src/main/java/com/google/devtools/build/lib/rules/cpp/LinkBuildVariables.java - bazel - Git at Google

 // 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.base.Predicates;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.rules.cpp.CcToolchainFeatures.FeatureConfiguration;
 import com.google.devtools.build.lib.rules.cpp.CcToolchainVariables.SequenceBuilder;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import net.starlark.java.eval.EvalException;

 // LINT.IfChange
 /** Enum covering all build variables we create for all various {@link CppLinkAction}. */
 public enum LinkBuildVariables {
   /** Entries in the linker runtime search path (usually set by -rpath flag) */
   RUNTIME_LIBRARY_SEARCH_DIRECTORIES("runtime_library_search_directories"),
   /** Entries in the linker search path (usually set by -L flag) */
   LIBRARY_SEARCH_DIRECTORIES("library_search_directories"),
   /** Flags providing files to link as inputs in the linker invocation */
   LIBRARIES_TO_LINK("libraries_to_link"),
   /** Thinlto param file produced by thinlto-indexing action consumed by the final link action. */
   THINLTO_PARAM_FILE("thinlto_param_file"),
   /** Location of def file used on Windows with MSVC */
   DEF_FILE_PATH("def_file_path"),
   /** Location where hinlto should write thinlto_param_file flags when indexing. */
   THINLTO_INDEXING_PARAM_FILE("thinlto_indexing_param_file"),

   THINLTO_PREFIX_REPLACE("thinlto_prefix_replace"),
   /**
    * A build variable to let the LTO indexing step know how to map from the minimized bitcode file
    * to the full bitcode file used by the LTO Backends.
    */
   THINLTO_OBJECT_SUFFIX_REPLACE("thinlto_object_suffix_replace"),
   /**
    * A build variable for the path to the merged object file, which is an object file that is
    * created during the LTO indexing step and needs to be passed to the final link.
    */
   THINLTO_MERGED_OBJECT_FILE("thinlto_merged_object_file"),
   /** Location of linker param file created by bazel to overcome command line length limit */
   LINKER_PARAM_FILE("linker_param_file"),
   /** execpath of the output of the linker. */
   OUTPUT_EXECPATH("output_execpath"),
   /** "yes"|"no" depending on whether interface library should be generated. */
   GENERATE_INTERFACE_LIBRARY("generate_interface_library"),
   /** Path to the interface library builder tool. */
   INTERFACE_LIBRARY_BUILDER("interface_library_builder_path"),
   /** Input for the interface library ifso builder tool. */
   INTERFACE_LIBRARY_INPUT("interface_library_input_path"),
   /** Path where to generate interface library using the ifso builder tool. */
   INTERFACE_LIBRARY_OUTPUT("interface_library_output_path"),
   /** Linker flags coming from the --linkopt or linkopts attribute. */
   USER_LINK_FLAGS("user_link_flags"),
   /** A build variable giving linkstamp paths. */
   LINKSTAMP_PATHS("linkstamp_paths"),
   /** Presence of this variable indicates that PIC code should be generated. */
   FORCE_PIC("force_pic"),
   /** Presence of this variable indicates that the debug symbols should be stripped. */
   STRIP_DEBUG_SYMBOLS("strip_debug_symbols"),
   /** Truthy when current action is a cc_test linking action, falsey otherwise. */
   IS_CC_TEST("is_cc_test"),
   /**
    * Presence of this variable indicates that files were compiled with fission (debug info is in
    * .dwo files instead of .o files and linker needs to know).
    */
   IS_USING_FISSION("is_using_fission"),
   /** Path to the fdo instrument. */
   FDO_INSTRUMENT_PATH("fdo_instrument_path"),
   /** Path to the context sensitive fdo instrument. */
   CS_FDO_INSTRUMENT_PATH("cs_fdo_instrument_path"),
   /** Path to the Propeller Optimize linker profile artifact */
   PROPELLER_OPTIMIZE_LD_PATH("propeller_optimize_ld_path"),
   /** The name of the runtime solib symlink of the shared library. */
   RUNTIME_SOLIB_NAME("runtime_solib_name");

   private final String variableName;

