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-rw-r--r--compiler/rustc_typeck/src/check/callee.rs675
1 files changed, 0 insertions, 675 deletions
diff --git a/compiler/rustc_typeck/src/check/callee.rs b/compiler/rustc_typeck/src/check/callee.rs
deleted file mode 100644
index 75f5aced8..000000000
--- a/compiler/rustc_typeck/src/check/callee.rs
+++ /dev/null
@@ -1,675 +0,0 @@
-use super::method::MethodCallee;
-use super::{Expectation, FnCtxt, TupleArgumentsFlag};
-use crate::type_error_struct;
-
-use rustc_errors::{struct_span_err, Applicability, Diagnostic};
-use rustc_hir as hir;
-use rustc_hir::def::{self, Namespace, Res};
-use rustc_hir::def_id::DefId;
-use rustc_infer::{
- infer,
- traits::{self, Obligation},
-};
-use rustc_infer::{
- infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind},
- traits::ObligationCause,
-};
-use rustc_middle::ty::adjustment::{
- Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability,
-};
-use rustc_middle::ty::subst::{Subst, SubstsRef};
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
-use rustc_span::def_id::LocalDefId;
-use rustc_span::symbol::{sym, Ident};
-use rustc_span::Span;
-use rustc_target::spec::abi;
-use rustc_trait_selection::autoderef::Autoderef;
-use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
-
-use std::iter;
-
-/// Checks that it is legal to call methods of the trait corresponding
-/// to `trait_id` (this only cares about the trait, not the specific
-/// method that is called).
-pub fn check_legal_trait_for_method_call(
- tcx: TyCtxt<'_>,
- span: Span,
- receiver: Option<Span>,
- expr_span: Span,
- trait_id: DefId,
-) {
- if tcx.lang_items().drop_trait() == Some(trait_id) {
- let mut err = struct_span_err!(tcx.sess, span, E0040, "explicit use of destructor method");
- err.span_label(span, "explicit destructor calls not allowed");
-
- let (sp, suggestion) = receiver
- .and_then(|s| tcx.sess.source_map().span_to_snippet(s).ok())
- .filter(|snippet| !snippet.is_empty())
- .map(|snippet| (expr_span, format!("drop({snippet})")))
- .unwrap_or_else(|| (span, "drop".to_string()));
-
- err.span_suggestion(
- sp,
- "consider using `drop` function",
- suggestion,
- Applicability::MaybeIncorrect,
- );
-
- err.emit();
- }
-}
-
-enum CallStep<'tcx> {
- Builtin(Ty<'tcx>),
- DeferredClosure(LocalDefId, ty::FnSig<'tcx>),
- /// E.g., enum variant constructors.
- Overloaded(MethodCallee<'tcx>),
-}
-
-impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
- pub fn check_call(
- &self,
- call_expr: &'tcx hir::Expr<'tcx>,
- callee_expr: &'tcx hir::Expr<'tcx>,
- arg_exprs: &'tcx [hir::Expr<'tcx>],
- expected: Expectation<'tcx>,
- ) -> Ty<'tcx> {
- let original_callee_ty = match &callee_expr.kind {
- hir::ExprKind::Path(hir::QPath::Resolved(..) | hir::QPath::TypeRelative(..)) => self
- .check_expr_with_expectation_and_args(
- callee_expr,
- Expectation::NoExpectation,
- arg_exprs,
- ),
- _ => self.check_expr(callee_expr),
- };
-
- let expr_ty = self.structurally_resolved_type(call_expr.span, original_callee_ty);
-
- let mut autoderef = self.autoderef(callee_expr.span, expr_ty);
- let mut result = None;
- while result.is_none() && autoderef.next().is_some() {
- result = self.try_overloaded_call_step(call_expr, callee_expr, arg_exprs, &autoderef);
- }
- self.register_predicates(autoderef.into_obligations());
-
- let output = match result {
- None => {
- // this will report an error since original_callee_ty is not a fn
- self.confirm_builtin_call(
- call_expr,
- callee_expr,
- original_callee_ty,
- arg_exprs,
- expected,
- )
- }
-
- Some(CallStep::Builtin(callee_ty)) => {
- self.confirm_builtin_call(call_expr, callee_expr, callee_ty, arg_exprs, expected)
