com.google.devtools.common.options.ParamsFilePreProcessor Maven / Gradle / Ivy
// 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.
*
* 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 preProcess(List 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 parse(Path paramsFile)
throws IOException, OptionsParsingException;
}