| // 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 com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableSetMultimap; |
| import com.google.common.collect.Iterables; |
| import com.google.devtools.build.lib.actions.Artifact; |
| import com.google.devtools.build.lib.rules.cpp.Link.LinkStaticness; |
| import com.google.devtools.build.lib.rules.cpp.LinkerInputs.LibraryToLink; |
| import com.google.devtools.build.lib.vfs.FileSystemUtils; |
| import java.util.ArrayList; |
| import java.util.HashSet; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * A structured representation of the link outputs of a C++ rule. |
| */ |
| public class CcLinkingOutputs { |
| |
| public static final CcLinkingOutputs EMPTY = new Builder().build(); |
| |
| private final ImmutableList<LibraryToLink> staticLibraries; |
| |
| private final ImmutableList<LibraryToLink> picStaticLibraries; |
| |
| private final ImmutableList<LibraryToLink> dynamicLibraries; |
| |
| private final ImmutableList<LibraryToLink> executionDynamicLibraries; |
| |
| private CcLinkingOutputs(ImmutableList<LibraryToLink> staticLibraries, |
| ImmutableList<LibraryToLink> picStaticLibraries, |
| ImmutableList<LibraryToLink> dynamicLibraries, |
| ImmutableList<LibraryToLink> executionDynamicLibraries) { |
| this.staticLibraries = staticLibraries; |
| this.picStaticLibraries = picStaticLibraries; |
| this.dynamicLibraries = dynamicLibraries; |
| this.executionDynamicLibraries = executionDynamicLibraries; |
| } |
| |
| public ImmutableList<LibraryToLink> getStaticLibraries() { |
| return staticLibraries; |
| } |
| |
| public ImmutableList<LibraryToLink> getPicStaticLibraries() { |
| return picStaticLibraries; |
| } |
| |
| public ImmutableList<LibraryToLink> getDynamicLibraries() { |
| return dynamicLibraries; |
| } |
| |
| public ImmutableList<LibraryToLink> getExecutionDynamicLibraries() { |
| return executionDynamicLibraries; |
| } |
| |
| /** |
| * Returns a map from library identifiers to sets of LibraryToLink from this CcLinkingOutputs |
| * which share that library identifier. |
| */ |
| public ImmutableSetMultimap<String, LibraryToLink> getLibrariesByIdentifier() { |
| return getLibrariesByIdentifier( |
| Iterables.concat( |
| staticLibraries, picStaticLibraries, dynamicLibraries, executionDynamicLibraries)); |
| } |
| |
| /** |
| * Gathers up a map from library identifiers to sets of LibraryToLink which share that library |
| * identifier. |
| */ |
| public static ImmutableSetMultimap<String, LibraryToLink> getLibrariesByIdentifier( |
| Iterable<LibraryToLink> inputs) { |
| ImmutableSetMultimap.Builder<String, LibraryToLink> result = |
| new ImmutableSetMultimap.Builder<>(); |
| for (LibraryToLink library : inputs) { |
| Preconditions.checkNotNull(library.getLibraryIdentifier()); |
| result.put(library.getLibraryIdentifier(), library); |
| } |
| return result.build(); |
| } |
| |
| /** |
| * Add the ".a", ".pic.a" and/or ".so" files in appropriate order of preference depending on the |
| * link preferences. |
| * |
| * <p>This method tries to simulate a search path for adding static and dynamic libraries, |
| * allowing either to be preferred over the other depending on the link {@link LinkStaticness}. |
| * |
| * TODO(bazel-team): (2009) we should preserve the relative ordering of first and second |
| * choice libraries. E.g. if srcs=['foo.a','bar.so','baz.a'] then we should link them in the |
| * same order. Currently we link entries from the first choice list before those from the |
| * second choice list, i.e. in the order {@code ['bar.so', 'foo.a', 'baz.a']}. |
| * |
| * @param linkingStatically whether to prefer static over dynamic libraries. Should be |
| * <code>true</code> for binaries that are linked in fully static or mostly static mode. |
| * @param preferPic whether to prefer pic over non pic libraries (usually used when linking |
| * shared) |
| */ |
| public List<LibraryToLink> getPreferredLibraries( |
| boolean linkingStatically, boolean preferPic) { |
| return getPreferredLibraries(linkingStatically, preferPic, false); |
| } |
| |
| /** |
| * Returns the shared libraries that are linked against and therefore also need to be in the |
| * runfiles. |
| */ |
| public Iterable<Artifact> getLibrariesForRunfiles(boolean linkingStatically) { |
| List<LibraryToLink> libraries = |
| getPreferredLibraries(linkingStatically, /*preferPic*/false, true); |
| return PrecompiledFiles.getSharedLibrariesFrom(LinkerInputs.toLibraryArtifacts(libraries)); |
| } |
| |
| /** |
| * Add the ".a", ".pic.a" and/or ".so" files in appropriate order of |
| * preference depending on the link preferences. |
| */ |
| private List<LibraryToLink> getPreferredLibraries(boolean linkingStatically, boolean preferPic, |
| boolean forRunfiles) { |
| List<LibraryToLink> candidates = new ArrayList<>(); |
| // It's important that this code keeps the invariant that preferPic has no effect on the output |
| // of .so libraries. That is, the resulting list should contain the same .so files in the same |