- }
-
- Some(CallStep::DeferredClosure(def_id, fn_sig)) => {
- self.confirm_deferred_closure_call(call_expr, arg_exprs, expected, def_id, fn_sig)
- }
-
- Some(CallStep::Overloaded(method_callee)) => {
- self.confirm_overloaded_call(call_expr, arg_exprs, expected, method_callee)
- }
- };
-
- // we must check that return type of called functions is WF:
- self.register_wf_obligation(output.into(), call_expr.span, traits::WellFormed(None));
-
- output
- }
-
- fn try_overloaded_call_step(
- &self,
- call_expr: &'tcx hir::Expr<'tcx>,
- callee_expr: &'tcx hir::Expr<'tcx>,
- arg_exprs: &'tcx [hir::Expr<'tcx>],
- autoderef: &Autoderef<'a, 'tcx>,
- ) -> Option<CallStep<'tcx>> {
- let adjusted_ty =
- self.structurally_resolved_type(autoderef.span(), autoderef.final_ty(false));
- debug!(
- "try_overloaded_call_step(call_expr={:?}, adjusted_ty={:?})",
- call_expr, adjusted_ty
- );
-
- // If the callee is a bare function or a closure, then we're all set.
- match *adjusted_ty.kind() {
- ty::FnDef(..) | ty::FnPtr(_) => {
- let adjustments = self.adjust_steps(autoderef);
- self.apply_adjustments(callee_expr, adjustments);
- return Some(CallStep::Builtin(adjusted_ty));
- }
-
- ty::Closure(def_id, substs) => {
- let def_id = def_id.expect_local();
-
- // Check whether this is a call to a closure where we
- // haven't yet decided on whether the closure is fn vs
- // fnmut vs fnonce. If so, we have to defer further processing.
- if self.closure_kind(substs).is_none() {
- let closure_sig = substs.as_closure().sig();
- let closure_sig = self.replace_bound_vars_with_fresh_vars(
- call_expr.span,
- infer::FnCall,
- closure_sig,
- );
- let adjustments = self.adjust_steps(autoderef);
- self.record_deferred_call_resolution(
- def_id,
- DeferredCallResolution {
- call_expr,
- callee_expr,
- adjusted_ty,
- adjustments,
- fn_sig: closure_sig,
- closure_substs: substs,
- },
- );
- return Some(CallStep::DeferredClosure(def_id, closure_sig));
- }
- }
-
- // Hack: we know that there are traits implementing Fn for &F
- // where F:Fn and so forth. In the particular case of types
- // like `x: &mut FnMut()`, if there is a call `x()`, we would
- // normally translate to `FnMut::call_mut(&mut x, ())`, but
- // that winds up requiring `mut x: &mut FnMut()`. A little
- // over the top. The simplest fix by far is to just ignore
- // this case and deref again, so we wind up with
- // `FnMut::call_mut(&mut *x, ())`.
- ty::Ref(..) if autoderef.step_count() == 0 => {
- return None;
- }
-
- _ => {}
- }
-
- // Now, we look for the implementation of a Fn trait on the object's type.
- // We first do it with the explicit instruction to look for an impl of
- // `Fn<Tuple>`, with the tuple `Tuple` having an arity corresponding
- // to the number of call parameters.
- // If that fails (or_else branch), we try again without specifying the
- // shape of the tuple (hence the None). This allows to detect an Fn trait
- // is implemented, and use this information for diagnostic.
- self.try_overloaded_call_traits(call_expr, adjusted_ty, Some(arg_exprs))
- .or_else(|| self.try_overloaded_call_traits(call_expr, adjusted_ty, None))
- .map(|(autoref, method)| {
- let mut adjustments = self.adjust_steps(autoderef);
- adjustments.extend(autoref);
- self.apply_adjustments(callee_expr, adjustments);
- CallStep::Overloaded(method)
- })
- }
-
- fn try_overloaded_call_traits(
- &self,
- call_expr: &hir::Expr<'_>,
- adjusted_ty: Ty<'tcx>,
- opt_arg_exprs: Option<&'tcx [hir::Expr<'tcx>]>,
- ) -> Option<(Option<Adjustment<'tcx>>, MethodCallee<'tcx>)> {
- // Try the options that are least restrictive on the caller first.
