conan.tools.google

Important

This feature is still under development, while it is recommended and usable and we will try not to break them in future releases, some breaking changes might still happen if necessary to prepare for the Conan 2.0 release.

BazelDeps

Available since: 1.37.0

The BazelDeps helper will generate one conandeps/xxxx/BUILD file per dependency. This dependencies will be automatically added to the project if you add the following lines to the project’s WORKSPACE file:

load("@//conandeps:dependencies.bzl", "load_conan_dependencies")
load_conan_dependencies()

The dependencies should be added to the conanfile.py file as usual:

class BazelExampleConan(ConanFile):
    name = "bazel-example"
    ...
    generators = "BazelDeps", "BazelToolchain"
    requires = "boost/1.76.0"

BazelToolchain

Available since: 1.37.0

The BazelToolchain is the toolchain generator for Bazel. It will generate a file called conanbuild.conf containing two keys:

bazelrc_path: defining Bazel rc-path. Can be set using the conf tools.google.bazel:bazelrc_path.
bazel_configs: defining the configs to be activated in the bazelrc_path. Can be set with the conf tools.google.bazel:configs.

Example of a custom bazelrc file at ‘/path/to/mybazelrc’:

build:Release -c opt
build:RelWithDebInfo -c opt --copt=-O3 --copt=-DNDEBUG
build:MinSizeRel  -c opt --copt=-Os --copt=-DNDEBUG
build --color=yes
build:withTimeStamps --show_timestamps

Example of a Release profile:

[settings]
...
build_type=Release

[conf]
tools.google.bazel:bazelrc_path=/path/to/mybazelrc
tools.google.bazel:configs=["Release"]

The Bazel build helper will use that conanbuild.conf file to seamlessly call the configure and make script using these precalculated arguments. Note that the file can have a different name if you set the namespace argument in the constructor as explained below.

It supports the following methods and attributes:

constructor

def __init__(self, conanfile, namespace=None):

conanfile: the current recipe object. Always use self.
namespace: this argument avoids collisions when you have multiple toolchain calls in the same recipe. By setting this argument, the conanbuild.conf file used to pass information to the build helper will be named as: <namespace>_conanbuild.conf. The default value is None meaning that the name of the generated file is conanbuild.conf. This namespace must be also set with the same value in the constructor of the Bazel build helper so that it reads the information from the proper file.

Bazel

Available since: 1.37.0

The Bazel build helper is a wrapper around the command line invocation of bazel. It will abstract the calls like bazel build //main:hello-world into Python method calls.

The helper is intended to be used in the build() method, to call Bazel commands automatically when a package is being built directly by Conan (create, install)

from conan import ConanFile
from conan.tools.google import Bazel

class App(ConanFile):
    settings = "os", "arch", "compiler", "build_type"

    def build(self):
        bazel = Bazel(self)
        bazel.configure()
        bazel.build(label="//main:hello-world")

It supports the following methods:

constructor

def __init__(self, conanfile, namespace=None):

conanfile: the current recipe object. Always use self.
namespace: this argument avoids collisions when you have multiple toolchain calls in the same recipe. By setting this argument, the conanbuild.conf file used to pass information to the toolchain will be named as: <namespace>_conanbuild.conf. The default value is None meaning that the name of the generated file is conanbuild.conf. This namespace must be also set with the same value in the constructor of BazelToolchain so that it reads the information from the proper file.

build()

def build(self, args=None, label=None):

Calls the build system. Equivalent to bazel build {label} in the build folder.