use crate::check::intrinsicck::InlineAsmCtxt;
-use super::coercion::CoerceMany;
use super::compare_method::check_type_bounds;
use super::compare_method::{compare_impl_method, compare_ty_impl};
use super::*;
use rustc_hir::def::{DefKind, Res};
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::intravisit::Visitor;
-use rustc_hir::lang_items::LangItem;
use rustc_hir::{ItemKind, Node, PathSegment};
use rustc_infer::infer::outlives::env::OutlivesEnvironment;
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
use rustc_infer::infer::{DefiningAnchor, RegionVariableOrigin, TyCtxtInferExt};
use rustc_infer::traits::Obligation;
use rustc_lint::builtin::REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS;
use std::ops::ControlFlow;
-pub(super) fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) {
+pub fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) {
match tcx.sess.target.is_abi_supported(abi) {
Some(true) => (),
Some(false) => {
}
}
-/// Helper used for fns and closures. Does the grungy work of checking a function
-/// body and returns the function context used for that purpose, since in the case of a fn item
-/// there is still a bit more to do.
-///
-/// * ...
-/// * inherited: other fields inherited from the enclosing fn (if any)
-#[instrument(skip(inherited, body), level = "debug")]
-pub(super) fn check_fn<'a, 'tcx>(
- inherited: &'a Inherited<'tcx>,
- param_env: ty::ParamEnv<'tcx>,
- fn_sig: ty::FnSig<'tcx>,
- decl: &'tcx hir::FnDecl<'tcx>,
- fn_id: hir::HirId,
- body: &'tcx hir::Body<'tcx>,
- can_be_generator: Option<hir::Movability>,
- return_type_pre_known: bool,
-) -> (FnCtxt<'a, 'tcx>, Option<GeneratorTypes<'tcx>>) {
- // Create the function context. This is either derived from scratch or,
- // in the case of closures, based on the outer context.
- let mut fcx = FnCtxt::new(inherited, param_env, body.value.hir_id);
- fcx.ps.set(UnsafetyState::function(fn_sig.unsafety, fn_id));
- fcx.return_type_pre_known = return_type_pre_known;
-
- let tcx = fcx.tcx;
- let hir = tcx.hir();
-
- let declared_ret_ty = fn_sig.output();
-
- let ret_ty =
- fcx.register_infer_ok_obligations(fcx.infcx.replace_opaque_types_with_inference_vars(
- declared_ret_ty,
- body.value.hir_id,
- decl.output.span(),
- param_env,
- ));
- // If we replaced declared_ret_ty with infer vars, then we must be inferring
- // an opaque type, so set a flag so we can improve diagnostics.
- fcx.return_type_has_opaque = ret_ty != declared_ret_ty;
-
- fcx.ret_coercion = Some(RefCell::new(CoerceMany::new(ret_ty)));
-
- let span = body.value.span;
-
- fn_maybe_err(tcx, span, fn_sig.abi);
-
- if fn_sig.abi == Abi::RustCall {
- let expected_args = if let ImplicitSelfKind::None = decl.implicit_self { 1 } else { 2 };
-
- let err = || {
- let item = match tcx.hir().get(fn_id) {
- Node::Item(hir::Item { kind: ItemKind::Fn(header, ..), .. }) => Some(header),
- Node::ImplItem(hir::ImplItem {
- kind: hir::ImplItemKind::Fn(header, ..), ..
- }) => Some(header),
- Node::TraitItem(hir::TraitItem {
- kind: hir::TraitItemKind::Fn(header, ..),
- ..
- }) => Some(header),
- // Closures are RustCall, but they tuple their arguments, so shouldn't be checked
- Node::Expr(hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => None,
- node => bug!("Item being checked wasn't a function/closure: {:?}", node),
- };
-
- if let Some(header) = item {
- tcx.sess.span_err(header.span, "functions with the \"rust-call\" ABI must take a single non-self argument that is a tuple");
- }
- };
-
- if fn_sig.inputs().len() != expected_args {
- err()
- } else {
- // FIXME(CraftSpider) Add a check on parameter expansion, so we don't just make the ICE happen later on
- // This will probably require wide-scale changes to support a TupleKind obligation
- // We can't resolve this without knowing the type of the param
- if !matches!(fn_sig.inputs()[expected_args - 1].kind(), ty::Tuple(_) | ty::Param(_)) {
- err()
- }
- }
- }
-
- if body.generator_kind.is_some() && can_be_generator.is_some() {
- let yield_ty = fcx
- .next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::TypeInference, span });
- fcx.require_type_is_sized(yield_ty, span, traits::SizedYieldType);
-
- // Resume type defaults to `()` if the generator has no argument.
