src/main/protobuf/crosstool_config.proto - 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.
 //
 // File format for Blaze to configure Crosstool releases.

 syntax = "proto2";

 option java_package = "com.google.devtools.build.lib.view.config.crosstool";


 package com.google.devtools.build.lib.view.config.crosstool;

 // A description of a toolchain, which includes all the tools generally expected
 // to be available for building C/C++ targets, based on the GNU C compiler.
 //
 // System and cpu names are two overlapping concepts, which need to be both
 // supported at this time. The cpu name is the blaze command-line name for the
 // target system. The most common values are 'k8' and 'piii'. The system name is
 // a more generic identification of the executable system, based on the names
 // used by the GNU C compiler.
 //
 // Typically, the system name contains an identifier for the cpu (e.g. x86_64 or
 // alpha), an identifier for the machine (e.g. pc, or unknown), and an
 // identifier for the operating system (e.g. cygwin or linux-gnu). Typical
 // examples are 'x86_64-unknown-linux-gnu' and 'i686-unknown-cygwin'.
 //
 // The system name is used to determine if a given machine can execute a given
 // exectuable. In particular, it is used to check if the compilation products of
 // a toolchain can run on the host machine.
 message CToolchain {
   // Optional flag. Some option lists have a corresponding optional flag list.
   // These are appended at the end of the option list in case the corresponding
   // default setting is set.
   message OptionalFlag {
     required string default_setting_name = 1;
     repeated string flag = 2;
   }

   // A group of correlated flags. Supports parametrization via variable
   // expansion.
   // If a variable of list type is expanded, all flags in the flag group
   // will be expanded for each element of the list.
   // Only a single variable of list type may be referenced in a single flag
   // group; the same variable may be referenced multiple times.
   //
   // For example:
   // flag_group {
   //   flag: '-I'
   //   flag: '%{include_path}'
   // }
   // ... will get expanded to -I /to/path1 -I /to/path2 ... for each
   // include_path /to/pathN.
   //
   // Flag groups can be nested; if they are, the flag group must only contain
   // other flag groups (no flags) so the order is unambiguously specified.
   // Nested flag groups require build variables of nested list types, and
   // will be expanded recursively.
   //
   // For example:
   // flag_group {
   //   flag_group { flag: '--start-lib' }
   //   flag_group { flag: '%{object_files}' }
   //   flag_group { flag: '--end-lib' }
   // }
   // ... will get expanded to
   //   --start-lib a1.o a2.o ... --end-lib --start-lib b1.o b2.o .. --end-lib
   //   with %{object_files} being a variable of nested list type
   //   [['a1.o', 'a2.o', ...], ['b1.o', 'b2.o', ...], ...].
   //
   // TODO(bazel-team): Write more elaborate documentation and add a link to it.
   message FlagGroup {
     repeated string flag = 1;

     repeated FlagGroup flag_group = 2;
   }

   // A key/value pair to be added as an environment variable. The value of
   // this pair is expanded in the same way as is described in FlagGroup.
   // The key remains an unexpanded string literal.
   message EnvEntry {
     required string key = 1;
     required string value = 2;
   }

   // A set of features; used to support logical 'and' when specifying feature
   // requirements in FlagSet and Feature.
   message FeatureSet {
     repeated string feature = 1;
   }

   // A set of flags that are expanded in the command line for specific actions.
   message FlagSet {
     // The actions this flag set applies to; each flag set must specify at
     // least one action.
     repeated string action = 1;

     // The flags applied via this flag set.
     repeated FlagGroup flag_group = 2;

     // A list of feature sets defining when this flag set gets applied.  The
     // flag set will be applied when any of the feature sets fully apply, that
     // is, when all features of the feature set are enabled.
     //
     // If 'with_feature' is omitted, the flag set will be applied
     // unconditionally for every action specified.
     repeated FeatureSet with_feature = 3;

     // A list of build variables that this feature set needs, but which are
     // allowed to not be set. If any of the build variables listed is not
     // set, the feature set will not be expanded.
     //
     // NOTE: Consider alternatives before using this; usually tools should
     // consistently create the same set of files, even if empty; use this
     // only for backwards compatibility with already existing behavior in tools
     // that are currently not worth changing.
     repeated string expand_if_all_available = 4;
   }

