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Add `tag_for_variant` query 

This query allows for sharing code between `rustc_const_eval` and
`rustc_transmutability`.

Also moves `DummyMachine` to `rustc_const_eval`.
This commit is contained in:
Jack Wrenn 2024-03-20 17:45:14 +00:00
parent 9023f908cf
commit 2de9010f66
13 changed files with 347 additions and 292 deletions
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193
compiler/rustc_const_eval/src/const_eval/dummy_machine.rs Normal file
View File

@ -0,0 +1,193 @@
use crate::interpret::{self, HasStaticRootDefId, ImmTy, Immediate, InterpCx, PointerArithmetic};
use rustc_middle::mir::interpret::{AllocId, ConstAllocation, InterpResult};
use rustc_middle::mir::*;
use rustc_middle::query::TyCtxtAt;
use rustc_middle::ty;
use rustc_middle::ty::layout::TyAndLayout;
use rustc_span::def_id::DefId;
/// Macro for machine-specific `InterpError` without allocation.
/// (These will never be shown to the user, but they help diagnose ICEs.)
pub macro throw_machine_stop_str($($tt:tt)*) {{
// We make a new local type for it. The type itself does not carry any information,
// but its vtable (for the `MachineStopType` trait) does.
#[derive(Debug)]
struct Zst;
// Printing this type shows the desired string.
impl std::fmt::Display for Zst {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, $($tt)*)
}
}
impl rustc_middle::mir::interpret::MachineStopType for Zst {
fn diagnostic_message(&self) -> rustc_errors::DiagMessage {
self.to_string().into()
}
fn add_args(
self: Box<Self>,
_: &mut dyn FnMut(rustc_errors::DiagArgName, rustc_errors::DiagArgValue),
) {}
}
throw_machine_stop!(Zst)
}}
pub struct DummyMachine;
impl HasStaticRootDefId for DummyMachine {
fn static_def_id(&self) -> Option<rustc_hir::def_id::LocalDefId> {
None
}
}
impl<'mir, 'tcx: 'mir> interpret::Machine<'mir, 'tcx> for DummyMachine {
interpret::compile_time_machine!(<'mir, 'tcx>);
type MemoryKind = !;
const PANIC_ON_ALLOC_FAIL: bool = true;
#[inline(always)]
fn enforce_alignment(_ecx: &InterpCx<'mir, 'tcx, Self>) -> bool {
false // no reason to enforce alignment
}
fn enforce_validity(_ecx: &InterpCx<'mir, 'tcx, Self>, _layout: TyAndLayout<'tcx>) -> bool {
false
}
fn before_access_global(
_tcx: TyCtxtAt<'tcx>,
_machine: &Self,
_alloc_id: AllocId,
alloc: ConstAllocation<'tcx>,
_static_def_id: Option<DefId>,
is_write: bool,
) -> InterpResult<'tcx> {
if is_write {
throw_machine_stop_str!("can't write to global");
}
// If the static allocation is mutable, then we can't const prop it as its content
// might be different at runtime.
if alloc.inner().mutability.is_mut() {
throw_machine_stop_str!("can't access mutable globals in ConstProp");
}
Ok(())
}
fn find_mir_or_eval_fn(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_instance: ty::Instance<'tcx>,
_abi: rustc_target::spec::abi::Abi,
_args: &[interpret::FnArg<'tcx, Self::Provenance>],
_destination: &interpret::MPlaceTy<'tcx, Self::Provenance>,
_target: Option<BasicBlock>,
_unwind: UnwindAction,
) -> interpret::InterpResult<'tcx, Option<(&'mir Body<'tcx>, ty::Instance<'tcx>)>> {
unimplemented!()
}
fn panic_nounwind(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_msg: &str,
) -> interpret::InterpResult<'tcx> {
unimplemented!()
}
fn call_intrinsic(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_instance: ty::Instance<'tcx>,
_args: &[interpret::OpTy<'tcx, Self::Provenance>],
_destination: &interpret::MPlaceTy<'tcx, Self::Provenance>,
_target: Option<BasicBlock>,
_unwind: UnwindAction,
) -> interpret::InterpResult<'tcx> {
unimplemented!()
}
fn assert_panic(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_msg: &rustc_middle::mir::AssertMessage<'tcx>,
_unwind: UnwindAction,
) -> interpret::InterpResult<'tcx> {
unimplemented!()
}
fn binary_ptr_op(
ecx: &InterpCx<'mir, 'tcx, Self>,
bin_op: BinOp,
left: &interpret::ImmTy<'tcx, Self::Provenance>,
right: &interpret::ImmTy<'tcx, Self::Provenance>,
) -> interpret::InterpResult<'tcx, (ImmTy<'tcx, Self::Provenance>, bool)> {
use rustc_middle::mir::BinOp::*;
Ok(match bin_op {
Eq | Ne | Lt | Le | Gt | Ge => {
// Types can differ, e.g. fn ptrs with different `for`.
assert_eq!(left.layout.abi, right.layout.abi);
let size = ecx.pointer_size();
// Just compare the bits. ScalarPairs are compared lexicographically.
// We thus always compare pairs and simply fill scalars up with 0.
// If the pointer has provenance, `to_bits` will return `Err` and we bail out.
let left = match **left {
Immediate::Scalar(l) => (l.to_bits(size)?, 0),
Immediate::ScalarPair(l1, l2) => (l1.to_bits(size)?, l2.to_bits(size)?),
Immediate::Uninit => panic!("we should never see uninit data here"),
};
let right = match **right {
Immediate::Scalar(r) => (r.to_bits(size)?, 0),
Immediate::ScalarPair(r1, r2) => (r1.to_bits(size)?, r2.to_bits(size)?),
Immediate::Uninit => panic!("we should never see uninit data here"),
};
let res = match bin_op {
Eq => left == right,
Ne => left != right,
Lt => left < right,
Le => left <= right,
Gt => left > right,
Ge => left >= right,
_ => bug!(),
};
(ImmTy::from_bool(res, *ecx.tcx), false)
}
// Some more operations are possible with atomics.
// The return value always has the provenance of the *left* operand.
Add | Sub | BitOr | BitAnd | BitXor => {
throw_machine_stop_str!("pointer arithmetic is not handled")
}
_ => span_bug!(ecx.cur_span(), "Invalid operator on pointers: {:?}", bin_op),
})
}
fn expose_ptr(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_ptr: interpret::Pointer<Self::Provenance>,
) -> interpret::InterpResult<'tcx> {
unimplemented!()
}
fn init_frame_extra(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_frame: interpret::Frame<'mir, 'tcx, Self::Provenance>,
) -> interpret::InterpResult<
'tcx,
interpret::Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>,
> {
unimplemented!()
}
fn stack<'a>(
_ecx: &'a InterpCx<'mir, 'tcx, Self>,
) -> &'a [interpret::Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>] {
// Return an empty stack instead of panicking, as `cur_span` uses it to evaluate constants.
&[]
}
fn stack_mut<'a>(
_ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
) -> &'a mut Vec<interpret::Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>> {
unimplemented!()
}
}

