6 files changed, 58 insertions, 0 deletions

diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index 67deac35c..b7b7e1320 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -1840,7 +1840,18 @@ struct PrintExpressionContents
     o << "with_rtt ";
     printHeapTypeName(o, curr->rtt->type.getHeapType());
   }
+  void printUnreachableReplacement() {
+    // If we cannot print a valid unreachable instruction (say, a struct.get,
+    // where if the ref is unreachable, we don't know what heap type to print),
+    // then print the children in a block, which is good enough as this
+    // instruction is never reached anyhow.
+    printMedium(o, "block ");
+  }
   void visitStructGet(StructGet* curr) {
+    if (curr->ref->type == Type::unreachable) {
+      printUnreachableReplacement();
+      return;
+    }
     const auto& field =
       curr->ref->type.getHeapType().getStruct().fields[curr->index];
     if (field.type == Type::i32 && field.packedType != Field::not_packed) {
@@ -1857,6 +1868,10 @@ struct PrintExpressionContents
     o << curr->index;
   }
   void visitStructSet(StructSet* curr) {
+    if (curr->ref->type == Type::unreachable) {
+      printUnreachableReplacement();
+      return;
+    }
     printMedium(o, "struct.set ");
     printHeapTypeName(o, curr->ref->type.getHeapType());
     o << ' ';
diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index 6a1b72476..a9a69b244 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -2296,6 +2296,14 @@ void FunctionValidator::visitStructGet(StructGet* curr) {
   shouldBeTrue(getModule()->features.hasGC(),
                curr,
                "struct.get requires gc to be enabled");
+  if (curr->ref->type == Type::unreachable) {
+    return;
+  }
+  if (!shouldBeTrue(curr->ref->type.isStruct(),
+                    curr->ref,
+                    "struct.get ref must be a struct")) {
+    return;
+  }
   const auto& fields = curr->ref->type.getHeapType().getStruct().fields;
   shouldBeTrue(curr->index < fields.size(), curr, "bad struct.get field");
   auto field = fields[curr->index];
@@ -2315,6 +2323,14 @@ void FunctionValidator::visitStructSet(StructSet* curr) {
   shouldBeTrue(getModule()->features.hasGC(),
                curr,
                "struct.set requires gc to be enabled");
+  if (curr->ref->type == Type::unreachable) {
+    return;
+  }
+  if (!shouldBeTrue(curr->ref->type.isStruct(),
+                    curr->ref,
+                    "struct.set ref must be a struct")) {
+    return;
+  }
   if (curr->ref->type != Type::unreachable) {
     const auto& fields = curr->ref->type.getHeapType().getStruct().fields;
     shouldBeTrue(curr->index < fields.size(), curr, "bad struct.get field");
diff --git a/test/heap-types.wast b/test/heap-types.wast
index 7558e1676..87d751691 100644
--- a/test/heap-types.wast
+++ b/test/heap-types.wast
@@ -226,4 +226,12 @@
       )
     )
   )
+  (func $unreachables
+    (drop
+      (struct.get $struct.A 0 (unreachable))
+    )
+    (drop
+      (struct.set $struct.A 0 (unreachable) (unreachable))
+    )
+  )
 )
diff --git a/test/heap-types.wast.from-wast b/test/heap-types.wast.from-wast
index a93bd0d90..458842a7b 100644
--- a/test/heap-types.wast.from-wast
+++ b/test/heap-types.wast.from-wast
@@ -282,4 +282,17 @@
    )
   )
  )
+ (func $unreachables
+  (drop
+   (block 
+    (unreachable)
+   )
+  )
+  (drop
+   (block 
+    (unreachable)
+    (unreachable)
+   )
+  )
+ )
 )
diff --git a/test/heap-types.wast.fromBinary b/test/heap-types.wast.fromBinary
index d8ddb48ed..5e48da116 100644
--- a/test/heap-types.wast.fromBinary
+++ b/test/heap-types.wast.fromBinary
@@ -281,5 +281,8 @@
    )
   )
  )
+ (func $unreachables
+  (unreachable)
+ )
 )
 
diff --git a/test/heap-types.wast.fromBinary.noDebugInfo b/test/heap-types.wast.fromBinary.noDebugInfo
index 63f7e132e..d49d5fa1e 100644
--- a/test/heap-types.wast.fromBinary.noDebugInfo
+++ b/test/heap-types.wast.fromBinary.noDebugInfo
@@ -281,5 +281,8 @@
    )
   )
  )
+ (func $8
+  (unreachable)
+ )
 )