[Types] Add type sorting for Signatures (#3366)

1 files changed, 22 insertions, 9 deletions

diff --git a/src/wasm/wasm-type.cpp b/src/wasm/wasm-type.cpp
index f98077961..5e4d5e07f 100644
--- a/src/wasm/wasm-type.cpp
+++ b/src/wasm/wasm-type.cpp
@@ -383,15 +383,28 @@ bool Type::isRtt() const {
 }
 
 bool Type::operator<(const Type& other) const {
-  return std::lexicographical_compare(begin(),
-                                      end(),
-                                      other.begin(),
-                                      other.end(),
-                                      [](const Type& a, const Type& b) {
-                                        TODO_SINGLE_COMPOUND(a);
-                                        TODO_SINGLE_COMPOUND(b);
-                                        return a.getBasic() < b.getBasic();
-                                      });
+  auto comp = [](const Type& a, const Type& b) {
+    if (a.isBasic() && b.isBasic()) {
+      return a.getBasic() < b.getBasic();
+    }
+    if (a.isBasic()) {
+      return true;
+    }
+    if (b.isBasic()) {
+      return false;
+    }
+    // Both are compound.
+    auto aHeap = a.getHeapType();
+    auto bHeap = b.getHeapType();
+    if (aHeap.isSignature() && bHeap.isSignature()) {
+      return aHeap.getSignature() < bHeap.getSignature();
+    }
+    TODO_SINGLE_COMPOUND(a);
+    TODO_SINGLE_COMPOUND(b);
+    WASM_UNREACHABLE("unimplemented type comparison");
+  };
+  return std::lexicographical_compare(
+    begin(), end(), other.begin(), other.end(), comp);
 }
 
 unsigned Type::getByteSize() const {