chat: harden peg-native tool call parsing (#24329)

* chat: harden peg-native tool call parsing

accept an optional leading type: function field in
build_json_tools_flat_keys so openai style tool calls parse on
templates whose serialization opens on the name field.

return a clean error and log the unparsed fragment on a final peg
parse failure instead of throwing the raw parser position and input.

keep the raw arguments string in func_args_not_string when it is not
valid json instead of aborting the prompt render.

* chat: surface peg-native parse failures

a final peg parse failure threw the raw parser position and input. log
the unparsed fragment and raise a clearer error instead, so a model
output that does not match the expected format no longer fails silently
with an empty assistant turn.

minimal change, no behavior change on successful parses.

* chat: handle openai style tool calls in peg-native

* nits

* common: scope OpenAI wrapper grammar trigger via autoparser flag

* chat: gate type:function parsing leniency on the analysis flag

Thread accept_openai_wrapper from the generator to build_json_tools_flat_keys
so the leading "type": "function" field is accepted only when openai_wrapper_trigger is set.
This commit is contained in:
Pascal
2026-06-15 15:37:04 +02:00
committed by GitHub
parent 0ae3f450f0
commit 581e8eca8b
6 changed files with 35 additions and 10 deletions

View File

@@ -103,6 +103,10 @@ common_chat_params peg_generator::generate_parser(const common_chat_template &
data.grammar_triggers = {
{ COMMON_GRAMMAR_TRIGGER_TYPE_WORD, trigger_marker }
};
if (autoparser.tools.format.openai_wrapper_trigger) {
// model emits the OpenAI function wrapper, trigger on it
data.grammar_triggers.push_back({ COMMON_GRAMMAR_TRIGGER_TYPE_WORD, "{\"type\": \"function\"," });
}
}
}
@@ -224,13 +228,13 @@ common_peg_parser analyze_tools::build_tool_parser_json_native(parser_build_cont
auto single_tool_parser = p.standard_json_tools(
format.per_call_start, format.per_call_end, inputs.tools, inputs.parallel_tool_calls,
inputs.tool_choice == COMMON_CHAT_TOOL_CHOICE_REQUIRED, name_field, args_field, format.tools_array_wrapped,
format.fun_name_is_key, format.id_field, format.gen_id_field, format.parameter_order);
format.fun_name_is_key, format.id_field, format.gen_id_field, format.parameter_order, format.openai_wrapper_trigger);
tools_parser = p.trigger_rule("tool-calls", p.one_or_more(single_tool_parser + p.space()));
} else {
tools_parser = p.standard_json_tools(
format.section_start, format.section_end, inputs.tools, inputs.parallel_tool_calls,
inputs.tool_choice == COMMON_CHAT_TOOL_CHOICE_REQUIRED, name_field, args_field, format.tools_array_wrapped,
format.fun_name_is_key, format.id_field, format.gen_id_field, format.parameter_order);
format.fun_name_is_key, format.id_field, format.gen_id_field, format.parameter_order, format.openai_wrapper_trigger);
}
// Handle content wrappers if present