2 files changed, 16 insertions, 4 deletions
diff --git a/src/passes/Outlining.cpp b/src/passes/Outlining.cpp
index 429511557..b86e6cd17 100644
--- a/src/passes/Outlining.cpp
+++ b/src/passes/Outlining.cpp
@@ -304,6 +304,14 @@ struct Outlining : public Pass {
     // Position the outlined functions first in the functions vector to make
     // the outlining lit tests far more readable.
     moveOutlinedFunctions(module, substrings.size());
+
+    // Because we visit control flow in stringified order rather than normal
+    // postorder, IRBuilder is not able to properly track branches, so it may
+    // not have finalized blocks with the correct types. ReFinalize now to fix
+    // any issues.
+    PassRunner runner(getPassRunner());
+    runner.add(std::make_unique<ReFinalize>());
+    runner.run();
   }
 
   Name addOutlinedFunction(Module* module,
diff --git a/src/wasm/wasm-ir-builder.cpp b/src/wasm/wasm-ir-builder.cpp
index 0d46156be..5253c91ee 100644
--- a/src/wasm/wasm-ir-builder.cpp
+++ b/src/wasm/wasm-ir-builder.cpp
@@ -972,7 +972,12 @@ Result<> IRBuilder::visitEnd() {
       block->type = blockType;
       return block;
     }
-    return builder.makeBlock(label, {curr}, blockType);
+    auto* block = builder.makeBlock();
+    block->name = label;
+    block->list.push_back(curr);
+    block->finalize(blockType,
+                    scope.labelUsed ? Block::HasBreak : Block::NoBreak);
+    return block;
   };
 
   if (auto* func = scope.getFunction()) {
@@ -985,9 +990,8 @@ Result<> IRBuilder::visitEnd() {
   } else if (auto* block = scope.getBlock()) {
     assert(*expr == block);
     block->name = scope.label;
-    // TODO: Track branches so we can know whether this block is a target and
-    // finalize more efficiently.
-    block->finalize(block->type);
+    block->finalize(block->type,
+                    scope.labelUsed ? Block::HasBreak : Block::NoBreak);
     push(block);
   } else if (auto* loop = scope.getLoop()) {
     loop->body = *expr;