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Add E0606

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This commit is contained in:
Guillaume Gomez 2017-06-07 23:54:51 +02:00
parent 0e4b8ffccd
commit 30effc14e4
4 changed files with 83 additions and 64 deletions
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71
src/librustc_typeck/check/cast.rs
View file

@ -40,9 +40,11 @@
use super::{Diverges, FnCtxt};
use lint;
use errors::DiagnosticBuilder;
use hir::def_id::DefId;
use lint;
use rustc::hir;
use rustc::session::Session;
use rustc::traits;
use rustc::ty::{self, Ty, TypeFoldable};
use rustc::ty::cast::{CastKind, CastTy};
@ -112,6 +114,18 @@ enum CastError {
NonScalar,
}
fn make_invalid_casting_error<'a, 'gcx, 'tcx>(sess: &'a Session,
span: Span,
expr_ty: Ty<'tcx>,
cast_ty: Ty<'tcx>,
fcx: &FnCtxt<'a, 'gcx, 'tcx>)
-> DiagnosticBuilder<'a> {
struct_span_err!(sess, span, E0606,
"casting `{}` as `{}` is invalid",
fcx.ty_to_string(expr_ty),
fcx.ty_to_string(cast_ty))
}
impl<'a, 'gcx, 'tcx> CastCheck<'tcx> {
pub fn new(fcx: &FnCtxt<'a, 'gcx, 'tcx>,
expr: &'tcx hir::Expr,
@ -146,14 +160,9 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> {
match e {
CastError::NeedDeref => {
let error_span = self.span;
let mut err = make_invalid_casting_error(fcx.tcx.sess, self.span, self.expr_ty,
self.cast_ty, fcx);
let cast_ty = fcx.ty_to_string(self.cast_ty);
let mut err = fcx.type_error_struct(error_span,
|actual| {
format!("casting `{}` as `{}` is invalid",
actual,
cast_ty)
},
self.expr_ty);
err.span_label(error_span,
format!("cannot cast `{}` as `{}`",
fcx.ty_to_string(self.expr_ty),
@ -166,13 +175,8 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> {
}
CastError::NeedViaThinPtr |
CastError::NeedViaPtr => {
let mut err = fcx.type_error_struct(self.span,
|actual| {
format!("casting `{}` as `{}` is invalid",
actual,
fcx.ty_to_string(self.cast_ty))
},
self.expr_ty);
let mut err = make_invalid_casting_error(fcx.tcx.sess, self.span, self.expr_ty,
self.cast_ty, fcx);
if self.cast_ty.is_uint() {
err.help(&format!("cast through {} first",
match e {
@ -184,13 +188,7 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> {
err.emit();
}
CastError::NeedViaInt => {
fcx.type_error_struct(self.span,
|actual| {
format!("casting `{}` as `{}` is invalid",
actual,
fcx.ty_to_string(self.cast_ty))
},
self.expr_ty)
make_invalid_casting_error(fcx.tcx.sess, self.span, self.expr_ty, self.cast_ty, fcx)
.help(&format!("cast through {} first",
match e {
CastError::NeedViaInt => "an integer",
@ -198,6 +196,15 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> {
}))
.emit();
}
CastError::IllegalCast => {
make_invalid_casting_error(fcx.tcx.sess, self.span, self.expr_ty, self.cast_ty, fcx)
.emit();
}
CastError::DifferingKinds => {
make_invalid_casting_error(fcx.tcx.sess, self.span, self.expr_ty, self.cast_ty, fcx)
.note("vtable kinds may not match")
.emit();
}
CastError::CastToBool => {
struct_span_err!(fcx.tcx.sess, self.span, E0054, "cannot cast as `bool`")
.span_label(self.span, "unsupported cast")
@ -217,15 +224,6 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> {
primitive types. Consider using the `From` trait")
.emit();
}
CastError::IllegalCast => {
fcx.type_error_message(self.span,
|actual| {
format!("casting `{}` as `{}` is invalid",
actual,
fcx.ty_to_string(self.cast_ty))
},
self.expr_ty);
}
CastError::SizedUnsizedCast => {
fcx.type_error_message(self.span,
|actual| {
@ -236,17 +234,6 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> {
},
self.expr_ty)
}
CastError::DifferingKinds => {
fcx.type_error_struct(self.span,
|actual| {
format!("casting `{}` as `{}` is invalid",
actual,
fcx.ty_to_string(self.cast_ty))
},
self.expr_ty)
.note("vtable kinds may not match")
.emit();
}
}
}

19
src/librustc_typeck/diagnostics.rs
View file

@ -4251,6 +4251,25 @@ v as *const i8; // ok!