   // A set of environment variables that are expanded in the command line for
   // specific actions.
   message EnvSet {
     // The actions this env set applies to; each env set must specify at
     // least one action.
     repeated string action = 1;

     // The environment variables applied via this env set.
     repeated EnvEntry env_entry = 2;

     // A list of feature sets defining when this env set gets applied.  The
     // env set will be applied when any of the feature sets fully apply, that
     // is, when all features of the feature set are enabled.
     //
     // If 'with_feature' is omitted, the env set will be applied
     // unconditionally for every action specified.
     repeated FeatureSet with_feature = 3;
   }

   // Contains all flag specifications for one feature.
   // Next ID: 7
   message Feature {
     // The feature's name. Feature names are generally defined by Bazel; it is
     // possible to introduce a feature without a change to Bazel by adding a
     // 'feature' section to the toolchain and adding the corresponding string as
     // feature in the BUILD file.
     optional string name = 1;

     // If the given feature is enabled, the flag sets will be applied for the
     // actions in the modes that they are specified for.
     repeated FlagSet flag_set = 2;

     // If the given feature is enabled, the env sets will be applied for the
     // actions in the modes that they are specified for.
     repeated EnvSet env_set = 6;

     // A list of feature sets defining when this feature is supported by the
     // toolchain. The feature is supported if any of the feature sets fully
     // apply, that is, when all features of a feature set are enabled.
     //
     // If 'requires' is omitted, the feature is supported independently of which
     // other features are enabled.
     //
     // Use this for example to filter flags depending on the build mode enabled
     // (opt / fastbuild / dbg).
     repeated FeatureSet requires = 3;

     // A list of features that are automatically enabled when this feature is
     // enabled. If any of the implied features cannot be enabled, this feature
     // will (silently) not be enabled either.
     repeated string implies = 4;

     // A list of names this feature conflicts with.
     // A feature cannot be enabled if:
     // - 'provides' contains the name of a different feature that we want to
     //   enable.
     // - 'provides' contains the same value as a 'provides' in a different
     //   feature that we want to enable.
     //
     // Use this in order to ensure that incompatible features cannot be
     // accidentally activated at the same time, leading to hard to diagnose
     // compiler errors.
     repeated string provides = 5;
   }

   repeated Feature feature = 50;

   // The unique identifier of the toolchain within the crosstool release. It
   // must be possible to use this as a directory name in a path.
   // It has to match the following regex: [a-zA-Z_][\.\- \w]*
   required string toolchain_identifier = 1;

   // A basic toolchain description.
   required string host_system_name = 2;
   required string target_system_name = 3;
   required string target_cpu = 4;
   required string target_libc = 5;
   required string compiler = 6;

   required string abi_version = 7;
   required string abi_libc_version = 8;

   // Tool locations. Relative paths are resolved relative to the configuration
   // file directory.
   repeated ToolPath tool_path = 9;

   // Feature flags.
   // TODO(bazel-team): Sink those into 'Feature' instances.
   optional bool supports_gold_linker = 10 [default = false];
   optional bool supports_thin_archives = 11 [default = false];
   optional bool supports_start_end_lib = 28 [default = false];
   optional bool supports_interface_shared_objects = 32 [default = false];
   optional bool supports_embedded_runtimes = 40 [default = false];
   // If specified, Blaze finds statically linked / dynamically linked runtime
   // libraries in the declared crosstool filegroup. Otherwise, Blaze
   // looks in "[static|dynamic]-runtime-libs-$TARGET_CPU".
   optional string static_runtimes_filegroup = 45;
   optional string dynamic_runtimes_filegroup = 46;
   optional bool supports_incremental_linker = 41 [default = false];
   // This should be true, if the toolchain supports the D flag to ar, which
   // makes it output normalized archives that don't contain timestamps.
   optional bool supports_normalizing_ar = 26 [default = false];
   optional bool supports_fission = 43 [default = false];
   // Can generate dsym debug symbol information.
   optional bool supports_dsym = 51 [default = false];
   // Can generate a breakpad file. Requires that support_dsym=true,
   // otherwise an error will be thrown.
   optional bool supports_breakpad = 52 [default = false];
   optional bool needsPic = 12 [default = false];

