middle::intrinsicck -> rustc_passes

Author: Mark-Simulacrum

Cargo.lock

@@ -3613,6 +3613,8 @@ dependencies = [
  "rustc",
  "rustc_data_structures",
  "rustc_errors",
+ "rustc_index",
+ "rustc_target",
  "syntax",
  "syntax_pos",
 ]

src/librustc/error_codes.rs

@@ -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.

src/librustc/lib.rs

@@ -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;

src/librustc_interface/passes.rs

@@ -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);

src/librustc_passes/Cargo.toml

@@ -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" }

src/librustc_passes/error_codes.rs

@@ -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

src/librustc/middle/intrinsicck.rs renamed to src/librustc_passes/intrinsicck.rs

@@ -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(

src/librustc_passes/lib.rs

@@ -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);
 }