src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.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.Splitter;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Multimap;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration.LabelConverter;
 import com.google.devtools.build.lib.analysis.config.CompilationMode;
 import com.google.devtools.build.lib.analysis.config.FragmentOptions;
 import com.google.devtools.build.lib.analysis.config.PerLabelOptions;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.LabelSyntaxException;
 import com.google.devtools.build.lib.rules.cpp.CppConfiguration.LibcTop;
 import com.google.devtools.build.lib.rules.cpp.CppConfiguration.StripMode;
 import com.google.devtools.build.lib.util.OptionsUtils;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.view.config.crosstool.CrosstoolConfig.LipoMode;
 import com.google.devtools.common.options.Converter;
 import com.google.devtools.common.options.EnumConverter;
 import com.google.devtools.common.options.Option;
 import com.google.devtools.common.options.OptionsParsingException;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 /**
  * Command-line options for C++.
  */
 public class CppOptions extends FragmentOptions {

   /**
    * Converts a comma-separated list of compilation mode settings to a properly typed List.
    */
   public static class FissionOptionConverter implements Converter<List<CompilationMode>> {
     @Override
     public List<CompilationMode> convert(String input) throws OptionsParsingException {
       ImmutableSet.Builder<CompilationMode> modes = ImmutableSet.builder();
       if (input.equals("yes")) { // Special case: enable all modes.
         modes.add(CompilationMode.values());
       } else if (!input.equals("no")) { // "no" is another special case that disables all modes.
         CompilationMode.Converter modeConverter = new CompilationMode.Converter();
         for (String mode : Splitter.on(',').split(input)) {
           modes.add(modeConverter.convert(mode));
         }
       }
       return modes.build().asList();
     }

     @Override
     public String getTypeDescription() {
       return "a set of compilation modes";
     }
   }

   /**
    * The same as DynamicMode, but on command-line we also allow AUTO.
    */
   public enum DynamicModeFlag {
     OFF,
     DEFAULT,
     FULLY,
     AUTO
   }

   /**
    * Converter for DynamicModeFlag
    */
   public static class DynamicModeConverter extends EnumConverter<DynamicModeFlag> {
     public DynamicModeConverter() {
       super(DynamicModeFlag.class, "dynamic mode");
     }
   }

   /**
    * Converter for the --strip option.
    */
   public static class StripModeConverter extends EnumConverter<StripMode> {
     public StripModeConverter() {
       super(StripMode.class, "strip mode");
     }
   }

   private static final String LIBC_RELATIVE_LABEL = ":everything";

   /**
    * Converts a String, which is an absolute path or label into a LibcTop
    * object.
    */
   public static class LibcTopConverter implements Converter<LibcTop> {
     @Override
     public LibcTop convert(String input) throws OptionsParsingException {
       if (input.equals("default")) {
         // This is needed for defining config_setting() values, the syntactic form
         // of which must be a String, to match absence of a --grte_top option.
         // "--grte_top=default" works on the command-line too,
         // but that's an inconsequential side-effect, not the intended purpose.
         return null;
       }
       if (!input.startsWith("//")) {
         throw new OptionsParsingException("Not a label");
       }
       try {
         Label label = Label.parseAbsolute(input).getRelative(LIBC_RELATIVE_LABEL);
         return new LibcTop(label);
       } catch (LabelSyntaxException e) {
         throw new OptionsParsingException(e.getMessage());
       }
     }

     @Override
     public String getTypeDescription() {
       return "a label";
     }
   }

   /**
    * Converter for the --lipo option.
    */
   public static class LipoModeConverter extends EnumConverter<LipoMode> {
     public LipoModeConverter() {
       super(LipoMode.class, "LIPO mode");
     }
   }

   @Option(
     name = "lipo input collector",
     defaultValue = "false",
     category = "undocumented",
     help = "Internal flag, only used to create configurations with the LIPO-collector flag set."
   )
   public boolean lipoCollector;

   @Option(
     name = "crosstool_top",
     defaultValue = "@bazel_tools//tools/cpp:toolchain",
     category = "version",
     converter = LabelConverter.class,
     help = "The label of the crosstool package to be used for compiling C++ code."
   )
   public Label crosstoolTop;

   @Option(
     name = "compiler",
     defaultValue = "null",
     category = "version",
     help = "The C++ compiler to use for compiling the target."
   )
   public String cppCompiler;

   @Option(
     name = "glibc",
     defaultValue = "null",
     category = "version",
     help =
         "The version of glibc the target should be linked against. "
             + "By default, a suitable version is chosen based on --cpu."
   )
   public String glibc;

   // O intrepid reaper of unused options: Be warned that the [no]start_end_lib
   // option, however tempting to remove, has a use case. Look in our telemetry data.
   @Option(
     name = "start_end_lib",
     defaultValue = "true",
     category = "strategy", // but also adds edges to the action graph
     help = "Use the --start-lib/--end-lib ld options if supported by the toolchain."
   )
   public boolean useStartEndLib;

   @Option(
     name = "interface_shared_objects",
     defaultValue = "true",
     category = "strategy", // but also adds edges to the action graph
     help =
         "Use interface shared objects if supported by the toolchain. "
             + "All ELF toolchains currently support this setting."
   )
   public boolean useInterfaceSharedObjects;

