive(Clone, Debug, PartialEq, Eq, HashStable)]
#[derive(Clone, Debug)]
pub struct LocalState<'tcx, Tag: Provenance = AllocId> {
pub value: LocalValue<Tag>,
/// Don't modify if `Some`, this is only used to prevent computing the layout twice
#[stable_hasher(ignore)]
pub layout: Cell<Option<TyAndLayout<'tcx>>>,
}
/// Current value of a local variable
#[derive(Copy, Clone, PartialEq, Eq, HashStable, Debug)] // Miri debug-prints these
#[derive(Copy, Clone, Debug)] // Miri debug-prints these
pub enum LocalValue<Tag: Provenance = AllocId> {
/// This local is not currently alive, and cannot be used at all.
Dead,
@ -678,7 +674,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
body,
loc: Err(body.span), // Span used for errors caused during preamble.
return_to_block,
return_place: *return_place,
return_place: return_place.clone(),
// empty local array, we fill it in below, after we are inside the stack frame and
// all methods actually know about the frame
locals: IndexVec::new(),
@ -799,7 +795,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
let op = self
.local_to_op(self.frame(), mir::RETURN_PLACE, None)
.expect("return place should always be live");
let dest = self.frame().return_place;
let dest = self.frame().return_place.clone();
let err = self.copy_op(&op, &dest, /*allow_transmute*/ true);
trace!("return value: {:?}", self.dump_place(*dest));
// We delay actually short-circuiting on this error until *after* the stack frame is
@ -1021,31 +1017,3 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> std::fmt::Debug
}
}
}
impl<'ctx, 'mir, 'tcx, Tag: Provenance, Extra> HashStable<StableHashingContext<'ctx>>
for Frame<'mir, 'tcx, Tag, Extra>
where
Extra: HashStable<StableHashingContext<'ctx>>,
Tag: HashStable<StableHashingContext<'ctx>>,
{
fn hash_stable(&self, hcx: &mut StableHashingContext<'ctx>, hasher: &mut StableHasher) {
// Exhaustive match on fields to make sure we forget no field.
let Frame {
body,
instance,
return_to_block,
return_place,
locals,
loc,
extra,
tracing_span: _,
} = self;
body.hash_stable(hcx, hasher);
instance.hash_stable(hcx, hasher);
return_to_block.hash_stable(hcx, hasher);
return_place.hash_stable(hcx, hasher);
locals.hash_stable(hcx, hasher);
loc.hash_stable(hcx, hasher);
extra.hash_stable(hcx, hasher);
}
}

7
compiler/rustc_const_eval/src/interpret/intrinsics.rs
View file

@ -455,8 +455,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
for i in 0..dest_len {
let place = self.mplace_index(&dest, i)?;
let value =
if i == index { *elem } else { self.mplace_index(&input, i)?.into() };
let value = if i == index {
elem.clone()
} else {
self.mplace_index(&input, i)?.into()
};
self.copy_op(&value, &place.into(), /*allow_transmute*/ false)?;
}
}

12
compiler/rustc_const_eval/src/interpret/operand.rs
View file

@ -4,7 +4,6 @@
use std::fmt::Write;
use rustc_hir::def::Namespace;
use rustc_macros::HashStable;
use rustc_middle::ty::layout::{LayoutOf, PrimitiveExt, TyAndLayout};
use rustc_middle::ty::print::{FmtPrinter, PrettyPrinter, Printer};
use rustc_middle::ty::{ConstInt, DelaySpanBugEmitted, Ty};
@ -25,7 +24,7 @@ use super::{
/// operations and wide pointers. This idea was taken from rustc's codegen.
/// In particular, thanks to `ScalarPair`, arithmetic operations and casts can be entirely
/// defined on `Immediate`, and do not have to work with a `Place`.
#[derive(Copy, Clone, PartialEq, Eq, HashStable, Hash, Debug)]
#[derive(Copy, Clone, Debug)]
pub enum Immediate<Tag: Provenance = AllocId> {
/// A single scalar value (must have *initialized* `Scalar` ABI).
/// FIXME: we also currently often use this for ZST.
@ -112,7 +111,7 @@ impl<'tcx, Tag: Provenance> Immediate<Tag> {
// ScalarPair needs a type to interpret, so we often have an immediate and a type together
// as input for binary and cast operations.
#[derive(Copy, Clone, Debug)]
#[derive(Clone, Debug)]
pub struct ImmTy<'tcx, Tag: Provenance = AllocId> {
imm: Immediate<Tag>,
pub layout: TyAndLayout<'tcx>,
@ -182,13 +181,16 @@ impl<'tcx, Tag: Provenance> std::ops::Deref for ImmTy<'tcx, Tag> {
/// An `Operand` is the result of computing a `mir::Operand`. It can be immediate,
/// or still in memory. The latter is an optimization, to delay reading that chunk of
/// memory and to avoid having to store arbitrary-sized data here.
#[derive(Copy, Clone, PartialEq, Eq, HashStable, Hash, Debug)]
#[derive(Copy, Clone, Debug)]
pub enum Operand<Tag: Provenance = AllocId> {
Immediate(Immediate<Tag>),
Indirect(MemPlace<Tag>),
}
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
rustc_data_structures::static_assert_size!(Operand, 64);
#[derive(Clone, Debug)]
pub struct OpTy<'tcx, Tag: Provenance = AllocId> {
op: Operand<Tag>, // Keep this private; it helps enforce invariants.
pub layout: TyAndLayout<'tcx>,