- for (opt_trait_def_id, method_name, borrow) in [
- (self.tcx.lang_items().fn_trait(), Ident::with_dummy_span(sym::call), true),
- (self.tcx.lang_items().fn_mut_trait(), Ident::with_dummy_span(sym::call_mut), true),
- (self.tcx.lang_items().fn_once_trait(), Ident::with_dummy_span(sym::call_once), false),
- ] {
- let Some(trait_def_id) = opt_trait_def_id else { continue };
-
- let opt_input_types = opt_arg_exprs.map(|arg_exprs| {
- [self.tcx.mk_tup(arg_exprs.iter().map(|e| {
- self.next_ty_var(TypeVariableOrigin {
- kind: TypeVariableOriginKind::TypeInference,
- span: e.span,
- })
- }))]
- });
- let opt_input_types = opt_input_types.as_ref().map(AsRef::as_ref);
-
- if let Some(ok) = self.lookup_method_in_trait(
- call_expr.span,
- method_name,
- trait_def_id,
- adjusted_ty,
- opt_input_types,
- ) {
- let method = self.register_infer_ok_obligations(ok);
- let mut autoref = None;
- if borrow {
- // Check for &self vs &mut self in the method signature. Since this is either
- // the Fn or FnMut trait, it should be one of those.
- let ty::Ref(region, _, mutbl) = method.sig.inputs()[0].kind() else {
- // The `fn`/`fn_mut` lang item is ill-formed, which should have
- // caused an error elsewhere.
- self.tcx
- .sess
- .delay_span_bug(call_expr.span, "input to call/call_mut is not a ref?");
- return None;
- };
-
- let mutbl = match mutbl {
- hir::Mutability::Not => AutoBorrowMutability::Not,
- hir::Mutability::Mut => AutoBorrowMutability::Mut {
- // For initial two-phase borrow
- // deployment, conservatively omit
- // overloaded function call ops.
- allow_two_phase_borrow: AllowTwoPhase::No,
- },
- };
- autoref = Some(Adjustment {
- kind: Adjust::Borrow(AutoBorrow::Ref(*region, mutbl)),
- target: method.sig.inputs()[0],
- });
- }
- return Some((autoref, method));
- }
- }
-
- None
- }
-
- /// Give appropriate suggestion when encountering `||{/* not callable */}()`, where the
- /// likely intention is to call the closure, suggest `(||{})()`. (#55851)
- fn identify_bad_closure_def_and_call(
- &self,
- err: &mut Diagnostic,
- hir_id: hir::HirId,
- callee_node: &hir::ExprKind<'_>,
- callee_span: Span,
- ) {
- let hir = self.tcx.hir();
- let parent_hir_id = hir.get_parent_node(hir_id);
- let parent_node = hir.get(parent_hir_id);
- if let (
- hir::Node::Expr(hir::Expr {
- kind: hir::ExprKind::Closure(&hir::Closure { fn_decl_span, body, .. }),
- ..
- }),
- hir::ExprKind::Block(..),
- ) = (parent_node, callee_node)
- {
- let fn_decl_span = if hir.body(body).generator_kind
- == Some(hir::GeneratorKind::Async(hir::AsyncGeneratorKind::Closure))
- {
- // Actually need to unwrap a few more layers of HIR to get to
- // the _real_ closure...
- let async_closure = hir.get_parent_node(hir.get_parent_node(parent_hir_id));
- if let hir::Node::Expr(hir::Expr {
- kind: hir::ExprKind::Closure(&hir::Closure { fn_decl_span, .. }),
- ..
- }) = hir.get(async_closure)
- {
- fn_decl_span
- } else {
- return;
- }
- } else {
- fn_decl_span
- };
-
- let start = fn_decl_span.shrink_to_lo();
- let end = callee_span.shrink_to_hi();
- err.multipart_suggestion(
- "if you meant to create this closure and immediately call it, surround the \
- closure with parentheses",
- vec![(start, "(".to_string()), (end, ")".to_string())],
- Applicability::MaybeIncorrect,
- );
- }
- }
-
- /// Give appropriate suggestion when encountering `[("a", 0) ("b", 1)]`, where the
- /// likely intention is to create an array containing tuples.
