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mir: Add a new method to statement

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Avoid introducing a large number of changes when adding optional initialization fields.
This commit is contained in:
dianqk
2025-06-08 15:30:18 +08:00
parent 5ca574e85b
commit 9f9cd5e283
30 changed files with 295 additions and 330 deletions
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35
compiler/rustc_mir_transform/src/check_null.rs
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@@ -41,13 +41,12 @@ fn insert_null_check<'tcx>(
let const_raw_ptr = Ty::new_imm_ptr(tcx, tcx.types.unit);
let rvalue = Rvalue::Cast(CastKind::PtrToPtr, Operand::Copy(pointer), const_raw_ptr);
let thin_ptr = local_decls.push(LocalDecl::with_source_info(const_raw_ptr, source_info)).into();
stmts
.push(Statement { source_info, kind: StatementKind::Assign(Box::new((thin_ptr, rvalue))) });
stmts.push(Statement::new(source_info, StatementKind::Assign(Box::new((thin_ptr, rvalue)))));
// Transmute the pointer to a usize (equivalent to `ptr.addr()`).
let rvalue = Rvalue::Cast(CastKind::Transmute, Operand::Copy(thin_ptr), tcx.types.usize);
let addr = local_decls.push(LocalDecl::with_source_info(tcx.types.usize, source_info)).into();
stmts.push(Statement { source_info, kind: StatementKind::Assign(Box::new((addr, rvalue))) });
stmts.push(Statement::new(source_info, StatementKind::Assign(Box::new((addr, rvalue)))));
let zero = Operand::Constant(Box::new(ConstOperand {
span: source_info.span,
@@ -71,24 +70,24 @@ fn insert_null_check<'tcx>(
let rvalue = Rvalue::NullaryOp(NullOp::SizeOf, pointee_ty);
let sizeof_pointee =
local_decls.push(LocalDecl::with_source_info(tcx.types.usize, source_info)).into();
stmts.push(Statement {
stmts.push(Statement::new(
source_info,
kind: StatementKind::Assign(Box::new((sizeof_pointee, rvalue))),
});
StatementKind::Assign(Box::new((sizeof_pointee, rvalue))),
));
// Check that the pointee is not a ZST.
let is_pointee_not_zst =
local_decls.push(LocalDecl::with_source_info(tcx.types.bool, source_info)).into();
stmts.push(Statement {
stmts.push(Statement::new(
source_info,
kind: StatementKind::Assign(Box::new((
StatementKind::Assign(Box::new((
is_pointee_not_zst,
Rvalue::BinaryOp(
BinOp::Ne,
Box::new((Operand::Copy(sizeof_pointee), zero.clone())),
),
))),
});
));
// Pointer needs to be checked only if pointee is not a ZST.
Operand::Copy(is_pointee_not_zst)
@@ -97,38 +96,38 @@ fn insert_null_check<'tcx>(
// Check whether the pointer is null.
let is_null = local_decls.push(LocalDecl::with_source_info(tcx.types.bool, source_info)).into();
stmts.push(Statement {
stmts.push(Statement::new(
source_info,
kind: StatementKind::Assign(Box::new((
StatementKind::Assign(Box::new((
is_null,
Rvalue::BinaryOp(BinOp::Eq, Box::new((Operand::Copy(addr), zero))),
))),
});
));
// We want to throw an exception if the pointer is null and the pointee is not unconditionally
// allowed (which for all non-borrow place uses, is when the pointee is ZST).
let should_throw_exception =
local_decls.push(LocalDecl::with_source_info(tcx.types.bool, source_info)).into();
stmts.push(Statement {
stmts.push(Statement::new(
source_info,
kind: StatementKind::Assign(Box::new((
StatementKind::Assign(Box::new((
should_throw_exception,
Rvalue::BinaryOp(
BinOp::BitAnd,
Box::new((Operand::Copy(is_null), pointee_should_be_checked)),
),
))),
});
));
// The final condition whether this pointer usage is ok or not.
let is_ok = local_decls.push(LocalDecl::with_source_info(tcx.types.bool, source_info)).into();
stmts.push(Statement {
stmts.push(Statement::new(
source_info,
kind: StatementKind::Assign(Box::new((
StatementKind::Assign(Box::new((
is_ok,
Rvalue::UnaryOp(UnOp::Not, Operand::Copy(should_throw_exception)),
))),
});
));
// Emit a PointerCheck that asserts on the condition and otherwise triggers
// a AssertKind::NullPointerDereference.