rust/src/librustc_mir/transform/check_packed_ref.rs
Matthias Krüger 58023fedfc Fix more clippy warnings
Fixes more of:

clippy::unused_unit
clippy::op_ref
clippy::useless_format
clippy::needless_return
clippy::useless_conversion
clippy::bind_instead_of_map
clippy::into_iter_on_ref
clippy::redundant_clone
clippy::nonminimal_bool
clippy::redundant_closure
clippy::option_as_ref_deref
clippy::len_zero
clippy::iter_cloned_collect
clippy::filter_next
2020-06-09 18:51:08 +02:00

67 lines
2.5 KiB
Rust

use rustc_middle::mir::visit::{PlaceContext, Visitor};
use rustc_middle::mir::*;
use rustc_middle::ty::{self, TyCtxt};
use rustc_session::lint::builtin::UNALIGNED_REFERENCES;
use crate::transform::{MirPass, MirSource};
use crate::util;
pub struct CheckPackedRef;
impl<'tcx> MirPass<'tcx> for CheckPackedRef {
fn run_pass(&self, tcx: TyCtxt<'tcx>, src: MirSource<'tcx>, body: &mut Body<'tcx>) {
let param_env = tcx.param_env(src.instance.def_id());
let source_info = SourceInfo::outermost(body.span);
let mut checker = PackedRefChecker { body, tcx, param_env, source_info };
checker.visit_body(&body);
}
}
struct PackedRefChecker<'a, 'tcx> {
body: &'a Body<'tcx>,
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
source_info: SourceInfo,
}
impl<'a, 'tcx> Visitor<'tcx> for PackedRefChecker<'a, 'tcx> {
fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
// Make sure we know where in the MIR we are.
self.source_info = terminator.source_info;
self.super_terminator(terminator, location);
}
fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
// Make sure we know where in the MIR we are.
self.source_info = statement.source_info;
self.super_statement(statement, location);
}
fn visit_place(&mut self, place: &Place<'tcx>, context: PlaceContext, _location: Location) {
if context.is_borrow() {
if util::is_disaligned(self.tcx, self.body, self.param_env, *place) {
let source_info = self.source_info;
let lint_root = self.body.source_scopes[source_info.scope]
.local_data
.as_ref()
.assert_crate_local()
.lint_root;
self.tcx.struct_span_lint_hir(
UNALIGNED_REFERENCES,
lint_root,
source_info.span,
|lint| {
lint.build("reference to packed field is unaligned")
.note(
"fields of packed structs are not properly aligned, and creating \
a misaligned reference is undefined behavior (even if that \
reference is never dereferenced)",
)
.emit()
},
);
}
}
}
}