- fn maybe_suggest_bad_array_definition(
- &self,
- err: &mut Diagnostic,
- call_expr: &'tcx hir::Expr<'tcx>,
- callee_expr: &'tcx hir::Expr<'tcx>,
- ) -> bool {
- let hir_id = self.tcx.hir().get_parent_node(call_expr.hir_id);
- let parent_node = self.tcx.hir().get(hir_id);
- if let (
- hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Array(_), .. }),
- hir::ExprKind::Tup(exp),
- hir::ExprKind::Call(_, args),
- ) = (parent_node, &callee_expr.kind, &call_expr.kind)
- && args.len() == exp.len()
- {
- let start = callee_expr.span.shrink_to_hi();
- err.span_suggestion(
- start,
- "consider separating array elements with a comma",
- ",",
- Applicability::MaybeIncorrect,
- );
- return true;
- }
- false
- }
-
- fn confirm_builtin_call(
- &self,
- call_expr: &'tcx hir::Expr<'tcx>,
- callee_expr: &'tcx hir::Expr<'tcx>,
- callee_ty: Ty<'tcx>,
- arg_exprs: &'tcx [hir::Expr<'tcx>],
- expected: Expectation<'tcx>,
- ) -> Ty<'tcx> {
- let (fn_sig, def_id) = match *callee_ty.kind() {
- ty::FnDef(def_id, subst) => {
- let fn_sig = self.tcx.bound_fn_sig(def_id).subst(self.tcx, subst);
-
- // Unit testing: function items annotated with
- // `#[rustc_evaluate_where_clauses]` trigger special output
- // to let us test the trait evaluation system.
- if self.tcx.has_attr(def_id, sym::rustc_evaluate_where_clauses) {
- let predicates = self.tcx.predicates_of(def_id);
- let predicates = predicates.instantiate(self.tcx, subst);
- for (predicate, predicate_span) in
- predicates.predicates.iter().zip(&predicates.spans)
- {
- let obligation = Obligation::new(
- ObligationCause::dummy_with_span(callee_expr.span),
- self.param_env,
- *predicate,
- );
- let result = self.evaluate_obligation(&obligation);
- self.tcx
- .sess
- .struct_span_err(
- callee_expr.span,
- &format!("evaluate({:?}) = {:?}", predicate, result),
- )
- .span_label(*predicate_span, "predicate")
- .emit();
- }
- }
- (fn_sig, Some(def_id))
- }
- ty::FnPtr(sig) => (sig, None),
- _ => {
- let mut unit_variant = None;
- if let hir::ExprKind::Path(qpath) = &callee_expr.kind
- && let Res::Def(def::DefKind::Ctor(kind, def::CtorKind::Const), _)
- = self.typeck_results.borrow().qpath_res(qpath, callee_expr.hir_id)
- // Only suggest removing parens if there are no arguments
- && arg_exprs.is_empty()
- {
- let descr = match kind {
- def::CtorOf::Struct => "struct",
- def::CtorOf::Variant => "enum variant",
- };
- let removal_span =
- callee_expr.span.shrink_to_hi().to(call_expr.span.shrink_to_hi());
- unit_variant =
- Some((removal_span, descr, rustc_hir_pretty::qpath_to_string(qpath)));
- }
-
- let callee_ty = self.resolve_vars_if_possible(callee_ty);
- let mut err = type_error_struct!(
- self.tcx.sess,
- callee_expr.span,
- callee_ty,
- E0618,
- "expected function, found {}",
- match &unit_variant {
- Some((_, kind, path)) => format!("{kind} `{path}`"),
- None => format!("`{callee_ty}`"),
- }
- );
-
- self.identify_bad_closure_def_and_call(
- &mut err,
- call_expr.hir_id,
- &callee_expr.kind,
- callee_expr.span,
- );
-
- if let Some((removal_span, kind, path)) = &unit_variant {
- err.span_suggestion_verbose(
- *removal_span,
- &format!(
- "`{path}` is a unit {kind}, and does not take parentheses to be constructed",
- ),
- "",
- Applicability::MachineApplicable,
- );
- }
-
- let mut inner_callee_path = None;
- let def = match callee_expr.kind {
- hir::ExprKind::Path(ref qpath) => {
- self.typeck_results.borrow().qpath_res(qpath, callee_expr.hir_id)
- }
- hir::ExprKind::Call(ref inner_callee, _) => {
