Extensions > API reference > cc_common

cc_common

Utilities for C++ compilation, linking, and command line generation.

action_is_enabled

bool cc_common.action_is_enabled(feature_configuration, action_name)

Returns True if given action_config is enabled in the feature configuration.

Parameters

Parameter	Description
feature_configuration	required Feature configuration to be queried.
action_name	required Name of the action_config.

CcToolchainInfo

Provider cc_common.CcToolchainInfo

The key used to retrieve the provider that contains information about the C++ toolchain being used

compile

tuple cc_common.compile(actions, feature_configuration, cc_toolchain, srcs=[], public_hdrs=[], private_hdrs=[], includes=[], quote_includes=[], system_includes=[], framework_includes=[], defines=[], local_defines=[], include_prefix='', strip_include_prefix='', user_compile_flags=[], compilation_contexts=[], name, disallow_pic_outputs=False, disallow_nopic_outputs=False, additional_inputs=[], grep_includes=None)

Should be used for C++ compilation. Returns tuple of (CompilationContext, CcCompilationOutputs).

Parameters

Parameter	Description
actions	required actions object.
feature_configuration	required feature_configuration to be queried.
cc_toolchain	required CcToolchainInfo provider to be used.
srcs	default = [] The list of source files to be compiled.
public_hdrs	default = [] List of headers needed for compilation of srcs and may be included by dependent rules transitively.
private_hdrs	default = [] List of headers needed for compilation of srcs and NOT to be included by dependent rules.
includes	default = [] Search paths for header files referenced both by angle bracket and quotes. Usually passed with -I. Propagated to dependents transitively.
quote_includes	default = [] Search paths for header files referenced by quotes, e.g. #include "foo/bar/header.h". They can be either relative to the exec root or absolute. Usually passed with -iquote. Propagated to dependents transitively.
system_includes	default = [] Search paths for header files referenced by angle brackets, e.g. #include <foo/bar/header.h>. They can be either relative to the exec root or absolute. Usually passed with -isystem. Propagated to dependents transitively.
framework_includes	default = [] Search paths for header files from Apple frameworks. They can be either relative to the exec root or absolute. Usually passed with -F. Propagated to dependents transitively.
defines	default = [] Set of defines needed to compile this target. Each define is a string. Propagated to dependents transitively.
local_defines	default = [] Set of defines needed to compile this target. Each define is a string. Not propagated to dependents transitively.
include_prefix	default = '' The prefix to add to the paths of the headers of this rule. When set, the headers in the hdrs attribute of this rule are accessible at is the value of this attribute prepended to their repository-relative path. The prefix in the strip_include_prefix attribute is removed before this prefix is added.
strip_include_prefix	default = '' The prefix to strip from the paths of the headers of this rule. When set, the headers in the hdrs attribute of this rule are accessible at their path with this prefix cut off. If it's a relative path, it's taken as a package-relative one. If it's an absolute one, it's understood as a repository-relative path. The prefix in the include_prefix attribute is added after this prefix is stripped.
user_compile_flags	default = [] Additional list of compilation options.
compilation_contexts	default = [] Headers from dependencies used for compilation.
name	required This is used for naming the output artifacts of actions created by this method.
disallow_pic_outputs	default = False Whether PIC outputs should be created.
disallow_nopic_outputs	default = False Whether NOPIC outputs should be created.
additional_inputs	default = [] List of additional files needed for compilation of srcs
grep_includes	File; or None; default = None

configure_features

FeatureConfiguration cc_common.configure_features(ctx=None, cc_toolchain, requested_features=[], unsupported_features=[])

Creates a feature_configuration instance. Requires the cpp configuration fragment.

