[Wasm GC] Avoid extremely large outputs in TypeNamePrinter (#3667)

1 files changed, 22 insertions, 0 deletions

diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index 05a639158..4346fe705 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -96,9 +96,28 @@ struct TypeNamePrinter {
   void print(const Struct& struct_);
   void print(const Array& array);
   void print(const Rtt& rtt);
+
+  // FIXME: This hard limit on how many times we call print() avoids extremely
+  //        large outputs, which can be inconveniently large in some cases, but
+  //        we should have a better mechanism for this.
+  static const size_t MaxPrints = 100;
+
+  size_t prints = 0;
+
+  bool exceededLimit() {
+    if (prints >= MaxPrints) {
+      os << "?";
+      return true;
+    }
+    prints++;
+    return false;
+  }
 };
 
 void TypeNamePrinter::print(Type type) {
+  if (exceededLimit()) {
+    return;
+  }
   if (type.isBasic()) {
     os << type;
   } else if (type.isTuple()) {
@@ -119,6 +138,9 @@ void TypeNamePrinter::print(Type type) {
 }
 
 void TypeNamePrinter::print(HeapType type) {
+  if (exceededLimit()) {
+    return;
+  }
   if (type.isBasic()) {
     os << type;
     return;