OpenE2K
/
rust
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Create check_ref method to allow to check coercion with & types

This commit is contained in:
Guillaume Gomez 2016-10-28 14:27:42 +02:00
parent b2d0ec0eb4
commit c11fe553df
7 changed files with 114 additions and 69 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
src/libcollections/lib.rs
View File

@ -28,7 +28,6 @@
#![cfg_attr(test, allow(deprecated))] // rand
#![cfg_attr(not(stage0), deny(warnings))]
#![cfg_attr(not(stage0), feature(safe_suggestion))]
#![feature(alloc)]
#![feature(allow_internal_unstable)]

1
src/libcollections/string.rs
View File

@ -1231,7 +1231,6 @@ impl String {
/// assert_eq!(a.len(), 3);
/// ```
#[inline]
#[cfg_attr(not(stage0), safe_suggestion)]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn len(&self) -> usize {
self.vec.len()

2
src/librustc/infer/error_reporting.rs
View File

@ -549,7 +549,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
{
let expected_found = match values {
None => None,
Some(ref values) => match self.values_str(&values) {
Some(values) => match self.values_str(&values) {
Some((expected, found)) => Some((expected, found)),
None => {
// Derived error. Cancel the emitter.

116
src/librustc_typeck/check/demand.rs
View File

@ -19,28 +19,10 @@ use syntax_pos::{self, Span};
use rustc::hir;
use rustc::ty::{self, ImplOrTraitItem};
use hir::def_id::DefId;
use std::rc::Rc;
use super::method::probe;
struct MethodInfo<'tcx> {
ast: Option<ast::Attribute>,
id: DefId,
item: Rc<ImplOrTraitItem<'tcx>>,
}
impl<'tcx> MethodInfo<'tcx> {
fn new(ast: Option<ast::Attribute>, id: DefId, item: Rc<ImplOrTraitItem<'tcx>>) -> MethodInfo {
MethodInfo {
ast: ast,
id: id,
item: item,
}
}
}
impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
// Requires that the two types unify, and prints an error message if
// they don't.
@ -79,6 +61,46 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
}
}
fn check_ref(&self, expr: &hir::Expr, checked_ty: Ty<'tcx>,
expected: Ty<'tcx>) -> Option<String> {
match (&checked_ty.sty, &expected.sty) {
(&ty::TyRef(_, x_mutability), &ty::TyRef(_, y_mutability)) => {
// check if there is a mutability difference
if x_mutability.mutbl == hir::Mutability::MutImmutable &&
x_mutability.mutbl != y_mutability.mutbl &&
self.can_sub_types(&x_mutability.ty, y_mutability.ty).is_ok() {
if let Ok(src) = self.tcx.sess.codemap().span_to_snippet(expr.span) {
return Some(format!("try with `&mut {}`", &src.replace("&", "")));
}
}
None
}
(_, &ty::TyRef(_, mutability)) => {
// check if it can work when put into a ref
let ref_ty = match mutability.mutbl {
hir::Mutability::MutMutable => self.tcx.mk_mut_ref(
self.tcx.mk_region(ty::ReStatic),
checked_ty),
hir::Mutability::MutImmutable => self.tcx.mk_imm_ref(
self.tcx.mk_region(ty::ReStatic),
checked_ty),
};
if self.try_coerce(expr, ref_ty, expected).is_ok() {
if let Ok(src) = self.tcx.sess.codemap().span_to_snippet(expr.span) {
return Some(format!("try with `{}{}`",
match mutability.mutbl {
hir::Mutability::MutMutable => "&mut ",
hir::Mutability::MutImmutable => "&",
},
&src));
}
}
None
}
_ => None,
}
}
// Checks that the type of `expr` can be coerced to `expected`.
pub fn demand_coerce(&self, expr: &hir::Expr, checked_ty: Ty<'tcx>, expected: Ty<'tcx>) {
let expected = self.resolve_type_vars_with_obligations(expected);
@ -86,34 +108,23 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
let cause = self.misc(expr.span);
let expr_ty = self.resolve_type_vars_with_obligations(checked_ty);
let mode = probe::Mode::MethodCall;
let suggestions =
if let Ok(methods) = self.probe_return(syntax_pos::DUMMY_SP, mode, expected,
checked_ty, ast::DUMMY_NODE_ID) {
let suggestions = if let Some(s) = self.check_ref(expr, checked_ty, expected) {
Some(s)
} else if let Ok(methods) = self.probe_return(syntax_pos::DUMMY_SP,
mode,
expected,
checked_ty,
ast::DUMMY_NODE_ID) {
let suggestions: Vec<_> =
methods.iter()
.filter_map(|ref x| {
if let Some(id) = self.get_impl_id(&x.item) {
Some(MethodInfo::new(None, id, Rc::new(x.item.clone())))
} else {
None
}})
.map(|ref x| {
Rc::new(x.item.clone())
})
.collect();
if suggestions.len() > 0 {
let safe_suggestions: Vec<_> =
suggestions.iter()
.map(|ref x| MethodInfo::new(
self.find_attr(x.id, "safe_suggestion"),
x.id,
x.item.clone()))
.filter(|ref x| x.ast.is_some())
.collect();
Some(if safe_suggestions.len() > 0 {
self.get_best_match(&safe_suggestions)
} else {
format!("no safe suggestion found, here are functions which match your \
needs but be careful:\n - {}",
self.get_best_match(&suggestions))
})
Some(format!("here are some functions which \
might fulfill your needs:\n - {}",
self.get_best_match(&suggestions)))
} else {
None
}
@ -132,34 +143,29 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
}
}
fn get_best_match(&self, methods: &[MethodInfo<'tcx>]) -> String {
fn get_best_match(&self, methods: &[Rc<ImplOrTraitItem<'tcx>>]) -> String {
if methods.len() == 1 {
return format!(" - {}", methods[0].item.name());
return format!(" - {}", methods[0].name());
}
let no_argument_methods: Vec<&MethodInfo> =
let no_argument_methods: Vec<&Rc<ImplOrTraitItem<'tcx>>> =
methods.iter()
.filter(|ref x| self.has_not_input_arg(&*x.item))
.filter(|ref x| self.has_not_input_arg(&*x))
.collect();
if no_argument_methods.len() > 0 {
no_argument_methods.iter()
.map(|method| format!("{}", method.item.name()))
.take(5)
.map(|method| format!("{}", method.name()))
.collect::<Vec<String>>()
.join("\n - ")
} else {
methods.iter()
.map(|method| format!("{}", method.item.name()))
.take(5)
.map(|method| format!("{}", method.name()))
.collect::<Vec<String>>()
.join("\n - ")
}
}
fn get_impl_id(&self, impl_: &ImplOrTraitItem<'tcx>) -> Option<DefId> {
match *impl_ {
ty::ImplOrTraitItem::MethodTraitItem(ref m) => Some((*m).def_id),
_ => None,
}
}
fn has_not_input_arg(&self, method: &ImplOrTraitItem<'tcx>) -> bool {
match *method {
ImplOrTraitItem::MethodTraitItem(ref x) => {

