From f2ad79963c2dfba4f931bb231897133adcb8fcf1 Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Tue, 28 Aug 2018 16:49:05 -0700
Subject: [PATCH] Add a comment about "dynamic" heaps.

---
 lib/execute/src/memory.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/execute/src/memory.rs b/lib/execute/src/memory.rs
index fdd566c8d8..10069d95b3 100644
--- a/lib/execute/src/memory.rs
+++ b/lib/execute/src/memory.rs
@@ -63,6 +63,8 @@ impl LinearMemory {
         let new_bytes = (new_pages * PAGE_SIZE) as usize;
 
         if self.mmap.len() < new_bytes {
+            // If we have no maximum, this is a "dynamic" heap, and it's allowed
+            // to move.
             assert!(self.maximum.is_none());
             let mut new_mmap = memmap::MmapMut::map_anon(new_bytes).unwrap();
             new_mmap.copy_from_slice(&self.mmap);