3 files changed, 23 insertions, 9 deletions
diff --git a/src/tools/fuzzing.h b/src/tools/fuzzing.h
index 1afb4bf36..a3261ccbe 100644
--- a/src/tools/fuzzing.h
+++ b/src/tools/fuzzing.h
@@ -65,8 +65,12 @@ struct BinaryArgs {
 
 class TranslateToFuzzReader {
 public:
-  TranslateToFuzzReader(Module& wasm, std::vector<char>&& input);
-  TranslateToFuzzReader(Module& wasm, std::string& filename);
+  TranslateToFuzzReader(Module& wasm,
+                        std::vector<char>&& input,
+                        bool closedWorld = false);
+  TranslateToFuzzReader(Module& wasm,
+                        std::string& filename,
+                        bool closedWorld = false);
 
   void pickPasses(OptimizationOptions& options);
   void setAllowMemory(bool allowMemory_) { allowMemory = allowMemory_; }
@@ -77,6 +81,8 @@ public:
   Module& wasm;
 
 private:
+  // Whether the module will be tested in a closed-world environment.
+  bool closedWorld;
   Builder builder;
   Random random;
 
diff --git a/src/tools/fuzzing/fuzzing.cpp b/src/tools/fuzzing/fuzzing.cpp
index 7e87f4f58..ab200a126 100644
--- a/src/tools/fuzzing/fuzzing.cpp
+++ b/src/tools/fuzzing/fuzzing.cpp
@@ -32,8 +32,10 @@ namespace {
 } // anonymous namespace
 
 TranslateToFuzzReader::TranslateToFuzzReader(Module& wasm,
-                                             std::vector<char>&& input)
-  : wasm(wasm), builder(wasm), random(std::move(input), wasm.features) {
+                                             std::vector<char>&& input,
+                                             bool closedWorld)
+  : wasm(wasm), closedWorld(closedWorld), builder(wasm),
+    random(std::move(input), wasm.features) {
 
   // Half the time add no unreachable code so that we'll execute the most code
   // as possible with no early exits.
@@ -50,9 +52,11 @@ TranslateToFuzzReader::TranslateToFuzzReader(Module& wasm,
 }
 
 TranslateToFuzzReader::TranslateToFuzzReader(Module& wasm,
-                                             std::string& filename)
-  : TranslateToFuzzReader(
-      wasm, read_file<std::vector<char>>(filename, Flags::Binary)) {}
+                                             std::string& filename,
+                                             bool closedWorld)
+  : TranslateToFuzzReader(wasm,
+                          read_file<std::vector<char>>(filename, Flags::Binary),
+                          closedWorld) {}
 
 void TranslateToFuzzReader::pickPasses(OptimizationOptions& options) {
   // Pick random passes to further shape the wasm. This is similar to how we
@@ -197,8 +201,11 @@ void TranslateToFuzzReader::pickPasses(OptimizationOptions& options) {
       case 41:
         // GC specific passes.
         if (wasm.features.hasGC()) {
-          // Most of these depend on closed world, so just set that.
+          // Most of these depend on closed world, so just set that. Set it both
+          // on the global pass options, and in the internal state of this
+          // TranslateToFuzzReader instance.
           options.passOptions.closedWorld = true;
+          closedWorld = true;
 
           switch (upTo(16)) {
             case 0:
diff --git a/src/tools/wasm-opt.cpp b/src/tools/wasm-opt.cpp
index 3e429a976..2f8d22580 100644
--- a/src/tools/wasm-opt.cpp
+++ b/src/tools/wasm-opt.cpp
@@ -303,7 +303,8 @@ int main(int argc, const char* argv[]) {
     }
   }
   if (translateToFuzz) {
-    TranslateToFuzzReader reader(wasm, options.extra["infile"]);
+    TranslateToFuzzReader reader(
+      wasm, options.extra["infile"], options.passOptions.closedWorld);
     if (fuzzPasses) {
       reader.pickPasses(options);
     }