| // Copyright 2015 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.nativedeps; |
| |
| import static com.google.devtools.build.lib.rules.cpp.CppRuleClasses.STATIC_LINKING_MODE; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.collect.Iterables; |
| import com.google.common.collect.Sets; |
| import com.google.devtools.build.lib.actions.Artifact; |
| import com.google.devtools.build.lib.actions.ArtifactRoot; |
| import com.google.devtools.build.lib.analysis.RuleContext; |
| import com.google.devtools.build.lib.analysis.actions.ActionConstructionContext; |
| import com.google.devtools.build.lib.analysis.actions.SymlinkAction; |
| import com.google.devtools.build.lib.analysis.config.BuildConfiguration; |
| import com.google.devtools.build.lib.cmdline.RepositoryName; |
| import com.google.devtools.build.lib.collect.nestedset.NestedSet; |
| import com.google.devtools.build.lib.packages.RuleClass.ConfiguredTargetFactory.RuleErrorException; |
| import com.google.devtools.build.lib.rules.cpp.ArtifactCategory; |
| import com.google.devtools.build.lib.rules.cpp.CcCommon; |
| import com.google.devtools.build.lib.rules.cpp.CcInfo; |
| import com.google.devtools.build.lib.rules.cpp.CcToolchainFeatures.FeatureConfiguration; |
| import com.google.devtools.build.lib.rules.cpp.CcToolchainProvider; |
| import com.google.devtools.build.lib.rules.cpp.CppBuildInfo; |
| import com.google.devtools.build.lib.rules.cpp.CppConfiguration; |
| import com.google.devtools.build.lib.rules.cpp.CppHelper; |
| import com.google.devtools.build.lib.rules.cpp.CppLinkAction; |
| import com.google.devtools.build.lib.rules.cpp.CppLinkActionBuilder; |
| import com.google.devtools.build.lib.rules.cpp.CppRuleClasses; |
| import com.google.devtools.build.lib.rules.cpp.CppSemantics; |
| import com.google.devtools.build.lib.rules.cpp.FdoContext; |
| import com.google.devtools.build.lib.rules.cpp.LibraryToLink; |
| import com.google.devtools.build.lib.rules.cpp.LibraryToLink.CcLinkingContext; |
| import com.google.devtools.build.lib.rules.cpp.LibraryToLink.CcLinkingContext.Linkstamp; |
| import com.google.devtools.build.lib.rules.cpp.Link; |
| import com.google.devtools.build.lib.rules.cpp.Link.LinkTargetType; |
| import com.google.devtools.build.lib.rules.cpp.Link.LinkingMode; |
| import com.google.devtools.build.lib.rules.cpp.LtoCompilationContext; |
| import com.google.devtools.build.lib.util.Fingerprint; |
| import com.google.devtools.build.lib.vfs.PathFragment; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * Helper class to create a dynamic library for rules which support integration with native code. |
| * |
| * <p>This library gets created by the build system by linking all C++ libraries in the transitive |
| * closure of the dependencies into a standalone dynamic library, with some exceptions. It usually |
| * does not include neverlink libraries or C++ binaries (or their transitive dependencies). Note |
| * that some rules are implicitly neverlink. |
| */ |
| public abstract class NativeDepsHelper { |
| /** |
| * An implementation of {@link |
| * com.google.devtools.build.lib.rules.cpp.CppLinkAction.LinkArtifactFactory} that can create |
| * artifacts anywhere. |
| * |
| * <p>Necessary because the actions of nativedeps libraries should be shareable, and thus cannot |
| * be under the package directory. |
| */ |
| private static final CppLinkAction.LinkArtifactFactory SHAREABLE_LINK_ARTIFACT_FACTORY = |
| new CppLinkAction.LinkArtifactFactory() { |
| @Override |
| public Artifact create( |
