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middle::intrinsicck -> rustc_passes

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Mark-Simulacrum committed Oct 4, 2019
1 parent 82bfd8e commit 7c3f65b3c4691ff0df270505ebfab89f171c0d28
@@ -3613,6 +3613,8 @@ dependencies = [
"rustc",
"rustc_data_structures",
"rustc_errors",
"rustc_index",
"rustc_target",
"syntax",
"syntax_pos",
]
@@ -1566,33 +1566,6 @@ It is not possible to use stability attributes outside of the standard library.
Also, for now, it is not possible to write deprecation messages either.
"##,

E0512: r##"
Transmute with two differently sized types was attempted. Erroneous code
example:
```compile_fail,E0512
fn takes_u8(_: u8) {}
fn main() {
unsafe { takes_u8(::std::mem::transmute(0u16)); }
// error: cannot transmute between types of different sizes,
// or dependently-sized types
}
```
Please use types with same size or use the expected type directly. Example:
```
fn takes_u8(_: u8) {}
fn main() {
unsafe { takes_u8(::std::mem::transmute(0i8)); } // ok!
// or:
unsafe { takes_u8(0u8); } // ok!
}
```
"##,

E0517: r##"
This error indicates that a `#[repr(..)]` attribute was placed on an
unsupported item.
@@ -1787,84 +1760,6 @@ See [RFC 1522] for more details.
[RFC 1522]: https://github.com/rust-lang/rfcs/blob/master/text/1522-conservative-impl-trait.md
"##,

E0591: r##"
Per [RFC 401][rfc401], if you have a function declaration `foo`:
```
// For the purposes of this explanation, all of these
// different kinds of `fn` declarations are equivalent:
struct S;
fn foo(x: S) { /* ... */ }
# #[cfg(for_demonstration_only)]
extern "C" { fn foo(x: S); }
# #[cfg(for_demonstration_only)]
impl S { fn foo(self) { /* ... */ } }
```
the type of `foo` is **not** `fn(S)`, as one might expect.
Rather, it is a unique, zero-sized marker type written here as `typeof(foo)`.
However, `typeof(foo)` can be _coerced_ to a function pointer `fn(S)`,
so you rarely notice this:
```
# struct S;
# fn foo(_: S) {}
let x: fn(S) = foo; // OK, coerces
```
The reason that this matter is that the type `fn(S)` is not specific to
any particular function: it's a function _pointer_. So calling `x()` results
in a virtual call, whereas `foo()` is statically dispatched, because the type
of `foo` tells us precisely what function is being called.
As noted above, coercions mean that most code doesn't have to be
concerned with this distinction. However, you can tell the difference
when using **transmute** to convert a fn item into a fn pointer.
This is sometimes done as part of an FFI:
```compile_fail,E0591
extern "C" fn foo(userdata: Box<i32>) {
/* ... */
}
# fn callback(_: extern "C" fn(*mut i32)) {}
# use std::mem::transmute;
# unsafe {
let f: extern "C" fn(*mut i32) = transmute(foo);
callback(f);
# }
```
Here, transmute is being used to convert the types of the fn arguments.
This pattern is incorrect because, because the type of `foo` is a function
**item** (`typeof(foo)`), which is zero-sized, and the target type (`fn()`)
is a function pointer, which is not zero-sized.
This pattern should be rewritten. There are a few possible ways to do this:
- change the original fn declaration to match the expected signature,
and do the cast in the fn body (the preferred option)
- cast the fn item fo a fn pointer before calling transmute, as shown here:
```
# extern "C" fn foo(_: Box<i32>) {}
# use std::mem::transmute;
# unsafe {
let f: extern "C" fn(*mut i32) = transmute(foo as extern "C" fn(_));
let f: extern "C" fn(*mut i32) = transmute(foo as usize); // works too
# }
```
The same applies to transmutes to `*mut fn()`, which were observed in practice.
Note though that use of this type is generally incorrect.
The intention is typically to describe a function pointer, but just `fn()`
alone suffices for that. `*mut fn()` is a pointer to a fn pointer.
(Since these values are typically just passed to C code, however, this rarely
makes a difference in practice.)
[rfc401]: https://github.com/rust-lang/rfcs/blob/master/text/0401-coercions.md
"##,

E0593: r##"
You tried to supply an `Fn`-based type with an incorrect number of arguments
than what was expected.
@@ -106,7 +106,6 @@ pub mod middle {
pub mod diagnostic_items;
pub mod exported_symbols;
pub mod free_region;
pub mod intrinsicck;
pub mod lib_features;
pub mod lang_items;
pub mod mem_categorization;
@@ -780,7 +780,6 @@ pub fn default_provide(providers: &mut ty::query::Providers<'_>) {
ty::provide(providers);
traits::provide(providers);
stability::provide(providers);
middle::intrinsicck::provide(providers);
reachable::provide(providers);
rustc_passes::provide(providers);
rustc_traits::provide(providers);
@@ -15,3 +15,5 @@ rustc_data_structures = { path = "../librustc_data_structures" }
syntax = { path = "../libsyntax" }
syntax_pos = { path = "../libsyntax_pos" }
errors = { path = "../librustc_errors", package = "rustc_errors" }
rustc_target = { path = "../librustc_target" }
rustc_index = { path = "../librustc_index" }
@@ -396,6 +396,111 @@ If you don't know the basics of Rust, you can go look to the Rust Book to get
started: https://doc.rust-lang.org/book/
"##,