20
compiler/rustc_const_eval/src/const_eval/eval_queries.rs
View File

@ -3,7 +3,7 @@ use either::{Left, Right};
use rustc_hir::def::DefKind;
use rustc_middle::mir::interpret::{AllocId, ErrorHandled, InterpErrorInfo};
use rustc_middle::mir::{self, ConstAlloc, ConstValue};
use rustc_middle::query::TyCtxtAt;
use rustc_middle::query::{Key, TyCtxtAt};
use rustc_middle::traits::Reveal;
use rustc_middle::ty::layout::LayoutOf;
use rustc_middle::ty::print::with_no_trimmed_paths;
@ -243,6 +243,24 @@ pub(crate) fn turn_into_const_value<'tcx>(
op_to_const(&ecx, &mplace.into(), /* for diagnostics */ false)
}
/// Computes the tag (if any) for a given type and variant.
#[instrument(skip(tcx), level = "debug")]
pub fn tag_for_variant_provider<'tcx>(
tcx: TyCtxt<'tcx>,
(ty, variant_index): (Ty<'tcx>, abi::VariantIdx),
) -> Option<ty::ScalarInt> {
assert!(ty.is_enum());
let ecx = InterpCx::new(
tcx,
ty.default_span(tcx),
ty::ParamEnv::reveal_all(),
crate::const_eval::DummyMachine,
);
ecx.tag_for_variant(ty, variant_index).unwrap().map(|(tag, _tag_field)| tag)
}
#[instrument(skip(tcx), level = "debug")]
pub fn eval_to_const_value_raw_provider<'tcx>(
tcx: TyCtxt<'tcx>,

