# Copyright 2025 qBraid
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Module defining function to convert a CUDA-Q kernel to a QASM2 string.
"""
from __future__ import annotations
from typing import TYPE_CHECKING
import cudaq
from qbraid.transpiler.annotations import weight
from qbraid.transpiler.exceptions import ProgramConversionError
if TYPE_CHECKING:
from cudaq import PyKernel
from qbraid.programs.typer import Qasm2StringType
[docs]
@weight(1)
def cudaq_to_qasm2(kernel: PyKernel) -> Qasm2StringType:
"""Converts a CUDA-Q kernel to QASM2."""
# cudaq 0.14 needs the kernel compiled before translation; without it translate
# fails with "has multiple entrypoints" once a process holds more than one kernel.
kernel.compile()
qasm = cudaq.translate(kernel, format="openqasm2")
# cudaq.translate reports failure by returning "{translation failed}"
# (with the error printed to stderr) instead of raising.
if "OPENQASM" not in qasm:
raise ProgramConversionError(f"cudaq.translate failed to produce QASM2: {qasm!r}")
return qasm