39
compiler/rustc_const_eval/src/interpret/place.rs
View file

@ -5,7 +5,6 @@
use std::hash::Hash;
use rustc_ast::Mutability;
use rustc_macros::HashStable;
use rustc_middle::mir;
use rustc_middle::ty;
use rustc_middle::ty::layout::{LayoutOf, PrimitiveExt, TyAndLayout};
@ -17,7 +16,7 @@ use super::{
Pointer, Provenance, Scalar, ScalarMaybeUninit,
};
#[derive(Copy, Clone, Hash, PartialEq, Eq, HashStable, Debug)]
#[derive(Copy, Clone, Hash, PartialEq, Eq, Debug)]
/// Information required for the sound usage of a `MemPlace`.
pub enum MemPlaceMeta<Tag: Provenance = AllocId> {
/// The unsized payload (e.g. length for slices or vtable pointer for trait objects).
@ -47,7 +46,7 @@ impl<Tag: Provenance> MemPlaceMeta<Tag> {
}
}
#[derive(Copy, Clone, Hash, PartialEq, Eq, HashStable, Debug)]
#[derive(Copy, Clone, Hash, PartialEq, Eq, Debug)]
pub struct MemPlace<Tag: Provenance = AllocId> {
/// The pointer can be a pure integer, with the `None` tag.
pub ptr: Pointer<Option<Tag>>,
@ -60,7 +59,22 @@ pub struct MemPlace<Tag: Provenance = AllocId> {
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
rustc_data_structures::static_assert_size!(MemPlace, 40);
#[derive(Copy, Clone, Hash, PartialEq, Eq, HashStable, Debug)]
/// A MemPlace with its layout. Constructing it is only possible in this module.
#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
pub struct MPlaceTy<'tcx, Tag: Provenance = AllocId> {
mplace: MemPlace<Tag>,
pub layout: TyAndLayout<'tcx>,
/// rustc does not have a proper way to represent the type of a field of a `repr(packed)` struct:
/// it needs to have a different alignment than the field type would usually have.
/// So we represent this here with a separate field that "overwrites" `layout.align`.
/// This means `layout.align` should never be used for a `MPlaceTy`!
pub align: Align,
}
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
rustc_data_structures::static_assert_size!(MPlaceTy<'_>, 64);
#[derive(Copy, Clone, Debug)]
pub enum Place<Tag: Provenance = AllocId> {
/// A place referring to a value allocated in the `Memory` system.
Ptr(MemPlace<Tag>),
@ -73,7 +87,7 @@ pub enum Place<Tag: Provenance = AllocId> {
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
rustc_data_structures::static_assert_size!(Place, 48);
#[derive(Copy, Clone, Debug)]
#[derive(Clone, Debug)]
pub struct PlaceTy<'tcx, Tag: Provenance = AllocId> {
place: Place<Tag>, // Keep this private; it helps enforce invariants.
pub layout: TyAndLayout<'tcx>,
@ -95,21 +109,6 @@ impl<'tcx, Tag: Provenance> std::ops::Deref for PlaceTy<'tcx, Tag> {
}
}
/// A MemPlace with its layout. Constructing it is only possible in this module.
#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
pub struct MPlaceTy<'tcx, Tag: Provenance = AllocId> {
mplace: MemPlace<Tag>,
pub layout: TyAndLayout<'tcx>,
/// rustc does not have a proper way to represent the type of a field of a `repr(packed)` struct:
/// it needs to have a different alignment than the field type would usually have.
/// So we represent this here with a separate field that "overwrites" `layout.align`.
/// This means `layout.align` should never be used for a `MPlaceTy`!
pub align: Align,
}
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
rustc_data_structures::static_assert_size!(MPlaceTy<'_>, 64);
impl<'tcx, Tag: Provenance> std::ops::Deref for MPlaceTy<'tcx, Tag> {
type Target = MemPlace<Tag>;
#[inline(always)]

8
compiler/rustc_const_eval/src/interpret/projection.rs
View file

@ -157,7 +157,7 @@ where
variant: VariantIdx,
) -> InterpResult<'tcx, PlaceTy<'tcx, M::PointerTag>> {
// Downcast just changes the layout
let mut base = *base;
let mut base = base.clone();
base.layout = base.layout.for_variant(self, variant);
Ok(base)
}
@ -168,7 +168,7 @@ where
variant: VariantIdx,
) -> InterpResult<'tcx, OpTy<'tcx, M::PointerTag>> {
// Downcast just changes the layout
let mut base = *base;
let mut base = base.clone();
base.layout = base.layout.for_variant(self, variant);
Ok(base)
}
@ -350,7 +350,7 @@ where
use rustc_middle::mir::ProjectionElem::*;
Ok(match proj_elem {
OpaqueCast(ty) => {
let mut place = *base;
let mut place = base.clone();
place.layout = self.layout_of(ty)?;
place
}
@ -379,7 +379,7 @@ where
use rustc_middle::mir::ProjectionElem::*;
Ok(match proj_elem {
OpaqueCast(ty) => {
let mut op = *base;
let mut op = base.clone();
op.layout = self.layout_of(ty)?;
op
}