2
compiler/rustc_const_eval/src/const_eval/mod.rs
View File

@ -7,12 +7,14 @@ use rustc_middle::ty::{self, Ty};
use crate::interpret::format_interp_error;
mod dummy_machine;
mod error;
mod eval_queries;
mod fn_queries;
mod machine;
mod valtrees;
pub use dummy_machine::*;
pub use error::*;
pub use eval_queries::*;
pub use fn_queries::*;

156
compiler/rustc_const_eval/src/interpret/discriminant.rs
View File

@ -2,7 +2,7 @@
use rustc_middle::mir;
use rustc_middle::ty::layout::{LayoutOf, PrimitiveExt};
use rustc_middle::ty::{self, Ty};
use rustc_middle::ty::{self, ScalarInt, Ty};
use rustc_target::abi::{self, TagEncoding};
use rustc_target::abi::{VariantIdx, Variants};
@ -28,78 +28,27 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
throw_ub!(UninhabitedEnumVariantWritten(variant_index))
}
match dest.layout().variants {
abi::Variants::Single { index } => {
assert_eq!(index, variant_index);
}
abi::Variants::Multiple {
tag_encoding: TagEncoding::Direct,
tag: tag_layout,
tag_field,
..
} => {
match self.tag_for_variant(dest.layout().ty, variant_index)? {
Some((tag, tag_field)) => {
// No need to validate that the discriminant here because the
// `TyAndLayout::for_variant()` call earlier already checks the variant is valid.
let discr_val = dest
.layout()
.ty
.discriminant_for_variant(*self.tcx, variant_index)
.unwrap()
.val;
// raw discriminants for enums are isize or bigger during
// their computation, but the in-memory tag is the smallest possible
// representation
let size = tag_layout.size(self);
let tag_val = size.truncate(discr_val);
// `TyAndLayout::for_variant()` call earlier already checks the
// variant is valid.
let tag_dest = self.project_field(dest, tag_field)?;
self.write_scalar(Scalar::from_uint(tag_val, size), &tag_dest)?;
self.write_scalar(tag, &tag_dest)
}
abi::Variants::Multiple {
tag_encoding:
TagEncoding::Niche { untagged_variant, ref niche_variants, niche_start },
tag: tag_layout,
tag_field,
..
} => {
// No need to validate that the discriminant here because the
// `TyAndLayout::for_variant()` call earlier already checks the variant is valid.
if variant_index != untagged_variant {
let variants_start = niche_variants.start().as_u32();
let variant_index_relative = variant_index
.as_u32()
.checked_sub(variants_start)
.expect("overflow computing relative variant idx");
// We need to use machine arithmetic when taking into account `niche_start`:
// tag_val = variant_index_relative + niche_start_val
let tag_layout = self.layout_of(tag_layout.primitive().to_int_ty(*self.tcx))?;
let niche_start_val = ImmTy::from_uint(niche_start, tag_layout);
let variant_index_relative_val =
ImmTy::from_uint(variant_index_relative, tag_layout);
let tag_val = self.wrapping_binary_op(
mir::BinOp::Add,
&variant_index_relative_val,
&niche_start_val,
)?;
// Write result.
let niche_dest = self.project_field(dest, tag_field)?;
self.write_immediate(*tag_val, &niche_dest)?;
} else {
// The untagged variant is implicitly encoded simply by having a value that is
// outside the niche variants. But what if the data stored here does not
// actually encode this variant? That would be bad! So let's double-check...
let actual_variant = self.read_discriminant(&dest.to_op(self)?)?;
if actual_variant != variant_index {
throw_ub!(InvalidNichedEnumVariantWritten { enum_ty: dest.layout().ty });
}
None => {
// No need to write the tag here, because an untagged variant is
// implicitly encoded. For `Niche`-optimized enums, it's by
// simply by having a value that is outside the niche variants.
// But what if the data stored here does not actually encode
// this variant? That would be bad! So let's double-check...
let actual_variant = self.read_discriminant(&dest.to_op(self)?)?;
if actual_variant != variant_index {
throw_ub!(InvalidNichedEnumVariantWritten { enum_ty: dest.layout().ty });
}
Ok(())
}
}
Ok(())
}
/// Read discriminant, return the runtime value as well as the variant index.
@ -277,4 +226,77 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
};
Ok(ImmTy::from_scalar(discr_value, discr_layout))
}
/// Computes the tag value and its field number (if any) of a given variant
/// of type `ty`.
pub(crate) fn tag_for_variant(
&self,
ty: Ty<'tcx>,
variant_index: VariantIdx,
) -> InterpResult<'tcx, Option<(ScalarInt, usize)>> {
match self.layout_of(ty)?.variants {
abi::Variants::Single { index } => {
assert_eq!(index, variant_index);
Ok(None)
}
abi::Variants::Multiple {
tag_encoding: TagEncoding::Direct,
tag: tag_layout,
tag_field,
..
} => {
// raw discriminants for enums are isize or bigger during
// their computation, but the in-memory tag is the smallest possible
// representation
let discr = self.discriminant_for_variant(ty, variant_index)?;
let discr_size = discr.layout.size;
let discr_val = discr.to_scalar().to_bits(discr_size)?;
let tag_size = tag_layout.size(self);
let tag_val = tag_size.truncate(discr_val);
let tag = ScalarInt::try_from_uint(tag_val, tag_size).unwrap();
Ok(Some((tag, tag_field)))
}
abi::Variants::Multiple {
tag_encoding: TagEncoding::Niche { untagged_variant, .. },
..
} if untagged_variant == variant_index => {
// The untagged variant is implicitly encoded simply by having a
// value that is outside the niche variants.
Ok(None)
}
abi::Variants::Multiple {
tag_encoding:
TagEncoding::Niche { untagged_variant, ref niche_variants, niche_start },
tag: tag_layout,
tag_field,
..
} => {
assert!(variant_index != untagged_variant);
let variants_start = niche_variants.start().as_u32();
let variant_index_relative = variant_index
.as_u32()
.checked_sub(variants_start)
.expect("overflow computing relative variant idx");
// We need to use machine arithmetic when taking into account `niche_start`:
// tag_val = variant_index_relative + niche_start_val
let tag_layout = self.layout_of(tag_layout.primitive().to_int_ty(*self.tcx))?;
let niche_start_val = ImmTy::from_uint(niche_start, tag_layout);
let variant_index_relative_val =
ImmTy::from_uint(variant_index_relative, tag_layout);
let tag = self
.wrapping_binary_op(
mir::BinOp::Add,
&variant_index_relative_val,
&niche_start_val,
)?
.to_scalar()
.try_to_int()
.unwrap();
Ok(Some((tag, tag_field)))
}
}
}
}