E0591: r##"
Per [RFC 401][rfc401], if you have a function declaration `foo`:
```
// For the purposes of this explanation, all of these
// different kinds of `fn` declarations are equivalent:
struct S;
fn foo(x: S) { /* ... */ }
# #[cfg(for_demonstration_only)]
extern "C" { fn foo(x: S); }
# #[cfg(for_demonstration_only)]
impl S { fn foo(self) { /* ... */ } }
```
the type of `foo` is **not** `fn(S)`, as one might expect.
Rather, it is a unique, zero-sized marker type written here as `typeof(foo)`.
However, `typeof(foo)` can be _coerced_ to a function pointer `fn(S)`,
so you rarely notice this:
```
# struct S;
# fn foo(_: S) {}
let x: fn(S) = foo; // OK, coerces
```
The reason that this matter is that the type `fn(S)` is not specific to
any particular function: it's a function _pointer_. So calling `x()` results
in a virtual call, whereas `foo()` is statically dispatched, because the type
of `foo` tells us precisely what function is being called.
As noted above, coercions mean that most code doesn't have to be
concerned with this distinction. However, you can tell the difference
when using **transmute** to convert a fn item into a fn pointer.
This is sometimes done as part of an FFI:
```compile_fail,E0591
extern "C" fn foo(userdata: Box<i32>) {
/* ... */
}
# fn callback(_: extern "C" fn(*mut i32)) {}
# use std::mem::transmute;
# unsafe {
let f: extern "C" fn(*mut i32) = transmute(foo);
callback(f);
# }
```
Here, transmute is being used to convert the types of the fn arguments.
This pattern is incorrect because, because the type of `foo` is a function
**item** (`typeof(foo)`), which is zero-sized, and the target type (`fn()`)
is a function pointer, which is not zero-sized.
This pattern should be rewritten. There are a few possible ways to do this:
- change the original fn declaration to match the expected signature,
and do the cast in the fn body (the preferred option)
- cast the fn item fo a fn pointer before calling transmute, as shown here:
```
# extern "C" fn foo(_: Box<i32>) {}
# use std::mem::transmute;
# unsafe {
let f: extern "C" fn(*mut i32) = transmute(foo as extern "C" fn(_));
let f: extern "C" fn(*mut i32) = transmute(foo as usize); // works too
# }
```
The same applies to transmutes to `*mut fn()`, which were observed in practice.
Note though that use of this type is generally incorrect.
The intention is typically to describe a function pointer, but just `fn()`
alone suffices for that. `*mut fn()` is a pointer to a fn pointer.
(Since these values are typically just passed to C code, however, this rarely
makes a difference in practice.)
[rfc401]: https://github.com/rust-lang/rfcs/blob/master/text/0401-coercions.md
"##,

E0512: r##"
Transmute with two differently sized types was attempted. Erroneous code
example:
```compile_fail,E0512
fn takes_u8(_: u8) {}
fn main() {
unsafe { takes_u8(::std::mem::transmute(0u16)); }
// error: cannot transmute between types of different sizes,
// or dependently-sized types
}
```
Please use types with same size or use the expected type directly. Example:
```
fn takes_u8(_: u8) {}
fn main() {
unsafe { takes_u8(::std::mem::transmute(0i8)); } // ok!
// or:
unsafe { takes_u8(0u8); } // ok!
}
```
"##,

;
E0226, // only a single explicit lifetime bound is permitted
E0472, // asm! is unsupported on this target
@@ -1,14 +1,14 @@
use crate::hir::def::{Res, DefKind};
use crate::hir::def_id::DefId;
use crate::ty::{self, Ty, TyCtxt};
use crate::ty::layout::{LayoutError, Pointer, SizeSkeleton, VariantIdx};
use crate::ty::query::Providers;
use rustc::hir::def::{Res, DefKind};
use rustc::hir::def_id::DefId;
use rustc::ty::{self, Ty, TyCtxt};
use rustc::ty::layout::{LayoutError, Pointer, SizeSkeleton, VariantIdx};
use rustc::ty::query::Providers;

use rustc_target::spec::abi::Abi::RustIntrinsic;
use rustc_index::vec::Idx;
use syntax_pos::{Span, sym};
use crate::hir::intravisit::{self, Visitor, NestedVisitorMap};
use crate::hir;
use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
use rustc::hir;

fn check_mod_intrinsics(tcx: TyCtxt<'_>, module_def_id: DefId) {
tcx.hir().visit_item_likes_in_module(
@@ -29,9 +29,11 @@ pub mod loops;
pub mod dead;
pub mod entry;
mod liveness;
mod intrinsicck;

pub fn provide(providers: &mut Providers<'_>) {
entry::provide(providers);
loops::provide(providers);
liveness::provide(providers);
intrinsicck::provide(providers);
}

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