we already have the constant's type, no need to recompute from the de…

…f_id
oli-obk · Jun 9, 2016 · 225a6a2 · 225a6a2
1 parent 59d858a
commit 225a6a2
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Showing 2 changed files with 7 additions and 7 deletions.
diff --git a/src/interpreter/mod.rs b/src/interpreter/mod.rs
@@ -1184,13 +1184,12 @@ impl<'a, 'b, 'mir, 'tcx> FnEvalContext<'a, 'b, 'mir, 'tcx> {
         use rustc::mir::repr::Operand::*;
         match *op {
             Consume(ref lvalue) => Ok(self.eval_lvalue(lvalue)?.to_ptr()),
-            Constant(mir::Constant { ref literal, .. }) => {
+            Constant(mir::Constant { ref literal, ty, .. }) => {
                 use rustc::mir::repr::Literal::*;
                 match *literal {
                     Value { ref value } => Ok(self.const_to_ptr(value)?),
                     Item { def_id, substs } => {
-                        let item_ty = self.tcx.lookup_item_type(def_id).subst(self.tcx, substs);
-                        if item_ty.ty.is_fn() {
+                        if ty.is_fn() {
                             Err(EvalError::Unimplemented("unimplemented: mentions of function items".to_string()))
                         } else {
                             let cid = ConstantId {

diff --git a/src/interpreter/stepper.rs b/src/interpreter/stepper.rs
@@ -8,7 +8,7 @@ use super::{
 };
 use error::EvalResult;
 use rustc::mir::repr as mir;
-use rustc::ty::subst::{self, Subst};
+use rustc::ty::subst;
 use rustc::hir::def_id::DefId;
 use rustc::mir::visit::{Visitor, LvalueContext};
 use syntax::codemap::Span;
@@ -151,9 +151,10 @@ impl<'a, 'b, 'mir, 'tcx> Visitor<'tcx> for ConstantExtractor<'a, 'b, 'mir, 'tcx>
             // already computed by rustc
             mir::Literal::Value { .. } => {}
             mir::Literal::Item { def_id, substs } => {
-                let item_ty = self.gecx.tcx.lookup_item_type(def_id).subst(self.gecx.tcx, substs);
-                if item_ty.ty.is_fn() {
-                    // unimplemented
+                if constant.ty.is_fn() {
+                    // No need to do anything here, even if function pointers are implemented,
+                    // because the type is the actual function, not the signature of the function.
+                    // Thus we can simply create a zero sized allocation in `evaluate_operand`
                 } else {
                     self.static_item(def_id, substs, constant.span);
                 }