diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs
index 06728b2e6257c..d28c5079c02d0 100644
--- a/src/librustc_metadata/decoder.rs
+++ b/src/librustc_metadata/decoder.rs
@@ -13,7 +13,8 @@
 use cstore::{self, CrateMetadata, MetadataBlob, NativeLibrary};
 use schema::*;
 
-use rustc::hir::map::{DefKey, DefPath, DefPathData, DefPathHash};
+use rustc::hir::map::{DefKey, DefPath, DefPathData, DefPathHash,
+                      DisambiguatedDefPathData};
 use rustc::hir;
 use rustc::middle::cstore::{LinkagePreference, ExternConstBody,
                             ExternBodyNestedBodies};
@@ -1061,7 +1062,23 @@ impl<'a, 'tcx> CrateMetadata {
 
     #[inline]
     pub fn def_key(&self, index: DefIndex) -> DefKey {
-        self.def_path_table.def_key(index)
+        if !self.is_proc_macro(index) {
+            self.def_path_table.def_key(index)
+        } else {
+            // FIXME(#49271) - It would be better if the DefIds were consistent
+            //                 with the DefPathTable, but for proc-macro crates
+            //                 they aren't.
+            let name = self.proc_macros
+                           .as_ref()
+                           .unwrap()[index.to_proc_macro_index()].0;
+            DefKey {
+                parent: Some(CRATE_DEF_INDEX),
+                disambiguated_data: DisambiguatedDefPathData {
+                    data: DefPathData::MacroDef(name.as_str()),
+                    disambiguator: 0,
+                }
+            }
+        }
     }
 
     // Returns the path leading to the thing with this `id`.
diff --git a/src/llvm b/src/llvm
index 9f81beaf32608..6ceaaa4b0176a 160000
--- a/src/llvm
+++ b/src/llvm
@@ -1 +1 @@
-Subproject commit 9f81beaf32608fbe1fe0f2a82f974e800e9d8c62
+Subproject commit 6ceaaa4b0176a200e4bbd347d6a991ab6c776ede
diff --git a/src/rustllvm/llvm-rebuild-trigger b/src/rustllvm/llvm-rebuild-trigger
index 3cd044708cee2..63af7a0d538e9 100644
--- a/src/rustllvm/llvm-rebuild-trigger
+++ b/src/rustllvm/llvm-rebuild-trigger
@@ -1,4 +1,4 @@
 # If this file is modified, then llvm will be (optionally) cleaned and then rebuilt.
 # The actual contents of this file do not matter, but to trigger a change on the
 # build bots then the contents should be changed so git updates the mtime.
-2018-02-09
+2018-03-06