   LinkBuildVariables(String variableName) {
     this.variableName = variableName;
   }

   public String getVariableName() {
     return variableName;
   }

   public static CcToolchainVariables.Builder setupLtoIndexingVariables(
       PathFragment binDirectoryPath,
       String thinltoParamFile,
       String thinltoMergedObjectFile,
       CcToolchainProvider ccToolchainProvider,
       FeatureConfiguration featureConfiguration,
       PathFragment ltoOutputRootPrefix,
       PathFragment ltoObjRootPrefix)
       throws EvalException {
     CcToolchainVariables.Builder buildVariables = CcToolchainVariables.builder();

     // This is a lto-indexing action and we want it to populate param file.
     buildVariables.addStringVariable(
         THINLTO_INDEXING_PARAM_FILE.getVariableName(), thinltoParamFile);
     // TODO(b/33846234): Remove once all the relevant crosstools don't depend on the variable.
     buildVariables.addStringVariable("thinlto_optional_params_file", "=" + thinltoParamFile);

     // Given "fullbitcode_prefix;thinlto_index_prefix;native_object_prefix", replaces
     // fullbitcode_prefix with thinlto_index_prefix to generate the index and imports files.
     // fullbitcode_prefix is the empty string because we are appending a prefix to the fullbitcode
     // instead of replacing it. This argument is passed to the linker.
     // The native objects generated after the LTOBackend action are stored in a directory by
     // replacing the prefix "fullbitcode_prefix" with "native_object_prefix", and this is used
     // when generating the param file in the indexing step, which will be used during the final
     // link step.
     if (!ltoOutputRootPrefix.equals(ltoObjRootPrefix)) {
       buildVariables.addStringVariable(
           THINLTO_PREFIX_REPLACE.getVariableName(),
           ";"
               + binDirectoryPath.getRelative(ltoOutputRootPrefix)
               + "/;"
               + binDirectoryPath.getRelative(ltoObjRootPrefix)
               + "/");
     } else {
       buildVariables.addStringVariable(
           THINLTO_PREFIX_REPLACE.getVariableName(),
           ";" + binDirectoryPath.getRelative(ltoOutputRootPrefix) + "/");
     }

     String objectFileExtension =
         ccToolchainProvider
             .getFeatures()
             .getArtifactNameExtensionForCategory(ArtifactCategory.OBJECT_FILE);
     if (!featureConfiguration.isEnabled(CppRuleClasses.NO_USE_LTO_INDEXING_BITCODE_FILE)) {
       buildVariables.addStringVariable(
           THINLTO_OBJECT_SUFFIX_REPLACE.getVariableName(),
           Iterables.getOnlyElement(CppFileTypes.LTO_INDEXING_OBJECT_FILE.getExtensions())
               + ";"
               + objectFileExtension);
     }

     buildVariables.addStringVariable(
         THINLTO_MERGED_OBJECT_FILE.getVariableName(), thinltoMergedObjectFile);

     buildVariables.addStringVariable(GENERATE_INTERFACE_LIBRARY.getVariableName(), "no");
     buildVariables.addStringVariable(INTERFACE_LIBRARY_BUILDER.getVariableName(), "ignored");
     buildVariables.addStringVariable(INTERFACE_LIBRARY_INPUT.getVariableName(), "ignored");
     buildVariables.addStringVariable(INTERFACE_LIBRARY_OUTPUT.getVariableName(), "ignored");
     return buildVariables;
   }

   public static CcToolchainVariables.Builder setupLinkingVariables(
       String outputFile,
       String runtimeSolibName,
       String thinltoParamFile,
       CcToolchainProvider ccToolchainProvider,
       FeatureConfiguration featureConfiguration,
       String interfaceLibraryBuilder,
       String interfaceLibraryOutput,
       FdoContext fdoContext)
       throws EvalException {
     CcToolchainVariables.Builder buildVariables = CcToolchainVariables.builder();
     if (thinltoParamFile != null) {
       // This is a normal link action and we need to use param file created by lto-indexing.
       buildVariables.addStringVariable(
           LinkBuildVariables.THINLTO_PARAM_FILE.getVariableName(), thinltoParamFile);
     }