- let resume_ty = fn_sig.inputs().get(0).copied().unwrap_or_else(|| tcx.mk_unit());
-
- fcx.resume_yield_tys = Some((resume_ty, yield_ty));
- }
-
- GatherLocalsVisitor::new(&fcx).visit_body(body);
-
- // C-variadic fns also have a `VaList` input that's not listed in `fn_sig`
- // (as it's created inside the body itself, not passed in from outside).
- let maybe_va_list = if fn_sig.c_variadic {
- let span = body.params.last().unwrap().span;
- let va_list_did = tcx.require_lang_item(LangItem::VaList, Some(span));
- let region = fcx.next_region_var(RegionVariableOrigin::MiscVariable(span));
-
- Some(tcx.bound_type_of(va_list_did).subst(tcx, &[region.into()]))
- } else {
- None
- };
-
- // Add formal parameters.
- let inputs_hir = hir.fn_decl_by_hir_id(fn_id).map(|decl| &decl.inputs);
- let inputs_fn = fn_sig.inputs().iter().copied();
- for (idx, (param_ty, param)) in inputs_fn.chain(maybe_va_list).zip(body.params).enumerate() {
- // Check the pattern.
- let ty_span = try { inputs_hir?.get(idx)?.span };
- fcx.check_pat_top(¶m.pat, param_ty, ty_span, false);
-
- // Check that argument is Sized.
- // The check for a non-trivial pattern is a hack to avoid duplicate warnings
- // for simple cases like `fn foo(x: Trait)`,
- // where we would error once on the parameter as a whole, and once on the binding `x`.
- if param.pat.simple_ident().is_none() && !tcx.features().unsized_fn_params {
- fcx.require_type_is_sized(param_ty, param.pat.span, traits::SizedArgumentType(ty_span));
- }
-
- fcx.write_ty(param.hir_id, param_ty);
- }
-
- inherited.typeck_results.borrow_mut().liberated_fn_sigs_mut().insert(fn_id, fn_sig);
-
- fcx.in_tail_expr = true;
- if let ty::Dynamic(..) = declared_ret_ty.kind() {
- // FIXME: We need to verify that the return type is `Sized` after the return expression has
- // been evaluated so that we have types available for all the nodes being returned, but that
- // requires the coerced evaluated type to be stored. Moving `check_return_expr` before this
- // causes unsized errors caused by the `declared_ret_ty` to point at the return expression,
- // while keeping the current ordering we will ignore the tail expression's type because we
- // don't know it yet. We can't do `check_expr_kind` while keeping `check_return_expr`
- // because we will trigger "unreachable expression" lints unconditionally.
- // Because of all of this, we perform a crude check to know whether the simplest `!Sized`
- // case that a newcomer might make, returning a bare trait, and in that case we populate
- // the tail expression's type so that the suggestion will be correct, but ignore all other
- // possible cases.
- fcx.check_expr(&body.value);
- fcx.require_type_is_sized(declared_ret_ty, decl.output.span(), traits::SizedReturnType);
- } else {
- fcx.require_type_is_sized(declared_ret_ty, decl.output.span(), traits::SizedReturnType);
- fcx.check_return_expr(&body.value, false);
- }
- fcx.in_tail_expr = false;
-
- // We insert the deferred_generator_interiors entry after visiting the body.
- // This ensures that all nested generators appear before the entry of this generator.
- // resolve_generator_interiors relies on this property.
- let gen_ty = if let (Some(_), Some(gen_kind)) = (can_be_generator, body.generator_kind) {
- let interior = fcx
- .next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::MiscVariable, span });
- fcx.deferred_generator_interiors.borrow_mut().push((body.id(), interior, gen_kind));
-
- let (resume_ty, yield_ty) = fcx.resume_yield_tys.unwrap();
- Some(GeneratorTypes {
- resume_ty,
- yield_ty,
- interior,
- movability: can_be_generator.unwrap(),
- })
- } else {
- None
- };
-
- // Finalize the return check by taking the LUB of the return types
- // we saw and assigning it to the expected return type. This isn't
- // really expected to fail, since the coercions would have failed
- // earlier when trying to find a LUB.
- let coercion = fcx.ret_coercion.take().unwrap().into_inner();
- let mut actual_return_ty = coercion.complete(&fcx);
- debug!("actual_return_ty = {:?}", actual_return_ty);
- if let ty::Dynamic(..) = declared_ret_ty.kind() {
- // We have special-cased the case where the function is declared
- // `-> dyn Foo` and we don't actually relate it to the
- // `fcx.ret_coercion`, so just substitute a type variable.
- actual_return_ty =
- fcx.next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::DynReturnFn, span });
- debug!("actual_return_ty replaced with {:?}", actual_return_ty);
- }
-
- // HACK(oli-obk, compiler-errors): We should be comparing this against
- // `declared_ret_ty`, but then anything uninferred would be inferred to
- // the opaque type itself. That again would cause writeback to assume
- // we have a recursive call site and do the sadly stabilized fallback to `()`.