| ActionConstructionContext actionConstructionContext, |
| RepositoryName repositoryName, |
| BuildConfiguration configuration, |
| PathFragment rootRelativePath) { |
| return actionConstructionContext.getShareableArtifact( |
| rootRelativePath, configuration.getBinDirectory(repositoryName)); |
| } |
| }; |
| |
| private NativeDepsHelper() {} |
| |
| private static final String ANDROID_UNIQUE_DIR = "nativedeps"; |
| |
| /** |
| * Creates an Action to create a dynamic library for Android by linking all native code (C/C++) |
| * libraries in the transitive dependency closure of a rule. |
| * |
| * <p>We link the native deps in the equivalent of linkstatic=1, linkshared=1 mode. |
| * |
| * <p>linkstatic=1 means mostly-static mode, i.e. we select the ".a" (or ".pic.a") files, but we |
| * don't include "-static" in linkopts. |
| * |
| * <p>linkshared=1 means we prefer the ".pic.a" files to the ".a" files, and the LinkTargetType is |
| * set to DYNAMIC_LIBRARY which causes Link.java to include "-shared" in the linker options. |
| * |
| * <p>It is possible that this function may have no work to do if there are no native libraries in |
| * the transitive closure, or if the only native libraries in the transitive closure are already |
| * shared libraries. In this case, this function returns {@code null}. |
| * |
| * @param ruleContext the rule context to determine the native deps library |
| * @param ccInfo the {@link CcInfo} for the rule, collected with linkstatic = 1 and linkshared = 1 |
| * @param cppSemantics to use for linkstamp compiles |
| * @return the native deps library, or null if there was no code which needed to be linked in the |
| * transitive closure. |
| */ |
| public static Artifact linkAndroidNativeDepsIfPresent( |
| final RuleContext ruleContext, |
| CcInfo ccInfo, |
| final BuildConfiguration configuration, |
| CcToolchainProvider toolchain, |
| CppSemantics cppSemantics) |
| throws InterruptedException, RuleErrorException { |
| if (!containsCodeToLink(ccInfo.getCcLinkingContext().getLibraries())) { |
| return null; |
| } |
| |
| PathFragment labelName = PathFragment.create(ruleContext.getLabel().getName()); |
| String libraryIdentifier = ruleContext.getUniqueDirectory(ANDROID_UNIQUE_DIR) |
| .getRelative(labelName.replaceName("lib" + labelName.getBaseName())) |
| .getPathString(); |
| Artifact nativeDeps = ruleContext.getUniqueDirectoryArtifact(ANDROID_UNIQUE_DIR, |
| labelName.replaceName("lib" + labelName.getBaseName() + ".so"), |
| configuration.getBinDirectory(ruleContext.getRule().getRepository())); |
| |
| return createNativeDepsAction( |
| ruleContext, |
| ccInfo, |
| /* extraLinkOpts= */ ImmutableList.of(), |
| configuration, |
| toolchain, |
| nativeDeps, |
| libraryIdentifier, |
| configuration.getBinDirectory(ruleContext.getRule().getRepository()), |
| /* useDynamicRuntime= */ false, |
| cppSemantics) |
| .getLibrary(); |
| } |
| |
| /** Determines if there is any code to be linked in the input iterable. */ |
| private static boolean containsCodeToLink(Iterable<LibraryToLink> libraries) { |
| for (LibraryToLink library : libraries) { |
| if (containsCodeToLink(library)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /** Determines if the input library is or contains an archive which must be linked. */ |
| private static boolean containsCodeToLink(LibraryToLink library) { |
| if (library.getStaticLibrary() == null && library.getPicStaticLibrary() == null) { |
| // this is a shared library so we're going to have to copy it |
| return false; |
| } |
