Files
sglang/test/registered/unit/speculative/test_spec_utils.py
laoyao0822 187b700406 Keep speculative grammar traversal scalar-safe
EAGLE verification can pass torch scalar tensors through the speculative tree traversal before calling grammar backends. xgrammar/tvm_ffi requires Python int token ids, so normalize traversal indices and draft token ids at the boundary while leaving tensor storage unchanged.

Constraint: xgrammar/tvm_ffi rejects torch scalar tensors for GrammarMatcher.accept_token
Rejected: Coerce tokens inside every grammar backend | the invalid value originates in speculative traversal and should be fixed before backend dispatch
Confidence: high
Scope-risk: narrow
Directive: Keep grammar backend calls scalar-Python typed; do not pass torch scalar tensors through accept_token
Tested: remote g0034 cjy-glm5-new PYTHONPATH=python python -m pytest -q test/registered/unit/speculative/test_spec_utils.py test/registered/unit/configs/test_nsa_index_layers.py test/registered/unit/models/test_deepseek_index_skip_weight_loading.py -> 19 passed
Tested: remote g0034 cjy-glm5-new py_compile for modified runtime files
Not-tested: live decode replay after this commit
2026-06-21 05:24:05 +08:00

46 lines
1.4 KiB
Python

import torch
from sglang.srt.constrained.base_grammar_backend import BaseGrammarObject
from sglang.srt.speculative.spec_utils import traverse_tree
class _TypeCheckingGrammar(BaseGrammarObject):
def __init__(self):
super().__init__()
self.accepted = []
self.rollback_calls = []
def accept_token(self, token: int) -> None:
if not isinstance(token, int):
raise TypeError(f"expected Python int token, got {type(token)!r}")
self.accepted.append(token)
def rollback(self, k: int):
self.rollback_calls.append(k)
def fill_vocab_mask(self, vocab_mask: torch.Tensor, idx: int) -> None:
vocab_mask[idx].fill_(-1)
def allocate_vocab_mask(self, vocab_size: int, batch_size: int, device):
return torch.zeros((batch_size, (vocab_size + 31) // 32), dtype=torch.int32)
def test_traverse_tree_passes_python_int_tokens_to_grammar():
grammar = _TypeCheckingGrammar()
retrieve_next_token = torch.tensor([1, -1], dtype=torch.int32)
retrieve_next_sibling = torch.tensor([-1, -1], dtype=torch.int32)
draft_tokens = torch.tensor([0, 5], dtype=torch.int64)
allocate_token_bitmask = torch.zeros((2, 2), dtype=torch.int32)
traverse_tree(
retrieve_next_token,
retrieve_next_sibling,
draft_tokens,
grammar,
allocate_token_bitmask,
vocab_size=64,
)
assert grammar.accepted == [5]
assert grammar.rollback_calls == [1]