move unsafety checking to MIR

No functional changes intended.

Author: arielb1

src/librustc/dep_graph/dep_node.rs

@@ -445,6 +445,7 @@ define_dep_nodes!( <'tcx>
     [] BorrowCheckKrate,
     [] BorrowCheck(DefId),
     [] MirBorrowCheck(DefId),
+    [] UnsafetyViolations(DefId),
 
     [] RvalueCheck(DefId),
     [] Reachability,

src/librustc/diagnostics.rs

@@ -479,40 +479,6 @@ fn main() {
 ```
 "##,
 
-E0133: r##"
-Unsafe code was used outside of an unsafe function or block.
-
-Erroneous code example:
-
-```compile_fail,E0133
-unsafe fn f() { return; } // This is the unsafe code
-
-fn main() {
-    f(); // error: call to unsafe function requires unsafe function or block
-}
-```
-
-Using unsafe functionality is potentially dangerous and disallowed by safety
-checks. Examples:
-
-* Dereferencing raw pointers
-* Calling functions via FFI
-* Calling functions marked unsafe
-
-These safety checks can be relaxed for a section of the code by wrapping the
-unsafe instructions with an `unsafe` block. For instance:
-
-```
-unsafe fn f() { return; }
-
-fn main() {
-    unsafe { f(); } // ok!
-}
-```
-
-See also https://doc.rust-lang.org/book/first-edition/unsafe.html
-"##,
-
 // This shouldn't really ever trigger since the repeated value error comes first
 E0136: r##"
 A binary can only have one entry point, and by default that entry point is the

src/librustc/ich/impls_mir.rs

@@ -33,6 +33,7 @@ impl_stable_hash_for!(struct mir::LocalDecl<'tcx> {
 });
 impl_stable_hash_for!(struct mir::UpvarDecl { debug_name, by_ref });
 impl_stable_hash_for!(struct mir::BasicBlockData<'tcx> { statements, terminator, is_cleanup });
+impl_stable_hash_for!(struct mir::UnsafetyViolation { source_info, description, lint_node_id });
 
 impl<'gcx> HashStable<StableHashingContext<'gcx>>
 for mir::Terminator<'gcx> {
@@ -364,7 +365,26 @@ for mir::ProjectionElem<'gcx, V, T>
 }
 
 impl_stable_hash_for!(struct mir::VisibilityScopeData { span, parent_scope });
-impl_stable_hash_for!(struct mir::VisibilityScopeInfo { lint_root });
+impl_stable_hash_for!(struct mir::VisibilityScopeInfo {
+    lint_root, safety
+});
+
+impl<'gcx> HashStable<StableHashingContext<'gcx>> for mir::Safety {
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut StableHashingContext<'gcx>,
+                                          hasher: &mut StableHasher<W>) {
+        mem::discriminant(self).hash_stable(hcx, hasher);
+
+        match *self {
+            mir::Safety::Safe |
+            mir::Safety::BuiltinUnsafe |
+            mir::Safety::FnUnsafe => {}
+            mir::Safety::ExplicitUnsafe(node_id) => {
+                node_id.hash_stable(hcx, hasher);
+            }
+        }
+    }
+}
 
 impl<'gcx> HashStable<StableHashingContext<'gcx>> for mir::Operand<'gcx> {
     fn hash_stable<W: StableHasherResult>(&self,

src/librustc/lib.rs

@@ -111,7 +111,6 @@ pub mod middle {
     pub mod dataflow;
     pub mod dead;
     pub mod dependency_format;
-    pub mod effect;
     pub mod entry;
     pub mod exported_symbols;
     pub mod free_region;