| // order. |
| if (linkingStatically) { // Prefer the static libraries. |
| if (preferPic) { |
| // First choice is the PIC static libraries. |
| // Second choice is the other static libraries (may cause link error if they're not PIC, |
| // but I think this is preferable to linking dynamically when you asked for statically). |
| candidates.addAll(picStaticLibraries); |
| candidates.addAll(staticLibraries); |
| } else { |
| // First choice is the non-pic static libraries (best performance); |
| // second choice is the staticPicLibraries (at least they're static; |
| // we can live with the extra overhead of PIC). |
| candidates.addAll(staticLibraries); |
| candidates.addAll(picStaticLibraries); |
| } |
| candidates.addAll(forRunfiles ? executionDynamicLibraries : dynamicLibraries); |
| } else { |
| // First choice is the dynamicLibraries. |
| candidates.addAll(forRunfiles ? executionDynamicLibraries : dynamicLibraries); |
| if (preferPic) { |
| // Second choice is the staticPicLibraries (at least they're PIC, so we won't get a |
| // link error). |
| candidates.addAll(picStaticLibraries); |
| candidates.addAll(staticLibraries); |
| } else { |
| candidates.addAll(staticLibraries); |
| candidates.addAll(picStaticLibraries); |
| } |
| } |
| return filterCandidates(candidates); |
| } |
| |
| /** |
| * Helper method to filter the candidates by removing equivalent library |
| * entries from the list of candidates. |
| * |
| * @param candidates the library candidates to filter |
| * @return the list of libraries with equivalent duplicate libraries removed. |
| */ |
| private List<LibraryToLink> filterCandidates(List<LibraryToLink> candidates) { |
| List<LibraryToLink> libraries = new ArrayList<>(); |
| Set<String> identifiers = new HashSet<>(); |
| for (LibraryToLink library : candidates) { |
| Preconditions.checkNotNull(library.getLibraryIdentifier()); |
| if (identifiers.add(library.getLibraryIdentifier())) { |
| libraries.add(library); |
| } |
| } |
| return libraries; |
| } |
| |
| /** |
| * Returns the library identifier of an artifact: a string that is different for different |
| * libraries, but is the same for the shared, static and pic versions of the same library. |
| */ |
| public static String libraryIdentifierOf(Artifact libraryArtifact) { |
| String name = libraryArtifact.getRootRelativePath().getPathString(); |
| String basename = FileSystemUtils.removeExtension(name); |
| // Need to special-case file types with double extension. |
| return name.endsWith(".pic.a") |
| ? FileSystemUtils.removeExtension(basename) |
| : name.endsWith(".nopic.a") |
| ? FileSystemUtils.removeExtension(basename) |
| : name.endsWith(".pic.lo") |
| ? FileSystemUtils.removeExtension(basename) |
| : basename; |
| } |
| |
| public static Builder builder() { |
| return new Builder(); |
| } |
| |
| public static final class Builder { |
| private final Set<LibraryToLink> staticLibraries = new LinkedHashSet<>(); |
| private final Set<LibraryToLink> picStaticLibraries = new LinkedHashSet<>(); |
| private final Set<LibraryToLink> dynamicLibraries = new LinkedHashSet<>(); |
| private final Set<LibraryToLink> executionDynamicLibraries = new LinkedHashSet<>(); |
| |
| public CcLinkingOutputs build() { |
| return new CcLinkingOutputs(ImmutableList.copyOf(staticLibraries), |
| ImmutableList.copyOf(picStaticLibraries), ImmutableList.copyOf(dynamicLibraries), |
| ImmutableList.copyOf(executionDynamicLibraries)); |
| } |
| |
| public Builder merge(CcLinkingOutputs outputs) { |
| staticLibraries.addAll(outputs.getStaticLibraries()); |
| picStaticLibraries.addAll(outputs.getPicStaticLibraries()); |
| dynamicLibraries.addAll(outputs.getDynamicLibraries()); |
| executionDynamicLibraries.addAll(outputs.getExecutionDynamicLibraries()); |
| return this; |
| } |
| |
| public Builder addStaticLibrary(LibraryToLink library) { |
| staticLibraries.add(library); |
| return this; |
| } |
| |
| public Builder addStaticLibraries(Iterable<LibraryToLink> libraries) { |
| Iterables.addAll(staticLibraries, libraries); |
| return this; |
| } |
| |
| public Builder addPicStaticLibrary(LibraryToLink library) { |
| picStaticLibraries.add(library); |
| return this; |
| } |
| |
| public Builder addPicStaticLibraries(Iterable<LibraryToLink> libraries) { |
| Iterables.addAll(picStaticLibraries, libraries); |
| return this; |
| } |
| |
| public Builder addDynamicLibrary(LibraryToLink library) { |
| dynamicLibraries.add(library); |
| return this; |
| } |
| |
| public Builder addDynamicLibraries(Iterable<LibraryToLink> libraries) { |
| Iterables.addAll(dynamicLibraries, libraries); |
| return this; |
| } |
| |
| public Builder addExecutionDynamicLibrary(LibraryToLink library) { |
| executionDynamicLibraries.add(library); |
| return this; |
| } |
| |
| public Builder addExecutionDynamicLibraries(Iterable<LibraryToLink> libraries) { |
| Iterables.addAll(executionDynamicLibraries, libraries); |
| return this; |
| } |
| } |
| } |