| Iterable<Artifact> objectFiles; |
| if (library.getObjectFiles() != null) { |
| objectFiles = library.getObjectFiles(); |
| } else if (library.getPicObjectFiles() != null) { |
| objectFiles = library.getPicObjectFiles(); |
| } else { |
| // this is an opaque library so we're going to have to link it |
| return true; |
| } |
| for (Artifact object : objectFiles) { |
| if (!Link.SHARED_LIBRARY_FILETYPES.matches(object.getFilename())) { |
| // this library was built with a non-shared-library object so we should link it |
| return true; |
| } |
| } |
| // there weren't any artifacts besides shared libraries compiled in the library |
| return false; |
| } |
| |
| public static NativeDepsRunfiles createNativeDepsAction( |
| final RuleContext ruleContext, |
| CcInfo ccInfo, |
| Collection<String> extraLinkOpts, |
| BuildConfiguration configuration, |
| CcToolchainProvider toolchain, |
| Artifact nativeDeps, |
| String libraryIdentifier, |
| ArtifactRoot bindirIfShared, |
| boolean useDynamicRuntime, |
| CppSemantics cppSemantics) |
| throws InterruptedException, RuleErrorException { |
| CcLinkingContext ccLinkingContext = ccInfo.getCcLinkingContext(); |
| Preconditions.checkState( |
| ruleContext.isLegalFragment(CppConfiguration.class), |
| "%s does not have access to CppConfiguration", |
| ruleContext.getRule().getRuleClass()); |
| List<String> linkopts = new ArrayList<>(extraLinkOpts); |
| linkopts.addAll(ccLinkingContext.getFlattenedUserLinkFlags()); |
| |
| CppHelper.checkLinkstampsUnique(ruleContext, ccLinkingContext.getLinkstamps()); |
| ImmutableSet<Linkstamp> linkstamps = ImmutableSet.copyOf(ccLinkingContext.getLinkstamps()); |
| List<Artifact> buildInfoArtifacts = linkstamps.isEmpty() |
| ? ImmutableList.<Artifact>of() |
| : ruleContext.getAnalysisEnvironment().getBuildInfo( |
| ruleContext, CppBuildInfo.KEY, configuration); |
| |
| boolean shareNativeDeps = configuration.getFragment(CppConfiguration.class).shareNativeDeps(); |
| NestedSet<LibraryToLink> linkerInputs = ccLinkingContext.getLibraries(); |
| Artifact sharedLibrary; |
| if (shareNativeDeps) { |
| PathFragment sharedPath = |
| getSharedNativeDepsPath( |
| ccLinkingContext.getStaticModeParamsForDynamicLibraryLibraries(), |
| linkopts, |
| linkstamps.stream() |
| .map(CcLinkingContext.Linkstamp::getArtifact) |
| .collect(ImmutableList.toImmutableList()), |
| buildInfoArtifacts, |
| ruleContext.getFeatures()); |
| libraryIdentifier = sharedPath.getPathString(); |
| sharedLibrary = ruleContext.getShareableArtifact( |
| sharedPath.replaceName(sharedPath.getBaseName() + ".so"), |
| configuration.getBinDirectory(ruleContext.getRule().getRepository())); |
| } else { |
| sharedLibrary = nativeDeps; |
| } |
| FdoContext fdoContext = toolchain.getFdoContext(); |
| FeatureConfiguration featureConfiguration = |
| CcCommon.configureFeaturesOrReportRuleError( |
| ruleContext, |
| /* requestedFeatures= */ ImmutableSet.<String>builder() |
| .addAll(ruleContext.getFeatures()) |
| .add(STATIC_LINKING_MODE) |
| .build(), |
| /* unsupportedFeatures= */ ruleContext.getDisabledFeatures(), |
| toolchain); |
| CppLinkActionBuilder builder = |
| new CppLinkActionBuilder( |
| ruleContext, |
| sharedLibrary, |
| configuration, |
| toolchain, |
| fdoContext, |
| featureConfiguration, |
| cppSemantics); |
| if (useDynamicRuntime) { |
| builder.setRuntimeInputs( |
| ArtifactCategory.DYNAMIC_LIBRARY, |
| toolchain.getDynamicRuntimeLinkMiddleman(ruleContext, featureConfiguration), |
| toolchain.getDynamicRuntimeLinkInputs(ruleContext, featureConfiguration)); |