```
"##,
E0606: r##"
An incompatible cast was attempted.
Erroneous code example:
```compile_fail,E0606
let x = &0u8; // Here, `x` is a `&u8`.
let y: u32 = x as u32; // error: casting `&u8` as `u32` is invalid
```
When casting, keep in mind that only primitive types cast be casted into each
others. Example:
```
let x = &0u8;
let y: u32 = *x as u32; // We dereference it first and then cast it.
```
"##,
E0609: r##"
Attempted to access a non-existent field in a struct.

13
src/test/compile-fail/E0606.rs Normal file
View file

@ -0,0 +1,13 @@
// Copyright 2017 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 main() {
&0u8 as u8; //~ ERROR E0606
}

44
src/test/ui/mismatched_types/cast-rfc0401.stderr
View file

@ -1,4 +1,4 @@
error: casting `*const U` as `*const V` is invalid
error[E0606]: casting `*const U` as `*const V` is invalid
--> $DIR/cast-rfc0401.rs:13:5
|
13 | u as *const V
@ -6,7 +6,7 @@ error: casting `*const U` as `*const V` is invalid
|
= note: vtable kinds may not match
error: casting `*const U` as `*const str` is invalid
error[E0606]: casting `*const U` as `*const str` is invalid
--> $DIR/cast-rfc0401.rs:18:5
|
18 | u as *const str
@ -60,19 +60,19 @@ error[E0605]: non-scalar cast: `std::option::Option<&*const u8>` as `*const u8`
|
= note: an `as` expression can only be used to convert between primitive types. Consider using the `From` trait
error: casting `*const u8` as `f32` is invalid
error[E0606]: casting `*const u8` as `f32` is invalid
--> $DIR/cast-rfc0401.rs:45:13
|
45 | let _ = v as f32;
| ^^^^^^^^
error: casting `fn() {main}` as `f64` is invalid
error[E0606]: casting `fn() {main}` as `f64` is invalid
--> $DIR/cast-rfc0401.rs:46:13
|
46 | let _ = main as f64;
| ^^^^^^^^^^^
error: casting `&*const u8` as `usize` is invalid
error[E0606]: casting `&*const u8` as `usize` is invalid
--> $DIR/cast-rfc0401.rs:47:13
|
47 | let _ = &v as usize;
@ -80,7 +80,7 @@ error: casting `&*const u8` as `usize` is invalid
|
= help: cast through a raw pointer first
error: casting `f32` as `*const u8` is invalid
error[E0606]: casting `f32` as `*const u8` is invalid
--> $DIR/cast-rfc0401.rs:48:13
|
48 | let _ = f as *const u8;
@ -108,7 +108,7 @@ error[E0604]: only `u8` can be cast as `char`, not `u32`
51 | let _ = 0x61u32 as char;
| ^^^^^^^^^^^^^^^
error: casting `bool` as `f32` is invalid
error[E0606]: casting `bool` as `f32` is invalid
--> $DIR/cast-rfc0401.rs:53:13
|
53 | let _ = false as f32;
@ -116,7 +116,7 @@ error: casting `bool` as `f32` is invalid
|
= help: cast through an integer first
error: casting `E` as `f32` is invalid
error[E0606]: casting `E` as `f32` is invalid
--> $DIR/cast-rfc0401.rs:54:13
|
54 | let _ = E::A as f32;
@ -124,7 +124,7 @@ error: casting `E` as `f32` is invalid
|
= help: cast through an integer first
error: casting `char` as `f32` is invalid
error[E0606]: casting `char` as `f32` is invalid
--> $DIR/cast-rfc0401.rs:55:13
|
55 | let _ = 'a' as f32;
@ -132,25 +132,25 @@ error: casting `char` as `f32` is invalid
|
= help: cast through an integer first