   @Option(
     name = "fission",
     defaultValue = "no",
     converter = FissionOptionConverter.class,
     category = "semantics",
     help =
         "Specifies which compilation modes use fission for C++ compilations and links. "
             + " May be any combination of {'fastbuild', 'dbg', 'opt'} or the special values 'yes' "
             + " to enable all modes and 'no' to disable all modes."
   )
   public List<CompilationMode> fissionModes;

   @Option(
     name = "build_test_dwp",
     defaultValue = "false",
     category = "semantics",
     help =
         "If enabled, when building C++ tests statically and with fission the .dwp file "
             + " for the test binary will be automatically built as well."
   )
   public boolean buildTestDwp;

   @Option(
     name = "dynamic_mode",
     defaultValue = "default",
     converter = DynamicModeConverter.class,
     category = "semantics",
     help =
         "Determines whether C++ binaries will be linked dynamically.  'default' means "
             + "blaze will choose whether to link dynamically.  'fully' means all libraries "
             + "will be linked dynamically. 'off' means that all libraries will be linked "
             + "in mostly static mode."
   )
   public DynamicModeFlag dynamicMode;

   @Option(
     name = "force_pic",
     defaultValue = "false",
     category = "semantics",
     help =
         "If enabled, all C++ compilations produce position-independent code (\"-fPIC\"),"
             + " links prefer PIC pre-built libraries over non-PIC libraries, and links produce"
             + " position-independent executables (\"-pie\")."
   )
   public boolean forcePic;

   @Option(
     name = "force_ignore_dash_static",
     defaultValue = "false",
     category = "semantics",
     help = "If set, '-static' options in the linkopts of cc_* rules will be ignored."
   )
   public boolean forceIgnoreDashStatic;

   @Option(
     name = "experimental_skip_static_outputs",
     defaultValue = "false",
     category = "semantics",
     help =
         "This flag is experimental and may go away at any time.  "
             + "If true, linker output for mostly-static C++ executables is a tiny amount of "
             + "dummy dependency information, and NOT a usable binary.  Kludge, but can reduce "
             + "network and disk I/O load (and thus, continuous build cycle times) by a lot.  "
             + "NOTE: use of this flag REQUIRES --distinct_host_configuration."
   )
   public boolean skipStaticOutputs;

   // TODO(djasper): Remove once it has been removed from the global blazerc.
   @Option(
     name = "send_transitive_header_module_srcs",
     defaultValue = "true",
     category = "semantics",
     help = "Obsolete. Don't use."
   )
   public boolean sendTransitiveHeaderModuleSrcs;

   @Option(
     name = "process_headers_in_dependencies",
     defaultValue = "false",
     category = "semantics",
     help =
         "When building a target //a:a, process headers in all targets that //a:a depends "
             + "on (if header processing is enabled for the toolchain)."
   )
   public boolean processHeadersInDependencies;

   @Option(
     name = "copt",
     allowMultiple = true,
     defaultValue = "",
     category = "flags",
     help = "Additional options to pass to gcc."
   )
   public List<String> coptList;

   @Option(
     name = "cxxopt",
     defaultValue = "",
     category = "flags",
     allowMultiple = true,
     help = "Additional option to pass to gcc when compiling C++ source files."
   )
   public List<String> cxxoptList;

   @Option(
     name = "conlyopt",
     allowMultiple = true,
     defaultValue = "",
     category = "flags",
     help = "Additional option to pass to gcc when compiling C source files."
   )
   public List<String> conlyoptList;

   @Option(
     name = "linkopt",
     defaultValue = "",
     category = "flags",
     allowMultiple = true,
     help = "Additional option to pass to gcc when linking."
   )
   public List<String> linkoptList;

   @Option(
     name = "ltoindexopt",
     defaultValue = "",
     category = "flags",
     allowMultiple = true,
     help = "Additional option to pass to the LTO indexing step (under --features=thin_lto)."
   )
   public List<String> ltoindexoptList;

   @Option(
     name = "stripopt",
     allowMultiple = true,
     defaultValue = "",
     category = "flags",
     help = "Additional options to pass to strip when generating a '<name>.stripped' binary."
   )
   public List<String> stripoptList;

   @Option(
     name = "custom_malloc",
     defaultValue = "null",
     category = "semantics",
     help =
         "Specifies a custom malloc implementation. This setting overrides malloc "
             + "attributes in build rules.",
     converter = LabelConverter.class
   )
   public Label customMalloc;

   @Option(
     name = "legacy_whole_archive",
     defaultValue = "true",
     category = "semantics",
     help =
         "When on, use --whole-archive for cc_binary rules that have "
             + "linkshared=1 and either linkstatic=1 or '-static' in linkopts. "
             + "This is for backwards compatibility only. "
             + "A better alternative is to use alwayslink=1 where required."
   )
   public boolean legacyWholeArchive;

   @Option(
     name = "strip",
     defaultValue = "sometimes",
     category = "flags",
     help =
         "Specifies whether to strip binaries and shared libraries "
             + " (using \"-Wl,--strip-debug\").  The default value of 'sometimes'"
             + " means strip iff --compilation_mode=fastbuild.",
     converter = StripModeConverter.class
   )
   public StripMode stripBinaries;