| } else { |
| builder.setRuntimeInputs( |
| ArtifactCategory.STATIC_LIBRARY, |
| toolchain.getStaticRuntimeLinkMiddleman(ruleContext, featureConfiguration), |
| toolchain.getStaticRuntimeLinkInputs(ruleContext, featureConfiguration)); |
| } |
| LtoCompilationContext.Builder ltoCompilationContext = new LtoCompilationContext.Builder(); |
| for (LibraryToLink lib : linkerInputs) { |
| if (lib.getPicLtoCompilationContext() != null |
| && !lib.getPicLtoCompilationContext().isEmpty()) { |
| ltoCompilationContext.addAll(lib.getPicLtoCompilationContext()); |
| } else if (lib.getLtoCompilationContext() != null |
| && !lib.getLtoCompilationContext().isEmpty()) { |
| ltoCompilationContext.addAll(lib.getLtoCompilationContext()); |
| } |
| } |
| |
| Iterable<Artifact> nonCodeInputs = ccLinkingContext.getNonCodeInputs(); |
| if (nonCodeInputs == null) { |
| nonCodeInputs = ImmutableList.of(); |
| } |
| |
| builder |
| .setLinkArtifactFactory(SHAREABLE_LINK_ARTIFACT_FACTORY) |
| .setLinkerFiles(toolchain.getLinkerFiles()) |
| .addLibrariesToLink(linkerInputs) |
| .setLinkType(LinkTargetType.DYNAMIC_LIBRARY) |
| .setLinkingMode(LinkingMode.STATIC) |
| .setLibraryIdentifier(libraryIdentifier) |
| .addLinkopts(linkopts) |
| .setNativeDeps(true) |
| .addLinkstamps(linkstamps) |
| .addLtoCompilationContext(ltoCompilationContext.build()) |
| .addNonCodeInputs(nonCodeInputs); |
| |
| if (builder.hasLtoBitcodeInputs() && featureConfiguration.isEnabled(CppRuleClasses.THIN_LTO)) { |
| builder.setLtoIndexing(true); |
| builder.setUsePicForLtoBackendActions( |
| toolchain.usePicForDynamicLibraries(featureConfiguration)); |
| CppLinkAction indexAction = builder.build(); |
| if (indexAction != null) { |
| ruleContext.registerAction(indexAction); |
| } |
| builder.setLtoIndexing(false); |
| } |
| |
| CppLinkAction linkAction = builder.build(); |
| ruleContext.registerAction(linkAction); |
| Artifact linkerOutput = linkAction.getPrimaryOutput(); |
| |
| if (shareNativeDeps) { |
| // Collect dynamic-linker-resolvable symlinks for C++ runtime library dependencies. |
| // Note we only need these symlinks when --share_native_deps is on, as shared native deps |
| // mangle path names such that the library's conventional _solib RPATH entry |
| // no longer resolves (because the target directory's relative depth gets lost). |
| List<Artifact> runtimeSymlinks; |
| if (useDynamicRuntime) { |
| runtimeSymlinks = new LinkedList<>(); |
| for (final Artifact runtimeInput : |
| toolchain.getDynamicRuntimeLinkInputs(ruleContext, featureConfiguration)) { |
| final Artifact runtimeSymlink = |
| ruleContext.getPackageRelativeArtifact( |
| getRuntimeLibraryPath(ruleContext, runtimeInput), bindirIfShared); |
| // Since runtime library symlinks are underneath the target's output directory and |
| // multiple targets may share the same output directory, we need to make sure this |
| // symlink's generating action is only set once. |
| ruleContext.registerAction(SymlinkAction.toArtifact( |
| ruleContext.getActionOwner(), runtimeInput, runtimeSymlink, null)); |
| runtimeSymlinks.add(runtimeSymlink); |
| } |
| } else { |
| runtimeSymlinks = ImmutableList.of(); |
| } |
| |
| ruleContext.registerAction(SymlinkAction.toArtifact( |
| ruleContext.getActionOwner(), linkerOutput, nativeDeps, null)); |
| return new NativeDepsRunfiles(nativeDeps, runtimeSymlinks); |
| } |
| |
| return new NativeDepsRunfiles(linkerOutput, ImmutableList.<Artifact>of()); |
| } |
| |
| /** |
| * Returns the path, relative to the runfiles prefix, of a runtime library |
