use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::LateContext;
use rustc_middle::mir::interpret::{ConstValue, Scalar};
-use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst};
+use rustc_middle::ty::{GenericArg, GenericArgKind};
use rustc_middle::ty::{
self, AdtDef, Binder, BoundRegion, DefIdTree, FnSig, IntTy, ParamEnv, Predicate, PredicateKind, ProjectionTy,
Region, RegionKind, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, UintTy, VariantDef, VariantDiscr,
}
}
-/// Walks into `ty` and returns `true` if any inner type is the same as `other_ty`
-pub fn contains_ty<'tcx>(ty: Ty<'tcx>, other_ty: Ty<'tcx>) -> bool {
- ty.walk().any(|inner| match inner.unpack() {
- GenericArgKind::Type(inner_ty) => other_ty == inner_ty,
- GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
- })
-}
-
/// Walks into `ty` and returns `true` if any inner type is an instance of the given adt
/// constructor.
pub fn contains_adt_constructor<'tcx>(ty: Ty<'tcx>, adt: AdtDef<'tcx>) -> bool {
/// * [`get_trait_def_id`](super::get_trait_def_id) to get a trait [`DefId`].
/// * [Common tools for writing lints] for an example how to use this function and other options.
///
-/// [Common tools for writing lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/common_tools_writing_lints.md#checking-if-a-type-implements-a-specific-trait
+/// [Common tools for writing lints]: https://github.com/rust-lang/rust-clippy/blob/master/book/src/development/common_tools_writing_lints.md#checking-if-a-type-implements-a-specific-trait
pub fn implements_trait<'tcx>(
cx: &LateContext<'tcx>,
ty: Ty<'tcx>,
}
false
},
- ty::Dynamic(binder, _) => {
+ ty::Dynamic(binder, _, _) => {
for predicate in binder.iter() {
if let ty::ExistentialPredicate::Trait(ref trait_ref) = predicate.skip_binder() {
if cx.tcx.has_attr(trait_ref.def_id, sym::must_use) {
peel(ty, 0)
}
-/// Peels off all references on the type.Returns the underlying type, the number of references
+/// Peels off all references on the type. Returns the underlying type, the number of references
/// removed, and whether the pointer is ultimately mutable or not.
pub fn peel_mid_ty_refs_is_mutable(ty: Ty<'_>) -> (Ty<'_>, usize, Mutability) {
fn f(ty: Ty<'_>, count: usize, mutability: Mutability) -> (Ty<'_>, usize, Mutability) {
/// A signature for a function like type.
#[derive(Clone, Copy)]
pub enum ExprFnSig<'tcx> {
- Sig(Binder<'tcx, FnSig<'tcx>>),
+ Sig(Binder<'tcx, FnSig<'tcx>>, Option<DefId>),
Closure(Option<&'tcx FnDecl<'tcx>>, Binder<'tcx, FnSig<'tcx>>),
- Trait(Binder<'tcx, Ty<'tcx>>, Option<Binder<'tcx, Ty<'tcx>>>),
+ Trait(Binder<'tcx, Ty<'tcx>>, Option<Binder<'tcx, Ty<'tcx>>>, Option<DefId>),
}
impl<'tcx> ExprFnSig<'tcx> {
/// Gets the argument type at the given offset. This will return `None` when the index is out of
/// bounds only for variadic functions, otherwise this will panic.
pub fn input(self, i: usize) -> Option<Binder<'tcx, Ty<'tcx>>> {
match self {
- Self::Sig(sig) => {
+ Self::Sig(sig, _) => {
if sig.c_variadic() {
sig.inputs().map_bound(|inputs| inputs.get(i).copied()).transpose()
} else {
}
},
Self::Closure(_, sig) => Some(sig.input(0).map_bound(|ty| ty.tuple_fields()[i])),
- Self::Trait(inputs, _) => Some(inputs.map_bound(|ty| ty.tuple_fields()[i])),
+ Self::Trait(inputs, _, _) => Some(inputs.map_bound(|ty| ty.tuple_fields()[i])),
}
}
/// functions, otherwise this will panic.
pub fn input_with_hir(self, i: usize) -> Option<(Option<&'tcx hir::Ty<'tcx>>, Binder<'tcx, Ty<'tcx>>)> {
match self {
- Self::Sig(sig) => {
+ Self::Sig(sig, _) => {
if sig.c_variadic() {
sig.inputs()
.map_bound(|inputs| inputs.get(i).copied())
decl.and_then(|decl| decl.inputs.get(i)),
sig.input(0).map_bound(|ty| ty.tuple_fields()[i]),
)),
- Self::Trait(inputs, _) => Some((None, inputs.map_bound(|ty| ty.tuple_fields()[i]))),
+ Self::Trait(inputs, _, _) => Some((None, inputs.map_bound(|ty| ty.tuple_fields()[i]))),
}
}
/// specified.