   @Option(
     name = "fdo_instrument",
     defaultValue = "null",
     converter = OptionsUtils.PathFragmentConverter.class,
     category = "flags",
     implicitRequirements = {"--copt=-Wno-error"},
     help =
         "Generate binaries with FDO instrumentation. Specify the relative "
             + "directory name for the .gcda files at runtime with GCC compiler. "
             + "With Clang/LLVM compiler, it also accepts the directory name under"
             + "which the raw profile file(s) will be dumped at runtime."
   )
   public PathFragment fdoInstrument;

   @Option(
     name = "fdo_optimize",
     defaultValue = "null",
     category = "flags",
     help =
         "Use FDO profile information to optimize compilation. Specify the name "
             + "of the zip file containing the .gcda file tree or an afdo file containing "
             + "an auto profile. This flag also accepts files specified as labels, for "
             + "example //foo/bar:file.afdo. Such labels must refer to input files; you may "
             + "need to add an exports_files directive to the corresponding package to make "
             + "the file visible to Blaze. It also accepts an indexed LLVM profile file."
   )
   public String fdoOptimize;

   @Option(
     name = "autofdo_lipo_data",
     defaultValue = "false",
     category = "flags",
     help =
         "If true then the directory name for non-LIPO targets will have a "
             + "'-lipodata' suffix in AutoFDO mode."
   )
   public boolean autoFdoLipoData;

   @Option(
     name = "lipo",
     defaultValue = "off",
     converter = LipoModeConverter.class,
     category = "flags",
     help =
         "Enable LIPO optimization (lightweight inter-procedural optimization, The allowed "
             + "values for  this option are 'off' and 'binary', which enables LIPO. This option "
             + "only has an effect when FDO is also enabled. Currently LIPO is only supported "
             + "when building a single cc_binary rule."
   )
   public LipoMode lipoMode;

   @Option(
     name = "lipo_context",
     defaultValue = "null",
     category = "flags",
     converter = LabelConverter.class,
     implicitRequirements = {"--linkopt=-Wl,--warn-unresolved-symbols"},
     help = "Specifies the binary from which the LIPO profile information comes."
   )
   public Label lipoContext;

   @Option(
     name = "experimental_stl",
     converter = LabelConverter.class,
     defaultValue = "null",
     category = "version",
     help =
         "If set, use this label instead of the default STL implementation. "
             + "This option is EXPERIMENTAL and may go away in a future release."
   )
   public Label stl;

   @Option(
     name = "save_temps",
     defaultValue = "false",
     category = "what",
     help =
         "If set, temporary outputs from gcc will be saved.  "
             + "These include .s files (assembler code), .i files (preprocessed C) and "
             + ".ii files (preprocessed C++)."
   )
   public boolean saveTemps;

   @Option(
     name = "per_file_copt",
     allowMultiple = true,
     converter = PerLabelOptions.PerLabelOptionsConverter.class,
     defaultValue = "",
     category = "semantics",
     help =
         "Additional options to selectively pass to gcc when compiling certain files. "
             + "This option can be passed multiple times. "
             + "Syntax: regex_filter@option_1,option_2,...,option_n. Where regex_filter stands "
             + "for a list of include and exclude regular expression patterns (Also see "
             + "--instrumentation_filter). option_1 to option_n stand for "
             + "arbitrary command line options. If an option contains a comma it has to be "
             + "quoted with a backslash. Options can contain @. Only the first @ is used to "
             + "split the string. Example: "
             + "--per_file_copt=//foo/.*\\.cc,-//foo/bar\\.cc@-O0 adds the -O0 "
             + "command line option to the gcc command line of all cc files in //foo/ "
             + "except bar.cc."
   )
   public List<PerLabelOptions> perFileCopts;

   @Option(
     name = "host_crosstool_top",
     defaultValue = "null",
     converter = LabelConverter.class,
     category = "semantics",
     help =
         "By default, the --crosstool_top and --compiler options are also used "
             + "for the host configuration. If this flag is provided, Blaze uses the default libc "
             + "and compiler for the given crosstool_top."
   )
   public Label hostCrosstoolTop;

   @Option(
     name = "host_copt",
     allowMultiple = true,
     defaultValue = "",
     category = "flags",
     help = "Additional options to pass to gcc for host tools."
   )
   public List<String> hostCoptList;

   @Option(
     name = "grte_top",
     defaultValue = "null", // The default value is chosen by the toolchain.
     category = "version",
     converter = LibcTopConverter.class,
     help =
         "A label to a checked-in libc library. The default value is selected by the crosstool "
             + "toolchain, and you almost never need to override it."
   )
   public LibcTop libcTop;

   @Option(
     name = "host_grte_top",
     defaultValue = "null", // The default value is chosen by the toolchain.
     category = "version",
     converter = LibcTopConverter.class,
     help =
         "If specified, this setting overrides the libc top-level directory (--grte_top) "
             + "for the host configuration."
   )
   public LibcTop hostLibcTop;

   @Option(
     name = "output_symbol_counts",
     defaultValue = "false",
     category = "flags",
     help =
         "If enabled, every C++ binary linked with gold will store the number of used "
             + "symbols per object file in a .sc file."
   )
   public boolean symbolCounts;

   @Option(
     name = "experimental_inmemory_dotd_files",
     defaultValue = "false",
     category = "experimental",
     help =
         "If enabled, C++ .d files will be passed through in memory directly from the remote "
             + "build nodes instead of being written to disk."
   )
   public boolean inmemoryDotdFiles;