     // output exec path
     buildVariables.addStringVariable(
         LinkBuildVariables.OUTPUT_EXECPATH.getVariableName(), outputFile);

     buildVariables.addStringVariable(
         LinkBuildVariables.RUNTIME_SOLIB_NAME.getVariableName(), runtimeSolibName);

     if (!ccToolchainProvider.isToolConfiguration()
         && fdoContext != null
         && featureConfiguration.isEnabled(CppRuleClasses.PROPELLER_OPTIMIZE)
         && fdoContext.getPropellerOptimizeInputFile() != null
         && fdoContext.getPropellerOptimizeInputFile().getLdArtifact() != null) {
       buildVariables.addStringVariable(
           LinkBuildVariables.PROPELLER_OPTIMIZE_LD_PATH.getVariableName(),
           fdoContext.getPropellerOptimizeInputFile().getLdArtifact().getExecPathString());
     }

     boolean shouldGenerateInterfaceLibrary =
         outputFile != null && interfaceLibraryBuilder != null && interfaceLibraryOutput != null;
     buildVariables.addStringVariable(
         GENERATE_INTERFACE_LIBRARY.getVariableName(),
         shouldGenerateInterfaceLibrary ? "yes" : "no");
     buildVariables.addStringVariable(
         INTERFACE_LIBRARY_BUILDER.getVariableName(),
         shouldGenerateInterfaceLibrary ? interfaceLibraryBuilder : "ignored");
     buildVariables.addStringVariable(
         INTERFACE_LIBRARY_INPUT.getVariableName(),
         shouldGenerateInterfaceLibrary ? outputFile : "ignored");
     buildVariables.addStringVariable(
         INTERFACE_LIBRARY_OUTPUT.getVariableName(),
         shouldGenerateInterfaceLibrary ? interfaceLibraryOutput : "ignored");

     return buildVariables;
   }

   public static CcToolchainVariables.Builder setupCommonVariables(
       boolean isUsingLinkerNotArchiver,
       boolean isCreatingSharedLibrary,
       String paramFile,
       boolean mustKeepDebug,
       CcToolchainProvider ccToolchainProvider,
       FeatureConfiguration featureConfiguration,
       boolean useTestOnlyFlags,
       Iterable<String> userLinkFlags,
       FdoContext fdoContext,
       NestedSet<String> runtimeLibrarySearchDirectories,
       SequenceBuilder librariesToLink,
       NestedSet<String> librarySearchDirectories)
       throws EvalException {
     CcToolchainVariables.Builder buildVariables =
         CcToolchainVariables.builder(ccToolchainProvider.getBuildVars());
     CppConfiguration cppConfiguration = ccToolchainProvider.getCppConfiguration();

     // pic
     if (cppConfiguration.forcePic()) {
       buildVariables.addStringVariable(FORCE_PIC.getVariableName(), "");
     }

     if (!mustKeepDebug && cppConfiguration.shouldStripBinaries()) {
       buildVariables.addStringVariable(STRIP_DEBUG_SYMBOLS.getVariableName(), "");
     }

     if (isUsingLinkerNotArchiver
         && CcToolchainProvider.shouldCreatePerObjectDebugInfo(
             featureConfiguration, cppConfiguration)) {
       buildVariables.addStringVariable(IS_USING_FISSION.getVariableName(), "");
     }

     if (!cppConfiguration.useCcTestFeature()) {
       buildVariables.addBooleanValue(IS_CC_TEST.getVariableName(), useTestOnlyFlags);
     }

     buildVariables.addStringSequenceVariable(
         RUNTIME_LIBRARY_SEARCH_DIRECTORIES.getVariableName(), runtimeLibrarySearchDirectories);

     if (librariesToLink != null) {
       buildVariables.addCustomBuiltVariable(LIBRARIES_TO_LINK.getVariableName(), librariesToLink);
     }

     buildVariables.addStringSequenceVariable(
         LIBRARY_SEARCH_DIRECTORIES.getVariableName(), librarySearchDirectories);