pub fn output(self) -> Option<Binder<'tcx, Ty<'tcx>>> {
match self {
- Self::Sig(sig) | Self::Closure(_, sig) => Some(sig.output()),
- Self::Trait(_, output) => output,
+ Self::Sig(sig, _) | Self::Closure(_, sig) => Some(sig.output()),
+ Self::Trait(_, output, _) => output,
+ }
+ }
+
+ pub fn predicates_id(&self) -> Option<DefId> {
+ if let ExprFnSig::Sig(_, id) | ExprFnSig::Trait(_, _, id) = *self {
+ id
+ } else {
+ None
}
}
}
/// If the expression is function like, get the signature for it.
pub fn expr_sig<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> Option<ExprFnSig<'tcx>> {
if let Res::Def(DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) | DefKind::AssocFn, id) = path_res(cx, expr) {
- Some(ExprFnSig::Sig(cx.tcx.fn_sig(id)))
+ Some(ExprFnSig::Sig(cx.tcx.fn_sig(id), Some(id)))
} else {
ty_sig(cx, cx.typeck_results().expr_ty_adjusted(expr).peel_refs())
}
}
-fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'tcx>> {
+/// If the type is function like, get the signature for it.
+pub fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'tcx>> {
+ if ty.is_box() {
+ return ty_sig(cx, ty.boxed_ty());
+ }
match *ty.kind() {
ty::Closure(id, subs) => {
let decl = id
.and_then(|id| cx.tcx.hir().fn_decl_by_hir_id(cx.tcx.hir().local_def_id_to_hir_id(id)));
Some(ExprFnSig::Closure(decl, subs.as_closure().sig()))
},
- ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst(cx.tcx, subs))),
- ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig)),
- ty::Dynamic(bounds, _) => {
+ ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst(cx.tcx, subs), Some(id))),
+ ty::Opaque(id, _) => sig_from_bounds(cx, ty, cx.tcx.item_bounds(id), cx.tcx.opt_parent(id)),
+ ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig, None)),
+ ty::Dynamic(bounds, _, _) => {
let lang_items = cx.tcx.lang_items();
match bounds.principal() {
Some(bound)
.projection_bounds()
.find(|p| lang_items.fn_once_output().map_or(false, |id| id == p.item_def_id()))
.map(|p| p.map_bound(|p| p.term.ty().unwrap()));
- Some(ExprFnSig::Trait(bound.map_bound(|b| b.substs.type_at(0)), output))
+ Some(ExprFnSig::Trait(bound.map_bound(|b| b.substs.type_at(0)), output, None))
},
_ => None,
}
},
ty::Projection(proj) => match cx.tcx.try_normalize_erasing_regions(cx.param_env, ty) {
Ok(normalized_ty) if normalized_ty != ty => ty_sig(cx, normalized_ty),
- _ => sig_for_projection(cx, proj).or_else(|| sig_from_bounds(cx, ty)),
+ _ => sig_for_projection(cx, proj).or_else(|| sig_from_bounds(cx, ty, cx.param_env.caller_bounds(), None)),
},
- ty::Param(_) => sig_from_bounds(cx, ty),
+ ty::Param(_) => sig_from_bounds(cx, ty, cx.param_env.caller_bounds(), None),
_ => None,
}
}
-fn sig_from_bounds<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'tcx>> {
+fn sig_from_bounds<'tcx>(
+ cx: &LateContext<'tcx>,
+ ty: Ty<'tcx>,
+ predicates: &'tcx [Predicate<'tcx>],
+ predicates_id: Option<DefId>,
+) -> Option<ExprFnSig<'tcx>> {
let mut inputs = None;
let mut output = None;
let lang_items = cx.tcx.lang_items();
- for (pred, _) in all_predicates_of(cx.tcx, cx.typeck_results().hir_owner.to_def_id()) {
+ for pred in predicates {
match pred.kind().skip_binder() {
PredicateKind::Trait(p)
if (lang_items.fn_trait() == Some(p.def_id())
|| lang_items.fn_once_trait() == Some(p.def_id()))
&& p.self_ty() == ty =>
{
- if inputs.is_some() {
+ let i = pred.kind().rebind(p.trait_ref.substs.type_at(1));
+ if inputs.map_or(false, |inputs| i != inputs) {
// Multiple different fn trait impls. Is this even allowed?