   // Compiler flags for C/C++/Asm compilation.
   repeated string compiler_flag = 13;
   repeated OptionalFlag optional_compiler_flag = 35;
   // Additional compiler flags for C++ compilation.
   repeated string cxx_flag = 14;
   repeated OptionalFlag optional_cxx_flag = 36;
   // Additional unfiltered compiler flags for C/C++/Asm compilation.
   // These are not subject to nocopt filtering in cc_* rules.
   repeated string unfiltered_cxx_flag = 25;
   repeated OptionalFlag optional_unfiltered_cxx_flag = 37;
   // Linker flags.
   repeated string linker_flag = 15;
   repeated OptionalFlag optional_linker_flag = 38;
   // Additional linker flags when linking dynamic libraries.
   repeated string dynamic_library_linker_flag = 27;
   repeated OptionalFlag optional_dynamic_library_linker_flag = 39;
   // Additional test-only linker flags.
   repeated string test_only_linker_flag = 49;
   // Objcopy flags for embedding files into binaries.
   repeated string objcopy_embed_flag = 16;
   // Ld flags for embedding files into binaries. This is used by filewrapper
   // since it calls ld directly and needs to know what -m flag to pass.
   repeated string ld_embed_flag = 23;
   // Ar flags for combining object files into archives. If this is not set, it
   // defaults to "rcsD".
   repeated string ar_flag = 47;
   // Ar flags for combining object files into archives when thin_archives is
   // enabled. If this is not set, it defaults to "rcsDT".
   repeated string ar_thin_archives_flag = 48;
   // Additional compiler flags that are added for cc_plugin rules of type 'gcc'
   repeated string gcc_plugin_compiler_flag = 34;

   // Additional compiler and linker flags depending on the compilation mode.
   repeated CompilationModeFlags compilation_mode_flags = 17;

   // Additional compiler and linker flags depending on the LIPO mode.
   repeated LipoModeFlags lipo_mode_flags = 44;

   // Additional linker flags depending on the linking mode.
   repeated LinkingModeFlags linking_mode_flags = 18;

   // Plugin header directories for gcc and mao plugins. If none are set, the
   // toolchain does not support plugins. Relative paths are resolved relative
   // to the configuration file directory.
   repeated string gcc_plugin_header_directory = 19;
   repeated string mao_plugin_header_directory = 20;

   // Make variables that are made accessible to rules.
   repeated MakeVariable make_variable = 21;

   // Built-in include directories for C++ compilation. These should be the exact
   // paths used by the compiler, and are generally relative to the exec root.
   // The paths used by the compiler can be determined by 'gcc -Wp,-v some.c'.
   // We currently use the C++ paths also for C compilation, which is safe as
   // long as there are no name clashes between C++ and C header files.
   //
   // Relative paths are resolved relative to the configuration file directory.
   //
   // If the compiler has --sysroot support, then these paths should use
   // %sysroot% rather than the include path, and specify the sysroot attribute
   // in order to give blaze the information necessary to make the correct
   // replacements.
   repeated string cxx_builtin_include_directory = 22;

   // The built-in sysroot. If this attribute is not present, blaze does not
   // allow using a different sysroot, i.e. through the --grte_top option. Also
   // see the documentation above.
   optional string builtin_sysroot = 24;

   // The location and version of the default Python (in absence of
   // --python_top and --python_version, respectively. The default
   // --python_mode is always 'opt'.) For backward compatibility, if these
   // attributes are not set, Blaze will use the crosstool v11-13 default
   // values: "/usr/grte/v1" and "python2.4".
   optional string default_python_top = 29;
   optional string default_python_version = 30;
   // Whether to preload swigdeps.so files in py_binaries and PAR files.
   // This overrides the commandline flag.
   optional bool python_preload_swigdeps = 42;

   // The default GRTE to use. This should be a label, and gets the same
   // treatment from Blaze as the --grte_top option. This setting is only used in
   // the absence of an explicit --grte_top option. If unset, Blaze will not pass
   // -sysroot by default. The local part must be 'everything', i.e.,
   // '//some/label:everything'. There can only be one GRTE library per package,
   // because the compiler expects the directory as a parameter of the -sysroot
   // option.
   // This may only be set to a non-empty value if builtin_sysroot is also set!
   optional string default_grte_top = 31;

