Produce instead of pointers

3 files changed, 34 insertions, 9 deletions

diff --git a/src/librustc/middle/const_val.rs b/src/librustc/middle/const_val.rs
index 589890947cd..cf322010e05 100644
--- a/src/librustc/middle/const_val.rs
+++ b/src/librustc/middle/const_val.rs
@@ -14,7 +14,7 @@ use hir::def_id::DefId;
 use ty::{self, TyCtxt, layout};
 use ty::subst::Substs;
 use rustc_const_math::*;
-use mir::interpret::Value;
+use mir::interpret::{Value, PrimVal};
 
 use graphviz::IntoCow;
 use errors::DiagnosticBuilder;
@@ -39,7 +39,7 @@ pub enum ConstVal<'tcx> {
     Function(DefId, &'tcx Substs<'tcx>),
     Aggregate(ConstAggregate<'tcx>),
     Unevaluated(DefId, &'tcx Substs<'tcx>),
-    /// A miri value, currently only produced if old ctfe fails, but miri succeeds
+    /// A miri value, currently only produced if --miri is enabled
     Value(Value),
 }
 
@@ -71,12 +71,37 @@ impl<'tcx> Decodable for ConstAggregate<'tcx> {
 }
 
 impl<'tcx> ConstVal<'tcx> {
-    pub fn to_const_int(&self) -> Option<ConstInt> {
+    pub fn to_u128(&self) -> Option<u128> {
         match *self {
-            ConstVal::Integral(i) => Some(i),
-            ConstVal::Bool(b) => Some(ConstInt::U8(b as u8)),
-            ConstVal::Char(ch) => Some(ConstInt::U32(ch as u32)),
-            _ => None
+            ConstVal::Integral(i) => i.to_u128(),
+            ConstVal::Bool(b) => Some(b as u128),
+            ConstVal::Char(ch) => Some(ch as u32 as u128),
+            ConstVal::Value(Value::ByVal(PrimVal::Bytes(b))) => {
+                Some(b)
+            },
+            _ => None,
+        }
+    }
+    pub fn unwrap_u64(&self) -> u64 {
+        match self.to_u128() {
+            Some(val) => {
+                assert_eq!(val as u64 as u128, val);
+                val as u64
+            },
+            None => bug!("expected constant u64, got {:#?}", self),
+        }
+    }
+    pub fn unwrap_usize<'a, 'gcx>(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> ConstUsize {
+        match *self {
+            ConstVal::Integral(ConstInt::Usize(i)) => i,
+            ConstVal::Value(Value::ByVal(PrimVal::Bytes(b))) => {
+                assert_eq!(b as u64 as u128, b);
+                match ConstUsize::new(b as u64, tcx.sess.target.usize_ty) {
+                    Ok(val) => val,
+                    Err(e) => bug!("{:#?} is not a usize {:?}", self, e),
+                }
+            },
+            _ => bug!("expected constant u64, got {:#?}", self),
         }
     }
 }
diff --git a/src/librustc/middle/lang_items.rs b/src/librustc/middle/lang_items.rs
index 447ce46ee5c..3b37031cf46 100644
--- a/src/librustc/middle/lang_items.rs
+++ b/src/librustc/middle/lang_items.rs
@@ -280,6 +280,7 @@ language_item_table! {
     GeneratorTraitLangItem,          "generator",               gen_trait;
 
     EqTraitLangItem,                 "eq",                      eq_trait;
+    PartialOrdTraitLangItem,         "partial_ord",             partial_ord_trait;
     OrdTraitLangItem,                "ord",                     ord_trait;
 
     // A number of panic-related lang items. The `panic` item corresponds to
diff --git a/src/librustc/middle/mem_categorization.rs b/src/librustc/middle/mem_categorization.rs
index c532427cc9b..1c60ae36cd3 100644
--- a/src/librustc/middle/mem_categorization.rs
+++ b/src/librustc/middle/mem_categorization.rs
@@ -913,8 +913,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
 
         // Always promote `[T; 0]` (even when e.g. borrowed mutably).
         let promotable = match expr_ty.sty {
-            ty::TyArray(_, len) if
-                len.val.to_const_int().and_then(|i| i.to_u64()) == Some(0) => true,
+            ty::TyArray(_, len) if len.val.to_u128() == Some(0) => true,
             _ => promotable,
         };