librelane

# Copyright 2023 Efabless Corporation
#
# 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.
import os
import pytest
import tkinter
from pyfakefs.fake_filesystem_unittest import Patcher


@pytest.fixture
def _mock_fs():
    with Patcher() as patcher:
        patcher.fs.create_dir("/cwd")
        os.chdir("/cwd")
        yield


def test_escape():
    from openlane.common import TclUtils

    assert (
        TclUtils.escape("ringo") == r"ringo"
    ), ".escape altered a non-dangerous string"
    assert TclUtils.escape("r ingo") == r'"r ingo"', ".escape neglected whitespace"
    assert (
        TclUtils.escape("[expr ringo]") == r'"\[expr ringo]"'
    ), ".escape neglected expression braces"
    assert (
        TclUtils.escape("[expr $ringo]") == r'"\[expr \$ringo]"'
    ), ".escape neglected dollar sign"
    assert (
        TclUtils.escape("[expr \\$ringo]") == r'"\[expr \\\$ringo]"'
    ), ".escape neglected backslash"


@pytest.mark.usefixtures("_mock_fs")
def test_join():
    from openlane.common import TclUtils

    very_wild_list = [
        "{}{}{{}}{}{}{}{}{}{}{",
        "dollar\\ sign",
        "actual dollar $ign",
        '[exec {touch "need legal advice?"}]',
        '\\[exec {touch "better call saul"}]',
    ]

    very_wild_list_escaped = TclUtils.join(very_wild_list)
    interpreter = tkinter.Tcl()
    interpreter.eval(
        f"""
        set very_wild_variable [list {very_wild_list_escaped}]
        set length [llength $very_wild_variable]
        foreach i $very_wild_variable {{
            puts $i
        }}
        """
    )

    assert os.listdir("/cwd") == [], "Arbitrary code execution"
    assert interpreter.getvar("length") == 5, "Tcl list not escaped properly"


def test_eval_env():
    from openlane.common import TclUtils

    env_backup = os.environ.copy()

    result = TclUtils._eval_env(
        {"DESIGN_DIR": "/cwd", "PDK": "sky130A", "TMPDIR": "/cwd"},
        """
        if { ![info exists ::env(STD_CELL_LIBRARY)] } {
            set ::env(STD_CELL_LIBRARY) "sky130_fd_sc_hd"
        }
        if { $::env(STD_CELL_LIBRARY) == "sky130_fd_sc_hd" } {
            set ::env(WHATEVER) 1
        } else {
            set ::env(WHATEVER) 0
        }
        """,
    )

    expected = {
        "DESIGN_DIR": "/cwd",
        "PDK": "sky130A",
        "TMPDIR": "/cwd",
        "WHATEVER": "1",
        "STD_CELL_LIBRARY": "sky130_fd_sc_hd",
    }

    assert result == expected, "conditional evaluation test failed"

    assert os.environ == env_backup, "_eval_env leaked environment changes"

    os.environ["STD_CELL_LIBRARY"] = "sky130_fd_sc_hd"

    TclUtils._eval_env(
        {},
        """
        set ::env(STD_CELL_LIBRARY) "sky130_fd_sc_hs"
        """,
    )

    assert (
        os.getenv("STD_CELL_LIBRARY") == "sky130_fd_sc_hd"
    ), "env_from_tcl unset a previously set environment variable"

    del os.environ["STD_CELL_LIBRARY"]

    assert result == expected