4
compiler/rustc_const_eval/src/interpret/terminator.rs
View file

@ -444,7 +444,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
trace!("eval_fn_call: Will pass last argument by untupling");
Cow::from(
args.iter()
.map(|&a| Ok(a))
.map(|a| Ok(a.clone()))
.chain(
(0..untuple_arg.layout.fields.count())
.map(|i| self.operand_field(untuple_arg, i)),
@ -525,7 +525,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// We have to implement all "object safe receivers". So we have to go search for a
// pointer or `dyn Trait` type, but it could be wrapped in newtypes. So recursively
// unwrap those newtypes until we are there.
let mut receiver = args[0];
let mut receiver = args[0].clone();
let receiver_place = loop {
match receiver.layout.ty.kind() {
ty::Ref(..) | ty::RawPtr(..) => break self.deref_operand(&receiver)?,

14
compiler/rustc_const_eval/src/interpret/visitor.rs
View file

@ -13,7 +13,7 @@ use super::{InterpCx, MPlaceTy, Machine, OpTy, PlaceTy};
/// A thing that we can project into, and that has a layout.
/// This wouldn't have to depend on `Machine` but with the current type inference,
/// that's just more convenient to work with (avoids repeating all the `Machine` bounds).
pub trait Value<'mir, 'tcx, M: Machine<'mir, 'tcx>>: Copy {
pub trait Value<'mir, 'tcx, M: Machine<'mir, 'tcx>>: Sized {
/// Gets this value's layout.
fn layout(&self) -> TyAndLayout<'tcx>;
@ -54,7 +54,7 @@ pub trait Value<'mir, 'tcx, M: Machine<'mir, 'tcx>>: Copy {
/// A thing that we can project into given *mutable* access to `ecx`, and that has a layout.
/// This wouldn't have to depend on `Machine` but with the current type inference,
/// that's just more convenient to work with (avoids repeating all the `Machine` bounds).
pub trait ValueMut<'mir, 'tcx, M: Machine<'mir, 'tcx>>: Copy {
pub trait ValueMut<'mir, 'tcx, M: Machine<'mir, 'tcx>>: Sized {
/// Gets this value's layout.
fn layout(&self) -> TyAndLayout<'tcx>;
@ -106,12 +106,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> Value<'mir, 'tcx, M> for OpTy<'tc
&self,
_ecx: &InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, OpTy<'tcx, M::PointerTag>> {
Ok(*self)
Ok(self.clone())
}
#[inline(always)]
fn from_op(op: &OpTy<'tcx, M::PointerTag>) -> Self {
*op
op.clone()
}
#[inline(always)]
@ -146,7 +146,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueMut<'mir, 'tcx, M>
&self,
_ecx: &InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, OpTy<'tcx, M::PointerTag>> {
Ok(*self)
Ok(self.clone())
}
#[inline(always)]
@ -154,12 +154,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueMut<'mir, 'tcx, M>
&self,
_ecx: &mut InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, OpTy<'tcx, M::PointerTag>> {
Ok(*self)
Ok(self.clone())
}
#[inline(always)]
fn from_op(op: &OpTy<'tcx, M::PointerTag>) -> Self {
*op
op.clone()
}
#[inline(always)]

2
compiler/rustc_mir_transform/src/const_prop.rs
View file

@ -516,7 +516,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
let l = self.use_ecx(|this| this.ecx.read_immediate(&this.ecx.eval_operand(left, None)?));
// Check for exceeding shifts *even if* we cannot evaluate the LHS.
if op == BinOp::Shr || op == BinOp::Shl {
let r = r?;
let r = r.clone()?;
// We need the type of the LHS. We cannot use `place_layout` as that is the type
// of the result, which for checked binops is not the same!
let left_ty = left.ty(self.local_decls, self.tcx);

6
compiler/rustc_mir_transform/src/const_prop_lint.rs
View file

@ -584,7 +584,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
});
// Check for exceeding shifts *even if* we cannot evaluate the LHS.
if op == BinOp::Shr || op == BinOp::Shl {
let r = r?;
let r = r.clone()?;
// We need the type of the LHS. We cannot use `place_layout` as that is the type
// of the result, which for checked binops is not the same!
let left_ty = left.ty(self.local_decls, self.tcx);
@ -616,10 +616,10 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
}
}
if let (Some(l), Some(r)) = (&l, &r) {
if let (Some(l), Some(r)) = (l, r) {
// The remaining operators are handled through `overflowing_binary_op`.
if self.use_ecx(source_info, |this| {
let (_res, overflow, _ty) = this.ecx.overflowing_binary_op(op, l, r)?;
let (_res, overflow, _ty) = this.ecx.overflowing_binary_op(op, &l, &r)?;
Ok(overflow)
})? {
self.report_assert_as_lint(