   // Additional dependencies for Blaze-built .deb packages. All Debian packages
   // that contain C++ binaries need to have the correct runtime
   // libraries installed, and those depend on the crosstool version, which is
   // why they are recorded here.
   repeated string debian_extra_requires = 33;

   // Next free id: 53
 }

 message ToolPath {
   required string name = 1;
   required string path = 2;
 }

 enum CompilationMode {
   FASTBUILD = 1;
   DBG = 2;
   OPT = 3;
   // This value is ignored and should not be used in new files.
   COVERAGE = 4;
 }

 message CompilationModeFlags {
   required CompilationMode mode = 1;
   repeated string compiler_flag = 2;
   repeated string cxx_flag = 3;
   // Linker flags that are added when compiling in a certain mode.
   repeated string linker_flag = 4;
 }

 enum LinkingMode {
   FULLY_STATIC = 1;
   MOSTLY_STATIC = 2;
   DYNAMIC = 3;
 }

 message LinkingModeFlags {
   required LinkingMode mode = 1;
   repeated string linker_flag = 2;
 }

 enum LipoMode {
   OFF = 1;
   BINARY = 2;
   // LIBRARY = 3;  // RESERVED
 }

 message LipoModeFlags {
   required LipoMode mode = 1;
   repeated string compiler_flag = 2;
   repeated string cxx_flag = 3;
   repeated string linker_flag = 4;
 }

 message MakeVariable {
   required string name = 1;
   required string value = 2;
 }

 message DefaultCpuToolchain {
   required string cpu = 1;
   required string toolchain_identifier = 2;
 }

 // An entire crosstool release, containing the version number, a default target
 // cpu, a default toolchain for each supported cpu type, and a set of
 // toolchains.
 message CrosstoolRelease {
   message DefaultSetting {
     required string name = 1;
     required bool default_value = 2;
   }

   // The major and minor version of the crosstool release.
   required string major_version = 1;
   required string minor_version = 2;

   // The default cpu to use if none was specified.
   required string default_target_cpu = 3;
   // The default toolchain to use for each given cpu.
   repeated DefaultCpuToolchain default_toolchain = 4;

   // The default settings used in this release.
   repeated DefaultSetting default_setting = 6;

   // All the toolchains in this release.
   repeated CToolchain toolchain = 5;
 }
	// 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.
	//
	// File format for Blaze to configure Crosstool releases.

	syntax = "proto2";

	option java_package = "com.google.devtools.build.lib.view.config.crosstool";


	package com.google.devtools.build.lib.view.config.crosstool;

	// A description of a toolchain, which includes all the tools generally expected
	// to be available for building C/C++ targets, based on the GNU C compiler.
	//
	// System and cpu names are two overlapping concepts, which need to be both
	// supported at this time. The cpu name is the blaze command-line name for the
	// target system. The most common values are 'k8' and 'piii'. The system name is
	// a more generic identification of the executable system, based on the names
	// used by the GNU C compiler.
	//
	// Typically, the system name contains an identifier for the cpu (e.g. x86_64 or
	// alpha), an identifier for the machine (e.g. pc, or unknown), and an
	// identifier for the operating system (e.g. cygwin or linux-gnu). Typical
	// examples are 'x86_64-unknown-linux-gnu' and 'i686-unknown-cygwin'.
	//
	// The system name is used to determine if a given machine can execute a given
	// exectuable. In particular, it is used to check if the compilation products of
	// a toolchain can run on the host machine.
	message CToolchain {
	// Optional flag. Some option lists have a corresponding optional flag list.
	// These are appended at the end of the option list in case the corresponding
	// default setting is set.
	message OptionalFlag {
	required string default_setting_name = 1;
	repeated string flag = 2;
	}

	// A group of correlated flags. Supports parametrization via variable
	// expansion.
	// If a variable of list type is expanded, all flags in the flag group
	// will be expanded for each element of the list.
	// Only a single variable of list type may be referenced in a single flag
	// group; the same variable may be referenced multiple times.
	//
	// For example:
	// flag_group {
	// flag: '-I'
	// flag: '%{include_path}'
	// }
	// ... will get expanded to -I /to/path1 -I /to/path2 ... for each
	// include_path /to/pathN.
	//
	// Flag groups can be nested; if they are, the flag group must only contain
	// other flag groups (no flags) so the order is unambiguously specified.
	// Nested flag groups require build variables of nested list types, and
	// will be expanded recursively.
	//
	// For example:
	// flag_group {
	// flag_group { flag: '--start-lib' }
	// flag_group { flag: '%{object_files}' }
	// flag_group { flag: '--end-lib' }
	// }
	// ... will get expanded to
	// --start-lib a1.o a2.o ... --end-lib --start-lib b1.o b2.o .. --end-lib
	// with %{object_files} being a variable of nested list type
	// [['a1.o', 'a2.o', ...], ['b1.o', 'b2.o', ...], ...].
	//
	// TODO(bazel-team): Write more elaborate documentation and add a link to it.
	message FlagGroup {
	repeated string flag = 1;