   @Option(
     name = "experimental_skip_unused_modules",
     defaultValue = "false",
     category = "experimental",
     help =
         "If enabled, not all transitive modules automatically become an action's inputs. Instead,"
             + " input discovery adds just the required ones."
   )
   public boolean skipUnusedModules;

   @Option(
     name = "experimental_prune_more_modules",
     defaultValue = "false",
     category = "experimental",
     help = "If enabled, modules pruning is used when building modules themselves."
   )
   public boolean pruneMoreModules;

   @Option(
     name = "experimental_omitfp",
     defaultValue = "false",
     category = "semantics",
     help =
         "If true, use libunwind for stack unwinding, and compile with "
             + "-fomit-frame-pointer and -fasynchronous-unwind-tables."
   )
   public boolean experimentalOmitfp;

   @Option(
     name = "share_native_deps",
     defaultValue = "true",
     category = "strategy",
     help =
         "If true, native libraries that contain identical functionality "
             + "will be shared among different targets"
   )
   public boolean shareNativeDeps;

   @Option(
     name = "strict_system_includes",
     defaultValue = "false",
     category = "strategy",
     help =
         "If true, headers found through system include paths (-isystem) are also required to be "
         + "declared."
   )
   public boolean strictSystemIncludes;

   @Override
   public FragmentOptions getHost(boolean fallback) {
     CppOptions host = (CppOptions) getDefault();

     // The crosstool options are partially copied from the target configuration.
     if (!fallback) {
       if (hostCrosstoolTop == null) {
         host.cppCompiler = cppCompiler;
         host.crosstoolTop = crosstoolTop;
         host.glibc = glibc;
       } else {
         host.crosstoolTop = hostCrosstoolTop;
       }
     }

     // hostLibcTop doesn't default to the target's libcTop.
     // Only an explicit command-line option will change it.
     // The default is whatever the host's crosstool (which might have been specified
     // by --host_crosstool_top, or --crosstool_top as a fallback) says it should be.
     host.libcTop = hostLibcTop;

     // -g0 is the default, but allowMultiple options cannot have default values so we just pass
     // -g0 first and let the user options override it.
     host.coptList = ImmutableList.<String>builder().add("-g0").addAll(hostCoptList).build();

     host.useStartEndLib = useStartEndLib;
     host.stripBinaries = StripMode.ALWAYS;
     host.fdoOptimize = null;
     host.lipoMode = LipoMode.OFF;
     host.inmemoryDotdFiles = inmemoryDotdFiles;

     return host;
   }

   @Override
   public void addAllLabels(Multimap<String, Label> labelMap) {
     labelMap.put("crosstool", crosstoolTop);
     if (hostCrosstoolTop != null) {
       labelMap.put("crosstool", hostCrosstoolTop);
     }

     if (libcTop != null) {
       Label libcLabel = libcTop.getLabel();
       if (libcLabel != null) {
         labelMap.put("crosstool", libcLabel);
       }
     }
     if (hostLibcTop != null) {
       Label libcLabel = hostLibcTop.getLabel();
       if (libcLabel != null) {
         labelMap.put("crosstool", libcLabel);
       }
     }
     addOptionalLabel(labelMap, "fdo", fdoOptimize);

     if (stl != null) {
       labelMap.put("STL", stl);
     }

     if (customMalloc != null) {
       labelMap.put("custom_malloc", customMalloc);
     }

     if (getLipoContextLabel() != null) {
       labelMap.put("lipo", getLipoContextLabel());
     }
   }

   @Override
   public Map<String, Set<Label>> getDefaultsLabels(BuildConfiguration.Options commonOptions) {
     Set<Label> crosstoolLabels = new LinkedHashSet<>();
     crosstoolLabels.add(crosstoolTop);
     if (hostCrosstoolTop != null) {
       crosstoolLabels.add(hostCrosstoolTop);
     }

     if (libcTop != null) {
       Label libcLabel = libcTop.getLabel();
       if (libcLabel != null) {
         crosstoolLabels.add(libcLabel);
       }
     }

     return ImmutableMap.of("CROSSTOOL", crosstoolLabels, "COVERAGE", ImmutableSet.<Label>of());
   }

   public boolean isFdo() {
     return fdoOptimize != null || fdoInstrument != null;
   }

   public boolean isLipoOptimization() {
     return lipoMode == LipoMode.BINARY && fdoOptimize != null && lipoContext != null;
   }

   public boolean isLipoOptimizationOrInstrumentation() {
     return lipoMode == LipoMode.BINARY
         && ((fdoOptimize != null && lipoContext != null) || fdoInstrument != null);
   }

   public Label getLipoContextLabel() {
     return (lipoMode == LipoMode.BINARY && fdoOptimize != null) ? lipoContext : null;
   }

   public LipoMode getLipoMode() {
     return lipoMode;
   }

   /**
    * FDO/LIPO is not yet compatible with dynamic configurations.
    **/
   @Override
   public boolean useStaticConfigurationsOverride() {
     // --lipo=binary is technically possible without FDO, even though it doesn't do anything.
     return isFdo() || getLipoMode() == LipoMode.BINARY;
   }

