Java tutorial
// 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.standalone; import com.google.common.collect.ImmutableMap; import com.google.devtools.build.lib.actions.ActionExecutionContext; import com.google.devtools.build.lib.actions.ActionStatusMessage; import com.google.devtools.build.lib.actions.ExecException; import com.google.devtools.build.lib.actions.ExecutionStrategy; import com.google.devtools.build.lib.actions.Executor; import com.google.devtools.build.lib.actions.Spawn; import com.google.devtools.build.lib.actions.SpawnActionContext; import com.google.devtools.build.lib.actions.Spawns; import com.google.devtools.build.lib.actions.UserExecException; import com.google.devtools.build.lib.cmdline.Label; import com.google.devtools.build.lib.rules.apple.AppleConfiguration; import com.google.devtools.build.lib.rules.apple.AppleHostInfo; import com.google.devtools.build.lib.rules.apple.DottedVersion; import com.google.devtools.build.lib.shell.AbnormalTerminationException; import com.google.devtools.build.lib.shell.Command; import com.google.devtools.build.lib.shell.CommandException; import com.google.devtools.build.lib.shell.TerminationStatus; import com.google.devtools.build.lib.util.CommandFailureUtils; import com.google.devtools.build.lib.util.OS; import com.google.devtools.build.lib.util.OsUtils; import com.google.devtools.build.lib.util.io.FileOutErr; import com.google.devtools.build.lib.vfs.Path; import java.io.File; import java.util.ArrayList; import java.util.List; /** * Strategy that uses subprocessing to execute a process. */ @ExecutionStrategy(name = { "standalone", "local" }, contextType = SpawnActionContext.class) public class StandaloneSpawnStrategy implements SpawnActionContext { private final boolean verboseFailures; private final Path processWrapper; private final Path execRoot; private final String productName; public StandaloneSpawnStrategy(Path execRoot, boolean verboseFailures, String productName) { this.verboseFailures = verboseFailures; this.execRoot = execRoot; this.processWrapper = execRoot.getRelative("_bin/process-wrapper" + OsUtils.executableExtension()); this.productName = productName; } /** * Executes the given {@code spawn}. */ @Override public void exec(Spawn spawn, ActionExecutionContext actionExecutionContext) throws ExecException { Executor executor = actionExecutionContext.getExecutor(); if (executor.reportsSubcommands()) { executor.reportSubcommand( Label.print(spawn.getOwner().getLabel()) + " [" + spawn.getResourceOwner().prettyPrint() + "]", spawn.asShellCommand(executor.getExecRoot())); } executor.getEventBus().post(ActionStatusMessage.runningStrategy(spawn.getResourceOwner(), "standalone")); int timeoutSeconds = Spawns.getTimeoutSeconds(spawn); // We must wrap the subprocess with process-wrapper to kill the process tree. // All actions therefore depend on the process-wrapper file. Since it's embedded, // we don't bother with declaring it as an input. List<String> args = new ArrayList<>(); if (OS.getCurrent() != OS.WINDOWS) { // TODO(bazel-team): process-wrapper seems to work on Windows, but requires // additional setup as it is an msys2 binary, so it needs msys2 DLLs on %PATH%. // Disable it for now to make the setup easier and to avoid further PATH hacks. // Ideally we should have a native implementation of process-wrapper for Windows. args.add(processWrapper.getPathString()); args.add(Integer.toString(timeoutSeconds)); args.add("5"); /* kill delay: give some time to print stacktraces and whatnot. */ // TODO(bazel-team): use process-wrapper redirection so we don't have to // pass test logs through the Java heap. args.add("-"); /* stdout. */ args.add("-"); /* stderr. */ } args.addAll(spawn.getArguments()); String cwd = executor.getExecRoot().getPathString(); Command cmd = new Command(args.toArray(new String[] {}), locallyDeterminedEnv(execRoot, productName, spawn.getEnvironment()), new