Make is_block_tail a variant of LocalInfo.

This commit is contained in:
Camille GILLOT 2023-03-10 09:08:10 +00:00
parent bcb161def7
commit d31386a52b
6 changed files with 26 additions and 39 deletions

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@ -6,8 +6,8 @@ use rustc_hir::intravisit::Visitor;
use rustc_index::vec::IndexVec;
use rustc_infer::infer::NllRegionVariableOrigin;
use rustc_middle::mir::{
Body, CastKind, ConstraintCategory, FakeReadCause, Local, Location, Operand, Place, Rvalue,
Statement, StatementKind, TerminatorKind,
Body, CastKind, ConstraintCategory, FakeReadCause, Local, LocalInfo, Location, Operand, Place,
Rvalue, Statement, StatementKind, TerminatorKind,
};
use rustc_middle::ty::adjustment::PointerCast;
use rustc_middle::ty::{self, RegionVid, TyCtxt};
@ -220,7 +220,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
);
err.span_label(body.source_info(drop_loc).span, message);
if let Some(info) = &local_decl.is_block_tail {
if let LocalInfo::BlockTailTemp(info) = local_decl.local_info() {
if info.tail_result_is_ignored {
// #85581: If the first mutable borrow's scope contains
// the second borrow, this suggestion isn't helpful.

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@ -785,13 +785,6 @@ pub struct LocalDecl<'tcx> {
/// generator.
pub internal: bool,
/// If this local is a temporary and `is_block_tail` is `Some`,
/// then it is a temporary created for evaluation of some
/// subexpression of some block's tail expression (with no
/// intervening statement context).
// FIXME(matthewjasper) Don't store in this in `Body`
pub is_block_tail: Option<BlockTailInfo>,
/// The type of this local.
pub ty: Ty<'tcx>,
@ -905,6 +898,10 @@ pub enum LocalInfo<'tcx> {
/// A temporary created during the creation of an aggregate
/// (e.g. a temporary for `foo` in `MyStruct { my_field: foo }`)
AggregateTemp,
/// A temporary created for evaluation of some subexpression of some block's tail expression
/// (with no intervening statement context).
// FIXME(matthewjasper) Don't store in this in `Body`
BlockTailTemp(BlockTailInfo),
/// A temporary created during the pass `Derefer` to avoid it's retagging
DerefTemp,
/// A temporary created for borrow checking.
@ -1018,7 +1015,6 @@ impl<'tcx> LocalDecl<'tcx> {
mutability: Mutability::Mut,
local_info: ClearCrossCrate::Set(Box::new(LocalInfo::Boring)),
internal: false,
is_block_tail: None,
ty,
user_ty: None,
source_info,
@ -1038,14 +1034,6 @@ impl<'tcx> LocalDecl<'tcx> {
self.mutability = Mutability::Not;
self
}
/// Converts `self` into same `LocalDecl` except tagged as internal temporary.
#[inline]
pub fn block_tail(mut self, info: BlockTailInfo) -> Self {
assert!(self.is_block_tail.is_none());
self.is_block_tail = Some(info);
self
}
}
#[derive(Clone, TyEncodable, TyDecodable, HashStable, TypeFoldable, TypeVisitable)]
@ -3106,7 +3094,7 @@ mod size_asserts {
use rustc_data_structures::static_assert_size;
// tidy-alphabetical-start
static_assert_size!(BasicBlockData<'_>, 144);
static_assert_size!(LocalDecl<'_>, 56);
static_assert_size!(LocalDecl<'_>, 40);
static_assert_size!(Statement<'_>, 32);
static_assert_size!(StatementKind<'_>, 16);
static_assert_size!(Terminator<'_>, 112);

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@ -804,7 +804,6 @@ macro_rules! make_mir_visitor {
source_info,
internal: _,
local_info: _,
is_block_tail: _,
} = local_decl;
self.visit_ty($(& $mutability)? *ty, TyContext::LocalDecl {

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@ -124,9 +124,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}
Category::Constant | Category::Place | Category::Rvalue(..) => {
let operand = unpack!(block = this.as_temp(block, scope, expr, Mutability::Mut));
let decl_info = this.local_decls[operand].local_info.as_mut().assert_crate_local();
if let LocalInfo::Boring = **decl_info {
**decl_info = local_info;
// Overwrite temp local info if we have something more interesting to record.
if !matches!(local_info, LocalInfo::Boring) {
let decl_info = this.local_decls[operand].local_info.as_mut().assert_crate_local();
if let LocalInfo::Boring | LocalInfo::BlockTailTemp(_) = **decl_info {
**decl_info = local_info;
}
}
block.and(Operand::Move(Place::from(operand)))
}

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@ -49,29 +49,28 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}
debug!("creating temp {:?} with block_context: {:?}", local_decl, this.block_context);
// Find out whether this temp is being created within the
// tail expression of a block whose result is ignored.
if let Some(tail_info) = this.block_context.currently_in_block_tail() {
local_decl = local_decl.block_tail(tail_info);
}
match expr.kind {
let local_info = match expr.kind {
ExprKind::StaticRef { def_id, .. } => {
assert!(!this.tcx.is_thread_local_static(def_id));
local_decl.internal = true;
**local_decl.local_info.as_mut().assert_crate_local() =
LocalInfo::StaticRef { def_id, is_thread_local: false };
LocalInfo::StaticRef { def_id, is_thread_local: false }
}
ExprKind::ThreadLocalRef(def_id) => {
assert!(this.tcx.is_thread_local_static(def_id));
local_decl.internal = true;
**local_decl.local_info.as_mut().assert_crate_local() =
LocalInfo::StaticRef { def_id, is_thread_local: true };
LocalInfo::StaticRef { def_id, is_thread_local: true }
}
ExprKind::NamedConst { def_id, .. } | ExprKind::ConstParam { def_id, .. } => {
**local_decl.local_info.as_mut().assert_crate_local() = LocalInfo::ConstRef { def_id };
LocalInfo::ConstRef { def_id }
}
_ => {}
}
// Find out whether this temp is being created within the
// tail expression of a block whose result is ignored.
_ if let Some(tail_info) = this.block_context.currently_in_block_tail() => {
LocalInfo::BlockTailTemp(tail_info)
}
_ => LocalInfo::Boring,
};
**local_decl.local_info.as_mut().assert_crate_local() = local_info;
this.local_decls.push(local_decl)
};
let temp_place = Place::from(temp);

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@ -2224,7 +2224,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
user_ty: if user_ty.is_empty() { None } else { Some(Box::new(user_ty)) },
source_info,
internal: false,
is_block_tail: None,
local_info: ClearCrossCrate::Set(Box::new(LocalInfo::User(BindingForm::Var(
VarBindingForm {
binding_mode,
@ -2253,7 +2252,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
user_ty: None,
source_info,
internal: false,
is_block_tail: None,
local_info: ClearCrossCrate::Set(Box::new(LocalInfo::User(BindingForm::RefForGuard))),
});
self.var_debug_info.push(VarDebugInfo {