Move EntityRef and entity_impl! into a new module.

The EntityRef trait is used by more than just the EntityMap now, so it
should live in its own module.

Also move the entity_impl! macro into the new module so it can be used
for defining new entity references anywhere.

lib/cretonne/src/ir/entities.rs

@@ -19,46 +19,9 @@
 //! The entity references all implement the `Display` trait in a way that matches the textual IL
 //! format.
 
-use entity_map::EntityRef;
-use packed_option::ReservedValue;
-use std::fmt::{self, Display, Formatter};
+use std::fmt;
 use std::u32;
 
-// Implement the common traits for a 32-bit entity reference.
-macro_rules! entity_impl {
-    // Basic traits.
-    ($entity:ident) => {
-        impl EntityRef for $entity {
-            fn new(index: usize) -> Self {
-                assert!(index < (u32::MAX as usize));
-                $entity(index as u32)
-            }
-
-            fn index(self) -> usize {
-                self.0 as usize
-            }
-        }
-
-        impl ReservedValue for $entity {
-            fn reserved_value() -> $entity {
-                $entity(u32::MAX)
-            }
-        }
-    };
-
-    // Include basic `Display` impl using the given display prefix.
-    // Display an `Ebb` reference as "ebb12".
-    ($entity:ident, $display_prefix:expr) => {
-        entity_impl!($entity);
-
-        impl Display for $entity {
-            fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
-                write!(fmt, "{}{}", $display_prefix, self.0)
-            }
-        }
-    }
-}
-
 /// An opaque reference to an extended basic block in a function.
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, PartialOrd, Ord)]
 pub struct Ebb(u32);
@@ -138,17 +101,17 @@ pub enum AnyEntity {
     SigRef(SigRef),
 }
 
-impl Display for AnyEntity {
-    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
+impl fmt::Display for AnyEntity {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            AnyEntity::Function => write!(fmt, "function"),
-            AnyEntity::Ebb(r) => r.fmt(fmt),
-            AnyEntity::Inst(r) => r.fmt(fmt),
-            AnyEntity::Value(r) => r.fmt(fmt),
-            AnyEntity::StackSlot(r) => r.fmt(fmt),
-            AnyEntity::JumpTable(r) => r.fmt(fmt),
-            AnyEntity::FuncRef(r) => r.fmt(fmt),
-            AnyEntity::SigRef(r) => r.fmt(fmt),
+            AnyEntity::Function => write!(f, "function"),
+            AnyEntity::Ebb(r) => r.fmt(f),
+            AnyEntity::Inst(r) => r.fmt(f),
+            AnyEntity::Value(r) => r.fmt(f),
+            AnyEntity::StackSlot(r) => r.fmt(f),
+            AnyEntity::JumpTable(r) => r.fmt(f),
+            AnyEntity::FuncRef(r) => r.fmt(f),
+            AnyEntity::SigRef(r) => r.fmt(f),
         }
     }
 }

lib/cretonne/src/ir/jumptable.rs

@@ -122,7 +122,7 @@ impl Display for JumpTableData {
 mod tests {
     use super::JumpTableData;
     use ir::Ebb;
-    use entity_map::EntityRef;
+    use entity_ref::EntityRef;
 
     #[test]
     fn empty() {

lib/cretonne/src/ir/layout.rs

@@ -982,7 +982,7 @@ impl<'f> Cursor<'f> {
 #[cfg(test)]
 mod tests {
     use super::{Layout, Cursor, CursorPosition};
-    use entity_map::EntityRef;
+    use entity_ref::EntityRef;
     use ir::{Ebb, Inst, ProgramOrder};
     use std::cmp::Ordering;
 

lib/cretonne/src/ir/progpoint.rs

@@ -1,6 +1,6 @@
 //! Program points.
 
-use entity_map::EntityRef;
+use entity_ref::EntityRef;
 use ir::{Ebb, Inst, ValueDef};
 use std::fmt;
 use std::u32;
@@ -122,7 +122,7 @@ pub trait ProgramOrder {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use entity_map::EntityRef;
+    use entity_ref::EntityRef;
     use ir::{Inst, Ebb};
 
     #[test]