     if (paramFile != null) {
       buildVariables.addStringVariable(LINKER_PARAM_FILE.getVariableName(), paramFile);
     }

     if (featureConfiguration.isEnabled(CppRuleClasses.FDO_INSTRUMENT)) {
       Preconditions.checkArgument(fdoContext.getBranchFdoProfile() == null);
       String fdoInstrument = cppConfiguration.getFdoInstrument();
       Preconditions.checkNotNull(fdoInstrument);
       buildVariables.addStringVariable(FDO_INSTRUMENT_PATH.getVariableName(), fdoInstrument);
     } else if (featureConfiguration.isEnabled(CppRuleClasses.CS_FDO_INSTRUMENT)) {
       String csFdoInstrument = ccToolchainProvider.getCSFdoInstrument();
       Preconditions.checkNotNull(csFdoInstrument);
       buildVariables.addStringVariable(CS_FDO_INSTRUMENT_PATH.getVariableName(), csFdoInstrument);
     }

     // For now, silently ignore linkopts if this is a static library
     userLinkFlags = isUsingLinkerNotArchiver ? userLinkFlags : ImmutableList.of();

     buildVariables.addStringSequenceVariable(
         LinkBuildVariables.USER_LINK_FLAGS.getVariableName(),
         removePieIfCreatingSharedLibrary(isCreatingSharedLibrary, userLinkFlags));
     return buildVariables;
   }

   private static Iterable<String> removePieIfCreatingSharedLibrary(
       boolean isCreatingSharedLibrary, Iterable<String> flags) {
     if (isCreatingSharedLibrary) {
       return Iterables.filter(
           flags,
           Predicates.not(
               Predicates.or(Predicates.equalTo("-pie"), Predicates.equalTo("-Wl,-pie"))));
     } else {
       return flags;
     }
   }
 }

 // LINT.ThenChange(//src/main/starlark/builtins_bzl/common/cc/link/link_build_variables.bzl)
	// 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.base.Predicates;
	import com.google.common.collect.ImmutableList;
	import com.google.common.collect.Iterables;
	import com.google.devtools.build.lib.collect.nestedset.NestedSet;
	import com.google.devtools.build.lib.rules.cpp.CcToolchainFeatures.FeatureConfiguration;
	import com.google.devtools.build.lib.rules.cpp.CcToolchainVariables.SequenceBuilder;
	import com.google.devtools.build.lib.vfs.PathFragment;
	import net.starlark.java.eval.EvalException;

	// LINT.IfChange
	/** Enum covering all build variables we create for all various {@link CppLinkAction}. */
	public enum LinkBuildVariables {
	/** Entries in the linker runtime search path (usually set by -rpath flag) */
	RUNTIME_LIBRARY_SEARCH_DIRECTORIES("runtime_library_search_directories"),
	/** Entries in the linker search path (usually set by -L flag) */
	LIBRARY_SEARCH_DIRECTORIES("library_search_directories"),
	/** Flags providing files to link as inputs in the linker invocation */
	LIBRARIES_TO_LINK("libraries_to_link"),
	/** Thinlto param file produced by thinlto-indexing action consumed by the final link action. */
	THINLTO_PARAM_FILE("thinlto_param_file"),
	/** Location of def file used on Windows with MSVC */
	DEF_FILE_PATH("def_file_path"),
	/** Location where hinlto should write thinlto_param_file flags when indexing. */
	THINLTO_INDEXING_PARAM_FILE("thinlto_indexing_param_file"),