 }
	// 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.Splitter;
	import com.google.common.collect.ImmutableList;
	import com.google.common.collect.ImmutableMap;
	import com.google.common.collect.ImmutableSet;
	import com.google.common.collect.Multimap;
	import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
	import com.google.devtools.build.lib.analysis.config.BuildConfiguration.LabelConverter;
	import com.google.devtools.build.lib.analysis.config.CompilationMode;
	import com.google.devtools.build.lib.analysis.config.FragmentOptions;
	import com.google.devtools.build.lib.analysis.config.PerLabelOptions;
	import com.google.devtools.build.lib.cmdline.Label;
	import com.google.devtools.build.lib.cmdline.LabelSyntaxException;
	import com.google.devtools.build.lib.rules.cpp.CppConfiguration.LibcTop;
	import com.google.devtools.build.lib.rules.cpp.CppConfiguration.StripMode;
	import com.google.devtools.build.lib.util.OptionsUtils;
	import com.google.devtools.build.lib.vfs.PathFragment;
	import com.google.devtools.build.lib.view.config.crosstool.CrosstoolConfig.LipoMode;
	import com.google.devtools.common.options.Converter;
	import com.google.devtools.common.options.EnumConverter;
	import com.google.devtools.common.options.Option;
	import com.google.devtools.common.options.OptionsParsingException;
	import java.util.LinkedHashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	/**
	* Command-line options for C++.
	*/
	public class CppOptions extends FragmentOptions {

	/**
	* Converts a comma-separated list of compilation mode settings to a properly typed List.
	*/
	public static class FissionOptionConverter implements Converter<List<CompilationMode>> {
	@Override
	public List<CompilationMode> convert(String input) throws OptionsParsingException {
	ImmutableSet.Builder<CompilationMode> modes = ImmutableSet.builder();
	if (input.equals("yes")) { // Special case: enable all modes.
	modes.add(CompilationMode.values());
	} else if (!input.equals("no")) { // "no" is another special case that disables all modes.
	CompilationMode.Converter modeConverter = new CompilationMode.Converter();
	for (String mode : Splitter.on(',').split(input)) {
	modes.add(modeConverter.convert(mode));
	}
	}
	return modes.build().asList();
	}

	@Override
	public String getTypeDescription() {
	return "a set of compilation modes";
	}
	}

	/**
	* The same as DynamicMode, but on command-line we also allow AUTO.
	*/
	public enum DynamicModeFlag {
	OFF,
	DEFAULT,
	FULLY,
	AUTO
	}

	/**
	* Converter for DynamicModeFlag
	*/
	public static class DynamicModeConverter extends EnumConverter<DynamicModeFlag> {
	public DynamicModeConverter() {
	super(DynamicModeFlag.class, "dynamic mode");
	}
	}

	/**
	* Converter for the --strip option.
	*/
	public static class StripModeConverter extends EnumConverter<StripMode> {
	public StripModeConverter() {
	super(StripMode.class, "strip mode");
	}
	}

	private static final String LIBC_RELATIVE_LABEL = ":everything";

	/**
	* Converts a String, which is an absolute path or label into a LibcTop
	* object.
	*/
	public static class LibcTopConverter implements Converter<LibcTop> {
	@Override
	public LibcTop convert(String input) throws OptionsParsingException {
	if (input.equals("default")) {
	// This is needed for defining config_setting() values, the syntactic form
	// of which must be a String, to match absence of a --grte_top option.
	// "--grte_top=default" works on the command-line too,
	// but that's an inconsequential side-effect, not the intended purpose.
	return null;
	}
	if (!input.startsWith("//")) {
	throw new OptionsParsingException("Not a label");
	}
	try {
	Label label = Label.parseAbsolute(input).getRelative(LIBC_RELATIVE_LABEL);
	return new LibcTop(label);
	} catch (LabelSyntaxException e) {
	throw new OptionsParsingException(e.getMessage());
	}
	}

	@Override
	public String getTypeDescription() {
	return "a label";
	}
	}

	/**
	* Converter for the --lipo option.
	*/
	public static class LipoModeConverter extends EnumConverter<LipoMode> {
	public LipoModeConverter() {
	super(LipoMode.class, "LIPO mode");
	}
	}

	@Option(
	name = "lipo input collector",
	defaultValue = "false",
	category = "undocumented",
	help = "Internal flag, only used to create configurations with the LIPO-collector flag set."
	)
	public boolean lipoCollector;

	@Option(
	name = "crosstool_top",
	defaultValue = "@bazel_tools//tools/cpp:toolchain",
	category = "version",
	converter = LabelConverter.class,
	help = "The label of the crosstool package to be used for compiling C++ code."
	)
	public Label crosstoolTop;

	@Option(
	name = "compiler",
	defaultValue = "null",
	category = "version",
	help = "The C++ compiler to use for compiling the target."
	)
	public String cppCompiler;

	@Option(
	name = "glibc",
	defaultValue = "null",
	category = "version",
	help =
	"The version of glibc the target should be linked against. "
	+ "By default, a suitable version is chosen based on --cpu."
	)
	public String glibc;

	// O intrepid reaper of unused options: Be warned that the [no]start_end_lib
	// option, however tempting to remove, has a use case. Look in our telemetry data.
	@Option(
	name = "start_end_lib",
	defaultValue = "true",
	category = "strategy", // but also adds edges to the action graph
	help = "Use the --start-lib/--end-lib ld options if supported by the toolchain."
	)
	public boolean useStartEndLib;

	@Option(
	name = "interface_shared_objects",
	defaultValue = "true",
	category = "strategy", // but also adds edges to the action graph
	help =
	"Use interface shared objects if supported by the toolchain. "
	+ "All ELF toolchains currently support this setting."
	)
	public boolean useInterfaceSharedObjects;