1
compiler/rustc_const_eval/src/lib.rs
View File

@ -40,6 +40,7 @@ rustc_fluent_macro::fluent_messages! { "../messages.ftl" }
pub fn provide(providers: &mut Providers) {
const_eval::provide(providers);
providers.tag_for_variant = const_eval::tag_for_variant_provider;
providers.eval_to_const_value_raw = const_eval::eval_to_const_value_raw_provider;
providers.eval_to_allocation_raw = const_eval::eval_to_allocation_raw_provider;
providers.eval_static_initializer = const_eval::eval_static_initializer_provider;

1
compiler/rustc_middle/src/query/erase.rs
View File

@ -234,6 +234,7 @@ trivial! {
Option<rustc_middle::middle::stability::DeprecationEntry>,
Option<rustc_middle::ty::Destructor>,
Option<rustc_middle::ty::ImplTraitInTraitData>,
Option<rustc_middle::ty::ScalarInt>,
Option<rustc_span::def_id::CrateNum>,
Option<rustc_span::def_id::DefId>,
Option<rustc_span::def_id::LocalDefId>,

9
compiler/rustc_middle/src/query/keys.rs
View File

@ -13,6 +13,7 @@ use rustc_query_system::query::DefIdCacheSelector;
use rustc_query_system::query::{DefaultCacheSelector, SingleCacheSelector, VecCacheSelector};
use rustc_span::symbol::{Ident, Symbol};
use rustc_span::{Span, DUMMY_SP};
use rustc_target::abi;
/// Placeholder for `CrateNum`'s "local" counterpart
#[derive(Copy, Clone, Debug)]
@ -502,6 +503,14 @@ impl<'tcx> Key for (DefId, Ty<'tcx>, GenericArgsRef<'tcx>, ty::ParamEnv<'tcx>) {
}
}
impl<'tcx> Key for (Ty<'tcx>, abi::VariantIdx) {
type CacheSelector = DefaultCacheSelector<Self>;
fn default_span(&self, _tcx: TyCtxt<'_>) -> Span {
DUMMY_SP
}
}
impl<'tcx> Key for (ty::Predicate<'tcx>, traits::WellFormedLoc) {
type CacheSelector = DefaultCacheSelector<Self>;

7
compiler/rustc_middle/src/query/mod.rs
View File

@ -1042,6 +1042,13 @@ rustc_queries! {
}
}
/// Computes the tag (if any) for a given type and variant.
query tag_for_variant(
key: (Ty<'tcx>, abi::VariantIdx)
) -> Option<ty::ScalarInt> {
desc { "computing variant tag for enum" }
}
/// Evaluates a constant and returns the computed allocation.
///
/// **Do not use this** directly, use the `eval_to_const_value` or `eval_to_valtree` instead.

