conan.tools.build

Building

conan.tools.build.build_jobs()

build_jobs(conanfile)

Returns the number of CPUs available for parallel builds. It returns the configuration value for tools.build:jobs if exists, otherwise, it defaults to the helper function _cpu_count(). _cpu_count() reads cgroup to detect the configured number of CPUs. Currently, there are two versions of cgroup available.

In the case of cgroup v1, if the data in cgroup is invalid, processor detection comes into play. Whenever processor detection is not enabled, build_jobs() will safely return 1.

In the case of cgroup v2, if no limit is set, processor detection is used. When the limit is set, the behavior is as described in cgroup v1.

Parameters:

conanfile – The current recipe object. Always use self.

Returns:

int with the number of jobs

conan.tools.build.cross_building()

cross_building(conanfile=None, skip_x64_x86=False)

Check if we are cross building comparing the build and host settings. Returns True in the case that we are cross-building.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • skip_x64_x86 – Do not consider cross building when building to 32 bits from 64 bits: x86_64 to x86, sparcv9 to sparc or ppc64 to ppc32

Returns:

bool value from tools.build.cross_building:cross_build if exists, otherwise, it returns True if we are cross-building, else, False.

conan.tools.build.can_run()

can_run(conanfile)

Validates whether is possible to run a non-native app on the same architecture. It’s a useful feature for the case your architecture can run more than one target. For instance, Mac M1 machines can run both armv8 and x86_64.

Parameters:

conanfile – The current recipe object. Always use self.

Returns:

bool value from tools.build.cross_building:can_run if exists, otherwise, it returns False if we are cross-building, else, True.

Cppstd

conan.tools.build.check_min_cppstd()

check_min_cppstd(conanfile, cppstd, gnu_extensions=False)

Check if current cppstd fits the minimal version required.

In case the current cppstd doesn’t fit the minimal version required by cppstd, a ConanInvalidConfiguration exception will be raised.

settings.compiler.cppstd must be defined, otherwise ConanInvalidConfiguration is raised

Parameters:

  • conanfile – The current recipe object. Always use self.

  • cppstd – Minimal cppstd version required

  • gnu_extensions – GNU extension is required (e.g gnu17)

conan.tools.build.check_max_cppstd()

check_max_cppstd(conanfile, cppstd, gnu_extensions=False)

Check if current cppstd fits the maximum version required.

In case the current cppstd doesn’t fit the maximum version required by cppstd, a ConanInvalidConfiguration exception will be raised.

settings.compiler.cppstd must be defined, otherwise ConanInvalidConfiguration is raised

Parameters:

  • conanfile – The current recipe object. Always use self.

  • cppstd – Maximum cppstd version required

  • gnu_extensions – GNU extension is required (e.g gnu17)

conan.tools.build.valid_min_cppstd()

valid_min_cppstd(conanfile, cppstd, gnu_extensions=False)

Validate if current cppstd fits the minimal version required.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • cppstd – Minimal cppstd version required

  • gnu_extensions – GNU extension is required (e.g gnu17). This option ONLY works on Linux.

Returns:

True, if current cppstd matches the required cppstd version. Otherwise, False.

conan.tools.build.valid_max_cppstd()

valid_max_cppstd(conanfile, cppstd, gnu_extensions=False)

Validate if current cppstd fits the maximum version required.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • cppstd – Maximum cppstd version required

  • gnu_extensions – GNU extension is required (e.g gnu17). This option ONLY works on Linux.