| * symlink for the native library for the specified rule. |
| */ |
| private static PathFragment getRuntimeLibraryPath(RuleContext ruleContext, Artifact lib) { |
| PathFragment relativePath = PathFragment.create(ruleContext.getLabel().getName()); |
| PathFragment libParentDir = |
| relativePath.replaceName(lib.getExecPath().getParentDirectory().getBaseName()); |
| String libName = lib.getExecPath().getBaseName(); |
| return libParentDir.getRelative(libName); |
| } |
| |
| /** |
| * Returns the path of the shared native library. The name must be |
| * generated based on the rule-specific inputs to the link actions. At this |
| * point this includes order-sensitive list of linker inputs and options |
| * collected from the transitive closure and linkstamp-related artifacts that |
| * are compiled during linking. All those inputs can be affected by modifying |
| * target attributes (srcs/deps/stamp/etc). However, target build |
| * configuration can be ignored since it will either change output directory |
| * (in case of different configuration instances) or will not affect anything |
| * (if two targets use same configuration). Final goal is for all native |
| * libraries that use identical linker command to use same output name. |
| * |
| * <p>TODO(bazel-team): (2010) Currently process of identifying parameters that can |
| * affect native library name is manual and should be kept in sync with the |
| * code in the CppLinkAction.Builder/CppLinkAction/Link classes which are |
| * responsible for generating linker command line. Ideally we should reuse |
| * generated command line for both purposes - selecting a name of the |
| * native library and using it as link action payload. For now, correctness |
| * of the method below is only ensured by validations in the |
| * CppLinkAction.Builder.build() method. |
| */ |
| private static PathFragment getSharedNativeDepsPath(Iterable<Artifact> linkerInputs, |
| Collection<String> linkopts, Iterable<Artifact> linkstamps, |
| Iterable<Artifact> buildInfoArtifacts, Collection<String> features) { |
| Fingerprint fp = new Fingerprint(); |
| int linkerInputsSize = 0; |
| for (Artifact input : linkerInputs) { |
| fp.addString(input.getExecPathString()); |
| linkerInputsSize++; |
| } |
| fp.addStrings(linkopts); |
| int linkstampsSize = 0; |
| for (Artifact input : linkstamps) { |
| fp.addString(input.getExecPathString()); |
| linkstampsSize++; |
| } |
| // TODO(b/120206809): remove debugging info here (and in this whole filename construction). |
| String linkstampsString = Integer.toString(linkstampsSize); |
| if (linkstampsSize > 1) { |
| Set<Artifact> identitySet = Sets.newIdentityHashSet(); |
| Iterables.addAll(identitySet, linkstamps); |
| if (identitySet.size() < linkstampsSize) { |
| linkstampsString += "_" + identitySet.size(); |
| } |
| ImmutableSet<Artifact> uniqueLinkStamps = ImmutableSet.copyOf(linkstamps); |
| if (uniqueLinkStamps.size() < linkstampsSize) { |
| linkstampsString += "__" + uniqueLinkStamps.size(); |
| } |
| } |
| int buildInfoSize = 0; |
| for (Artifact input : buildInfoArtifacts) { |
| fp.addString(input.getExecPathString()); |
| buildInfoSize++; |
| } |
| for (String feature : features) { |
| fp.addString(feature); |
| } |
| return PathFragment.create( |
| "_nativedeps/" |
| + linkerInputsSize |
| + "_" |
| + linkopts.size() |
| + "_" |
| + linkstampsString |
| + "_" |
| + buildInfoSize |
| + "_" |
| + features.size() |
| + "_" |
| + fp.hexDigestAndReset()); |
| } |
| } |