200
compiler/rustc_mir_transform/src/dataflow_const_prop.rs
View File

@ -2,52 +2,22 @@
//!
//! Currently, this pass only propagates scalar values.
use rustc_const_eval::interpret::{
HasStaticRootDefId, ImmTy, Immediate, InterpCx, OpTy, PlaceTy, PointerArithmetic, Projectable,
};
use rustc_const_eval::const_eval::{throw_machine_stop_str, DummyMachine};
use rustc_const_eval::interpret::{ImmTy, Immediate, InterpCx, OpTy, PlaceTy, Projectable};
use rustc_data_structures::fx::FxHashMap;
use rustc_hir::def::DefKind;
use rustc_middle::mir::interpret::{AllocId, ConstAllocation, InterpResult, Scalar};
use rustc_middle::mir::interpret::{InterpResult, Scalar};
use rustc_middle::mir::visit::{MutVisitor, PlaceContext, Visitor};
use rustc_middle::mir::*;
use rustc_middle::query::TyCtxtAt;
use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
use rustc_middle::ty::layout::LayoutOf;
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_mir_dataflow::value_analysis::{
Map, PlaceIndex, State, TrackElem, ValueAnalysis, ValueAnalysisWrapper, ValueOrPlace,
};
use rustc_mir_dataflow::{lattice::FlatSet, Analysis, Results, ResultsVisitor};
use rustc_span::def_id::DefId;
use rustc_span::DUMMY_SP;
use rustc_target::abi::{Abi, FieldIdx, Size, VariantIdx, FIRST_VARIANT};
/// Macro for machine-specific `InterpError` without allocation.
/// (These will never be shown to the user, but they help diagnose ICEs.)
pub(crate) macro throw_machine_stop_str($($tt:tt)*) {{
// We make a new local type for it. The type itself does not carry any information,
// but its vtable (for the `MachineStopType` trait) does.
#[derive(Debug)]
struct Zst;
// Printing this type shows the desired string.
impl std::fmt::Display for Zst {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, $($tt)*)
}
}
impl rustc_middle::mir::interpret::MachineStopType for Zst {
fn diagnostic_message(&self) -> rustc_errors::DiagMessage {
self.to_string().into()
}
fn add_args(
self: Box<Self>,
_: &mut dyn FnMut(rustc_errors::DiagArgName, rustc_errors::DiagArgValue),
) {}
}
throw_machine_stop!(Zst)
}}
// These constants are somewhat random guesses and have not been optimized.
// If `tcx.sess.mir_opt_level() >= 4`, we ignore the limits (this can become very expensive).
const BLOCK_LIMIT: usize = 100;
@ -888,165 +858,3 @@ impl<'tcx> Visitor<'tcx> for OperandCollector<'tcx, '_, '_, '_> {
}
}
}
pub(crate) struct DummyMachine;
impl HasStaticRootDefId for DummyMachine {
fn static_def_id(&self) -> Option<rustc_hir::def_id::LocalDefId> {
None
}
}
impl<'mir, 'tcx: 'mir> rustc_const_eval::interpret::Machine<'mir, 'tcx> for DummyMachine {
rustc_const_eval::interpret::compile_time_machine!(<'mir, 'tcx>);
type MemoryKind = !;
const PANIC_ON_ALLOC_FAIL: bool = true;
#[inline(always)]
fn enforce_alignment(_ecx: &InterpCx<'mir, 'tcx, Self>) -> bool {
false // no reason to enforce alignment
}
fn enforce_validity(_ecx: &InterpCx<'mir, 'tcx, Self>, _layout: TyAndLayout<'tcx>) -> bool {
false
}
fn before_access_global(
_tcx: TyCtxtAt<'tcx>,
_machine: &Self,
_alloc_id: AllocId,
alloc: ConstAllocation<'tcx>,
_static_def_id: Option<DefId>,
is_write: bool,
) -> InterpResult<'tcx> {
if is_write {
throw_machine_stop_str!("can't write to global");
}
// If the static allocation is mutable, then we can't const prop it as its content
// might be different at runtime.
if alloc.inner().mutability.is_mut() {
throw_machine_stop_str!("can't access mutable globals in ConstProp");
}
Ok(())
}
fn find_mir_or_eval_fn(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_instance: ty::Instance<'tcx>,
