Warn on memory segment overlaps (#3257)

We may fix this eventually, but it appears to not be urgent. For now at least
show a warning so toolchains have a chance to see there is something
they should fix.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/passes/MemoryPacking.cpp b/src/passes/MemoryPacking.cpp
index 3ab170ea9..6003274e8 100644
--- a/src/passes/MemoryPacking.cpp
+++ b/src/passes/MemoryPacking.cpp
@@ -232,6 +232,8 @@ bool MemoryPacking::canOptimize(const std::vector<Memory::Segment>& segments) {
       Address start = c->value.getInteger();
       DisjointSpans::Span span{start, start + segment.data.size()};
       if (space.addAndCheckOverlap(span)) {
+        std::cerr << "warning: active memory segments have overlap, which "
+                  << "prevents some optimizations.\n";
         return false;
       }
     }