// 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.build.buildjar.resourcejar;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.common.base.CharMatcher;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayDeque;
import java.util.Deque;
import javax.annotation.Nullable;
/** A command line options parser for {@link ResourceJarOptions}. */
public class ResourceJarOptionsParser {
/**
* Parses command line options into {@link ResourceJarOptions}, expanding any {@code @params}
* files.
*/
public static ResourceJarOptions parse(Iterable<String> args) throws IOException {
ResourceJarOptions.Builder builder = ResourceJarOptions.builder();
parse(builder, args);
return builder.build();
}
/**
* Parses command line options into a {@link ResourceJarOptions.Builder}, expanding any
* {@code @params} files.
*/
public static void parse(ResourceJarOptions.Builder builder, Iterable<String> args)
throws IOException {
Deque<String> argumentDeque = new ArrayDeque<>();
expandParamsFiles(argumentDeque, args);
parse(builder, argumentDeque);
}
private static final Splitter ARG_SPLITTER =
Splitter.on(CharMatcher.breakingWhitespace()).omitEmptyStrings().trimResults();
/**
* Pre-processes an argument list, expanding arguments of the form {@code @filename} by reading
* the content of the file and appending whitespace-delimited options to {@code argumentDeque}.
*/
private static void expandParamsFiles(Deque<String> argumentDeque, Iterable<String> args)
throws IOException {
for (String arg : args) {
if (arg.isEmpty()) {
continue;
}
if (arg.startsWith("@") && !arg.startsWith("@@")) {
Path paramsPath = Paths.get(arg.substring(1));
expandParamsFiles(
argumentDeque, ARG_SPLITTER.split(new String(Files.readAllBytes(paramsPath), UTF_8)));
} else {
argumentDeque.addLast(arg);
}
}
}
private static void parse(ResourceJarOptions.Builder builder, Deque<String> argumentDeque) {
while (!argumentDeque.isEmpty()) {
String next = argumentDeque.pollFirst();
switch (next) {
case "--output":
builder.setOutput(readOne(argumentDeque));
break;
case "--messages":
builder.setMessages(readList(argumentDeque));
break;
case "--resources":
builder.setResources(readList(argumentDeque));
break;
case "--resource_jars":
builder.setResourceJars(readList(argumentDeque));
break;
case "--classpath_resources":
builder.setClasspathResources(readList(argumentDeque));
break;
default:
if (next.isEmpty() && !argumentDeque.isEmpty()) {
throw new IllegalArgumentException("unknown option: " + next);
}
}
}
}
/** Returns the value of an option, or {@code null}. */
@Nullable
private static String readOne(Deque<String> argumentDeque) {
if (argumentDeque.isEmpty() || argumentDeque.peekFirst().startsWith("-")) {
return null;
}
return argumentDeque.pollFirst();
}
/** Returns a list of option values. */
private static ImmutableList<String> readList(Deque<String> argumentDeque) {
ImmutableList.Builder<String> result = ImmutableList.builder();
while (!argumentDeque.isEmpty() && !argumentDeque.peekFirst().startsWith("--")) {
result.add(argumentDeque.pollFirst());
}
return result.build();
}
}