CMakeToolchain¶
The CMakeToolchain
is the toolchain generator for CMake. It produces the toolchain file that can be used in the
command line invocation of CMake with the -DCMAKE_TOOLCHAIN_FILE=conan_toolchain.cmake
. This generator translates
the current package configuration, settings, and options, into CMake toolchain syntax.
It can be declared as:
from conan import ConanFile
class Pkg(ConanFile):
generators = "CMakeToolchain"
Or fully instantiated in the generate()
method:
from conan import ConanFile
from conan.tools.cmake import CMakeToolchain
class App(ConanFile):
settings = "os", "arch", "compiler", "build_type"
requires = "hello/0.1"
generators = "CMakeDeps"
options = {"shared": [True, False], "fPIC": [True, False]}
default_options = {"shared": False, "fPIC": True}
def generate(self):
tc = CMakeToolchain(self)
tc.variables["MYVAR"] = "MYVAR_VALUE"
tc.preprocessor_definitions["MYDEFINE"] = "MYDEF_VALUE"
tc.generate()
Note
The CMakeToolchain
is intended to run with the CMakeDeps
dependencies generator. Please do not use other
CMake legacy generators (like cmake
, or cmake_paths
) with it.
Generated files¶
This will generate the following files after a conan install
(or when building the package
in the cache) with the information provided in the generate()
method as well as information
translated from the current settings
:
conan_toolchain.cmake: containing the translation of Conan settings to CMake variables. Some things that will be defined in this file:
Definition of the CMake generator platform and generator toolset
Definition of the
CMAKE_POSITION_INDEPENDENT_CODE
, based onfPIC
option.Definition of the C++ standard as necessary
Definition of the standard library used for C++
Deactivation of rpaths in OSX
Definition of
CMAKE_VS_DEBUGGER_ENVIRONMENT
when on Windows with Visual Studio. This sets up thePATH
environment variable to point to directories containing DLLs, to allow debugging directly from the Visual Studio IDE without copying DLLs (requires CMake 3.27).
conanvcvars.bat: In some cases, the Visual Studio environment needs to be defined correctly for building, like when using the Ninja or NMake generators. If necessary, the
CMakeToolchain
will generate this script, so defining the correct Visual Studio prompt is easier.CMakePresets.json: This toolchain generates a standard CMakePresets.json file. For more information, refer to the documentation here. It currently uses version “3” of the JSON schema. Conan adds configure, build, and test preset entries to the JSON file:
- configurePresets storing the following information:
The generator to be used.
The path to the conan_toolchain.cmake.
Cache variables corresponding to the specified settings that cannot work if specified in the toolchain.
The CMAKE_BUILD_TYPE variable for single-configuration generators.
The BUILD_TESTING variable set to OFF when the configuration tools.build:skip_test is true.
An environment section, setting all the environment information related to the VirtualBuildEnv, if applicable. This environment can be modified in the generate() method of the recipe by passing an environment through the CMakeToolchain.presets_build_environment attribute. Generation of this section can be skipped by using the tools.cmake.cmaketoolchain:presets_environment configuration.
By default, preset names will be conan-xxxx, but the “conan-” prefix can be customized with the CMakeToolchain.presets_prefix = “conan” attribute.
Preset names are controlled by the layout() self.folders.build_folder_vars definition, which can contain a list of settings, options and/or
self.name
andself.version
like [“settings.compiler”, “settings.arch”, “options.shared”].If CMake is found as a direct tool_requires dependency, or if tools.cmake:cmake_program is set, the configure preset will include a cmakeExecutable field. This field represents the path to the CMake executable to be used for this preset. As stated in the CMake documentation, this field is reserved for use by IDEs and is not utilized by CMake itself.
- buildPresets storing the following information:
The configurePreset associated with this build preset.
- testPresets storing the following information:
The configurePreset associated with this build preset.
An environment section, setting all the environment information related to the VirtualRunEnv, if applicable. This environment can be modified in the generate() method of the recipe by passing an environment through the CMakeToolchain.presets_run_environment attribute. Please note that since this preset inherits from a configurePreset, it will also inherit its environment. Generation of this section can be skipped by using the`tools.cmake.cmaketoolchain:presets_environment` configuration.
CMakeUserPresets.json: If you declare a
layout()
in the recipe and yourCMakeLists.txt
file is found at theconanfile.source_folder
folder, aCMakeUserPresets.json
file will be generated (if doesn’t exist already) including automatically theCMakePresets.json
(at theconanfile.generators_folder
) to allow your IDE (Visual Studio, Visual Studio Code, CLion…) orcmake
tool to locate theCMakePresets.json
. The location of the generatedCMakeUserPresets.json
can be further tweaked by theuser_presets_path
attribute, as documented below. The version schema of the generatedCMakeUserPresets.json
is “4” and requires CMake >= 3.23. The file name of this file can be configured with theCMakeToolchain.user_presets_path = "CMakeUserPresets.json"`
attribute, so if you want to generate a “ConanPresets.json” instead to be included from your own file, you can definetc.user_presets_path = "ConanPresets.jon"
in thegenerate()
method. See extending your own CMake presets for a full example.Note: Conan will skip the generation of the
CMakeUserPresets.json
if it already exists and was not generated by Conan.Note: To list all available presets, use the
cmake --list-presets
command:
Note
The version schema of the generated CMakeUserPresets.json
is 4 (compatible
with CMake>=3.23) and the schema for the CMakePresets.json
is 3 (compatible with
CMake>=3.21).