Parameters

Parameter	Description
ctx	ctx; or None; default = None The rule context.
cc_toolchain	required cc_toolchain for which we configure features.
requested_features	default = [] List of features to be enabled.
unsupported_features	default = [] List of features that are unsupported by the current rule.

create_cc_toolchain_config_info

CcToolchainConfigInfo cc_common.create_cc_toolchain_config_info(ctx, features=[], action_configs=[], artifact_name_patterns=[], cxx_builtin_include_directories=[], toolchain_identifier, host_system_name=None, target_system_name, target_cpu, target_libc, compiler, abi_version=None, abi_libc_version=None, tool_paths=[], make_variables=[], builtin_sysroot=None, cc_target_os=None)

Creates a CcToolchainConfigInfo provider

Parameters

Parameter	Description
ctx	required The rule context.
features	default = [] A list of features.
action_configs	default = [] A list of action_configs.
artifact_name_patterns	default = [] A list of artifact_name_patterns.
cxx_builtin_include_directories	default = [] 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 -E -xc++ - -v'. 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 bazel the information necessary to make the correct replacements.
toolchain_identifier	required 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]*
host_system_name	string; or None; default = None Ignored.
target_system_name	required The GNU System Name.
target_cpu	required The target architecture string.
target_libc	required The libc version string (e.g. "glibc-2.2.2").
compiler	required The compiler version string (e.g. "gcc-4.1.1").
abi_version	string; or None; default = None The abi in use, which is a gcc version. E.g.: "gcc-3.4"
abi_libc_version	string; or None; default = None The glibc version used by the abi we're using.
tool_paths	default = [] A list of tool_paths.
make_variables	default = [] A list of make_variables.
builtin_sysroot	string; or None; default = None The built-in sysroot. If this attribute is not present, Bazel does not allow using a different sysroot, i.e. through the --grte_top option.
cc_target_os	string; or None; default = None Internal purpose only, do not use.

create_compilation_context

CompilationContext cc_common.create_compilation_context(headers=unbound, system_includes=unbound, includes=unbound, quote_includes=unbound, framework_includes=unbound, defines=unbound, local_defines=unbound)

Creates a CompilationContext.

Parameters

Parameter	Description
headers	default = unbound Set of headers needed to compile this target
system_includes	default = unbound Set of search paths for header files referenced by angle brackets, i.e. #include <foo/bar/header.h>. They can be either relative to the exec root or absolute. Usually passed with -isystem
includes	default = unbound Set of search paths for header files referenced both by angle bracket and quotes.Usually passed with -I
quote_includes	default = unbound Set of search paths for header files referenced by quotes, i.e. #include "foo/bar/header.h". They can be either relative to the exec root or absolute. Usually passed with -iquote
framework_includes	default = unbound Set of framework search paths for header files (Apple platform only)
defines	default = unbound Set of defines needed to compile this target. Each define is a string. Propagated transitively to dependents.
local_defines	default = unbound Set of defines needed to compile this target. Each define is a string. Not propagated transitively to dependents.

create_compilation_outputs

CcCompilationOutputs cc_common.create_compilation_outputs(objects=None, pic_objects=None)

Create compilation outputs object.

Parameters

Parameter	Description
objects	depset; or None; default = None List of object files.
pic_objects	depset; or None; default = None List of pic object files.

create_compile_variables

Variables cc_common.create_compile_variables(cc_toolchain, feature_configuration, source_file=None, output_file=None, user_compile_flags=None, include_directories=None, quote_include_directories=None, system_include_directories=None, framework_include_directories=None, preprocessor_defines=None, thinlto_index=None, thinlto_input_bitcode_file=None, thinlto_output_object_file=None, use_pic=False, add_legacy_cxx_options=False, variables_extension=unbound)

Returns variables used for compilation actions.