	THINLTO_PREFIX_REPLACE("thinlto_prefix_replace"),
	/**
	* A build variable to let the LTO indexing step know how to map from the minimized bitcode file
	* to the full bitcode file used by the LTO Backends.
	*/
	THINLTO_OBJECT_SUFFIX_REPLACE("thinlto_object_suffix_replace"),
	/**
	* A build variable for the path to the merged object file, which is an object file that is
	* created during the LTO indexing step and needs to be passed to the final link.
	*/
	THINLTO_MERGED_OBJECT_FILE("thinlto_merged_object_file"),
	/** Location of linker param file created by bazel to overcome command line length limit */
	LINKER_PARAM_FILE("linker_param_file"),
	/** execpath of the output of the linker. */
	OUTPUT_EXECPATH("output_execpath"),
	/** "yes"\|"no" depending on whether interface library should be generated. */
	GENERATE_INTERFACE_LIBRARY("generate_interface_library"),
	/** Path to the interface library builder tool. */
	INTERFACE_LIBRARY_BUILDER("interface_library_builder_path"),
	/** Input for the interface library ifso builder tool. */
	INTERFACE_LIBRARY_INPUT("interface_library_input_path"),
	/** Path where to generate interface library using the ifso builder tool. */
	INTERFACE_LIBRARY_OUTPUT("interface_library_output_path"),
	/** Linker flags coming from the --linkopt or linkopts attribute. */
	USER_LINK_FLAGS("user_link_flags"),
	/** A build variable giving linkstamp paths. */
	LINKSTAMP_PATHS("linkstamp_paths"),
	/** Presence of this variable indicates that PIC code should be generated. */
	FORCE_PIC("force_pic"),
	/** Presence of this variable indicates that the debug symbols should be stripped. */
	STRIP_DEBUG_SYMBOLS("strip_debug_symbols"),
	/** Truthy when current action is a cc_test linking action, falsey otherwise. */
	IS_CC_TEST("is_cc_test"),
	/**
	* Presence of this variable indicates that files were compiled with fission (debug info is in
	* .dwo files instead of .o files and linker needs to know).
	*/
	IS_USING_FISSION("is_using_fission"),
	/** Path to the fdo instrument. */
	FDO_INSTRUMENT_PATH("fdo_instrument_path"),
	/** Path to the context sensitive fdo instrument. */
	CS_FDO_INSTRUMENT_PATH("cs_fdo_instrument_path"),
	/** Path to the Propeller Optimize linker profile artifact */
	PROPELLER_OPTIMIZE_LD_PATH("propeller_optimize_ld_path"),
	/** The name of the runtime solib symlink of the shared library. */
	RUNTIME_SOLIB_NAME("runtime_solib_name");

	private final String variableName;

	LinkBuildVariables(String variableName) {
	this.variableName = variableName;
	}

	public String getVariableName() {
	return variableName;
	}

	public static CcToolchainVariables.Builder setupLtoIndexingVariables(
	PathFragment binDirectoryPath,
	String thinltoParamFile,
	String thinltoMergedObjectFile,
	CcToolchainProvider ccToolchainProvider,
	FeatureConfiguration featureConfiguration,
	PathFragment ltoOutputRootPrefix,
	PathFragment ltoObjRootPrefix)
	throws EvalException {
	CcToolchainVariables.Builder buildVariables = CcToolchainVariables.builder();

	// This is a lto-indexing action and we want it to populate param file.
	buildVariables.addStringVariable(
	THINLTO_INDEXING_PARAM_FILE.getVariableName(), thinltoParamFile);
	// TODO(b/33846234): Remove once all the relevant crosstools don't depend on the variable.
	buildVariables.addStringVariable("thinlto_optional_params_file", "=" + thinltoParamFile);

	// Given "fullbitcode_prefix;thinlto_index_prefix;native_object_prefix", replaces
	// fullbitcode_prefix with thinlto_index_prefix to generate the index and imports files.
	// fullbitcode_prefix is the empty string because we are appending a prefix to the fullbitcode
	// instead of replacing it. This argument is passed to the linker.
	// The native objects generated after the LTOBackend action are stored in a directory by
	// replacing the prefix "fullbitcode_prefix" with "native_object_prefix", and this is used
	// when generating the param file in the indexing step, which will be used during the final
	// link step.
	if (!ltoOutputRootPrefix.equals(ltoObjRootPrefix)) {
	buildVariables.addStringVariable(
	THINLTO_PREFIX_REPLACE.getVariableName(),
	";"
	+ binDirectoryPath.getRelative(ltoOutputRootPrefix)
	+ "/;"
	+ binDirectoryPath.getRelative(ltoObjRootPrefix)
	+ "/");
	} else {
	buildVariables.addStringVariable(
	THINLTO_PREFIX_REPLACE.getVariableName(),
	";" + binDirectoryPath.getRelative(ltoOutputRootPrefix) + "/");
	}

