// Copyright 2014 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.analysis.actions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.actions.ActionOwner;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.actions.ParameterFile;
import com.google.devtools.build.lib.analysis.AnalysisEnvironment;
import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
import com.google.devtools.build.lib.util.Preconditions;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.util.List;
import javax.annotation.Nullable;
import javax.annotation.concurrent.Immutable;
/**
* A command-line implementation that wraps another command line and puts the arguments in a
* parameter file if necessary
*
* <p>The Linux kernel has a limit for the command line length, and that can be easily reached
* if, for example, a command is listing all its inputs on the command line.
*/
@Immutable
public final class ParamFileHelper {
/**
* Returns a params file artifact or null for a given command description.
*
* <p>Returns null if parameter files are not to be used according to paramFileInfo, or if the
* command line is short enough that a parameter file is not needed.
*
* <p>Make sure to add the returned artifact (if not null) as an input of the corresponding
* action.
*
* @param executableArgs leading arguments that should never be wrapped in a parameter file
* @param arguments arguments to the command (in addition to executableArgs), OR
* @param commandLine a {@link CommandLine} that provides the arguments (in addition to
* executableArgs)
* @param paramFileInfo parameter file information
* @param configuration the configuration
* @param analysisEnvironment the analysis environment
* @param outputs outputs of the action (used to construct a filename for the params file)
*/
static Artifact getParamsFileMaybe(
List<String> executableArgs,
@Nullable Iterable<String> arguments,
@Nullable CommandLine commandLine,
@Nullable ParamFileInfo paramFileInfo,
BuildConfiguration configuration,
AnalysisEnvironment analysisEnvironment,
Iterable<Artifact> outputs) {
if (paramFileInfo == null) {
return null;
}
if (!paramFileInfo.always()
&& getParamFileSize(executableArgs, arguments, commandLine)
< configuration.getMinParamFileSize()) {
return null;
}
Artifact output = Iterables.getFirst(outputs, null);
Preconditions.checkNotNull(output);
PathFragment paramFilePath = ParameterFile.derivePath(output.getRootRelativePath());
return analysisEnvironment.getDerivedArtifact(paramFilePath, output.getRoot());
}
/**
* Creates a command line using an external params file.
*
* <p>Call this with the result of {@link #getParamsFileMaybe} if it is not null.
*
* @param executableArgs leading arguments that should never be wrapped in a parameter file
* @param paramFileInfo parameter file information
* @param parameterFile the output parameter file artifact
*/
public static CommandLine createWithParamsFile(
List<String> executableArgs, ParamFileInfo paramFileInfo, Artifact parameterFile) {
String pathWithFlag = paramFileInfo.getFlag() + parameterFile.getExecPathString();
Iterable<String> commandArgv = Iterables.concat(executableArgs, ImmutableList.of(pathWithFlag));
return CommandLine.of(commandArgv);
}
/**
* Creates an action to write the parameter file.
*
* @param arguments arguments to the command (in addition to executableArgs), OR
* @param commandLine a {@link CommandLine} that provides the arguments (in addition to
* executableArgs)
* @param owner owner of the action
* @param parameterFile the output parameter file artifact
* @param paramFileInfo parameter file information
*/
public static ParameterFileWriteAction createParameterFileWriteAction(
@Nullable Iterable<String> arguments,
@Nullable CommandLine commandLine,
ActionOwner owner,
Artifact parameterFile,
ParamFileInfo paramFileInfo) {
CommandLine paramFileContents = (commandLine != null) ? commandLine : CommandLine.of(arguments);
return new ParameterFileWriteAction(owner, parameterFile, paramFileContents,
paramFileInfo.getFileType(), paramFileInfo.getCharset());
}
/**
* Creates a command line without using a params file.
*
* <p>Call this if {@link #getParamsFileMaybe} returns null.
*
* @param executableArgs leading arguments that should never be wrapped in a parameter file
* @param arguments arguments to the command (in addition to executableArgs), OR
* @param commandLine a {@link CommandLine} that provides the arguments (in addition to
* executableArgs)
*/
public static CommandLine createWithoutParamsFile(
List<String> executableArgs, Iterable<String> arguments, CommandLine commandLine) {
if (commandLine == null) {
Iterable<String> commandArgv = Iterables.concat(executableArgs, arguments);
return CommandLine.of(commandArgv);
}
if (executableArgs.isEmpty()) {
return commandLine;
}
return CommandLine.concat(ImmutableList.copyOf(executableArgs), commandLine);
}
/**
* Estimates the params file size for the given arguments.
*/
private static int getParamFileSize(
List<String> executableArgs, Iterable<String> arguments, CommandLine commandLine) {
Iterable<String> actualArguments = (commandLine != null) ? commandLine.arguments() : arguments;
return getParamFileSize(executableArgs) + getParamFileSize(actualArguments);
}
private static int getParamFileSize(Iterable<String> args) {
int size = 0;
for (String s : args) {
size += s.length() + 1;
}
return size;
}
}