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also release/validate around non-Misc casts

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This commit is contained in:
Ralf Jung 2017-07-26 20:51:36 -07:00
parent b934506e68
commit 7ec50dfee3
1 changed files with 71 additions and 30 deletions
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101
src/librustc_mir/transform/add_validation.rs
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@ -171,42 +171,83 @@ impl MirPass for AddValidation {
}
// PART 3
// Add ReleaseValid/AcquireValid around Ref. Again an iterator does not seem very suited
// Add ReleaseValid/AcquireValid around Ref and Cast. Again an iterator does not seem very
// suited
// as we need to add new statements before and after each Ref.
for block_data in mir.basic_blocks_mut() {
// We want to insert statements around Ref commands as we iterate. To this end, we
// iterate backwards using indices.
for i in (0..block_data.statements.len()).rev() {
let (dest_lval, re, src_lval) = match block_data.statements[i].kind {
StatementKind::Assign(ref dest_lval, Rvalue::Ref(re, _, ref src_lval)) => {
(dest_lval.clone(), re, src_lval.clone())
},
_ => continue,
};
// So this is a ref, and we got all the data we wanted.
// Do an acquire of the result -- but only what it points to, so add a Deref
// projection.
let dest_lval = Projection { base: dest_lval, elem: ProjectionElem::Deref };
let dest_lval = Lvalue::Projection(Box::new(dest_lval));
let acquire_stmt = Statement {
source_info: block_data.statements[i].source_info,
kind: StatementKind::Validate(ValidationOp::Acquire,
vec![lval_to_operand(dest_lval)]),
};
block_data.statements.insert(i+1, acquire_stmt);
match block_data.statements[i].kind {
// When the borrow of this ref expires, we need to recover validation.
StatementKind::Assign(_, Rvalue::Ref(_, _, _)) => {
// Due to a lack of NLL; we can't capture anything directly here.
// Instead, we have to re-match and clone there.
let (dest_lval, re, src_lval) = match block_data.statements[i].kind {
StatementKind::Assign(ref dest_lval,
Rvalue::Ref(re, _, ref src_lval)) => {
(dest_lval.clone(), re, src_lval.clone())
},
_ => bug!("We already matched this."),
};
// So this is a ref, and we got all the data we wanted.
// Do an acquire of the result -- but only what it points to, so add a Deref
// projection.
let dest_lval = Projection { base: dest_lval, elem: ProjectionElem::Deref };
let dest_lval = Lvalue::Projection(Box::new(dest_lval));
let acquire_stmt = Statement {
source_info: block_data.statements[i].source_info,
kind: StatementKind::Validate(ValidationOp::Acquire,
vec![lval_to_operand(dest_lval)]),
};
block_data.statements.insert(i+1, acquire_stmt);
// The source is released until the region of the borrow ends.
let op = match re {
&RegionKind::ReScope(ce) => ValidationOp::Suspend(ce),
&RegionKind::ReErased =>
bug!("AddValidation pass must be run before erasing lifetimes"),
_ => ValidationOp::Release,
};
let release_stmt = Statement {
source_info: block_data.statements[i].source_info,
kind: StatementKind::Validate(op, vec![lval_to_operand(src_lval)]),
};
block_data.statements.insert(i, release_stmt);
// The source is released until the region of the borrow ends.
let op = match re {
&RegionKind::ReScope(ce) => ValidationOp::Suspend(ce),
&RegionKind::ReErased =>
bug!("AddValidation pass must be run before erasing lifetimes"),
_ => ValidationOp::Release,
};
let release_stmt = Statement {
source_info: block_data.statements[i].source_info,
kind: StatementKind::Validate(op, vec![lval_to_operand(src_lval)]),
};
block_data.statements.insert(i, release_stmt);
}
// Casts can change what validation does (e.g. unsizing)
StatementKind::Assign(_, Rvalue::Cast(kind, Operand::Consume(_), _))
if kind != CastKind::Misc =>
{
// Due to a lack of NLL; we can't capture anything directly here.
// Instead, we have to re-match and clone there.
let (dest_lval, src_lval) = match block_data.statements[i].kind {
StatementKind::Assign(ref dest_lval,
Rvalue::Cast(_, Operand::Consume(ref src_lval), _)) =>
{
(dest_lval.clone(), src_lval.clone())
},
_ => bug!("We already matched this."),
};
// Acquire of the result
let acquire_stmt = Statement {
source_info: block_data.statements[i].source_info,
kind: StatementKind::Validate(ValidationOp::Acquire,
vec![lval_to_operand(dest_lval)]),
};
block_data.statements.insert(i+1, acquire_stmt);
// Release of the input
let release_stmt = Statement {
source_info: block_data.statements[i].source_info,
kind: StatementKind::Validate(ValidationOp::Release,
vec![lval_to_operand(src_lval)]),
};
block_data.statements.insert(i, release_stmt);
}
_ => {},
}
}
}
}