	String objectFileExtension =
	ccToolchainProvider
	.getFeatures()
	.getArtifactNameExtensionForCategory(ArtifactCategory.OBJECT_FILE);
	if (!featureConfiguration.isEnabled(CppRuleClasses.NO_USE_LTO_INDEXING_BITCODE_FILE)) {
	buildVariables.addStringVariable(
	THINLTO_OBJECT_SUFFIX_REPLACE.getVariableName(),
	Iterables.getOnlyElement(CppFileTypes.LTO_INDEXING_OBJECT_FILE.getExtensions())
	+ ";"
	+ objectFileExtension);
	}

	buildVariables.addStringVariable(
	THINLTO_MERGED_OBJECT_FILE.getVariableName(), thinltoMergedObjectFile);

	buildVariables.addStringVariable(GENERATE_INTERFACE_LIBRARY.getVariableName(), "no");
	buildVariables.addStringVariable(INTERFACE_LIBRARY_BUILDER.getVariableName(), "ignored");
	buildVariables.addStringVariable(INTERFACE_LIBRARY_INPUT.getVariableName(), "ignored");
	buildVariables.addStringVariable(INTERFACE_LIBRARY_OUTPUT.getVariableName(), "ignored");
	return buildVariables;
	}

	public static CcToolchainVariables.Builder setupLinkingVariables(
	String outputFile,
	String runtimeSolibName,
	String thinltoParamFile,
	CcToolchainProvider ccToolchainProvider,
	FeatureConfiguration featureConfiguration,
	String interfaceLibraryBuilder,
	String interfaceLibraryOutput,
	FdoContext fdoContext)
	throws EvalException {
	CcToolchainVariables.Builder buildVariables = CcToolchainVariables.builder();
	if (thinltoParamFile != null) {
	// This is a normal link action and we need to use param file created by lto-indexing.
	buildVariables.addStringVariable(
	LinkBuildVariables.THINLTO_PARAM_FILE.getVariableName(), thinltoParamFile);
	}

	// output exec path
	buildVariables.addStringVariable(
	LinkBuildVariables.OUTPUT_EXECPATH.getVariableName(), outputFile);

	buildVariables.addStringVariable(
	LinkBuildVariables.RUNTIME_SOLIB_NAME.getVariableName(), runtimeSolibName);

	if (!ccToolchainProvider.isToolConfiguration()
	&& fdoContext != null
	&& featureConfiguration.isEnabled(CppRuleClasses.PROPELLER_OPTIMIZE)
	&& fdoContext.getPropellerOptimizeInputFile() != null
	&& fdoContext.getPropellerOptimizeInputFile().getLdArtifact() != null) {
	buildVariables.addStringVariable(
	LinkBuildVariables.PROPELLER_OPTIMIZE_LD_PATH.getVariableName(),
	fdoContext.getPropellerOptimizeInputFile().getLdArtifact().getExecPathString());
	}

	boolean shouldGenerateInterfaceLibrary =
	outputFile != null && interfaceLibraryBuilder != null && interfaceLibraryOutput != null;
	buildVariables.addStringVariable(
	GENERATE_INTERFACE_LIBRARY.getVariableName(),
	shouldGenerateInterfaceLibrary ? "yes" : "no");
	buildVariables.addStringVariable(
	INTERFACE_LIBRARY_BUILDER.getVariableName(),
	shouldGenerateInterfaceLibrary ? interfaceLibraryBuilder : "ignored");
	buildVariables.addStringVariable(
	INTERFACE_LIBRARY_INPUT.getVariableName(),
	shouldGenerateInterfaceLibrary ? outputFile : "ignored");
	buildVariables.addStringVariable(
	INTERFACE_LIBRARY_OUTPUT.getVariableName(),
	shouldGenerateInterfaceLibrary ? interfaceLibraryOutput : "ignored");

