4 files changed, 20 insertions, 10 deletions

diff --git a/src/parser/parsers.h b/src/parser/parsers.h
index b6699aab6..4121788d7 100644
--- a/src/parser/parsers.h
+++ b/src/parser/parsers.h
@@ -1143,7 +1143,7 @@ ifelse(Ctx& ctx, const std::vector<Annotation>& annotations, bool folded) {
     ctx.setSrcLoc(annotations);
   }
 
-  ctx.makeIf(pos, annotations, label, *type);
+  CHECK_ERR(ctx.makeIf(pos, annotations, label, *type));
 
   if (folded && !ctx.in.takeSExprStart("then"sv)) {
     return ctx.in.err("expected 'then' before if instructions");
diff --git a/src/passes/Outlining.cpp b/src/passes/Outlining.cpp
index 68c3d0397..429511557 100644
--- a/src/passes/Outlining.cpp
+++ b/src/passes/Outlining.cpp
@@ -42,8 +42,8 @@ namespace wasm {
 struct ReconstructStringifyWalker
   : public StringifyWalker<ReconstructStringifyWalker> {
 
-  ReconstructStringifyWalker(Module* wasm)
-    : existingBuilder(*wasm), outlinedBuilder(*wasm) {
+  ReconstructStringifyWalker(Module* wasm, Function* func)
+    : existingBuilder(*wasm), outlinedBuilder(*wasm), func(func) {
     this->setModule(wasm);
     DBG(std::cerr << "\nexistingBuilder: " << &existingBuilder
                   << " outlinedBuilder: " << &outlinedBuilder << "\n");
@@ -77,6 +77,9 @@ struct ReconstructStringifyWalker
   // contain repeat sequences found in the program.
   IRBuilder outlinedBuilder;
 
+  // The function we are outlining from.
+  Function* func;
+
   void addUniqueSymbol(SeparatorReason reason) {
     if (auto curr = reason.getFuncStart()) {
       startExistingFunction(curr->func);
@@ -108,6 +111,8 @@ struct ReconstructStringifyWalker
       DBG(desc = "Loop Start at ");
     } else if (reason.getEnd()) {
       ASSERT_OK(existingBuilder.visitEnd());
+      // Reset the function in case we just ended the function scope.
+      existingBuilder.setFunction(func);
       // Outlining performs an unnested walk of the Wasm module, visiting
       // each scope one at a time. IRBuilder, in contrast, expects to
       // visit several nested scopes at a time. Thus, calling end() finalizes
@@ -346,15 +351,16 @@ struct Outlining : public Pass {
 
   void outline(Module* module, Sequences seqByFunc) {
     // TODO: Make this a function-parallel sub-pass.
-    ReconstructStringifyWalker reconstruct(module);
     std::vector<Name> keys(seqByFunc.size());
     std::transform(seqByFunc.begin(),
                    seqByFunc.end(),
                    keys.begin(),
                    [](auto pair) { return pair.first; });
-    for (auto func : keys) {
-      reconstruct.sequences = std::move(seqByFunc[func]);
-      reconstruct.doWalkFunction(module->getFunction(func));
+    for (auto funcName : keys) {
+      auto* func = module->getFunction(funcName);
+      ReconstructStringifyWalker reconstruct(module, func);
+      reconstruct.sequences = std::move(seqByFunc[funcName]);
+      reconstruct.doWalkFunction(func);
     }
   }
 
diff --git a/src/wasm-ir-builder.h b/src/wasm-ir-builder.h
index 40689a879..0210c55e5 100644
--- a/src/wasm-ir-builder.h
+++ b/src/wasm-ir-builder.h
@@ -40,8 +40,7 @@ namespace wasm {
 // globals, tables, functions, etc.) to already exist in the module.
 class IRBuilder : public UnifiedExpressionVisitor<IRBuilder, Result<>> {
 public:
-  IRBuilder(Module& wasm, Function* func = nullptr)
-    : wasm(wasm), func(func), builder(wasm) {}
+  IRBuilder(Module& wasm) : wasm(wasm), builder(wasm) {}
 
   // Get the valid Binaryen IR expression representing the sequence of visited
   // instructions. The IRBuilder is reset and can be used with a fresh sequence
@@ -60,6 +59,10 @@ public:
   // pushed instruction.
   void setDebugLocation(const std::optional<Function::DebugLocation>&);
 
+  // Set the function used to add scratch locals when constructing an isolated
+  // sequence of IR.
+  void setFunction(Function* func) { this->func = func; }
+
   // Handle the boundaries of control flow structures. Users may choose to use
   // the corresponding `makeXYZ` function below instead of `visitXYZStart`, but
   // either way must call `visitEnd` and friends at the appropriate times.
@@ -234,7 +237,7 @@ public:
 
 private:
   Module& wasm;
-  Function* func;
+  Function* func = nullptr;
   Builder builder;
 
   // The location lacks debug info as it was marked as not having it.
diff --git a/src/wasm/wasm-ir-builder.cpp b/src/wasm/wasm-ir-builder.cpp
index 5e5decca4..398db68ff 100644
--- a/src/wasm/wasm-ir-builder.cpp
+++ b/src/wasm/wasm-ir-builder.cpp
@@ -981,6 +981,7 @@ Result<> IRBuilder::visitEnd() {
     if (scope.needsPopFixup()) {
       EHUtils::handleBlockNestedPops(func, wasm);
     }
+    this->func = nullptr;
   } else if (auto* block = scope.getBlock()) {
     assert(*expr == block);
     block->name = scope.label;