On-demand is_const_fn

2 files changed, 3 insertions, 17 deletions

diff --git a/src/librustc_mir/transform/copy_prop.rs b/src/librustc_mir/transform/copy_prop.rs
index 08a4961c6cd..dec0717e9e3 100644
--- a/src/librustc_mir/transform/copy_prop.rs
+++ b/src/librustc_mir/transform/copy_prop.rs
@@ -34,7 +34,6 @@ use rustc::mir::transform::{MirPass, MirSource};
 use rustc::mir::visit::MutVisitor;
 use rustc::ty::TyCtxt;
 use util::def_use::DefUseAnalysis;
-use transform::qualify_consts;
 
 pub struct CopyPropagation;
 
@@ -55,7 +54,7 @@ impl MirPass for CopyPropagation {
                 return
             }
             MirSource::Fn(function_node_id) => {
-                if qualify_consts::is_const_fn(tcx, tcx.hir.local_def_id(function_node_id)) {
+                if tcx.is_const_fn(tcx.hir.local_def_id(function_node_id)) {
                     // Don't run on const functions, as, again, trans might not be able to evaluate
                     // the optimized IR.
                     return
diff --git a/src/librustc_mir/transform/qualify_consts.rs b/src/librustc_mir/transform/qualify_consts.rs
index d60e761bc0b..8342d0ff491 100644
--- a/src/librustc_mir/transform/qualify_consts.rs
+++ b/src/librustc_mir/transform/qualify_consts.rs
@@ -19,7 +19,6 @@ use rustc_data_structures::indexed_vec::{IndexVec, Idx};
 use rustc::hir;
 use rustc::hir::map as hir_map;
 use rustc::hir::def_id::DefId;
-use rustc::hir::map::blocks::FnLikeNode;
 use rustc::traits::{self, Reveal};
 use rustc::ty::{self, TyCtxt, Ty, TypeFoldable};
 use rustc::ty::cast::CastTy;
@@ -109,18 +108,6 @@ impl fmt::Display for Mode {
     }
 }
 
-pub fn is_const_fn(tcx: TyCtxt, def_id: DefId) -> bool {
-    if let Some(node_id) = tcx.hir.as_local_node_id(def_id) {
-        if let Some(fn_like) = FnLikeNode::from_node(tcx.hir.get(node_id)) {
-            fn_like.constness() == hir::Constness::Const
-        } else {
-            false
-        }
-    } else {
-        tcx.sess.cstore.is_const_fn(def_id)
-    }
-}
-
 struct Qualifier<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     mode: Mode,
     span: Span,
@@ -766,7 +753,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Qualifier<'a, 'tcx, 'tcx> {
                 ty::TyFnDef(def_id, _, f) => {
                     (f.abi() == Abi::PlatformIntrinsic &&
                      self.tcx.item_name(def_id).as_str().starts_with("simd_shuffle"),
-                     is_const_fn(self.tcx, def_id))
+                     self.tcx.is_const_fn(def_id))
                 }
                 _ => (false, false)
             };
@@ -957,7 +944,7 @@ impl MirPass for QualifyAndPromoteConstants {
         let def_id = tcx.hir.local_def_id(id);
         let mode = match src {
             MirSource::Fn(_) => {
-                if is_const_fn(tcx, def_id) {
+                if tcx.is_const_fn(def_id) {
                     Mode::ConstFn
                 } else {
                     Mode::Fn