	repeated FlagGroup flag_group = 2;
	}

	// A key/value pair to be added as an environment variable. The value of
	// this pair is expanded in the same way as is described in FlagGroup.
	// The key remains an unexpanded string literal.
	message EnvEntry {
	required string key = 1;
	required string value = 2;
	}

	// A set of features; used to support logical 'and' when specifying feature
	// requirements in FlagSet and Feature.
	message FeatureSet {
	repeated string feature = 1;
	}

	// A set of flags that are expanded in the command line for specific actions.
	message FlagSet {
	// The actions this flag set applies to; each flag set must specify at
	// least one action.
	repeated string action = 1;

	// The flags applied via this flag set.
	repeated FlagGroup flag_group = 2;

	// A list of feature sets defining when this flag set gets applied. The
	// flag set will be applied when any of the feature sets fully apply, that
	// is, when all features of the feature set are enabled.
	//
	// If 'with_feature' is omitted, the flag set will be applied
	// unconditionally for every action specified.
	repeated FeatureSet with_feature = 3;

	// A list of build variables that this feature set needs, but which are
	// allowed to not be set. If any of the build variables listed is not
	// set, the feature set will not be expanded.
	//
	// NOTE: Consider alternatives before using this; usually tools should
	// consistently create the same set of files, even if empty; use this
	// only for backwards compatibility with already existing behavior in tools
	// that are currently not worth changing.
	repeated string expand_if_all_available = 4;
	}

	// A set of environment variables that are expanded in the command line for
	// specific actions.
	message EnvSet {
	// The actions this env set applies to; each env set must specify at
	// least one action.
	repeated string action = 1;

	// The environment variables applied via this env set.
	repeated EnvEntry env_entry = 2;

	// A list of feature sets defining when this env set gets applied. The
	// env set will be applied when any of the feature sets fully apply, that
	// is, when all features of the feature set are enabled.
	//
	// If 'with_feature' is omitted, the env set will be applied
	// unconditionally for every action specified.
	repeated FeatureSet with_feature = 3;
	}

	// Contains all flag specifications for one feature.
	// Next ID: 7
	message Feature {
	// The feature's name. Feature names are generally defined by Bazel; it is
	// possible to introduce a feature without a change to Bazel by adding a
	// 'feature' section to the toolchain and adding the corresponding string as
	// feature in the BUILD file.
	optional string name = 1;

	// If the given feature is enabled, the flag sets will be applied for the
	// actions in the modes that they are specified for.
	repeated FlagSet flag_set = 2;

	// If the given feature is enabled, the env sets will be applied for the
	// actions in the modes that they are specified for.
	repeated EnvSet env_set = 6;

	// A list of feature sets defining when this feature is supported by the
	// toolchain. The feature is supported if any of the feature sets fully
	// apply, that is, when all features of a feature set are enabled.
	//
	// If 'requires' is omitted, the feature is supported independently of which
	// other features are enabled.
	//
	// Use this for example to filter flags depending on the build mode enabled
	// (opt / fastbuild / dbg).
	repeated FeatureSet requires = 3;

	// A list of features that are automatically enabled when this feature is
	// enabled. If any of the implied features cannot be enabled, this feature
	// will (silently) not be enabled either.
	repeated string implies = 4;

	// A list of names this feature conflicts with.
	// A feature cannot be enabled if:
	// - 'provides' contains the name of a different feature that we want to
	// enable.
	// - 'provides' contains the same value as a 'provides' in a different
	// feature that we want to enable.
	//
	// Use this in order to ensure that incompatible features cannot be
	// accidentally activated at the same time, leading to hard to diagnose
	// compiler errors.
	repeated string provides = 5;
	}

	repeated Feature feature = 50;