Parameters

Parameter	Description
cc_toolchain	required cc_toolchain for which we are creating build variables.
feature_configuration	required Feature configuration to be queried.
source_file	default = None Optional source file for the compilation. Please prefer passing source_file here over appending it to the end of the command line generated from cc_common.get_memory_inefficient_command_line, as then it's in the power of the toolchain author to properly specify and position compiler flags.
output_file	default = None Optional output file of the compilation. Please prefer passing output_file here over appending it to the end of the command line generated from cc_common.get_memory_inefficient_command_line, as then it's in the power of the toolchain author to properly specify and position compiler flags.
user_compile_flags	sequence of strings; or None; default = None List of additional compilation flags (copts).
include_directories	depset; or None; default = None Depset of include directories.
quote_include_directories	depset; or None; default = None Depset of quote include directories.
system_include_directories	depset; or None; default = None Depset of system include directories.
framework_include_directories	depset; or None; default = None Depset of framework include directories.
preprocessor_defines	depset; or None; default = None Depset of preprocessor defines.
thinlto_index	string; or None; default = None LTO index file path.
thinlto_input_bitcode_file	string; or None; default = None Bitcode file that is input to LTO backend.
thinlto_output_object_file	string; or None; default = None Object file that is output by LTO backend.
use_pic	default = False When true the compilation will generate position independent code.
add_legacy_cxx_options	default = False Unused.
variables_extension	dict; default = unbound A dictionary of additional variables used by compile actions.

create_library_to_link

LibraryToLink cc_common.create_library_to_link(actions, feature_configuration=None, cc_toolchain=None, static_library=None, pic_static_library=None, dynamic_library=None, interface_library=None, pic_objects=unbound, objects=unbound, alwayslink=False, dynamic_library_symlink_path='', interface_library_symlink_path='')

Creates LibraryToLink

Parameters

Parameter	Description
actions	required actions object.
feature_configuration	default = None feature_configuration to be queried.
cc_toolchain	default = None CcToolchainInfo provider to be used.
static_library	File; or None; default = None File of static library to be linked.
pic_static_library	File; or None; default = None File of pic static library to be linked.
dynamic_library	File; or None; default = None File of dynamic library to be linked. Always used for runtime and used for linking if interface_library is not passed.
interface_library	File; or None; default = None File of interface library to be linked.
pic_objects	sequence of Files; default = unbound Experimental, do not use
objects	sequence of Files; default = unbound Experimental, do not use
alwayslink	default = False Whether to link the static library/objects in the --whole_archive block.
dynamic_library_symlink_path	string; default = '' Override the default path of the dynamic library link in the solib directory. Empty string to use the default.
interface_library_symlink_path	default = '' Override the default path of the interface library link in the solib directory. Empty string to use the default.

create_link_variables

Variables cc_common.create_link_variables(cc_toolchain, feature_configuration, library_search_directories=None, runtime_library_search_directories=None, user_link_flags=None, output_file=None, param_file=None, def_file=None, is_using_linker=True, is_linking_dynamic_library=False, must_keep_debug=True, use_test_only_flags=False, is_static_linking_mode=True)

Returns link variables used for linking actions.

Parameters

Parameter	Description
cc_toolchain	required cc_toolchain for which we are creating build variables.
feature_configuration	required Feature configuration to be queried.
library_search_directories	None; or depset; default = None Depset of directories where linker will look for libraries at link time.
runtime_library_search_directories	None; or depset; default = None Depset of directories where loader will look for libraries at runtime.
user_link_flags	None; or sequence; default = None List of additional link flags (linkopts).
output_file	default = None Optional output file path.
param_file	default = None Optional param file path.
def_file	default = None Optional .def file path.
is_using_linker	default = True True when using linker, False when archiver. Caller is responsible for keeping this in sync with action name used (is_using_linker = True for linking executable or dynamic library, is_using_linker = False for archiving static library).
is_linking_dynamic_library	default = False True when creating dynamic library, False when executable or static library. Caller is responsible for keeping this in sync with action name used. This field will be removed once b/65151735 is fixed.
must_keep_debug	default = True When set to True, bazel will expose 'strip_debug_symbols' variable, which is usually used to use the linker to strip debug symbols from the output file.
use_test_only_flags	default = False When set to true, 'is_cc_test' variable will be set.
is_static_linking_mode	default = True Unused.

create_linker_input

LinkerInput cc_common.create_linker_input(owner, libraries=None, user_link_flags=None, additional_inputs=None)

Creates a LinkerInput.