16
src/librustc_typeck/check/method/probe.rs
View File

@ -194,7 +194,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
// think cause spurious errors. Really though this part should
// take place in the `self.probe` below.
let steps = if mode == Mode::MethodCall {
match self.create_steps(span, self_ty) {
match self.create_steps(span, self_ty, &looking_for) {
Some(steps) => steps,
None => {
return Err(MethodError::NoMatch(NoMatchData::new(Vec::new(),
@ -247,7 +247,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
fn create_steps(&self,
span: Span,
self_ty: Ty<'tcx>)
self_ty: Ty<'tcx>,
looking_for: &LookingFor<'tcx>)
-> Option<Vec<CandidateStep<'tcx>>> {
// FIXME: we don't need to create the entire steps in one pass
@ -262,7 +263,10 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
})
.collect();
let final_ty = autoderef.unambiguous_final_ty();
let final_ty = match looking_for {
&LookingFor::MethodName(_) => autoderef.unambiguous_final_ty(),
&LookingFor::ReturnType(_) => self_ty,
};
match final_ty.sty {
ty::TyArray(elem_ty, _) => {
let dereferences = steps.len() - 1;
@ -628,13 +632,15 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> {
}
pub fn matches_return_type(&self, method: &ty::ImplOrTraitItem<'tcx>,
expected: ty::Ty<'tcx>) -> bool {
expected: ty::Ty<'tcx>) -> bool {
match *method {
ty::ImplOrTraitItem::MethodTraitItem(ref x) => {
self.probe(|_| {
let output = self.replace_late_bound_regions_with_fresh_var(
self.span, infer::FnCall, &x.fty.sig.output());
self.can_sub_types(output.0, expected).is_ok()
let substs = self.fresh_substs_for_item(self.span, method.def_id());
let output = output.0.subst(self.tcx, substs);
self.can_sub_types(output, expected).is_ok()
})
}
_ => false,

6
src/libsyntax/feature_gate.rs
View File

@ -652,12 +652,6 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
"internal implementation detail",
cfg_fn!(rustc_attrs))),
("safe_suggestion", Whitelisted, Gated(Stability::Unstable,
"safe_suggestion",
"the `#[safe_suggestion]` attribute \
is an experimental feature",
cfg_fn!(safe_suggestion))),
// FIXME: #14408 whitelist docs since rustdoc looks at them
("doc", Whitelisted, Ungated),

41
src/test/compile-fail/coerce_suggestions.rs Normal file
View File

@ -0,0 +1,41 @@
// 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.
fn test(_x: &mut String) {}
fn test2(_x: &mut i32) {}
fn main() {
let x: usize = String::new();
//^ ERROR E0308
//| NOTE expected type `usize`
//| NOTE found type `std::string::String`
//| NOTE here are some functions which might fulfill your needs:
let x: &str = String::new();
//^ ERROR E0308
//| NOTE expected type `&str`
//| NOTE found type `std::string::String`
//| NOTE try with `&String::new()`
let y = String::new();
test(&y);
//^ ERROR E0308
//| NOTE expected type `&mut std::string::String`
//| NOTE found type `&std::string::String`
//| NOTE try with `&mut y`
test2(&y);
//^ ERROR E0308
//| NOTE expected type `&mut i32`
//| NOTE found type `&std::string::String`
//| NOTE try with `&mut y`
let f;
f = box f;
//^ ERROR E0308
//| NOTE expected type `_`
//| NOTE found type `Box<_>`
}