3 files changed, 70 insertions, 6 deletions
diff --git a/src/passes/RemoveNonJSOps.cpp b/src/passes/RemoveNonJSOps.cpp
index b89ef60c0..14b4f7a77 100644
--- a/src/passes/RemoveNonJSOps.cpp
+++ b/src/passes/RemoveNonJSOps.cpp
@@ -349,19 +349,36 @@ struct StubUnsupportedJSOpsPass
     }
   }
 
+  void visitCallIndirect(CallIndirect* curr) {
+    // Indirect calls of the wrong type trap in wasm, but not in wasm2js. Remove
+    // the indirect call, but leave the arguments.
+    Builder builder(*getModule());
+    std::vector<Expression*> items;
+    for (auto* operand : curr->operands) {
+      items.push_back(builder.makeDrop(operand));
+    }
+    items.push_back(builder.makeDrop(curr->target));
+    stubOut(builder.makeBlock(items), curr->type);
+  }
+
   void stubOut(Expression* value, Type outputType) {
     Builder builder(*getModule());
+    // In some cases we can just replace with the value.
+    auto* replacement = value;
     if (outputType == Type::unreachable) {
       // This is unreachable anyhow; just leave the value instead of the
       // original node.
       assert(value->type == Type::unreachable);
-      replaceCurrent(value);
-    } else {
-      // Drop the value, and return something with the right output type.
-      replaceCurrent(
-        builder.makeSequence(builder.makeDrop(value),
-                             LiteralUtils::makeZero(outputType, *getModule())));
+    } else if (outputType != Type::none) {
+      // Drop the value if we need to.
+      if (value->type != Type::none) {
+        value = builder.makeDrop(value);
+      }
+      // Return something with the right output type.
+      replacement = builder.makeSequence(
+        value, LiteralUtils::makeZero(outputType, *getModule()));
     }
+    replaceCurrent(replacement);
   }
 };
 
diff --git a/test/passes/stub-unsupported-js.txt b/test/passes/stub-unsupported-js.txt
index 531c767c0..784431116 100644
--- a/test/passes/stub-unsupported-js.txt
+++ b/test/passes/stub-unsupported-js.txt
@@ -22,3 +22,29 @@
   )
  )
 )
+(module
+ (type $none_=>_none (func))
+ (type $none_=>_i32 (func (result i32)))
+ (type $none_=>_f32 (func (result f32)))
+ (table $0 2 2 funcref)
+ (elem (i32.const 1) $return-f32)
+ (func $return-f32 (result f32)
+  (f32.const 3.141590118408203)
+ )
+ (func $bad-indirect-call
+  (drop
+   (i32.const 1)
+  )
+ )
+ (func $bad-indirect-call-2 (result i32)
+  (block
+   (drop
+    (i64.const 1234)
+   )
+   (drop
+    (i32.const 1)
+   )
+  )
+  (i32.const 0)
+ )
+)
diff --git a/test/passes/stub-unsupported-js.wast b/test/passes/stub-unsupported-js.wast
index 6cfc7bef2..b68aef64f 100644
--- a/test/passes/stub-unsupported-js.wast
+++ b/test/passes/stub-unsupported-js.wast
@@ -12,3 +12,24 @@
   (f32.convert_i32_u (unreachable))
  )
 )
+(module
+ (type $none_=>_none (func))
+ (type $i64_=>_i32 (func (param $foo i64) (result i32)))
+ (table $0 2 2 funcref)
+ (elem (i32.const 1) $return-f32)
+ (func $return-f32 (result f32)
+  (f32.const 3.14159)
+ )
+ (func $bad-indirect-call
+  (call_indirect (type $none_=>_none) ;; note how it's the wrong type
+   (i32.const 1)
+  )
+ )
+ (func $bad-indirect-call-2 (result i32)
+  (call_indirect (type $i64_=>_i32) ;; note how it's the wrong type
+   (i64.const 1234)
+   (i32.const 1)
+  )
+ )
+)
+