Skip to content

Improve validator around field projections and checked bin ops #96788

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
May 7, 2022
Merged

Improve validator around field projections and checked bin ops #96788

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
5289bbe
Expand validator to be more precise on checked binary ops
JakobDegen May 6, 2022
c4168fd
Check that field projections have the correct type
JakobDegen May 6, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
100 changes: 96 additions & 4 deletions compiler/rustc_const_eval/src/transform/validate.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeFoldable};
use rustc_mir_dataflow::impls::MaybeStorageLive;
use rustc_mir_dataflow::storage::AlwaysLiveLocals;
use rustc_mir_dataflow::{Analysis, ResultsCursor};
use rustc_target::abi::Size;
use rustc_target::abi::{Size, VariantIdx};

#[derive(Copy, Clone, Debug)]
enum EdgeKind {
Expand Down Expand Up @@ -244,6 +244,60 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
self.fail(location, format!("bad index ({:?} != usize)", index_ty))
}
}
if let ProjectionElem::Field(f, ty) = elem {
let parent = Place { local, projection: self.tcx.intern_place_elems(proj_base) };
let parent_ty = parent.ty(&self.body.local_decls, self.tcx);
let fail_out_of_bounds = |this: &Self, location| {
this.fail(location, format!("Out of bounds field {:?} for {:?}", f, parent_ty));
};
let check_equal = |this: &Self, location, f_ty| {
if !this.mir_assign_valid_types(ty, f_ty) {
this.fail(
location,
format!(
"Field projection `{:?}.{:?}` specified type `{:?}`, but actual type is {:?}",
parent, f, ty, f_ty
)
)
}
};
match parent_ty.ty.kind() {
ty::Tuple(fields) => {
let Some(f_ty) = fields.get(f.as_usize()) else {
fail_out_of_bounds(self, location);
return;
};
check_equal(self, location, *f_ty);
}
ty::Adt(adt_def, substs) => {
let var = parent_ty.variant_index.unwrap_or(VariantIdx::from_u32(0));
let Some(field) = adt_def.variant(var).fields.get(f.as_usize()) else {
fail_out_of_bounds(self, location);
return;
};
check_equal(self, location, field.ty(self.tcx, substs));
}
ty::Closure(_, substs) => {
let substs = substs.as_closure();
let Some(f_ty) = substs.upvar_tys().nth(f.as_usize()) else {
fail_out_of_bounds(self, location);
return;
};
check_equal(self, location, f_ty);
}
ty::Generator(_, substs, _) => {
let substs = substs.as_generator();
let Some(f_ty) = substs.upvar_tys().nth(f.as_usize()) else {
fail_out_of_bounds(self, location);
return;
};
check_equal(self, location, f_ty);
}
_ => {
self.fail(location, format!("{:?} does not have fields", parent_ty.ty));
}
}
}
self.super_projection_elem(local, proj_base, elem, context, location);
}

Expand Down Expand Up @@ -291,7 +345,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
ty::Array(..) | ty::Slice(..)
);
}
Rvalue::BinaryOp(op, vals) | Rvalue::CheckedBinaryOp(op, vals) => {
Rvalue::BinaryOp(op, vals) => {
use BinOp::*;
let a = vals.0.ty(&self.body.local_decls, self.tcx);
let b = vals.1.ty(&self.body.local_decls, self.tcx);
Expand Down Expand Up @@ -355,17 +409,55 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
for x in [a, b] {
check_kinds!(
x,
"Cannot perform op on type {:?}",
"Cannot perform arithmetic on type {:?}",
ty::Uint(..) | ty::Int(..) | ty::Float(..)
)
}
if a != b {
self.fail(
location,
format!("Cannot perform op on unequal types {:?} and {:?}", a, b),
format!(
"Cannot perform arithmetic on unequal types {:?} and {:?}",
a, b
),
);
}
}
}
}
Rvalue::CheckedBinaryOp(op, vals) => {
use BinOp::*;
let a = vals.0.ty(&self.body.local_decls, self.tcx);
let b = vals.1.ty(&self.body.local_decls, self.tcx);
match op {
Add | Sub | Mul => {
for x in [a, b] {
check_kinds!(
x,
"Cannot perform checked arithmetic on type {:?}",
ty::Uint(..) | ty::Int(..)
)
}
if a != b {
self.fail(
location,
format!(
"Cannot perform checked arithmetic on unequal types {:?} and {:?}",
a, b
),
);
}
}
Shl | Shr => {
for x in [a, b] {
check_kinds!(
x,
"Cannot perform checked shift on non-integer type {:?}",
ty::Uint(..) | ty::Int(..)
)
}
}
_ => self.fail(location, format!("There is no checked version of {:?}", op)),
}
}
Rvalue::UnaryOp(op, operand) => {
Expand Down