return None;
}
- inputs = Some(pred.kind().rebind(p.trait_ref.substs.type_at(1)));
+ inputs = Some(i);
},
PredicateKind::Projection(p)
if Some(p.projection_ty.item_def_id) == lang_items.fn_once_output()
}
}
- inputs.map(|ty| ExprFnSig::Trait(ty, output))
+ inputs.map(|ty| ExprFnSig::Trait(ty, output, predicates_id))
}
fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: ProjectionTy<'tcx>) -> Option<ExprFnSig<'tcx>> {
|| lang_items.fn_mut_trait() == Some(p.def_id())
|| lang_items.fn_once_trait() == Some(p.def_id())) =>
{
- if inputs.is_some() {
+ let i = pred
+ .map_bound(|pred| pred.kind().rebind(p.trait_ref.substs.type_at(1)))
+ .subst(cx.tcx, ty.substs);
+
+ if inputs.map_or(false, |inputs| inputs != i) {
// Multiple different fn trait impls. Is this even allowed?
return None;
}
- inputs = Some(
- pred.map_bound(|pred| pred.kind().rebind(p.trait_ref.substs.type_at(1)))
- .subst(cx.tcx, ty.substs),
- );
+ inputs = Some(i);
},
PredicateKind::Projection(p) if Some(p.projection_ty.item_def_id) == lang_items.fn_once_output() => {
if output.is_some() {
}
}
- inputs.map(|ty| ExprFnSig::Trait(ty, output))
+ inputs.map(|ty| ExprFnSig::Trait(ty, output, None))
}
#[derive(Clone, Copy)]
_ => None,
}
}
+
+/// Checks if the type is a type parameter implementing `FnOnce`, but not `FnMut`.
+pub fn ty_is_fn_once_param<'tcx>(tcx: TyCtxt<'_>, ty: Ty<'tcx>, predicates: &'tcx [Predicate<'_>]) -> bool {
+ let ty::Param(ty) = *ty.kind() else {
+ return false;
+ };
+ let lang = tcx.lang_items();
+ let (Some(fn_once_id), Some(fn_mut_id), Some(fn_id))
+ = (lang.fn_once_trait(), lang.fn_mut_trait(), lang.fn_trait())
+ else {
+ return false;
+ };
+ predicates
+ .iter()
+ .try_fold(false, |found, p| {
+ if let PredicateKind::Trait(p) = p.kind().skip_binder()
+ && let ty::Param(self_ty) = p.trait_ref.self_ty().kind()
+ && ty.index == self_ty.index
+ {
+ // This should use `super_traits_of`, but that's a private function.
+ if p.trait_ref.def_id == fn_once_id {
+ return Some(true);
+ } else if p.trait_ref.def_id == fn_mut_id || p.trait_ref.def_id == fn_id {
+ return None;
+ }
+ }
+ Some(found)
+ })
+ .unwrap_or(false)
+}
+
+/// Comes up with an "at least" guesstimate for the type's size, not taking into
+/// account the layout of type parameters.
+pub fn approx_ty_size<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> u64 {
+ use rustc_middle::ty::layout::LayoutOf;
+ if !is_normalizable(cx, cx.param_env, ty) {
+ return 0;
+ }
+ match (cx.layout_of(ty).map(|layout| layout.size.bytes()), ty.kind()) {
+ (Ok(size), _) => size,
+ (Err(_), ty::Tuple(list)) => list.as_substs().types().map(|t| approx_ty_size(cx, t)).sum(),
+ (Err(_), ty::Array(t, n)) => {
+ n.try_eval_usize(cx.tcx, cx.param_env).unwrap_or_default() * approx_ty_size(cx, *t)
+ },
+ (Err(_), ty::Adt(def, subst)) if def.is_struct() => def
+ .variants()
+ .iter()
+ .map(|v| {
+ v.fields
+ .iter()
+ .map(|field| approx_ty_size(cx, field.ty(cx.tcx, subst)))
+ .sum::<u64>()
+ })
+ .sum(),
+ (Err(_), ty::Adt(def, subst)) if def.is_enum() => def
+ .variants()
+ .iter()
+ .map(|v| {
+ v.fields
+ .iter()
+ .map(|field| approx_ty_size(cx, field.ty(cx.tcx, subst)))
+ .sum::<u64>()
+ })
+ .max()
+ .unwrap_or_default(),
+ (Err(_), ty::Adt(def, subst)) if def.is_union() => def
+ .variants()
+ .iter()
+ .map(|v| {
+ v.fields
+ .iter()
+ .map(|field| approx_ty_size(cx, field.ty(cx.tcx, subst)))
+ .max()
+ .unwrap_or_default()
+ })
+ .max()
+ .unwrap_or_default(),
+ (Err(_), _) => 0,
+ }
+}
projects / rust.git / blobdiff