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Wrap recursion in ensure_sufficient_stack.
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@jumbatm
jumbatm committed Aug 17, 2020
1 parent 1321a2d commit bc15dd6
Showing 1 changed file with 91 additions and 88 deletions.
179 changes: 91 additions & 88 deletions src/librustc_lint/builtin.rs
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Expand Up @@ -29,6 +29,7 @@ use rustc_ast::tokenstream::{TokenStream, TokenTree};
use rustc_ast::visit::{FnCtxt, FnKind};
use rustc_ast_pretty::pprust::{self, expr_to_string};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::stack::ensure_sufficient_stack;
use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString};
use rustc_feature::{deprecated_attributes, AttributeGate, AttributeTemplate, AttributeType};
use rustc_feature::{GateIssue, Stability};
Expand Down Expand Up @@ -2188,16 +2189,17 @@ impl ClashingExternDeclarations {
kind.is_primitive() || matches!(kind, RawPtr(..) | Ref(..))
};

match (a_kind, b_kind) {
(Adt(a_def, a_substs), Adt(b_def, b_substs)) => {
let a = a.subst(cx.tcx, a_substs);
let b = b.subst(cx.tcx, b_substs);
debug!("Comparing {:?} and {:?}", a, b);
ensure_sufficient_stack(|| {
match (a_kind, b_kind) {
(Adt(a_def, a_substs), Adt(b_def, b_substs)) => {
let a = a.subst(cx.tcx, a_substs);
let b = b.subst(cx.tcx, b_substs);
debug!("Comparing {:?} and {:?}", a, b);

// Grab a flattened representation of all fields.
let a_fields = a_def.variants.iter().flat_map(|v| v.fields.iter());
let b_fields = b_def.variants.iter().flat_map(|v| v.fields.iter());
compare_layouts(a, b)
// Grab a flattened representation of all fields.
let a_fields = a_def.variants.iter().flat_map(|v| v.fields.iter());
let b_fields = b_def.variants.iter().flat_map(|v| v.fields.iter());
compare_layouts(a, b)
&& a_fields.eq_by(
b_fields,
|&ty::FieldDef { did: a_did, .. },
Expand All @@ -2211,88 +2213,89 @@ impl ClashingExternDeclarations {
)
},
)
}
(Array(a_ty, a_const), Array(b_ty, b_const)) => {
// For arrays, we also check the constness of the type.
a_const.val == b_const.val
&& structurally_same_type_impl(seen_types, cx, a_ty, b_ty, ckind)
}
(Slice(a_ty), Slice(b_ty)) => {
structurally_same_type_impl(seen_types, cx, a_ty, b_ty, ckind)
}
(RawPtr(a_tymut), RawPtr(b_tymut)) => {
a_tymut.mutbl == b_tymut.mutbl
&& structurally_same_type_impl(
seen_types,
cx,
&a_tymut.ty,
&b_tymut.ty,
ckind,
)
}
(Ref(_a_region, a_ty, a_mut), Ref(_b_region, b_ty, b_mut)) => {
// For structural sameness, we don't need the region to be same.
a_mut == b_mut
&& structurally_same_type_impl(seen_types, cx, a_ty, b_ty, ckind)
}
(FnDef(..), FnDef(..)) => {
let a_poly_sig = a.fn_sig(tcx);
let b_poly_sig = b.fn_sig(tcx);

// As we don't compare regions, skip_binder is fine.
let a_sig = a_poly_sig.skip_binder();
let b_sig = b_poly_sig.skip_binder();

(a_sig.abi, a_sig.unsafety, a_sig.c_variadic)
== (b_sig.abi, b_sig.unsafety, b_sig.c_variadic)
&& a_sig.inputs().iter().eq_by(b_sig.inputs().iter(), |a, b| {
structurally_same_type_impl(seen_types, cx, a, b, ckind)
})
&& structurally_same_type_impl(
seen_types,
cx,
a_sig.output(),
b_sig.output(),
ckind,
)
}
(Tuple(a_substs), Tuple(b_substs)) => {
a_substs.types().eq_by(b_substs.types(), |a_ty, b_ty| {
}
(Array(a_ty, a_const), Array(b_ty, b_const)) => {
// For arrays, we also check the constness of the type.
a_const.val == b_const.val
&& structurally_same_type_impl(seen_types, cx, a_ty, b_ty, ckind)
}
(Slice(a_ty), Slice(b_ty)) => {
structurally_same_type_impl(seen_types, cx, a_ty, b_ty, ckind)
})
}
// For these, it's not quite as easy to define structural-sameness quite so easily.
// For the purposes of this lint, take the conservative approach and mark them as
// not structurally same.
(Dynamic(..), Dynamic(..))
| (Error(..), Error(..))
| (Closure(..), Closure(..))
| (Generator(..), Generator(..))
| (GeneratorWitness(..), GeneratorWitness(..))
| (Projection(..), Projection(..))
| (Opaque(..), Opaque(..)) => false,