Parameters

Parameter	Description
owner	required The label of the target that produced all files used in this input.
libraries	None; or depset; default = None List of LibraryToLink.
user_link_flags	None; or depset of strings; or sequence of strings; default = None User link flags passed as strings. Accepts either [String], [[String]] or depset(String). The latter is discouraged as it's only kept for compatibility purposes, the depset is flattened. If you want to propagate user_link_flags via unflattened depsets() wrap them in a LinkerInput so that they are not flattened till the end.
additional_inputs	None; or depset; default = None For additional inputs to the linking action, e.g.: linking scripts.

create_linking_context

LinkingContext cc_common.create_linking_context(linker_inputs=None, libraries_to_link=None, user_link_flags=None, additional_inputs=None)

Creates a LinkingContext.

Parameters

Parameter	Description
linker_inputs	None; or depset; default = None Depset of LinkerInput.
libraries_to_link	None; or sequence; default = None Deprecated. This parameter is deprecated and will be removed soon. Please do not depend on it. It is disabled with --+incompatible_require_linker_input_cc_api. Use this flag to verify your code is compatible with its imminent removal. List of LibraryToLink.
user_link_flags	None; or sequence; default = None Deprecated. This parameter is deprecated and will be removed soon. Please do not depend on it. It is disabled with --+incompatible_require_linker_input_cc_api. Use this flag to verify your code is compatible with its imminent removal. List of user link flags passed as strings.
additional_inputs	None; or sequence; default = None Deprecated. This parameter is deprecated and will be removed soon. Please do not depend on it. It is disabled with --+incompatible_require_linker_input_cc_api. Use this flag to verify your code is compatible with its imminent removal. For additional inputs to the linking action, e.g.: linking scripts.

create_linking_context_from_compilation_outputs

tuple cc_common.create_linking_context_from_compilation_outputs(actions, feature_configuration, cc_toolchain, compilation_outputs, user_link_flags=[], linking_contexts=[], name, language='c++', alwayslink=False, additional_inputs=[], disallow_static_libraries=False, disallow_dynamic_library=False, grep_includes=None)

Should be used for creating library rules that can propagate information downstream in order to be linked later by a top level rule that does transitive linking to create an executable or dynamic library. Returns tuple of (CcLinkingContext, CcLinkingOutputs).

Parameters

Parameter	Description
actions	required actions object.
feature_configuration	required feature_configuration to be queried.
cc_toolchain	required CcToolchainInfo provider to be used.
compilation_outputs	required Compilation outputs containing object files to link.
user_link_flags	default = [] Additional list of linking options.
linking_contexts	default = [] Libraries from dependencies. These libraries will be linked into the output artifact of the link() call, be it a binary or a library.
name	required This is used for naming the output artifacts of actions created by this method.
language	default = 'c++' Only C++ supported for now. Do not use this parameter.
alwayslink	default = False Whether this library should always be linked.
additional_inputs	default = [] For additional inputs to the linking action, e.g.: linking scripts.
disallow_static_libraries	default = False Whether static libraries should be created.
disallow_dynamic_library	default = False Whether a dynamic library should be created.
grep_includes	File; or None; default = None

do_not_use_tools_cpp_compiler_present

None cc_common.do_not_use_tools_cpp_compiler_present

Do not use this field, its only puprose is to help with migration from config_setting.values{'compiler') to config_settings.flag_values{'@bazel_tools//tools/cpp:compiler'}

get_environment_variables

dict cc_common.get_environment_variables(feature_configuration, action_name, variables)

Returns environment variables to be set for given action.

Parameters

Parameter	Description
feature_configuration	required Feature configuration to be queried.
action_name	required Name of the action. Has to be one of the names in @bazel_tools//tools/build_defs/cc:action_names.bzl (https://github.com/bazelbuild/bazel/blob/master/tools/build_defs/cc/action_names.bzl)
variables	required Build variables to be used for template expansion.

get_execution_requirements

sequence cc_common.get_execution_requirements(feature_configuration, action_name)

Returns execution requirements for given action.

