Turn an assertion on not colliding with an internal name into an error (#4422)

Without this, the result in a build without assertions might be quite
confusing. See #4410

Also make the internal names more obviously internal names.

2 files changed, 6 insertions, 3 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 95658cbe7..4804626da 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -6508,7 +6508,10 @@ void WasmBinaryBuilder::visitRethrow(Rethrow* curr) {
   BYN_TRACE("zz node: Rethrow\n");
   curr->target = getExceptionTargetName(getU32LEB());
   // This special target is valid only for delegates
-  assert(curr->target != DELEGATE_CALLER_TARGET);
+  if (curr->target == DELEGATE_CALLER_TARGET) {
+    throwError(std::string("rethrow target cannot use internal name ") +
+               DELEGATE_CALLER_TARGET.str);
+  }
   curr->finalize();
 }
 
diff --git a/src/wasm/wasm.cpp b/src/wasm/wasm.cpp
index d220b7162..aac8b44fe 100644
--- a/src/wasm/wasm.cpp
+++ b/src/wasm/wasm.cpp
@@ -91,8 +91,8 @@ Name NEG_NAN("-nan");
 Name CASE("case");
 Name BR("br");
 Name FUNCREF("funcref");
-Name FAKE_RETURN("fake_return_waka123");
-Name DELEGATE_CALLER_TARGET("delegate_caller_target_waka123");
+Name FAKE_RETURN("__binaryen_fake_return");
+Name DELEGATE_CALLER_TARGET("__binaryen_delegate_caller_target");
 Name MUT("mut");
 Name SPECTEST("spectest");
 Name PRINT("print");