[Wasm GC] Handle call_ref in DeadArgument return refinement (#4038)

2 files changed, 73 insertions, 0 deletions

diff --git a/src/passes/DeadArgumentElimination.cpp b/src/passes/DeadArgumentElimination.cpp
index 601acfc5c..419ae1aca 100644
--- a/src/passes/DeadArgumentElimination.cpp
+++ b/src/passes/DeadArgumentElimination.cpp
@@ -682,6 +682,18 @@ private:
         return false;
       }
     }
+    for (auto* call : FindAll<CallRef>(func->body).list) {
+      if (call->isReturn) {
+        auto targetType = call->target->type;
+        if (targetType == Type::unreachable) {
+          continue;
+        }
+        if (!processReturnType(
+              targetType.getHeapType().getSignature().results)) {
+          return false;
+        }
+      }
+    }
     assert(refinedType != originalType);
 
     // If the refined type is unreachable then nothing actually returns from
diff --git a/test/lit/passes/dae-gc-refine-return.wast b/test/lit/passes/dae-gc-refine-return.wast
index 9f945a5b3..128b5fbcf 100644
--- a/test/lit/passes/dae-gc-refine-return.wast
+++ b/test/lit/passes/dae-gc-refine-return.wast
@@ -382,4 +382,65 @@
    (call $tail-caller-indirect-no)
   )
  )
+
+ ;; As above, but with a tail call by function reference.
+ ;; CHECK:      (func $tail-callee-call_ref (result (ref ${}))
+ ;; CHECK-NEXT:  (unreachable)
+ ;; CHECK-NEXT: )
+ (func $tail-callee-call_ref (result (ref ${}))
+  (unreachable)
+ )
+ ;; CHECK:      (func $tail-caller-call_ref-yes (result (ref ${}))
+ ;; CHECK-NEXT:  (return_call_ref
+ ;; CHECK-NEXT:   (ref.null $return_{})
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT: )
+ (func $tail-caller-call_ref-yes (result anyref)
+  (return_call_ref (ref.null $return_{}))
+ )
+ ;; CHECK:      (func $tail-caller-call_ref-no (result anyref)
+ ;; CHECK-NEXT:  (if
+ ;; CHECK-NEXT:   (i32.const 1)
+ ;; CHECK-NEXT:   (return
+ ;; CHECK-NEXT:    (ref.null any)
+ ;; CHECK-NEXT:   )
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT:  (return_call_ref
+ ;; CHECK-NEXT:   (ref.null $return_{})
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT: )
+ (func $tail-caller-call_ref-no (result anyref)
+  (if (i32.const 1)
+   (return (ref.null any))
+  )
+  (return_call_ref (ref.null $return_{}))
+ )
+ ;; CHECK:      (func $tail-caller-call_ref-unreachable
+ ;; CHECK-NEXT:  (unreachable)
+ ;; CHECK-NEXT: )
+ (func $tail-caller-call_ref-unreachable (result anyref)
+  ;; An unreachable means there is no function signature to even look at. We
+  ;; should not hit an assertion on such things.
+  (return_call_ref (unreachable))
+ )
+ ;; CHECK:      (func $tail-call-caller-call_ref
+ ;; CHECK-NEXT:  (drop
+ ;; CHECK-NEXT:   (call $tail-caller-call_ref-yes)
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT:  (drop
+ ;; CHECK-NEXT:   (call $tail-caller-call_ref-no)
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT:  (call $tail-caller-call_ref-unreachable)
+ ;; CHECK-NEXT: )
+ (func $tail-call-caller-call_ref
+  (drop
+   (call $tail-caller-call_ref-yes)
+  )
+  (drop
+   (call $tail-caller-call_ref-no)
+  )
+  (drop
+   (call $tail-caller-call_ref-unreachable)
+  )
+ )
 )