Parameters

Parameter	Description
feature_configuration	required Feature configuration to be queried.
action_name	required Name of the action. Has to be one of the names in @bazel_tools//tools/build_defs/cc:action_names.bzl (https://github.com/bazelbuild/bazel/blob/master/tools/build_defs/cc/action_names.bzl)

get_memory_inefficient_command_line

sequence cc_common.get_memory_inefficient_command_line(feature_configuration, action_name, variables)

Returns flattened command line flags for given action, using given variables for expansion. Flattens nested sets and ideally should not be used, or at least should not outlive analysis. Work on memory efficient function returning Args is ongoing.

Parameters

Parameter	Description
feature_configuration	required Feature configuration to be queried.
action_name	required Name of the action. Has to be one of the names in @bazel_tools//tools/build_defs/cc:action_names.bzl (https://github.com/bazelbuild/bazel/blob/master/tools/build_defs/cc/action_names.bzl)
variables	required Build variables to be used for template expansions.

get_tool_for_action

string cc_common.get_tool_for_action(feature_configuration, action_name)

Returns tool path for given action.

Parameters

Parameter	Description
feature_configuration	required Feature configuration to be queried.
action_name	required Name of the action. Has to be one of the names in @bazel_tools//tools/build_defs/cc:action_names.bzl (https://github.com/bazelbuild/bazel/blob/master/tools/build_defs/cc/action_names.bzl)

is_enabled

bool cc_common.is_enabled(feature_configuration, feature_name)

Returns True if given feature is enabled in the feature configuration.

Parameters

Parameter	Description
feature_configuration	required Feature configuration to be queried.
feature_name	required Name of the feature.

link

CcLinkingOutputs cc_common.link(actions, feature_configuration, cc_toolchain, compilation_outputs=None, user_link_flags=[], linking_contexts=[], name, language='c++', output_type='executable', link_deps_statically=True, stamp=0, additional_inputs=[], grep_includes=None, additional_outputs=unbound)

Should be used for C++ transitive linking.

Parameters

Parameter	Description
actions	required actions object.
feature_configuration	required feature_configuration to be queried.
cc_toolchain	required CcToolchainInfo provider to be used.
compilation_outputs	CcCompilationOutputs; or None; default = None Compilation outputs containing object files to link.
user_link_flags	default = [] Additional list of linker options.
linking_contexts	default = [] Linking contexts from dependencies to be linked into the linking context generated by this rule.
name	required This is used for naming the output artifacts of actions created by this method.
language	default = 'c++' Only C++ supported for now. Do not use this parameter.
output_type	default = 'executable' Can be either 'executable' or 'dynamic_library'.
link_deps_statically	default = True True to link dependencies statically, False dynamically.
stamp	default = 0 Whether to include build information in the linked executable, if output_type is 'executable'. If 1, build information is always included. If 0 (the default build information is always excluded. If -1, uses the default behavior, which may be overridden by the --[no]stamp flag. This should be unset (or set to 0) when generating the executable output for test rules.
additional_inputs	sequence; or depset; default = [] For additional inputs to the linking action, e.g.: linking scripts.
grep_includes	File; or None; default = None
additional_outputs	sequence; default = unbound For additional outputs to the linking action, e.g.: map files.

merge_cc_infos

CcInfo cc_common.merge_cc_infos(direct_cc_infos=[], cc_infos=[])

Merges multiple CcInfos into one.

Parameters

Parameter	Description
direct_cc_infos	default = [] List of CcInfos to be merged, whose headers will be exported by the direct fields in the returned provider.
cc_infos	default = [] List of CcInfos to be merged, whose headers will not be exported by the direct fields in the returned provider.

merge_compilation_contexts

CompilationContext cc_common.merge_compilation_contexts(compilation_contexts=[])

Merges multiple CompilationContextss into one.

Parameters

Parameter	Description
compilation_contexts	default = [] List of CompilationContextss to be merged. The headers of each context will be exported by the direct fields in the returned provider.

merge_compilation_outputs

CcCompilationOutputs cc_common.merge_compilation_outputs(compilation_outputs=[])

Merge compilation outputs.

Parameters

Parameter	Description
compilation_outputs	default = []