Add TODO

1 files changed, 7 insertions, 0 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/WasmTarget.java b/src/main/java/org/shedlang/compiler/backends/wasm/WasmTarget.java
index c53f9779..6c3dec78 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/WasmTarget.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/WasmTarget.java
@@ -63,6 +63,13 @@ public enum WasmTarget {
     }
 
     public WasmValueType functionPointerType() {
+        // TODO: there's a problem here: wasm64 uses 32-bit function pointers,
+        // but C uses void* for all pointers, which will be 64-bit on wasm64.
+        // We could either:
+        // * Change the C definition of a closure to use a 32-bit int, and cast
+        //   it to a void* on use, or
+        // * Change the Wasm backend to treat Patio function pointers as 64-bit,
+        //   and convert from 32-bit to 64-bit when referencing table indices.
         return WasmValueType.I32;
     }