// These definitely should have been caught above.
(Bool, Bool) | (Char, Char) | (Never, Never) | (Str, Str) => unreachable!(),

// An Adt and a primitive or pointer type. This can be FFI-safe if non-null
// enum layout optimisation is being applied.
(Adt(..), other_kind) | (other_kind, Adt(..))
if is_primitive_or_pointer(other_kind) =>
{
let (primitive, adt) =
if is_primitive_or_pointer(&a.kind) { (a, b) } else { (b, a) };
if let Some(ty) = crate::types::repr_nullable_ptr(cx, adt, ckind) {
ty == primitive
} else {
compare_layouts(a, b)
}
(RawPtr(a_tymut), RawPtr(b_tymut)) => {
a_tymut.mutbl == b_tymut.mutbl
&& structurally_same_type_impl(
seen_types,
cx,
&a_tymut.ty,
&b_tymut.ty,
ckind,
)
}
(Ref(_a_region, a_ty, a_mut), Ref(_b_region, b_ty, b_mut)) => {
// For structural sameness, we don't need the region to be same.
a_mut == b_mut
&& structurally_same_type_impl(seen_types, cx, a_ty, b_ty, ckind)
}
(FnDef(..), FnDef(..)) => {
let a_poly_sig = a.fn_sig(tcx);
let b_poly_sig = b.fn_sig(tcx);

// As we don't compare regions, skip_binder is fine.
let a_sig = a_poly_sig.skip_binder();
let b_sig = b_poly_sig.skip_binder();

(a_sig.abi, a_sig.unsafety, a_sig.c_variadic)
== (b_sig.abi, b_sig.unsafety, b_sig.c_variadic)
&& a_sig.inputs().iter().eq_by(b_sig.inputs().iter(), |a, b| {
structurally_same_type_impl(seen_types, cx, a, b, ckind)
})
&& structurally_same_type_impl(
seen_types,
cx,
a_sig.output(),
b_sig.output(),
ckind,
)
}
(Tuple(a_substs), Tuple(b_substs)) => {
a_substs.types().eq_by(b_substs.types(), |a_ty, b_ty| {
structurally_same_type_impl(seen_types, cx, a_ty, b_ty, ckind)
})
}
// For these, it's not quite as easy to define structural-sameness quite so easily.
// For the purposes of this lint, take the conservative approach and mark them as
// not structurally same.
(Dynamic(..), Dynamic(..))
| (Error(..), Error(..))
| (Closure(..), Closure(..))
| (Generator(..), Generator(..))
| (GeneratorWitness(..), GeneratorWitness(..))
| (Projection(..), Projection(..))
| (Opaque(..), Opaque(..)) => false,

// These definitely should have been caught above.
(Bool, Bool) | (Char, Char) | (Never, Never) | (Str, Str) => unreachable!(),

// An Adt and a primitive or pointer type. This can be FFI-safe if non-null
// enum layout optimisation is being applied.
(Adt(..), other_kind) | (other_kind, Adt(..))
if is_primitive_or_pointer(other_kind) =>
{
let (primitive, adt) =
if is_primitive_or_pointer(&a.kind) { (a, b) } else { (b, a) };
if let Some(ty) = crate::types::repr_nullable_ptr(cx, adt, ckind) {
ty == primitive
} else {
compare_layouts(a, b)
}
}
// Otherwise, just compare the layouts. This may fail to lint for some
// incompatible types, but at the very least, will stop reads into
// uninitialised memory.
_ => compare_layouts(a, b),
}
// Otherwise, just compare the layouts. This may fail to lint for some
// incompatible types, but at the very least, will stop reads into
// uninitialised memory.
_ => compare_layouts(a, b),
}
})
}
}
let mut seen_types = FxHashSet::default();
Expand Down

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