	@Option(
	name = "fission",
	defaultValue = "no",
	converter = FissionOptionConverter.class,
	category = "semantics",
	help =
	"Specifies which compilation modes use fission for C++ compilations and links. "
	+ " May be any combination of {'fastbuild', 'dbg', 'opt'} or the special values 'yes' "
	+ " to enable all modes and 'no' to disable all modes."
	)
	public List<CompilationMode> fissionModes;

	@Option(
	name = "build_test_dwp",
	defaultValue = "false",
	category = "semantics",
	help =
	"If enabled, when building C++ tests statically and with fission the .dwp file "
	+ " for the test binary will be automatically built as well."
	)
	public boolean buildTestDwp;

	@Option(
	name = "dynamic_mode",
	defaultValue = "default",
	converter = DynamicModeConverter.class,
	category = "semantics",
	help =
	"Determines whether C++ binaries will be linked dynamically. 'default' means "
	+ "blaze will choose whether to link dynamically. 'fully' means all libraries "
	+ "will be linked dynamically. 'off' means that all libraries will be linked "
	+ "in mostly static mode."
	)
	public DynamicModeFlag dynamicMode;

	@Option(
	name = "force_pic",
	defaultValue = "false",
	category = "semantics",
	help =
	"If enabled, all C++ compilations produce position-independent code (\"-fPIC\"),"
	+ " links prefer PIC pre-built libraries over non-PIC libraries, and links produce"
	+ " position-independent executables (\"-pie\")."
	)
	public boolean forcePic;

	@Option(
	name = "force_ignore_dash_static",
	defaultValue = "false",
	category = "semantics",
	help = "If set, '-static' options in the linkopts of cc_* rules will be ignored."
	)
	public boolean forceIgnoreDashStatic;

	@Option(
	name = "experimental_skip_static_outputs",
	defaultValue = "false",
	category = "semantics",
	help =
	"This flag is experimental and may go away at any time. "
	+ "If true, linker output for mostly-static C++ executables is a tiny amount of "
	+ "dummy dependency information, and NOT a usable binary. Kludge, but can reduce "
	+ "network and disk I/O load (and thus, continuous build cycle times) by a lot. "
	+ "NOTE: use of this flag REQUIRES --distinct_host_configuration."
	)
	public boolean skipStaticOutputs;

	// TODO(djasper): Remove once it has been removed from the global blazerc.
	@Option(
	name = "send_transitive_header_module_srcs",
	defaultValue = "true",
	category = "semantics",
	help = "Obsolete. Don't use."
	)
	public boolean sendTransitiveHeaderModuleSrcs;

	@Option(
	name = "process_headers_in_dependencies",
	defaultValue = "false",
	category = "semantics",
	help =
	"When building a target //a:a, process headers in all targets that //a:a depends "
	+ "on (if header processing is enabled for the toolchain)."
	)
	public boolean processHeadersInDependencies;

	@Option(
	name = "copt",
	allowMultiple = true,
	defaultValue = "",
	category = "flags",
	help = "Additional options to pass to gcc."
	)
	public List<String> coptList;

	@Option(
	name = "cxxopt",
	defaultValue = "",
	category = "flags",
	allowMultiple = true,
	help = "Additional option to pass to gcc when compiling C++ source files."
	)
	public List<String> cxxoptList;

	@Option(
	name = "conlyopt",
	allowMultiple = true,
	defaultValue = "",
	category = "flags",
	help = "Additional option to pass to gcc when compiling C source files."
	)
	public List<String> conlyoptList;

	@Option(
	name = "linkopt",
	defaultValue = "",
	category = "flags",
	allowMultiple = true,
	help = "Additional option to pass to gcc when linking."
	)
	public List<String> linkoptList;

	@Option(
	name = "ltoindexopt",
	defaultValue = "",
	category = "flags",
	allowMultiple = true,
	help = "Additional option to pass to the LTO indexing step (under --features=thin_lto)."
	)
	public List<String> ltoindexoptList;

	@Option(
	name = "stripopt",
	allowMultiple = true,
	defaultValue = "",
	category = "flags",
	help = "Additional options to pass to strip when generating a '<name>.stripped' binary."
	)
	public List<String> stripoptList;

	@Option(
	name = "custom_malloc",
	defaultValue = "null",
	category = "semantics",
	help =
	"Specifies a custom malloc implementation. This setting overrides malloc "
	+ "attributes in build rules.",
	converter = LabelConverter.class
	)
	public Label customMalloc;

	@Option(
	name = "legacy_whole_archive",
	defaultValue = "true",
	category = "semantics",
	help =
	"When on, use --whole-archive for cc_binary rules that have "
	+ "linkshared=1 and either linkstatic=1 or '-static' in linkopts. "
	+ "This is for backwards compatibility only. "
	+ "A better alternative is to use alwayslink=1 where required."
	)
	public boolean legacyWholeArchive;

	@Option(
	name = "strip",
	defaultValue = "sometimes",
	category = "flags",
	help =
	"Specifies whether to strip binaries and shared libraries "
	+ " (using \"-Wl,--strip-debug\"). The default value of 'sometimes'"
	+ " means strip iff --compilation_mode=fastbuild.",
	converter = StripModeConverter.class
	)
	public StripMode stripBinaries;