- fcx.demand_suptype(span, ret_ty, actual_return_ty);
-
- // Check that a function marked as `#[panic_handler]` has signature `fn(&PanicInfo) -> !`
- if let Some(panic_impl_did) = tcx.lang_items().panic_impl()
- && panic_impl_did == hir.local_def_id(fn_id).to_def_id()
- {
- check_panic_info_fn(tcx, panic_impl_did.expect_local(), fn_sig, decl, declared_ret_ty);
- }
-
- // Check that a function marked as `#[alloc_error_handler]` has signature `fn(Layout) -> !`
- if let Some(alloc_error_handler_did) = tcx.lang_items().oom()
- && alloc_error_handler_did == hir.local_def_id(fn_id).to_def_id()
- {
- check_alloc_error_fn(tcx, alloc_error_handler_did.expect_local(), fn_sig, decl, declared_ret_ty);
- }
-
- (fcx, gen_ty)
-}
-
-fn check_panic_info_fn(
- tcx: TyCtxt<'_>,
- fn_id: LocalDefId,
- fn_sig: ty::FnSig<'_>,
- decl: &hir::FnDecl<'_>,
- declared_ret_ty: Ty<'_>,
-) {
- let Some(panic_info_did) = tcx.lang_items().panic_info() else {
- tcx.sess.err("language item required, but not found: `panic_info`");
- return;
- };
-
- if *declared_ret_ty.kind() != ty::Never {
- tcx.sess.span_err(decl.output.span(), "return type should be `!`");
- }
-
- let inputs = fn_sig.inputs();
- if inputs.len() != 1 {
- tcx.sess.span_err(tcx.def_span(fn_id), "function should have one argument");
- return;
- }
-
- let arg_is_panic_info = match *inputs[0].kind() {
- ty::Ref(region, ty, mutbl) => match *ty.kind() {
- ty::Adt(ref adt, _) => {
- adt.did() == panic_info_did && mutbl == hir::Mutability::Not && !region.is_static()
- }
- _ => false,
- },
- _ => false,
- };
-
- if !arg_is_panic_info {
- tcx.sess.span_err(decl.inputs[0].span, "argument should be `&PanicInfo`");
- }
-
- let DefKind::Fn = tcx.def_kind(fn_id) else {
- let span = tcx.def_span(fn_id);
- tcx.sess.span_err(span, "should be a function");
- return;
- };
-
- let generic_counts = tcx.generics_of(fn_id).own_counts();
- if generic_counts.types != 0 {
- let span = tcx.def_span(fn_id);
- tcx.sess.span_err(span, "should have no type parameters");
- }
- if generic_counts.consts != 0 {
- let span = tcx.def_span(fn_id);
- tcx.sess.span_err(span, "should have no const parameters");
- }
-}
-
-fn check_alloc_error_fn(
- tcx: TyCtxt<'_>,
- fn_id: LocalDefId,
- fn_sig: ty::FnSig<'_>,
- decl: &hir::FnDecl<'_>,
- declared_ret_ty: Ty<'_>,
-) {
- let Some(alloc_layout_did) = tcx.lang_items().alloc_layout() else {
- tcx.sess.err("language item required, but not found: `alloc_layout`");
- return;
- };
-
- if *declared_ret_ty.kind() != ty::Never {
- tcx.sess.span_err(decl.output.span(), "return type should be `!`");
- }
-
- let inputs = fn_sig.inputs();
- if inputs.len() != 1 {
- tcx.sess.span_err(tcx.def_span(fn_id), "function should have one argument");
- return;
- }
-
- let arg_is_alloc_layout = match inputs[0].kind() {
- ty::Adt(ref adt, _) => adt.did() == alloc_layout_did,
- _ => false,
- };
-
- if !arg_is_alloc_layout {
- tcx.sess.span_err(decl.inputs[0].span, "argument should be `Layout`");
- }
-
- let DefKind::Fn = tcx.def_kind(fn_id) else {
- let span = tcx.def_span(fn_id);
- tcx.sess.span_err(span, "`#[alloc_error_handler]` should be a function");
- return;
- };
-
- let generic_counts = tcx.generics_of(fn_id).own_counts();
- if generic_counts.types != 0 {
- let span = tcx.def_span(fn_id);
- tcx.sess.span_err(span, "`#[alloc_error_handler]` function should have no type parameters");
- }
- if generic_counts.consts != 0 {
- let span = tcx.def_span(fn_id);
- tcx.sess
- .span_err(span, "`#[alloc_error_handler]` function should have no const parameters");
- }
-}
-
fn check_struct(tcx: TyCtxt<'_>, def_id: LocalDefId) {
let def = tcx.adt_def(def_id);
let span = tcx.def_span(def_id);
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