| // 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.rules.cpp; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.devtools.build.lib.actions.ActionExecutionContext; |
| import com.google.devtools.build.lib.actions.ActionKeyContext; |
| import com.google.devtools.build.lib.actions.ActionOwner; |
| import com.google.devtools.build.lib.actions.Artifact; |
| import com.google.devtools.build.lib.analysis.WorkspaceStatusAction; |
| import com.google.devtools.build.lib.analysis.actions.AbstractFileWriteAction; |
| import com.google.devtools.build.lib.collect.nestedset.NestedSet; |
| import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable; |
| import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec; |
| import com.google.devtools.build.lib.util.Fingerprint; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.io.OutputStreamWriter; |
| import java.io.Writer; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| |
| /** |
| * An action that creates a C++ header containing the build information in the form of #define |
| * directives. |
| */ |
| @Immutable |
| @AutoCodec |
| public final class WriteBuildInfoHeaderAction extends AbstractFileWriteAction { |
| private static final String GUID = "7243b846-b2f2-4057-97a4-00e2da6c6ffd"; |
| |
| private final boolean writeVolatileInfo; |
| private final boolean writeStableInfo; |
| |
| /** |
| * Creates an action that writes a C++ header with the build information. |
| * |
| * <p>It reads the set of build info keys from an action context that is usually contributed to |
| * Bazel by the workspace status module, and the value associated with said keys from the |
| * workspace status files (stable and volatile) written by the workspace status action. |
| * |
| * <p>Without input artifacts this action uses redacted build information. |
| * |
| * @param inputs Artifacts that contain build information, or an empty collection to use redacted |
| * build information |
| * @param primaryOutput the C++ header Artifact created by this action |
| * @param writeVolatileInfo whether to write the volatile part of the build information to the |
| * generated header |
| * @param writeStableInfo whether to write the non-volatile part of the build information to the |
| * generated header |
| */ |
| public WriteBuildInfoHeaderAction( |
| NestedSet<Artifact> inputs, |
| Artifact primaryOutput, |
| boolean writeVolatileInfo, |
| boolean writeStableInfo) { |
| super(ActionOwner.SYSTEM_ACTION_OWNER, inputs, primaryOutput, /*makeExecutable=*/ false); |
| if (!inputs.isEmpty()) { |
| // With non-empty inputs we should not generate both volatile and non-volatile data |
| // in the same header file. |
| Preconditions.checkState(writeVolatileInfo ^ writeStableInfo); |
| } |
| Preconditions.checkState( |
| primaryOutput.isConstantMetadata() == (writeVolatileInfo && !inputs.isEmpty())); |
| |
| this.writeVolatileInfo = writeVolatileInfo; |
| this.writeStableInfo = writeStableInfo; |
| } |
| |
| @Override |
| public DeterministicWriter newDeterministicWriter(ActionExecutionContext ctx) |
| throws IOException { |
| WorkspaceStatusAction.Context context = ctx.getContext(WorkspaceStatusAction.Context.class); |
| |
| final Map<String, WorkspaceStatusAction.Key> keys = new LinkedHashMap<>(); |
| if (writeVolatileInfo) { |
| keys.putAll(context.getVolatileKeys()); |
| } |
| |
| if (writeStableInfo) { |
| keys.putAll(context.getStableKeys()); |
| } |
| |
| final Map<String, String> values = new LinkedHashMap<>(); |
| for (Artifact valueFile : getInputs().toList()) { |
| values.putAll(WorkspaceStatusAction.parseValues(ctx.getInputPath(valueFile))); |
| } |
| |
| final boolean redacted = getInputs().isEmpty(); |
| |
| return new DeterministicWriter() { |
| @Override |
| public void writeOutputFile(OutputStream out) throws IOException { |
| Writer writer = new OutputStreamWriter(out, UTF_8); |
| |
| for (Map.Entry<String, WorkspaceStatusAction.Key> key : keys.entrySet()) { |
| String value = redacted ? key.getValue().getRedactedValue() |
| : values.containsKey(key.getKey()) ? values.get(key.getKey()) |
| : key.getValue().getDefaultValue(); |
| |
| switch (key.getValue().getType()) { |
| case INTEGER: |
| break; |
| |
| case STRING: |
| value = quote(value); |
| break; |
| |
| default: |
| throw new IllegalStateException(); |
| } |
| define(writer, key.getKey(), value); |
| |
| } |
| writer.flush(); |
| } |
| }; |
| } |
| |
| @Override |
| protected void computeKey(ActionKeyContext actionKeyContext, Fingerprint fp) { |
| fp.addString(GUID); |
| fp.addBoolean(writeStableInfo); |
| fp.addBoolean(writeVolatileInfo); |
| } |
| |
| @Override |
| public boolean executeUnconditionally() { |
| // Note: isVolatile must return true if executeUnconditionally can ever return true |
| // for this instance. |
| return isUnconditional(); |
| } |
| |
| @Override |
| public boolean isVolatile() { |
| return isUnconditional(); |
| } |
| |
| private boolean isUnconditional() { |
| // Because of special handling in the MetadataHandler, changed volatile build |
| // information does not trigger relinking of all libraries that have |
| // linkstamps. But we do want to regenerate the header in case libraries are |
| // relinked because of other reasons. |
| // Without inputs the contents of the header do not change, so there is no |
| // point in executing the action again in that case. |
| return writeVolatileInfo && !getInputs().isEmpty(); |
| } |
| |
| /** |
| * Quote a string with double quotes. |
| */ |
| private String quote(String string) { |
| // TODO(bazel-team): This is doesn't really work if the string contains quotes. Or a newline. |
| // Or a backslash. Or anything unusual, really. |
| return "\"" + string + "\""; |
| } |
| |
| /** |
| * Write a preprocessor define directive to a Writer. |
| */ |
| private void define(Writer writer, String name, String value) throws IOException { |
| writer.write("#define "); |
| writer.write(name); |
| writer.write(' '); |
| writer.write(value); |
| writer.write('\n'); |
| } |
| |
| @Override |
| protected String getRawProgressMessage() { |
| return null; |
| } |
| } |