Returns:

True, if current cppstd matches the required cppstd version. Otherwise, False.

conan.tools.build.default_cppstd()

default_cppstd(conanfile, compiler=None, compiler_version=None)

Get the default compiler.cppstd for the “conanfile.settings.compiler” and “conanfile settings.compiler_version” or for the parameters “compiler” and “compiler_version” if specified.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • compiler – Name of the compiler e.g. gcc

  • compiler_version – Version of the compiler e.g. 12

Returns:

The default compiler.cppstd for the specified compiler

conan.tools.build.supported_cppstd()

supported_cppstd(conanfile, compiler=None, compiler_version=None)

Get a list of supported compiler.cppstd for the “conanfile.settings.compiler” and “conanfile.settings.compiler_version” or for the parameters “compiler” and “compiler_version” if specified.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • compiler – Name of the compiler e.g: gcc

  • compiler_version – Version of the compiler e.g: 12

Returns:

a list of supported cppstd values.

conan.tools.build.cppstd_flag()

cppstd_flag(conanfile) → str

Returns flags specific to the C++ standard based on the conanfile.settings.compiler, conanfile.settings.compiler.version and conanfile.settings.compiler.cppstd.

It also considers when using GNU extension in settings.compiler.cppstd, reflecting it in the compiler flag. Currently, it supports GCC, Clang, AppleClang, MSVC, Intel, MCST-LCC.

In case there is no settings.compiler or settings.cppstd in the profile, the result will be an empty string.

Parameters:

conanfile – The current recipe object. Always use self.

Returns:

str with the standard C++ flag used by the compiler. e.g. “-std=c++11”, “/std:c++latest”

cstd

Warning

This feature is experimental and subject to breaking changes. See the Conan stability section for more information.

conan.tools.build.check_min_cstd()

check_min_cstd(conanfile, cstd, gnu_extensions=False)

Check if current cstd fits the minimal version required.

In case the current cstd doesn’t fit the minimal version required by cstd, a ConanInvalidConfiguration exception will be raised.

  1. If settings.compiler.cstd, the tool will use settings.compiler.cstd to compare

  2. It not settings.compiler.cstd, the tool will use compiler to compare (reading the default from cstd_default)

  3. If not settings.compiler is present (not declared in settings) will raise because it cannot compare.

  4. If can not detect the default cstd for settings.compiler, a exception will be raised.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • cstd – Minimal cstd version required

  • gnu_extensions – GNU extension is required (e.g gnu17)

conan.tools.build.check_max_cstd()

check_max_cstd(conanfile, cstd, gnu_extensions=False)

Check if current cstd fits the maximum version required.

In case the current cstd doesn’t fit the maximum version required by cstd, a ConanInvalidConfiguration exception will be raised.

  1. If settings.compiler.cstd, the tool will use settings.compiler.cstd to compare

  2. It not settings.compiler.cstd, the tool will use compiler to compare (reading the default from cstd_default)

  3. If not settings.compiler is present (not declared in settings) will raise because it cannot compare.

  4. If can not detect the default cstd for settings.compiler, a exception will be raised.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • cstd – Maximum cstd version required

  • gnu_extensions – GNU extension is required (e.g gnu17)

conan.tools.build.valid_min_cstd()

valid_min_cstd(conanfile, cstd, gnu_extensions=False)

Validate if current cstd fits the minimal version required.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • cstd – Minimal cstd version required

  • gnu_extensions – GNU extension is required (e.g gnu17). This option ONLY works on Linux.

Returns:

True, if current cstd matches the required cstd version. Otherwise, False.

conan.tools.build.valid_max_cstd()

valid_max_cstd(conanfile, cstd, gnu_extensions=False)

Validate if current cstd fits the maximum version required.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • cstd – Maximum cstd version required

  • gnu_extensions – GNU extension is required (e.g gnu17). This option ONLY works on Linux.

Returns:

True, if current cstd matches the required cstd version. Otherwise, False.

conan.tools.build.supported_cstd()

supported_cstd(conanfile, compiler=None, compiler_version=None)

Get a list of supported compiler.cstd for the “conanfile.settings.compiler” and “conanfile.settings.compiler_version” or for the parameters “compiler” and “compiler_version” if specified.

Parameters:

  • conanfile – The current recipe object. Always use self.

  • compiler – Name of the compiler e.g: gcc

  • compiler_version – Version of the compiler e.g: 12

Returns:

a list of supported cstd values.