gpt-oss : clean up workarounds

Author: aldehir

common/chat.cpp

@@ -1315,6 +1315,16 @@ static common_chat_params common_chat_params_init_gpt_oss(const common_chat_temp
     data.prompt = prompt;
     data.format = COMMON_CHAT_FORMAT_GPT_OSS;
 
+    // These special tokens are required to parse properly, so we include them
+    // even if parse_tool_calls is false.
+    data.preserved_tokens = {
+        "<|channel|>",
+        "<|constrain|>",
+        "<|message|>",
+        "<|start|>",
+        "<|end|>",
+    };
+
     if (inputs.tools.is_array() && !inputs.tools.empty()) {
         data.grammar_lazy = inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_REQUIRED;
         data.grammar = build_grammar([&](const common_grammar_builder & builder) {
@@ -1373,14 +1383,6 @@ static common_chat_params common_chat_params_init_gpt_oss(const common_chat_temp
                 COMMON_GRAMMAR_TRIGGER_TYPE_PATTERN,
                 "<\\|start\\|>assistant to"
             });
-
-            data.preserved_tokens = {
-                "<|channel|>",
-                "<|constrain|>",
-                "<|message|>",
-                "<|start|>",
-                "<|end|>",
-            };
         });
     }
 

src/llama-vocab.cpp

@@ -2339,13 +2339,6 @@ void llama_vocab::impl::load(llama_model_loader & ml, const LLM_KV & kv) {
             }
         }
 
-        // @ngxson : quick hack for gpt-oss, always render these tokens
-        for (const auto & t : token_to_id) {
-            if (t.first == "<|channel|>" || t.first == "<|message|>" || t.first == "<|start|>" || t.first == "<|constrain|>") {
-                id_to_token[t.second].attr = LLAMA_TOKEN_ATTR_USER_DEFINED;
-            }
-        }
-
         // sanity checks
         if (special_eos_id != LLAMA_TOKEN_NULL && special_eog_ids.count(special_eos_id) == 0) {
             special_eog_ids.insert(special_eos_id);
@@ -2388,7 +2381,6 @@ void llama_vocab::impl::load(llama_model_loader & ml, const LLM_KV & kv) {
 
             if (has_return && has_call && has_end) {
                 special_eog_ids.erase(end_id);
-                id_to_token[end_id].attr = LLAMA_TOKEN_ATTR_USER_DEFINED;
                 LLAMA_LOG_WARN("%s: special_eog_ids contains both '<|return|>' and '<|call|>' tokens, removing '<|end|>' token from EOG list\n", __func__);
             }
         }