error: casting `bool` as `*const u8` is invalid
error[E0606]: casting `bool` as `*const u8` is invalid
--> $DIR/cast-rfc0401.rs:57:13
|
57 | let _ = false as *const u8;
| ^^^^^^^^^^^^^^^^^^
error: casting `E` as `*const u8` is invalid
error[E0606]: casting `E` as `*const u8` is invalid
--> $DIR/cast-rfc0401.rs:58:13
|
58 | let _ = E::A as *const u8;
| ^^^^^^^^^^^^^^^^^
error: casting `char` as `*const u8` is invalid
error[E0606]: casting `char` as `*const u8` is invalid
--> $DIR/cast-rfc0401.rs:59:13
|
59 | let _ = 'a' as *const u8;
| ^^^^^^^^^^^^^^^^
error: casting `usize` as `*const [u8]` is invalid
error[E0606]: casting `usize` as `*const [u8]` is invalid
--> $DIR/cast-rfc0401.rs:61:13
|
61 | let _ = 42usize as *const [u8];
@ -162,37 +162,37 @@ error: cannot cast thin pointer `*const u8` to fat pointer `*const [u8]`
62 | let _ = v as *const [u8];
| ^^^^^^^^^^^^^^^^
error: casting `&Foo` as `*const str` is invalid
error[E0606]: casting `&Foo` as `*const str` is invalid
--> $DIR/cast-rfc0401.rs:64:13
|
64 | let _ = foo as *const str;
| ^^^^^^^^^^^^^^^^^
error: casting `&Foo` as `*mut str` is invalid
error[E0606]: casting `&Foo` as `*mut str` is invalid
--> $DIR/cast-rfc0401.rs:65:13
|
65 | let _ = foo as *mut str;
| ^^^^^^^^^^^^^^^
error: casting `fn() {main}` as `*mut str` is invalid
error[E0606]: casting `fn() {main}` as `*mut str` is invalid
--> $DIR/cast-rfc0401.rs:66:13
|
66 | let _ = main as *mut str;
| ^^^^^^^^^^^^^^^^
error: casting `&f32` as `*mut f32` is invalid
error[E0606]: casting `&f32` as `*mut f32` is invalid
--> $DIR/cast-rfc0401.rs:67:13
|
67 | let _ = &f as *mut f32;
| ^^^^^^^^^^^^^^
error: casting `&f32` as `*const f64` is invalid
error[E0606]: casting `&f32` as `*const f64` is invalid
--> $DIR/cast-rfc0401.rs:68:13
|
68 | let _ = &f as *const f64;
| ^^^^^^^^^^^^^^^^
error: casting `*const [i8]` as `usize` is invalid
error[E0606]: casting `*const [i8]` as `usize` is invalid
--> $DIR/cast-rfc0401.rs:69:13
|
69 | let _ = fat_sv as usize;
@ -200,7 +200,7 @@ error: casting `*const [i8]` as `usize` is invalid
|
= help: cast through a thin pointer first
error: casting `*const Foo` as `*const [u16]` is invalid
error[E0606]: casting `*const Foo` as `*const [u16]` is invalid
--> $DIR/cast-rfc0401.rs:78:13
|
78 | let _ = cf as *const [u16];
@ -208,7 +208,7 @@ error: casting `*const Foo` as `*const [u16]` is invalid
|
= note: vtable kinds may not match
error: casting `*const Foo` as `*const Bar` is invalid
error[E0606]: casting `*const Foo` as `*const Bar` is invalid
--> $DIR/cast-rfc0401.rs:79:13
|
79 | let _ = cf as *const Bar;
@ -234,7 +234,7 @@ error[E0277]: the trait bound `str: std::marker::Sized` is not satisfied
= help: the trait `std::marker::Sized` is not implemented for `str`
= note: required for the cast to the object type `Foo`
error: casting `&{float}` as `f32` is invalid
error[E0606]: casting `&{float}` as `f32` is invalid
--> $DIR/cast-rfc0401.rs:81:30
|
81 | vec![0.0].iter().map(|s| s as f32).collect::<Vec<f32>>();