_abi: rustc_target::spec::abi::Abi,
_args: &[rustc_const_eval::interpret::FnArg<'tcx, Self::Provenance>],
_destination: &rustc_const_eval::interpret::MPlaceTy<'tcx, Self::Provenance>,
_target: Option<BasicBlock>,
_unwind: UnwindAction,
) -> interpret::InterpResult<'tcx, Option<(&'mir Body<'tcx>, ty::Instance<'tcx>)>> {
unimplemented!()
}
fn panic_nounwind(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_msg: &str,
) -> interpret::InterpResult<'tcx> {
unimplemented!()
}
fn call_intrinsic(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_instance: ty::Instance<'tcx>,
_args: &[rustc_const_eval::interpret::OpTy<'tcx, Self::Provenance>],
_destination: &rustc_const_eval::interpret::MPlaceTy<'tcx, Self::Provenance>,
_target: Option<BasicBlock>,
_unwind: UnwindAction,
) -> interpret::InterpResult<'tcx> {
unimplemented!()
}
fn assert_panic(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_msg: &rustc_middle::mir::AssertMessage<'tcx>,
_unwind: UnwindAction,
) -> interpret::InterpResult<'tcx> {
unimplemented!()
}
fn binary_ptr_op(
ecx: &InterpCx<'mir, 'tcx, Self>,
bin_op: BinOp,
left: &rustc_const_eval::interpret::ImmTy<'tcx, Self::Provenance>,
right: &rustc_const_eval::interpret::ImmTy<'tcx, Self::Provenance>,
) -> interpret::InterpResult<'tcx, (ImmTy<'tcx, Self::Provenance>, bool)> {
use rustc_middle::mir::BinOp::*;
Ok(match bin_op {
Eq | Ne | Lt | Le | Gt | Ge => {
// Types can differ, e.g. fn ptrs with different `for`.
assert_eq!(left.layout.abi, right.layout.abi);
let size = ecx.pointer_size();
// Just compare the bits. ScalarPairs are compared lexicographically.
// We thus always compare pairs and simply fill scalars up with 0.
// If the pointer has provenance, `to_bits` will return `Err` and we bail out.
let left = match **left {
Immediate::Scalar(l) => (l.to_bits(size)?, 0),
Immediate::ScalarPair(l1, l2) => (l1.to_bits(size)?, l2.to_bits(size)?),
Immediate::Uninit => panic!("we should never see uninit data here"),
};
let right = match **right {
Immediate::Scalar(r) => (r.to_bits(size)?, 0),
Immediate::ScalarPair(r1, r2) => (r1.to_bits(size)?, r2.to_bits(size)?),
Immediate::Uninit => panic!("we should never see uninit data here"),
};
let res = match bin_op {
Eq => left == right,
Ne => left != right,
Lt => left < right,
Le => left <= right,
Gt => left > right,
Ge => left >= right,
_ => bug!(),
};
(ImmTy::from_bool(res, *ecx.tcx), false)
}
// Some more operations are possible with atomics.
// The return value always has the provenance of the *left* operand.
Add | Sub | BitOr | BitAnd | BitXor => {
throw_machine_stop_str!("pointer arithmetic is not handled")
}
_ => span_bug!(ecx.cur_span(), "Invalid operator on pointers: {:?}", bin_op),
})
}
fn expose_ptr(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_ptr: interpret::Pointer<Self::Provenance>,
) -> interpret::InterpResult<'tcx> {
unimplemented!()
}
fn init_frame_extra(
_ecx: &mut InterpCx<'mir, 'tcx, Self>,
_frame: rustc_const_eval::interpret::Frame<'mir, 'tcx, Self::Provenance>,
) -> interpret::InterpResult<
'tcx,
rustc_const_eval::interpret::Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>,
> {
unimplemented!()
}
fn stack<'a>(
_ecx: &'a InterpCx<'mir, 'tcx, Self>,
) -> &'a [rustc_const_eval::interpret::Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>]
{
// Return an empty stack instead of panicking, as `cur_span` uses it to evaluate constants.
&[]
}
fn stack_mut<'a>(
_ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
) -> &'a mut Vec<
rustc_const_eval::interpret::Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>,
> {
unimplemented!()
}
}

