* common, grammar: add recursive depth limit, make it a requirement
* catch more recursive functions
* common : tidy up peg parser changes
* grammar : reject candidates in a loop, without a depth limit
The depth limit in llama_grammar_reject_candidates_for_stack counted
the code points of a vocab token, so any token of 256 chars or more
was always rejected under a grammar, such as the 512-space token of
GLM-4.7-Flash or the long space tokens of Laguna-S-2.1.
The rejection now walks the code points with its own stack of levels
instead of recursing: there is no limit and no stack risk, whatever
the length of a token from the GGUF, and the masks match master.
* grammar : track rejected candidates as indices into the input
At a given code point a candidate only differs from its input by the
position of its code point pointer, so the levels now carry indices
into the input candidates instead of copies. The first level needs no
special case and the rejects map back to the input directly.
Grammar sampling gets faster than master on GLM-4.7, Laguna, Qwen3.6
and gemma-4 with the json, list and spaces grammars, same masks.
* nit : shorten the comment of llama_grammar_reject_step
* common : add depth_guard for schema walks
* grammar : move GRAMMAR_RECURSIVE_LIMIT into the .cpp
* common : reduce recursion limit for peg parser
* improve
---------
Co-authored-by: Alde Rojas <hello@alde.dev>
Co-authored-by: Pascal <admin@serveurperso.com>
* chat : reject JSON nested more than 128 levels before walking it
The schema builder, the jinja engine and the decision code walk request
JSON with recursion. A request nested deep enough overflows the stack of
the HTTP thread and llama-server dies (SIGBUS on macOS, SIGSEGV on Linux):
for a tool schema from a few hundred levels on macOS and about 10000 on
Linux.
Check the depth first and answer 400 past 128 levels: the chat inputs in
common_chat_templates_apply (tools, tool-call arguments,
chat_template_kwargs, json_schema), the json_schema of /completion, and the
whole /v1/systemone body. A gemma4 tool result that is too deep stays text.
* fix the root, not the call side
---------
Co-authored-by: Xuan Son Nguyen <son@huggingface.co>
