Auto merge of #35456 - birkenfeld:issue-33784, r=nikomatsakis
typeck: suggest (x.field)(...) to call struct fields even when x is a reference Fixes: #33784 Note: This is a reopen of #33785.
This commit is contained in:
commit
b42a384a80
@ -162,26 +162,34 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
|
||||
},
|
||||
rcvr_ty);
|
||||
|
||||
// If the item has the name of a field, give a help note
|
||||
if let (&ty::TyStruct(def, substs), Some(expr)) = (&rcvr_ty.sty, rcvr_expr) {
|
||||
if let Some(field) = def.struct_variant().find_field_named(item_name) {
|
||||
let expr_string = match tcx.sess.codemap().span_to_snippet(expr.span) {
|
||||
Ok(expr_string) => expr_string,
|
||||
_ => "s".into() // Default to a generic placeholder for the
|
||||
// expression when we can't generate a string
|
||||
// snippet
|
||||
};
|
||||
// If the method name is the name of a field with a function or closure type,
|
||||
// give a helping note that it has to be called as (x.f)(...).
|
||||
if let Some(expr) = rcvr_expr {
|
||||
for (ty, _) in self.autoderef(span, rcvr_ty) {
|
||||
if let ty::TyStruct(def, substs) = ty.sty {
|
||||
if let Some(field) = def.struct_variant().find_field_named(item_name) {
|
||||
let snippet = tcx.sess.codemap().span_to_snippet(expr.span);
|
||||
let expr_string = match snippet {
|
||||
Ok(expr_string) => expr_string,
|
||||
_ => "s".into() // Default to a generic placeholder for the
|
||||
// expression when we can't generate a
|
||||
// string snippet
|
||||
};
|
||||
|
||||
let field_ty = field.ty(tcx, substs);
|
||||
let field_ty = field.ty(tcx, substs);
|
||||
|
||||
if self.is_fn_ty(&field_ty, span) {
|
||||
err.span_note(span,
|
||||
&format!("use `({0}.{1})(...)` if you meant to call \
|
||||
the function stored in the `{1}` field",
|
||||
expr_string, item_name));
|
||||
} else {
|
||||
err.span_note(span, &format!("did you mean to write `{0}.{1}`?",
|
||||
expr_string, item_name));
|
||||
if self.is_fn_ty(&field_ty, span) {
|
||||
err.span_note(span, &format!(
|
||||
"use `({0}.{1})(...)` if you meant to call the function \
|
||||
stored in the `{1}` field",
|
||||
expr_string, item_name));
|
||||
} else {
|
||||
err.span_note(span, &format!(
|
||||
"did you mean to write `{0}.{1}`?",
|
||||
expr_string, item_name));
|
||||
}
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
46
src/test/compile-fail/issue-33784.rs
Normal file
46
src/test/compile-fail/issue-33784.rs
Normal file
@ -0,0 +1,46 @@
|
||||
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
|
||||
// file at the top-level directory of this distribution and at
|
||||
// http://rust-lang.org/COPYRIGHT.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||||
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||||
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
||||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
use std::ops::Deref;
|
||||
|
||||
struct Obj<F> where F: FnMut() -> u32 {
|
||||
fn_ptr: fn() -> (),
|
||||
closure: F,
|
||||
}
|
||||
|
||||
struct C {
|
||||
c_fn_ptr: fn() -> (),
|
||||
}
|
||||
|
||||
struct D(C);
|
||||
|
||||
impl Deref for D {
|
||||
type Target = C;
|
||||
fn deref(&self) -> &C {
|
||||
&self.0
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
fn empty() {}
|
||||
|
||||
fn main() {
|
||||
let o = Obj { fn_ptr: empty, closure: || 42 };
|
||||
let p = &o;
|
||||
p.closure(); //~ ERROR no method named `closure` found
|
||||
//~^ NOTE use `(p.closure)(...)` if you meant to call the function stored in the `closure` field
|
||||
let q = &p;
|
||||
q.fn_ptr(); //~ ERROR no method named `fn_ptr` found
|
||||
//~^ NOTE use `(q.fn_ptr)(...)` if you meant to call the function stored in the `fn_ptr` field
|
||||
let r = D(C { c_fn_ptr: empty });
|
||||
let s = &r;
|
||||
s.c_fn_ptr(); //~ ERROR no method named `c_fn_ptr` found
|
||||
//~^ NOTE use `(s.c_fn_ptr)(...)` if you meant to call the function stored in the `c_fn_ptr`
|
||||
}
|
Loading…
Reference in New Issue
Block a user