2
compiler/rustc_mir_transform/src/gvn.rs
View File

@ -82,6 +82,7 @@
//! Second, when writing constants in MIR, we do not write `Const::Slice` or `Const`
//! that contain `AllocId`s.
use rustc_const_eval::const_eval::DummyMachine;
use rustc_const_eval::interpret::{intern_const_alloc_for_constprop, MemoryKind};
use rustc_const_eval::interpret::{ImmTy, InterpCx, OpTy, Projectable, Scalar};
use rustc_data_structures::fx::FxIndexSet;
@ -101,7 +102,6 @@ use rustc_target::abi::{self, Abi, Size, VariantIdx, FIRST_VARIANT};
use smallvec::SmallVec;
use std::borrow::Cow;
use crate::dataflow_const_prop::DummyMachine;
use crate::ssa::{AssignedValue, SsaLocals};
use either::Either;

2
compiler/rustc_mir_transform/src/jump_threading.rs
View File

@ -36,6 +36,7 @@
//! cost by `MAX_COST`.
use rustc_arena::DroplessArena;
use rustc_const_eval::const_eval::DummyMachine;
use rustc_const_eval::interpret::{ImmTy, Immediate, InterpCx, OpTy, Projectable};
use rustc_data_structures::fx::FxHashSet;
use rustc_index::bit_set::BitSet;
@ -50,7 +51,6 @@ use rustc_span::DUMMY_SP;
use rustc_target::abi::{TagEncoding, Variants};
use crate::cost_checker::CostChecker;
use crate::dataflow_const_prop::DummyMachine;
pub struct JumpThreading;

2
compiler/rustc_mir_transform/src/known_panics_lint.rs
View File

@ -6,6 +6,7 @@
use std::fmt::Debug;
use rustc_const_eval::const_eval::DummyMachine;
use rustc_const_eval::interpret::{
format_interp_error, ImmTy, InterpCx, InterpResult, Projectable, Scalar,
};
@ -20,7 +21,6 @@ use rustc_middle::ty::{self, ConstInt, ParamEnv, ScalarInt, Ty, TyCtxt, TypeVisi
use rustc_span::Span;
use rustc_target::abi::{Abi, FieldIdx, HasDataLayout, Size, TargetDataLayout, VariantIdx};
use crate::dataflow_const_prop::DummyMachine;
use crate::errors::{AssertLint, AssertLintKind};
use crate::MirLint;