	return buildVariables;
	}

	public static CcToolchainVariables.Builder setupCommonVariables(
	boolean isUsingLinkerNotArchiver,
	boolean isCreatingSharedLibrary,
	String paramFile,
	boolean mustKeepDebug,
	CcToolchainProvider ccToolchainProvider,
	FeatureConfiguration featureConfiguration,
	boolean useTestOnlyFlags,
	Iterable<String> userLinkFlags,
	FdoContext fdoContext,
	NestedSet<String> runtimeLibrarySearchDirectories,
	SequenceBuilder librariesToLink,
	NestedSet<String> librarySearchDirectories)
	throws EvalException {
	CcToolchainVariables.Builder buildVariables =
	CcToolchainVariables.builder(ccToolchainProvider.getBuildVars());
	CppConfiguration cppConfiguration = ccToolchainProvider.getCppConfiguration();

	// pic
	if (cppConfiguration.forcePic()) {
	buildVariables.addStringVariable(FORCE_PIC.getVariableName(), "");
	}

	if (!mustKeepDebug && cppConfiguration.shouldStripBinaries()) {
	buildVariables.addStringVariable(STRIP_DEBUG_SYMBOLS.getVariableName(), "");
	}

	if (isUsingLinkerNotArchiver
	&& CcToolchainProvider.shouldCreatePerObjectDebugInfo(
	featureConfiguration, cppConfiguration)) {
	buildVariables.addStringVariable(IS_USING_FISSION.getVariableName(), "");
	}

	if (!cppConfiguration.useCcTestFeature()) {
	buildVariables.addBooleanValue(IS_CC_TEST.getVariableName(), useTestOnlyFlags);
	}

	buildVariables.addStringSequenceVariable(
	RUNTIME_LIBRARY_SEARCH_DIRECTORIES.getVariableName(), runtimeLibrarySearchDirectories);

	if (librariesToLink != null) {
	buildVariables.addCustomBuiltVariable(LIBRARIES_TO_LINK.getVariableName(), librariesToLink);
	}

	buildVariables.addStringSequenceVariable(
	LIBRARY_SEARCH_DIRECTORIES.getVariableName(), librarySearchDirectories);

	if (paramFile != null) {
	buildVariables.addStringVariable(LINKER_PARAM_FILE.getVariableName(), paramFile);
	}

	if (featureConfiguration.isEnabled(CppRuleClasses.FDO_INSTRUMENT)) {
	Preconditions.checkArgument(fdoContext.getBranchFdoProfile() == null);
	String fdoInstrument = cppConfiguration.getFdoInstrument();
	Preconditions.checkNotNull(fdoInstrument);
	buildVariables.addStringVariable(FDO_INSTRUMENT_PATH.getVariableName(), fdoInstrument);
	} else if (featureConfiguration.isEnabled(CppRuleClasses.CS_FDO_INSTRUMENT)) {
	String csFdoInstrument = ccToolchainProvider.getCSFdoInstrument();
	Preconditions.checkNotNull(csFdoInstrument);
	buildVariables.addStringVariable(CS_FDO_INSTRUMENT_PATH.getVariableName(), csFdoInstrument);
	}

	// For now, silently ignore linkopts if this is a static library
	userLinkFlags = isUsingLinkerNotArchiver ? userLinkFlags : ImmutableList.of();

	buildVariables.addStringSequenceVariable(
	LinkBuildVariables.USER_LINK_FLAGS.getVariableName(),
	removePieIfCreatingSharedLibrary(isCreatingSharedLibrary, userLinkFlags));
	return buildVariables;
	}

	private static Iterable<String> removePieIfCreatingSharedLibrary(
	boolean isCreatingSharedLibrary, Iterable<String> flags) {
	if (isCreatingSharedLibrary) {
	return Iterables.filter(
	flags,
	Predicates.not(
	Predicates.or(Predicates.equalTo("-pie"), Predicates.equalTo("-Wl,-pie"))));
	} else {
	return flags;
	}
	}
	}

	// LINT.ThenChange(//src/main/starlark/builtins_bzl/common/cc/link/link_build_variables.bzl)