	// The unique identifier of the toolchain within the crosstool release. It
	// must be possible to use this as a directory name in a path.
	// It has to match the following regex: [a-zA-Z_][\.\- \w]*
	required string toolchain_identifier = 1;

	// A basic toolchain description.
	required string host_system_name = 2;
	required string target_system_name = 3;
	required string target_cpu = 4;
	required string target_libc = 5;
	required string compiler = 6;

	required string abi_version = 7;
	required string abi_libc_version = 8;

	// Tool locations. Relative paths are resolved relative to the configuration
	// file directory.
	repeated ToolPath tool_path = 9;

	// Feature flags.
	// TODO(bazel-team): Sink those into 'Feature' instances.
	optional bool supports_gold_linker = 10 [default = false];
	optional bool supports_thin_archives = 11 [default = false];
	optional bool supports_start_end_lib = 28 [default = false];
	optional bool supports_interface_shared_objects = 32 [default = false];
	optional bool supports_embedded_runtimes = 40 [default = false];
	// If specified, Blaze finds statically linked / dynamically linked runtime
	// libraries in the declared crosstool filegroup. Otherwise, Blaze
	// looks in "[static\|dynamic]-runtime-libs-$TARGET_CPU".
	optional string static_runtimes_filegroup = 45;
	optional string dynamic_runtimes_filegroup = 46;
	optional bool supports_incremental_linker = 41 [default = false];
	// This should be true, if the toolchain supports the D flag to ar, which
	// makes it output normalized archives that don't contain timestamps.
	optional bool supports_normalizing_ar = 26 [default = false];
	optional bool supports_fission = 43 [default = false];
	// Can generate dsym debug symbol information.
	optional bool supports_dsym = 51 [default = false];
	// Can generate a breakpad file. Requires that support_dsym=true,
	// otherwise an error will be thrown.
	optional bool supports_breakpad = 52 [default = false];
	optional bool needsPic = 12 [default = false];

	// Compiler flags for C/C++/Asm compilation.
	repeated string compiler_flag = 13;
	repeated OptionalFlag optional_compiler_flag = 35;
	// Additional compiler flags for C++ compilation.
	repeated string cxx_flag = 14;
	repeated OptionalFlag optional_cxx_flag = 36;
	// Additional unfiltered compiler flags for C/C++/Asm compilation.
	// These are not subject to nocopt filtering in cc_* rules.
	repeated string unfiltered_cxx_flag = 25;
	repeated OptionalFlag optional_unfiltered_cxx_flag = 37;
	// Linker flags.
	repeated string linker_flag = 15;
	repeated OptionalFlag optional_linker_flag = 38;
	// Additional linker flags when linking dynamic libraries.
	repeated string dynamic_library_linker_flag = 27;
	repeated OptionalFlag optional_dynamic_library_linker_flag = 39;
	// Additional test-only linker flags.
	repeated string test_only_linker_flag = 49;
	// Objcopy flags for embedding files into binaries.
	repeated string objcopy_embed_flag = 16;
	// Ld flags for embedding files into binaries. This is used by filewrapper
	// since it calls ld directly and needs to know what -m flag to pass.
	repeated string ld_embed_flag = 23;
	// Ar flags for combining object files into archives. If this is not set, it
	// defaults to "rcsD".
	repeated string ar_flag = 47;
	// Ar flags for combining object files into archives when thin_archives is
	// enabled. If this is not set, it defaults to "rcsDT".
	repeated string ar_thin_archives_flag = 48;
	// Additional compiler flags that are added for cc_plugin rules of type 'gcc'
	repeated string gcc_plugin_compiler_flag = 34;

	// Additional compiler and linker flags depending on the compilation mode.
	repeated CompilationModeFlags compilation_mode_flags = 17;

	// Additional compiler and linker flags depending on the LIPO mode.
	repeated LipoModeFlags lipo_mode_flags = 44;

	// Additional linker flags depending on the linking mode.
	repeated LinkingModeFlags linking_mode_flags = 18;

	// Plugin header directories for gcc and mao plugins. If none are set, the
	// toolchain does not support plugins. Relative paths are resolved relative
	// to the configuration file directory.
	repeated string gcc_plugin_header_directory = 19;
	repeated string mao_plugin_header_directory = 20;