44
compiler/rustc_transmute/src/layout/tree.rs
View File

@ -174,10 +174,10 @@ pub(crate) mod rustc {
use crate::layout::rustc::{Def, Ref};
use rustc_middle::ty::layout::LayoutError;
use rustc_middle::ty::util::Discr;
use rustc_middle::ty::AdtDef;
use rustc_middle::ty::GenericArgsRef;
use rustc_middle::ty::ParamEnv;
use rustc_middle::ty::ScalarInt;
use rustc_middle::ty::VariantDef;
use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
use rustc_span::ErrorGuaranteed;
@ -331,14 +331,15 @@ pub(crate) mod rustc {
trace!(?adt_def, "treeifying enum");
let mut tree = Tree::uninhabited();
for (idx, discr) in adt_def.discriminants(tcx) {
for (idx, variant) in adt_def.variants().iter_enumerated() {
let tag = tcx.tag_for_variant((ty, idx));
tree = tree.or(Self::from_repr_c_variant(
ty,
*adt_def,
args_ref,
&layout_summary,
Some(discr),
adt_def.variant(idx),
tag,
variant,
tcx,
)?);
}
@ -393,7 +394,7 @@ pub(crate) mod rustc {
adt_def: AdtDef<'tcx>,
args_ref: GenericArgsRef<'tcx>,
layout_summary: &LayoutSummary,
discr: Option<Discr<'tcx>>,
tag: Option<ScalarInt>,
variant_def: &'tcx VariantDef,
tcx: TyCtxt<'tcx>,
) -> Result<Self, Err> {
@ -403,9 +404,6 @@ pub(crate) mod rustc {
let min_align = repr.align.unwrap_or(Align::ONE);
let max_align = repr.pack.unwrap_or(Align::MAX);
let clamp =
|align: Align| align.clamp(min_align, max_align).bytes().try_into().unwrap();
let variant_span = trace_span!(
"treeifying variant",
min_align = ?min_align,
@ -419,17 +417,12 @@ pub(crate) mod rustc {
)
.unwrap();
// The layout of the variant is prefixed by the discriminant, if any.
if let Some(discr) = discr {
trace!(?discr, "treeifying discriminant");
let discr_layout = alloc::Layout::from_size_align(
layout_summary.discriminant_size,
clamp(layout_summary.discriminant_align),
)
.unwrap();
trace!(?discr_layout, "computed discriminant layout");
variant_layout = variant_layout.extend(discr_layout).unwrap().0;
tree = tree.then(Self::from_discr(discr, tcx, layout_summary.discriminant_size));
// The layout of the variant is prefixed by the tag, if any.
if let Some(tag) = tag {
let tag_layout =
alloc::Layout::from_size_align(tag.size().bytes_usize(), 1).unwrap();
tree = tree.then(Self::from_tag(tag, tcx));
variant_layout = variant_layout.extend(tag_layout).unwrap().0;
}
// Next come fields.
@ -469,18 +462,19 @@ pub(crate) mod rustc {
Ok(tree)
}
pub fn from_discr(discr: Discr<'tcx>, tcx: TyCtxt<'tcx>, size: usize) -> Self {
pub fn from_tag(tag: ScalarInt, tcx: TyCtxt<'tcx>) -> Self {
use rustc_target::abi::Endian;
let size = tag.size();
let bits = tag.to_bits(size).unwrap();
let bytes: [u8; 16];
let bytes = match tcx.data_layout.endian {
Endian::Little => {
bytes = discr.val.to_le_bytes();
&bytes[..size]
bytes = bits.to_le_bytes();
&bytes[..size.bytes_usize()]
}
Endian::Big => {
bytes = discr.val.to_be_bytes();
&bytes[bytes.len() - size..]
bytes = bits.to_be_bytes();
&bytes[bytes.len() - size.bytes_usize()..]
}
};
Self::Seq(bytes.iter().map(|&b| Self::from_bits(b)).collect())