| // Copyright 2016 The Bazel Authors. All rights reserved. |
| // |
| // 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. |
| |
| package com.google.devtools.build.lib.syntax; |
| |
| import com.google.devtools.build.lib.events.Location; |
| |
| /** This class contains Bazel-specific functions to extend or interoperate with Skylark. */ |
| public final class SkylarkUtils { |
| |
| private static final String PHASE_KEY = "$phase"; |
| |
| /** A phase for enabling or disabling certain builtin functions */ |
| public enum Phase { |
| WORKSPACE, |
| LOADING, |
| ANALYSIS |
| } |
| |
| public static void setPhase(Environment env, Phase phase) { |
| env.setupDynamic(PHASE_KEY, phase); |
| } |
| |
| private static Phase getPhase(Environment env) { |
| Phase phase = (Phase) env.dynamicLookup(PHASE_KEY); |
| return phase == null ? Phase.ANALYSIS : phase; |
| } |
| |
| /** |
| * Checks that the current Environment is in the loading or the workspace phase. |
| * |
| * @param symbol name of the function being only authorized thus. |
| */ |
| public static void checkLoadingOrWorkspacePhase(Environment env, String symbol, Location loc) |
| throws EvalException { |
| if (getPhase(env) == Phase.ANALYSIS) { |
| throw new EvalException(loc, symbol + "() cannot be called during the analysis phase"); |
| } |
| } |
| |
| /** |
| * Checks that the current Environment is in the loading phase. |
| * |
| * @param symbol name of the function being only authorized thus. |
| */ |
| public static void checkLoadingPhase(Environment env, String symbol, Location loc) |
| throws EvalException { |
| if (getPhase(env) != Phase.LOADING) { |
| throw new EvalException(loc, symbol + "() can only be called during the loading phase"); |
| } |
| } |
| } |