File(cwd), OS.getCurrent() == OS.WINDOWS && timeoutSeconds >= 0 ? timeoutSeconds * 1000 : -1); FileOutErr outErr = actionExecutionContext.getFileOutErr(); try { cmd.execute(/* stdin */ new byte[] {}, Command.NO_OBSERVER, outErr.getOutputStream(), outErr.getErrorStream(), /*killSubprocessOnInterrupt*/ true); } catch (AbnormalTerminationException e) { TerminationStatus status = e.getResult().getTerminationStatus(); boolean timedOut = !status.exited() && (status.timedout() || status.getTerminatingSignal() == 14 /* SIGALRM */); String message = CommandFailureUtils.describeCommandFailure(verboseFailures, spawn.getArguments(), spawn.getEnvironment(), cwd); throw new UserExecException(String.format("%s: %s", message, e), timedOut); } catch (CommandException e) { String message = CommandFailureUtils.describeCommandFailure(verboseFailures, spawn.getArguments(), spawn.getEnvironment(), cwd); throw new UserExecException(message, e); } } @Override public String toString() { return "standalone"; } @Override public boolean willExecuteRemotely(boolean remotable) { return false; } /** * Adds to the given environment all variables that are dependent on system state of the host * machine. * * <p>Admittedly, hermeticity is "best effort" in such cases; these environment values should be * as tied to configuration parameters as possible. * * <p>For example, underlying iOS toolchains require that SDKROOT resolve to an absolute system * path, but, when selecting which SDK to resolve, the version number comes from build * configuration. * * @return the new environment, comprised of the old environment plus any new variables * @throws UserExecException if any variables dependent on system state could not be resolved */ public static ImmutableMap<String, String> locallyDeterminedEnv(Path execRoot, String productName, ImmutableMap<String, String> env) throws UserExecException { // TODO(bazel-team): Remove apple-specific logic from this class. ImmutableMap.Builder<String, String> newEnvBuilder = ImmutableMap.builder(); newEnvBuilder.putAll(env); // Empty developer dir indicates to use the system default. // TODO(bazel-team): Bazel's view of the xcode version and developer dir // should be explicitly set for build hermiticity. String developerDir = ""; if (env.containsKey(AppleConfiguration.XCODE_VERSION_ENV_NAME)) { developerDir = getDeveloperDir(execRoot, productName, env.get(AppleConfiguration.XCODE_VERSION_ENV_NAME)); newEnvBuilder.put("DEVELOPER_DIR", developerDir); } if (env.containsKey(AppleConfiguration.APPLE_SDK_VERSION_ENV_NAME)) { // The Apple platform is needed to select the appropriate SDK. if (!env.containsKey(AppleConfiguration.APPLE_SDK_PLATFORM_ENV_NAME)) { throw new UserExecException("Could not resolve apple platform for determining SDK"); } String iosSdkVersion = env.get(AppleConfiguration.APPLE_SDK_VERSION_ENV_NAME); String appleSdkPlatform = env.get(AppleConfiguration.APPLE_SDK_PLATFORM_ENV_NAME); newEnvBuilder.put("SDKROOT", getSdkRootEnv(execRoot, productName, developerDir, iosSdkVersion, appleSdkPlatform)); } return newEnvBuilder.build(); } private static String getDeveloperDir(Path execRoot, String productName, String xcodeVersion) throws UserExecException { if (OS.getCurrent() != OS.DARWIN) { throw new UserExecException("Cannot locate xcode developer directory on non-darwin operating system"); } return AppleHostInfo.getDeveloperDir(execRoot, DottedVersion.fromString(xcodeVersion), productName); } private static String getSdkRootEnv(Path execRoot, String productName, String developerDir, String iosSdkVersion, String appleSdkPlatform) throws UserExecException { if (OS.getCurrent() != OS.DARWIN) { throw new UserExecException("Cannot locate iOS SDK on non-darwin operating system"); } return AppleHostInfo.getSdkRoot(execRoot, developerDir, iosSdkVersion, appleSdkPlatform, productName); } @Override public boolean shouldPropagateExecException() { return false; } }