[Bug] [Relax][ONNX] Runtime-shape Reshape import passes TensorType to relax.op.reshape

[Anemone220]

Expected behavior

The Relax ONNX frontend should import a valid ONNX Reshape whose shape input is a runtime INT64 tensor, or report that feature as unsupported.

Actual behavior

The script constructs a valid ONNX model. onnx.checker.check_model and ONNX Runtime session construction succeed. from_onnx fails while converting Reshape:

Error converting operator Reshape, with inputs: [data, shape]
Traceback (most recent call last):
  ...
  File ".../src/relax/op/tensor/manipulate.cc", line 1014, in InferTypeReshape
    TVM_FFI_VISIT_THROW(TypeError, call)
TypeError: Reshape requires the input new shape to be Shape. However, the given one is relax.TensorType

Environment

• OS: macOS 15.6 (Darwin 24.6.0, arm64)
• Python: 3.12.2
• TVM: c7b458e (tag v0.26.0; package reports 0.26.dev0)
• ONNX: 1.17.0
• ONNX Runtime: 1.21.1
• Frontend: tvm.relax.frontend.onnx.from_onnx

Steps to reproduce

The following self-contained script constructs the model:

#!/usr/bin/env python3
"""Reproduce the Relax ONNX runtime-shape Reshape import failure."""

import onnx
import onnxruntime as ort
from onnx import TensorProto, helper
from tvm.relax.frontend.onnx import from_onnx


def main() -> None:
    data = helper.make_tensor_value_info("data", TensorProto.FLOAT, [2, 3])
    shape = helper.make_tensor_value_info("shape", TensorProto.INT64, [2])
    out = helper.make_tensor_value_info("out", TensorProto.FLOAT, [3, 2])
    graph = helper.make_graph(
        [helper.make_node("Reshape", ["data", "shape"], ["out"])],
        "reshape_runtime_shape",
        [data, shape],
        [out],
    )
    model = helper.make_model(graph, opset_imports=[helper.make_opsetid("", 18)])

    onnx.checker.check_model(model)
    ort.InferenceSession(model.SerializeToString(), providers=["CPUExecutionProvider"])
    from_onnx(model, opset=18, keep_params_in_input=True)


if __name__ == "__main__":
    main()

Analysis

The runtime Reshape shape input is represented as relax.TensorType, while Relax reshape expects a Shape argument. The failure occurs during ONNX import.

Triage

• needs-triage