- // If the call spans more than one line and the callee kind is
- // itself another `ExprCall`, that's a clue that we might just be
- // missing a semicolon (Issue #51055)
- let call_is_multiline =
- self.tcx.sess.source_map().is_multiline(call_expr.span);
- if call_is_multiline {
- err.span_suggestion(
- callee_expr.span.shrink_to_hi(),
- "consider using a semicolon here",
- ";",
- Applicability::MaybeIncorrect,
- );
- }
- if let hir::ExprKind::Path(ref inner_qpath) = inner_callee.kind {
- inner_callee_path = Some(inner_qpath);
- self.typeck_results.borrow().qpath_res(inner_qpath, inner_callee.hir_id)
- } else {
- Res::Err
- }
- }
- _ => Res::Err,
- };
-
- if !self.maybe_suggest_bad_array_definition(&mut err, call_expr, callee_expr) {
- err.span_label(call_expr.span, "call expression requires function");
- }
-
- if let Some(span) = self.tcx.hir().res_span(def) {
- let callee_ty = callee_ty.to_string();
- let label = match (unit_variant, inner_callee_path) {
- (Some((_, kind, path)), _) => Some(format!("{kind} `{path}` defined here")),
- (_, Some(hir::QPath::Resolved(_, path))) => self
- .tcx
- .sess
- .source_map()
- .span_to_snippet(path.span)
- .ok()
- .map(|p| format!("`{p}` defined here returns `{callee_ty}`")),
- _ => {
- match def {
- // Emit a different diagnostic for local variables, as they are not
- // type definitions themselves, but rather variables *of* that type.
- Res::Local(hir_id) => Some(format!(
- "`{}` has type `{}`",
- self.tcx.hir().name(hir_id),
- callee_ty
- )),
- Res::Def(kind, def_id) if kind.ns() == Some(Namespace::ValueNS) => {
- Some(format!(
- "`{}` defined here",
- self.tcx.def_path_str(def_id),
- ))
- }
- _ => Some(format!("`{callee_ty}` defined here")),
- }
- }
- };
- if let Some(label) = label {
- err.span_label(span, label);
- }
- }
- err.emit();
-
- // This is the "default" function signature, used in case of error.
- // In that case, we check each argument against "error" in order to
- // set up all the node type bindings.
- (
- ty::Binder::dummy(self.tcx.mk_fn_sig(
- self.err_args(arg_exprs.len()).into_iter(),
- self.tcx.ty_error(),
- false,
- hir::Unsafety::Normal,
- abi::Abi::Rust,
- )),
- None,
- )
- }
- };
-
- // Replace any late-bound regions that appear in the function
- // signature with region variables. We also have to
- // renormalize the associated types at this point, since they
- // previously appeared within a `Binder<>` and hence would not
- // have been normalized before.
- let fn_sig = self.replace_bound_vars_with_fresh_vars(call_expr.span, infer::FnCall, fn_sig);
- let fn_sig = self.normalize_associated_types_in(call_expr.span, fn_sig);
-
- // Call the generic checker.
- let expected_arg_tys = self.expected_inputs_for_expected_output(
- call_expr.span,
- expected,
- fn_sig.output(),
- fn_sig.inputs(),
- );
- self.check_argument_types(
- call_expr.span,
- call_expr,
- fn_sig.inputs(),
- expected_arg_tys,
- arg_exprs,
- fn_sig.c_variadic,
- TupleArgumentsFlag::DontTupleArguments,
- def_id,
- );
-
- fn_sig.output()
- }
-
- fn confirm_deferred_closure_call(
- &self,
- call_expr: &'tcx hir::Expr<'tcx>,
- arg_exprs: &'tcx [hir::Expr<'tcx>],
- expected: Expectation<'tcx>,
- closure_def_id: LocalDefId,
- fn_sig: ty::FnSig<'tcx>,
- ) -> Ty<'tcx> {
- // `fn_sig` is the *signature* of the closure being called. We
- // don't know the full details yet (`Fn` vs `FnMut` etc), but we
- // do know the types expected for each argument and the return
- // type.