	@Option(
	name = "fdo_instrument",
	defaultValue = "null",
	converter = OptionsUtils.PathFragmentConverter.class,
	category = "flags",
	implicitRequirements = {"--copt=-Wno-error"},
	help =
	"Generate binaries with FDO instrumentation. Specify the relative "
	+ "directory name for the .gcda files at runtime with GCC compiler. "
	+ "With Clang/LLVM compiler, it also accepts the directory name under"
	+ "which the raw profile file(s) will be dumped at runtime."
	)
	public PathFragment fdoInstrument;

	@Option(
	name = "fdo_optimize",
	defaultValue = "null",
	category = "flags",
	help =
	"Use FDO profile information to optimize compilation. Specify the name "
	+ "of the zip file containing the .gcda file tree or an afdo file containing "
	+ "an auto profile. This flag also accepts files specified as labels, for "
	+ "example //foo/bar:file.afdo. Such labels must refer to input files; you may "
	+ "need to add an exports_files directive to the corresponding package to make "
	+ "the file visible to Blaze. It also accepts an indexed LLVM profile file."
	)
	public String fdoOptimize;

	@Option(
	name = "autofdo_lipo_data",
	defaultValue = "false",
	category = "flags",
	help =
	"If true then the directory name for non-LIPO targets will have a "
	+ "'-lipodata' suffix in AutoFDO mode."
	)
	public boolean autoFdoLipoData;

	@Option(
	name = "lipo",
	defaultValue = "off",
	converter = LipoModeConverter.class,
	category = "flags",
	help =
	"Enable LIPO optimization (lightweight inter-procedural optimization, The allowed "
	+ "values for this option are 'off' and 'binary', which enables LIPO. This option "
	+ "only has an effect when FDO is also enabled. Currently LIPO is only supported "
	+ "when building a single cc_binary rule."
	)
	public LipoMode lipoMode;

	@Option(
	name = "lipo_context",
	defaultValue = "null",
	category = "flags",
	converter = LabelConverter.class,
	implicitRequirements = {"--linkopt=-Wl,--warn-unresolved-symbols"},
	help = "Specifies the binary from which the LIPO profile information comes."
	)
	public Label lipoContext;

	@Option(
	name = "experimental_stl",
	converter = LabelConverter.class,
	defaultValue = "null",
	category = "version",
	help =
	"If set, use this label instead of the default STL implementation. "
	+ "This option is EXPERIMENTAL and may go away in a future release."
	)
	public Label stl;

	@Option(
	name = "save_temps",
	defaultValue = "false",
	category = "what",
	help =
	"If set, temporary outputs from gcc will be saved. "
	+ "These include .s files (assembler code), .i files (preprocessed C) and "
	+ ".ii files (preprocessed C++)."
	)
	public boolean saveTemps;

	@Option(
	name = "per_file_copt",
	allowMultiple = true,
	converter = PerLabelOptions.PerLabelOptionsConverter.class,
	defaultValue = "",
	category = "semantics",
	help =
	"Additional options to selectively pass to gcc when compiling certain files. "
	+ "This option can be passed multiple times. "
	+ "Syntax: regex_filter@option_1,option_2,...,option_n. Where regex_filter stands "
	+ "for a list of include and exclude regular expression patterns (Also see "
	+ "--instrumentation_filter). option_1 to option_n stand for "
	+ "arbitrary command line options. If an option contains a comma it has to be "
	+ "quoted with a backslash. Options can contain @. Only the first @ is used to "
	+ "split the string. Example: "
	+ "--per_file_copt=//foo/.*\\.cc,-//foo/bar\\.cc@-O0 adds the -O0 "
	+ "command line option to the gcc command line of all cc files in //foo/ "
	+ "except bar.cc."
	)
	public List<PerLabelOptions> perFileCopts;

	@Option(
	name = "host_crosstool_top",
	defaultValue = "null",
	converter = LabelConverter.class,
	category = "semantics",
	help =
	"By default, the --crosstool_top and --compiler options are also used "
	+ "for the host configuration. If this flag is provided, Blaze uses the default libc "
	+ "and compiler for the given crosstool_top."
	)
	public Label hostCrosstoolTop;

	@Option(
	name = "host_copt",
	allowMultiple = true,
	defaultValue = "",
	category = "flags",
	help = "Additional options to pass to gcc for host tools."
	)
	public List<String> hostCoptList;

	@Option(
	name = "grte_top",
	defaultValue = "null", // The default value is chosen by the toolchain.
	category = "version",
	converter = LibcTopConverter.class,
	help =
	"A label to a checked-in libc library. The default value is selected by the crosstool "
	+ "toolchain, and you almost never need to override it."
	)
	public LibcTop libcTop;

	@Option(
	name = "host_grte_top",
	defaultValue = "null", // The default value is chosen by the toolchain.
	category = "version",
	converter = LibcTopConverter.class,
	help =
	"If specified, this setting overrides the libc top-level directory (--grte_top) "
	+ "for the host configuration."
	)
	public LibcTop hostLibcTop;

	@Option(
	name = "output_symbol_counts",
	defaultValue = "false",
	category = "flags",
	help =
	"If enabled, every C++ binary linked with gold will store the number of used "
	+ "symbols per object file in a .sc file."
	)
	public boolean symbolCounts;

