| // Copyright 2017 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.common.options; |
| |
| import java.io.IOException; |
| import java.nio.file.FileSystem; |
| import java.nio.file.Path; |
| import java.util.List; |
| |
| /** |
| * Defines an {@link ArgsPreProcessor} that will determine if the arguments list contains a "params" |
| * file that contains a list of options to be parsed. |
| * |
| * <p>Params files are used when the argument list of {@link Option} exceed the shells commandline |
| * length. A params file argument is defined as a path starting with @. It will also be the only |
| * entry in an argument list. |
| */ |
| public abstract class ParamsFilePreProcessor implements ArgsPreProcessor { |
| |
| static final String ERROR_MESSAGE_FORMAT = "Error reading params file: %s %s"; |
| |
| static final String TOO_MANY_ARGS_ERROR_MESSAGE_FORMAT = |
| "A params file must be the only argument: %s"; |
| |
| static final String UNFINISHED_QUOTE_MESSAGE_FORMAT = "Unfinished quote %s at %s"; |
| |
| private final FileSystem fs; |
| |
| ParamsFilePreProcessor(FileSystem fs) { |
| this.fs = fs; |
| } |
| |
| /** |
| * Parses the param file path and replaces the arguments list with the contents if one exists. |
| * |
| * @param args A list of arguments that may contain @<path> to a params file. |
| * @return A list of arguments suitable for parsing. |
| * @throws OptionsParsingException if the path does not exist. |
| */ |
| @Override |
| public List<String> preProcess(List<String> args) throws OptionsParsingException { |
| if (!args.isEmpty() && args.get(0).startsWith("@")) { |
| if (args.size() > 1) { |
| throw new OptionsParsingException( |
| String.format(TOO_MANY_ARGS_ERROR_MESSAGE_FORMAT, args), args.get(0)); |
| } |
| Path path = fs.getPath(args.get(0).substring(1)); |
| try { |
| return parse(path); |
| } catch (RuntimeException | IOException e) { |
| throw new OptionsParsingException( |
| String.format(ERROR_MESSAGE_FORMAT, path, e.getMessage()), args.get(0), e); |
| } |
| } |
| return args; |
| } |
| |
| /** |
| * Parses the paramsFile and returns a list of argument tokens to be further processed by the |
| * {@link OptionsParser}. |
| * |
| * @param paramsFile The path of the params file to parse. |
| * @return a list of argument tokens. |
| * @throws IOException if there is an error reading paramsFile. |
| * @throws OptionsParsingException if there is an error reading paramsFile. |
| */ |
| protected abstract List<String> parse(Path paramsFile) |
| throws IOException, OptionsParsingException; |
| } |