[C-API] Add utility to go between types and heap types (#4792)

3 files changed, 33 insertions, 0 deletions

diff --git a/src/binaryen-c.cpp b/src/binaryen-c.cpp
index 0cc4bb115..e2afe66dc 100644
--- a/src/binaryen-c.cpp
+++ b/src/binaryen-c.cpp
@@ -184,6 +184,21 @@ BinaryenPackedType BinaryenPackedTypeInt16(void) {
   return Field::PackedType::i16;
 }
 
+// Heap types
+
+BinaryenHeapType BinaryenTypeGetHeapType(BinaryenType type) {
+  return Type(type).getHeapType().getID();
+}
+bool BinaryenTypeIsNullable(BinaryenType type) {
+  return Type(type).isNullable();
+}
+BinaryenType BinaryenTypeFromHeapType(BinaryenHeapType heapType,
+                                      bool nullable) {
+  return Type(HeapType(heapType),
+              nullable ? Nullability::Nullable : Nullability::NonNullable)
+    .getID();
+}
+
 // TypeSystem
 
 BinaryenTypeSystem BinaryenTypeSystemEquirecursive() {
diff --git a/src/binaryen-c.h b/src/binaryen-c.h
index bf8ed01bb..7b5c22bf9 100644
--- a/src/binaryen-c.h
+++ b/src/binaryen-c.h
@@ -129,6 +129,15 @@ BINARYEN_API BinaryenPackedType BinaryenPackedTypeNotPacked(void);
 BINARYEN_API BinaryenPackedType BinaryenPackedTypeInt8(void);
 BINARYEN_API BinaryenPackedType BinaryenPackedTypeInt16(void);
 
+// Heap types
+
+typedef uintptr_t BinaryenHeapType;
+
+BINARYEN_API BinaryenHeapType BinaryenTypeGetHeapType(BinaryenType type);
+BINARYEN_API bool BinaryenTypeIsNullable(BinaryenType type);
+BINARYEN_API BinaryenType BinaryenTypeFromHeapType(BinaryenHeapType heapType,
+                                                   bool nullable);
+
 // TypeSystem
 
 typedef uint32_t BinaryenTypeSystem;
diff --git a/test/example/c-api-kitchen-sink.c b/test/example/c-api-kitchen-sink.c
index cb156c7c1..28e784a05 100644
--- a/test/example/c-api-kitchen-sink.c
+++ b/test/example/c-api-kitchen-sink.c
@@ -287,6 +287,15 @@ void test_types() {
   printf("BinaryenPackedTypeInt8: %d\n", i8);
   BinaryenPackedType i16 = BinaryenPackedTypeInt16();
   printf("BinaryenPackedTypeInt16: %d\n", i16);
+
+  BinaryenHeapType eq = BinaryenTypeGetHeapType(eqref);
+  BinaryenType ref_null_eq = BinaryenTypeFromHeapType(eq, true);
+  assert(BinaryenTypeGetHeapType(ref_null_eq) == eq);
+  assert(BinaryenTypeIsNullable(ref_null_eq));
+  BinaryenType ref_eq = BinaryenTypeFromHeapType(eq, false);
+  assert(ref_eq != ref_null_eq);
+  assert(BinaryenTypeGetHeapType(ref_eq) == eq);
+  assert(!BinaryenTypeIsNullable(ref_eq));
 }
 
 void test_features() {