	@Option(
	name = "experimental_inmemory_dotd_files",
	defaultValue = "false",
	category = "experimental",
	help =
	"If enabled, C++ .d files will be passed through in memory directly from the remote "
	+ "build nodes instead of being written to disk."
	)
	public boolean inmemoryDotdFiles;

	@Option(
	name = "experimental_skip_unused_modules",
	defaultValue = "false",
	category = "experimental",
	help =
	"If enabled, not all transitive modules automatically become an action's inputs. Instead,"
	+ " input discovery adds just the required ones."
	)
	public boolean skipUnusedModules;

	@Option(
	name = "experimental_prune_more_modules",
	defaultValue = "false",
	category = "experimental",
	help = "If enabled, modules pruning is used when building modules themselves."
	)
	public boolean pruneMoreModules;

	@Option(
	name = "experimental_omitfp",
	defaultValue = "false",
	category = "semantics",
	help =
	"If true, use libunwind for stack unwinding, and compile with "
	+ "-fomit-frame-pointer and -fasynchronous-unwind-tables."
	)
	public boolean experimentalOmitfp;

	@Option(
	name = "share_native_deps",
	defaultValue = "true",
	category = "strategy",
	help =
	"If true, native libraries that contain identical functionality "
	+ "will be shared among different targets"
	)
	public boolean shareNativeDeps;

	@Option(
	name = "strict_system_includes",
	defaultValue = "false",
	category = "strategy",
	help =
	"If true, headers found through system include paths (-isystem) are also required to be "
	+ "declared."
	)
	public boolean strictSystemIncludes;

	@Override
	public FragmentOptions getHost(boolean fallback) {
	CppOptions host = (CppOptions) getDefault();

	// The crosstool options are partially copied from the target configuration.
	if (!fallback) {
	if (hostCrosstoolTop == null) {
	host.cppCompiler = cppCompiler;
	host.crosstoolTop = crosstoolTop;
	host.glibc = glibc;
	} else {
	host.crosstoolTop = hostCrosstoolTop;
	}
	}

	// hostLibcTop doesn't default to the target's libcTop.
	// Only an explicit command-line option will change it.
	// The default is whatever the host's crosstool (which might have been specified
	// by --host_crosstool_top, or --crosstool_top as a fallback) says it should be.
	host.libcTop = hostLibcTop;

	// -g0 is the default, but allowMultiple options cannot have default values so we just pass
	// -g0 first and let the user options override it.
	host.coptList = ImmutableList.<String>builder().add("-g0").addAll(hostCoptList).build();

	host.useStartEndLib = useStartEndLib;
	host.stripBinaries = StripMode.ALWAYS;
	host.fdoOptimize = null;
	host.lipoMode = LipoMode.OFF;
	host.inmemoryDotdFiles = inmemoryDotdFiles;

	return host;
	}

	@Override
	public void addAllLabels(Multimap<String, Label> labelMap) {
	labelMap.put("crosstool", crosstoolTop);
	if (hostCrosstoolTop != null) {
	labelMap.put("crosstool", hostCrosstoolTop);
	}

	if (libcTop != null) {
	Label libcLabel = libcTop.getLabel();
	if (libcLabel != null) {
	labelMap.put("crosstool", libcLabel);
	}
	}
	if (hostLibcTop != null) {
	Label libcLabel = hostLibcTop.getLabel();
	if (libcLabel != null) {
	labelMap.put("crosstool", libcLabel);
	}
	}
	addOptionalLabel(labelMap, "fdo", fdoOptimize);

	if (stl != null) {
	labelMap.put("STL", stl);
	}

	if (customMalloc != null) {
	labelMap.put("custom_malloc", customMalloc);
	}

	if (getLipoContextLabel() != null) {
	labelMap.put("lipo", getLipoContextLabel());
	}
	}

	@Override
	public Map<String, Set<Label>> getDefaultsLabels(BuildConfiguration.Options commonOptions) {
	Set<Label> crosstoolLabels = new LinkedHashSet<>();
	crosstoolLabels.add(crosstoolTop);
	if (hostCrosstoolTop != null) {
	crosstoolLabels.add(hostCrosstoolTop);
	}

	if (libcTop != null) {
	Label libcLabel = libcTop.getLabel();
	if (libcLabel != null) {
	crosstoolLabels.add(libcLabel);
	}
	}

	return ImmutableMap.of("CROSSTOOL", crosstoolLabels, "COVERAGE", ImmutableSet.<Label>of());
	}

	public boolean isFdo() {
	return fdoOptimize != null \|\| fdoInstrument != null;
	}

	public boolean isLipoOptimization() {
	return lipoMode == LipoMode.BINARY && fdoOptimize != null && lipoContext != null;
	}

	public boolean isLipoOptimizationOrInstrumentation() {
	return lipoMode == LipoMode.BINARY
	&& ((fdoOptimize != null && lipoContext != null) \|\| fdoInstrument != null);
	}

	public Label getLipoContextLabel() {
	return (lipoMode == LipoMode.BINARY && fdoOptimize != null) ? lipoContext : null;
	}

	public LipoMode getLipoMode() {
	return lipoMode;
	}

	/**
	* FDO/LIPO is not yet compatible with dynamic configurations.
	**/
	@Override
	public boolean useStaticConfigurationsOverride() {
	// --lipo=binary is technically possible without FDO, even though it doesn't do anything.
	return isFdo() \|\| getLipoMode() == LipoMode.BINARY;
	}

	}