-
- let expected_arg_tys = self.expected_inputs_for_expected_output(
- call_expr.span,
- expected,
- fn_sig.output(),
- fn_sig.inputs(),
- );
-
- self.check_argument_types(
- call_expr.span,
- call_expr,
- fn_sig.inputs(),
- expected_arg_tys,
- arg_exprs,
- fn_sig.c_variadic,
- TupleArgumentsFlag::TupleArguments,
- Some(closure_def_id.to_def_id()),
- );
-
- fn_sig.output()
- }
-
- fn confirm_overloaded_call(
- &self,
- call_expr: &'tcx hir::Expr<'tcx>,
- arg_exprs: &'tcx [hir::Expr<'tcx>],
- expected: Expectation<'tcx>,
- method_callee: MethodCallee<'tcx>,
- ) -> Ty<'tcx> {
- let output_type = self.check_method_argument_types(
- call_expr.span,
- call_expr,
- Ok(method_callee),
- arg_exprs,
- TupleArgumentsFlag::TupleArguments,
- expected,
- );
-
- self.write_method_call(call_expr.hir_id, method_callee);
- output_type
- }
-}
-
-#[derive(Debug)]
-pub struct DeferredCallResolution<'tcx> {
- call_expr: &'tcx hir::Expr<'tcx>,
- callee_expr: &'tcx hir::Expr<'tcx>,
- adjusted_ty: Ty<'tcx>,
- adjustments: Vec<Adjustment<'tcx>>,
- fn_sig: ty::FnSig<'tcx>,
- closure_substs: SubstsRef<'tcx>,
-}
-
-impl<'a, 'tcx> DeferredCallResolution<'tcx> {
- pub fn resolve(self, fcx: &FnCtxt<'a, 'tcx>) {
- debug!("DeferredCallResolution::resolve() {:?}", self);
-
- // we should not be invoked until the closure kind has been
- // determined by upvar inference
- assert!(fcx.closure_kind(self.closure_substs).is_some());
-
- // We may now know enough to figure out fn vs fnmut etc.
- match fcx.try_overloaded_call_traits(self.call_expr, self.adjusted_ty, None) {
- Some((autoref, method_callee)) => {
- // One problem is that when we get here, we are going
- // to have a newly instantiated function signature
- // from the call trait. This has to be reconciled with
- // the older function signature we had before. In
- // principle we *should* be able to fn_sigs(), but we
- // can't because of the annoying need for a TypeTrace.
- // (This always bites me, should find a way to
- // refactor it.)
- let method_sig = method_callee.sig;
-
- debug!("attempt_resolution: method_callee={:?}", method_callee);
-
- for (method_arg_ty, self_arg_ty) in
- iter::zip(method_sig.inputs().iter().skip(1), self.fn_sig.inputs())
- {
- fcx.demand_eqtype(self.call_expr.span, *self_arg_ty, *method_arg_ty);
- }
-
- fcx.demand_eqtype(self.call_expr.span, method_sig.output(), self.fn_sig.output());
-
- let mut adjustments = self.adjustments;
- adjustments.extend(autoref);
- fcx.apply_adjustments(self.callee_expr, adjustments);
-
- fcx.write_method_call(self.call_expr.hir_id, method_callee);
- }
- None => {
- // This can happen if `#![no_core]` is used and the `fn/fn_mut/fn_once`
- // lang items are not defined (issue #86238).
- let mut err = fcx.inh.tcx.sess.struct_span_err(
- self.call_expr.span,
- "failed to find an overloaded call trait for closure call",
- );
- err.help(
- "make sure the `fn`/`fn_mut`/`fn_once` lang items are defined \
- and have associated `call`/`call_mut`/`call_once` functions",
- );
- err.emit();
- }
- }
- }
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-09 19:25:36 +0000