/*
* Copyright 2014-present Facebook, Inc.
*
* 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.facebook.buck.rules.macros;
import com.facebook.buck.model.BuildTarget;
import com.facebook.buck.model.MacroException;
import com.facebook.buck.rules.BuildRuleResolver;
import com.facebook.buck.rules.CellPathResolver;
import com.facebook.buck.util.environment.Platform;
import com.google.common.collect.ImmutableList;
/**
* Expands $(env XYZ) to use the appropriate shell expansion for the current platform. It does not
* expand the value of the environment variable in place. Rather, the intention is for the variable
* to be interpreted when a shell command is invoked.
*/
public class EnvironmentVariableMacroExpander extends AbstractMacroExpander<String> {
private final Platform platform;
public EnvironmentVariableMacroExpander(Platform platform) {
this.platform = platform;
}
@Override
public Class<String> getInputClass() {
return String.class;
}
@Override
protected String parse(
BuildTarget target, CellPathResolver cellNames, ImmutableList<String> input)
throws MacroException {
if (input.size() != 1) {
throw new MacroException(String.format("expected a single argument: %s", input));
}
return input.get(0);
}
@Override
public String expandFrom(
BuildTarget target, CellPathResolver cellNames, BuildRuleResolver resolver, String var)
throws MacroException {
if (platform == Platform.WINDOWS) {
if ("pwd".equalsIgnoreCase(var)) {
var = "cd";
}
return "%" + var + "%";
} else {
return "${" + var + "}";
}
}
}