Index: lib/sanitizer_common/sanitizer_allocator_secondary.h
===================================================================
--- lib/sanitizer_common/sanitizer_allocator_secondary.h
+++ lib/sanitizer_common/sanitizer_allocator_secondary.h
@@ -64,11 +64,20 @@
 typedef LargeMmapAllocatorPtrArrayDynamic DefaultLargeMmapAllocatorPtrArray;
 #endif
 
+// No-op implementation of `ObjectMap`.
+struct LocalObjectMap {
+  template <typename T>
+  static T *Map(T *target_address, uptr num_elements = 1) {
+    return target_address;
+  }
+};
+
 // This class can (de)allocate only large chunks of memory using mmap/unmap.
 // The main purpose of this allocator is to cover large and rare allocation
 // sizes not covered by more efficient allocators (e.g. SizeClassAllocator64).
 template <class MapUnmapCallback = NoOpMapUnmapCallback,
-          class PtrArrayT = DefaultLargeMmapAllocatorPtrArray>
+          class PtrArrayT = DefaultLargeMmapAllocatorPtrArray,
+          class ObjectMap = LocalObjectMap>
 class LargeMmapAllocator {
  public:
   void InitLinkerInitialized() {
@@ -202,9 +211,10 @@
 
   void EnsureSortedChunks() {
     if (chunks_sorted_) return;
-    Sort(reinterpret_cast<uptr *>(chunks_), n_chunks_);
+    Header **chunks = ObjectMap::Map(chunks_, n_chunks_);
+    Sort(reinterpret_cast<uptr *>(chunks), n_chunks_);
     for (uptr i = 0; i < n_chunks_; i++)
-      chunks_[i]->chunk_idx = i;
+      ObjectMap::Map(chunks[i])->chunk_idx = i;
     chunks_sorted_ = true;
   }
 
@@ -272,12 +282,13 @@
   // The allocator must be locked when calling this function.
   void ForEachChunk(ForEachChunkCallback callback, void *arg) {
     EnsureSortedChunks();  // Avoid doing the sort while iterating.
+    Header **chunks = ObjectMap::Map(chunks_, n_chunks_);
     for (uptr i = 0; i < n_chunks_; i++) {
-      auto t = chunks_[i];
+      Header *t = chunks[i];
       callback(reinterpret_cast<uptr>(GetUser(t)), arg);
       // Consistency check: verify that the array did not change.
-      CHECK_EQ(chunks_[i], t);
-      CHECK_EQ(chunks_[i]->chunk_idx, i);
+      CHECK_EQ(chunks[i], t);
+      CHECK_EQ(ObjectMap::Map(chunks[i])->chunk_idx, i);
     }
   }