+use super::method::probe::{IsSuggestion, Mode, ProbeScope};
use super::method::MethodCallee;
use super::{DefIdOrName, Expectation, FnCtxt, TupleArgumentsFlag};
use crate::type_error_struct;
-use rustc_errors::{struct_span_err, Applicability, Diagnostic};
+use rustc_ast::util::parser::PREC_POSTFIX;
+use rustc_errors::{struct_span_err, Applicability, Diagnostic, StashKey};
use rustc_hir as hir;
use rustc_hir::def::{self, Namespace, Res};
use rustc_hir::def_id::DefId;
}
}
+#[derive(Debug)]
enum CallStep<'tcx> {
Builtin(Ty<'tcx>),
DeferredClosure(LocalDefId, ty::FnSig<'tcx>),
return None;
}
+ ty::Error(_) => {
+ return None;
+ }
+
_ => {}
}
}
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()
+ if let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = &callee_expr.kind
+ && let [segment] = path.segments
+ && let Some(mut diag) = self
+ .tcx
+ .sess
+ .diagnostic()
+ .steal_diagnostic(segment.ident.span, StashKey::CallIntoMethod)
{
- 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) {
- if let Some((maybe_def, output_ty, _)) = self.extract_callable_info(callee_expr, callee_ty)
- && !self.type_is_sized_modulo_regions(self.param_env, output_ty, callee_expr.span)
+ // Try suggesting `foo(a)` -> `a.foo()` if possible.
+ if let Some(ty) =
+ self.suggest_call_as_method(
+ &mut diag,
+ segment,
+ arg_exprs,
+ call_expr,
+ expected
+ )
{
- let descr = match maybe_def {
- DefIdOrName::DefId(def_id) => self.tcx.def_kind(def_id).descr(def_id),
- DefIdOrName::Name(name) => name,
- };
- err.span_label(
- callee_expr.span,
- format!("this {descr} returns an unsized value `{output_ty}`, so it cannot be called")
- );
- if let DefIdOrName::DefId(def_id) = maybe_def
- && let Some(def_span) = self.tcx.hir().span_if_local(def_id)
- {
- err.span_label(def_span, "the callable type is defined here");
- }
+ diag.emit();
+ return ty;
} else {
- err.span_label(call_expr.span, "call expression requires function");
+ diag.emit();
}
}
- 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();
+ self.report_invalid_callee(call_expr, callee_expr, callee_ty, arg_exprs);
// This is the "default" function signature, used in case of error.
// In that case, we check each argument against "error" in order to
fn_sig.output()
}
+ /// Attempts to reinterpret `method(rcvr, args...)` as `rcvr.method(args...)`
+ /// and suggesting the fix if the method probe is successful.
+ fn suggest_call_as_method(
+ &self,
+ diag: &mut Diagnostic,
+ segment: &'tcx hir::PathSegment<'tcx>,
+ arg_exprs: &'tcx [hir::Expr<'tcx>],
+ call_expr: &'tcx hir::Expr<'tcx>,
+ expected: Expectation<'tcx>,
+ ) -> Option<Ty<'tcx>> {
+ if let [callee_expr, rest @ ..] = arg_exprs {
+ let callee_ty = self.check_expr(callee_expr);
+ // First, do a probe with `IsSuggestion(true)` to avoid emitting
+ // any strange errors. If it's successful, then we'll do a true
+ // method lookup.
+ let Ok(pick) = self
+ .probe_for_name(
+ call_expr.span,
+ Mode::MethodCall,
+ segment.ident,
+ IsSuggestion(true),
+ callee_ty,
+ call_expr.hir_id,
+ // We didn't record the in scope traits during late resolution
+ // so we need to probe AllTraits unfortunately
+ ProbeScope::AllTraits,
+ ) else {
+ return None;
+ };
+
+ let pick = self.confirm_method(
+ call_expr.span,
+ callee_expr,
+ call_expr,
+ callee_ty,
+ pick,
+ segment,
+ );
+ if pick.illegal_sized_bound.is_some() {
+ return None;
+ }
+
+ let up_to_rcvr_span = segment.ident.span.until(callee_expr.span);
+ let rest_span = callee_expr.span.shrink_to_hi().to(call_expr.span.shrink_to_hi());
+ let rest_snippet = if let Some(first) = rest.first() {
+ self.tcx
+ .sess
+ .source_map()
+ .span_to_snippet(first.span.to(call_expr.span.shrink_to_hi()))
+ } else {
+ Ok(")".to_string())
+ };
+
+ if let Ok(rest_snippet) = rest_snippet {
+ let sugg = if callee_expr.precedence().order() >= PREC_POSTFIX {
+ vec![
+ (up_to_rcvr_span, "".to_string()),
+ (rest_span, format!(".{}({rest_snippet}", segment.ident)),
+ ]
+ } else {
+ vec![
+ (up_to_rcvr_span, "(".to_string()),
+ (rest_span, format!(").{}({rest_snippet}", segment.ident)),
+ ]
+ };
+ let self_ty = self.resolve_vars_if_possible(pick.callee.sig.inputs()[0]);
+ diag.multipart_suggestion(
+ format!(
+ "use the `.` operator to call the method `{}{}` on `{self_ty}`",
+ self.tcx
+ .associated_item(pick.callee.def_id)
+ .trait_container(self.tcx)
+ .map_or_else(
+ || String::new(),
+ |trait_def_id| self.tcx.def_path_str(trait_def_id) + "::"
+ ),
+ segment.ident
+ ),
+ sugg,
+ Applicability::MaybeIncorrect,
+ );
+
+ // Let's check the method fully now
+ let return_ty = self.check_method_argument_types(
+ segment.ident.span,
+ call_expr,
+ Ok(pick.callee),
+ rest,
+ TupleArgumentsFlag::DontTupleArguments,
+ expected,
+ );
+
+ return Some(return_ty);
+ }
+ }
+
+ None
+ }
+
+ fn report_invalid_callee(
+ &self,
+ call_expr: &'tcx hir::Expr<'tcx>,
+ callee_expr: &'tcx hir::Expr<'tcx>,
+ callee_ty: Ty<'tcx>,
+ arg_exprs: &'tcx [hir::Expr<'tcx>],
+ ) {
+ 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) {
+ if let Some((maybe_def, output_ty, _)) =
+ self.extract_callable_info(callee_expr, callee_ty)
+ && !self.type_is_sized_modulo_regions(self.param_env, output_ty, callee_expr.span)
+ {
+ let descr = match maybe_def {
+ DefIdOrName::DefId(def_id) => self.tcx.def_kind(def_id).descr(def_id),
+ DefIdOrName::Name(name) => name,
+ };
+ err.span_label(
+ callee_expr.span,
+ format!("this {descr} returns an unsized value `{output_ty}`, so it cannot be called")
+ );
+ if let DefIdOrName::DefId(def_id) = maybe_def
+ && let Some(def_span) = self.tcx.hir().span_if_local(def_id)
+ {
+ err.span_label(def_span, "the callable type is defined here");
+ }
+ } else {
+ 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();
+ }
+
fn confirm_deferred_closure_call(
&self,
call_expr: &'tcx hir::Expr<'tcx>,
projects / rust.git / blobdiff