	// Make variables that are made accessible to rules.
	repeated MakeVariable make_variable = 21;

	// Built-in include directories for C++ compilation. These should be the exact
	// paths used by the compiler, and are generally relative to the exec root.
	// The paths used by the compiler can be determined by 'gcc -Wp,-v some.c'.
	// We currently use the C++ paths also for C compilation, which is safe as
	// long as there are no name clashes between C++ and C header files.
	//
	// Relative paths are resolved relative to the configuration file directory.
	//
	// If the compiler has --sysroot support, then these paths should use
	// %sysroot% rather than the include path, and specify the sysroot attribute
	// in order to give blaze the information necessary to make the correct
	// replacements.
	repeated string cxx_builtin_include_directory = 22;

	// The built-in sysroot. If this attribute is not present, blaze does not
	// allow using a different sysroot, i.e. through the --grte_top option. Also
	// see the documentation above.
	optional string builtin_sysroot = 24;

	// The location and version of the default Python (in absence of
	// --python_top and --python_version, respectively. The default
	// --python_mode is always 'opt'.) For backward compatibility, if these
	// attributes are not set, Blaze will use the crosstool v11-13 default
	// values: "/usr/grte/v1" and "python2.4".
	optional string default_python_top = 29;
	optional string default_python_version = 30;
	// Whether to preload swigdeps.so files in py_binaries and PAR files.
	// This overrides the commandline flag.
	optional bool python_preload_swigdeps = 42;

	// The default GRTE to use. This should be a label, and gets the same
	// treatment from Blaze as the --grte_top option. This setting is only used in
	// the absence of an explicit --grte_top option. If unset, Blaze will not pass
	// -sysroot by default. The local part must be 'everything', i.e.,
	// '//some/label:everything'. There can only be one GRTE library per package,
	// because the compiler expects the directory as a parameter of the -sysroot
	// option.
	// This may only be set to a non-empty value if builtin_sysroot is also set!
	optional string default_grte_top = 31;

	// Additional dependencies for Blaze-built .deb packages. All Debian packages
	// that contain C++ binaries need to have the correct runtime
	// libraries installed, and those depend on the crosstool version, which is
	// why they are recorded here.
	repeated string debian_extra_requires = 33;

	// Next free id: 53
	}

	message ToolPath {
	required string name = 1;
	required string path = 2;
	}

	enum CompilationMode {
	FASTBUILD = 1;
	DBG = 2;
	OPT = 3;
	// This value is ignored and should not be used in new files.
	COVERAGE = 4;
	}

	message CompilationModeFlags {
	required CompilationMode mode = 1;
	repeated string compiler_flag = 2;
	repeated string cxx_flag = 3;
	// Linker flags that are added when compiling in a certain mode.
	repeated string linker_flag = 4;
	}

	enum LinkingMode {
	FULLY_STATIC = 1;
	MOSTLY_STATIC = 2;
	DYNAMIC = 3;
	}

	message LinkingModeFlags {
	required LinkingMode mode = 1;
	repeated string linker_flag = 2;
	}

	enum LipoMode {
	OFF = 1;
	BINARY = 2;
	// LIBRARY = 3; // RESERVED
	}

	message LipoModeFlags {
	required LipoMode mode = 1;
	repeated string compiler_flag = 2;
	repeated string cxx_flag = 3;
	repeated string linker_flag = 4;
	}

	message MakeVariable {
	required string name = 1;
	required string value = 2;
	}

	message DefaultCpuToolchain {
	required string cpu = 1;
	required string toolchain_identifier = 2;
	}

	// An entire crosstool release, containing the version number, a default target
	// cpu, a default toolchain for each supported cpu type, and a set of
	// toolchains.
	message CrosstoolRelease {
	message DefaultSetting {
	required string name = 1;
	required bool default_value = 2;
	}

	// The major and minor version of the crosstool release.
	required string major_version = 1;
	required string minor_version = 2;

	// The default cpu to use if none was specified.
	required string default_target_cpu = 3;
	// The default toolchain to use for each given cpu.
	repeated DefaultCpuToolchain default_toolchain = 4;

	// The default settings used in this release.
	repeated DefaultSetting default_setting = 6;

	// All the toolchains in this release.
	repeated CToolchain toolchain = 5;
	}