Customization¶
preprocessor_definitions¶
This attribute allows defining compiler preprocessor definitions, for multiple configurations (Debug, Release, etc).
def generate(self):
tc = CMakeToolchain(self)
tc.preprocessor_definitions["MYDEF"] = "MyValue"
tc.preprocessor_definitions.debug["MYCONFIGDEF"] = "MyDebugValue"
tc.preprocessor_definitions.release["MYCONFIGDEF"] = "MyReleaseValue"
# Setting to None will add the definition with no value
tc.preprocessor_definitions["NOVALUE_DEF"] = None
tc.generate()
This will be translated to:
One
add_compile_definitions()
definition forMYDEF
inconan_toolchain.cmake
file.One
add_compile_definitions()
definition, using a cmake generator expression inconan_toolchain.cmake
file, using the different values for different configurations.
cache_variables¶
This attribute allows defining CMake cache-variables. These variables, unlike the variables
, are single-config. They
will be stored in the CMakePresets.json
file (at the cacheVariables in the configurePreset) and will be
applied with -D
arguments when calling cmake.configure
using the CMake() build helper.
def generate(self):
tc = CMakeToolchain(self)
tc.cache_variables["foo"] = True
tc.cache_variables["foo2"] = False
tc.cache_variables["var"] = "23"
The booleans assigned to a cache_variable will be translated to ON
and OFF
symbols in CMake.
variables¶
This attribute allows defining CMake variables, for multiple configurations (Debug, Release, etc). These variables should be used to define things related to the toolchain and for the majority of cases cache_variables is what you probably want to use. Also, take into account that as these variables are defined inside the conan_toolchain.cmake file, and the toolchain is loaded several times by CMake, the definition of these variables will be done at those points as well.
def generate(self):
tc = CMakeToolchain(self)
tc.variables["MYVAR"] = "MyValue"
tc.variables.debug["MYCONFIGVAR"] = "MyDebugValue"
tc.variables.release["MYCONFIGVAR"] = "MyReleaseValue"
tc.generate()
This will be translated to:
One
set()
definition forMYVAR
inconan_toolchain.cmake
file.One
set()
definition, using a cmake generator expression inconan_toolchain.cmake
file, using the different values for different configurations.
The booleans assigned to a variable will be translated to ON
and OFF
symbols in CMake:
def generate(self):
tc = CMakeToolchain(self)
tc.variables["FOO"] = True
tc.variables["VAR"] = False
tc.generate()
Will generate the sentences: set(FOO ON ...)
and set(VAR OFF ...)
.
user_presets_path¶
This attribute allows specifying the location of the generated CMakeUserPresets.json
file.
Accepted values:
An absolute path
A path relative to
self.source_folder
The boolean value
False
, to suppress the generation of the file altogether.
For example, we can prevent the generator from creating CMakeUserPresets.json
in the
following way:
def generate(self):
tc = CMakeToolchain(self)
tc.user_presets_path = False
tc.generate()
presets_build_environment, presets_run_environment¶
These attributes enable the modification of the build and run environments associated with the presets, respectively, by assigning an Environment. This can be accomplished in the generate() method.
For example, you can override the value of an environment variable already set in the build environment:
def generate(self):
buildenv = VirtualBuildEnv(self)
buildenv.environment().define("MY_BUILD_VAR", "MY_BUILDVAR_VALUE_OVERRIDDEN")
buildenv.generate()
tc = CMakeToolchain(self)
tc.presets_build_environment = buildenv.environment()
tc.generate()
Or generate a new environment and compose it with an already existing one:
def generate(self):
runenv = VirtualRunEnv(self)
runenv.environment().define("MY_RUN_VAR", "MY_RUNVAR_SET_IN_GENERATE")
runenv.generate()
env = Environment()
env.define("MY_ENV_VAR", "MY_ENV_VAR_VALUE")
env = env.vars(self, scope="run")
env.save_script("other_env")
tc = CMakeToolchain(self)
tc.presets_run_environment = runenv.environment().compose_env(env)
tc.generate()
Extra compilation flags¶
You can use the following attributes to append extra compilation flags to the toolchain:
extra_cxxflags (defaulted to
[]
) for additional cxxflagsextra_cflags (defaulted to
[]
) for additional cflagsextra_sharedlinkflags (defaulted to
[]
) for additional shared link flagsextra_exelinkflags (defaulted to
[]
) for additional exe link flags
Note
flags order of preference: Flags specified in the tools.build configuration, such as cxxflags, cflags, sharedlinkflags and exelinkflags, will always take precedence over those set by the CMakeToolchain attributes.
presets_prefix¶
By default it is "conan"
, and it will generate CMake presets named “conan-xxxx”.
This is done to avoid potential name clashes with users own presets.
CONAN_RUNTIME_LIB_DIRS¶
This variable contains a list of directories that contain runtime libraries (like DLLs) from all dependencies in the host context. This is intended to be used when relying on CMake functionality to collect shared libraries to create a relocatable bundle, as per the example below.
Just pass the CONAN_RUNTIME_LIB_DIRS
variable to the DIRECTORIES
argument
in the install(RUNTIME_DEPENDENCY_SET ...)`
invocation.
install(RUNTIME_DEPENDENCY_SET my_app_deps
PRE_EXCLUDE_REGEXES
[[api-ms-win-.*]]
[[ext-ms-.*]]
[[kernel32\.dll]]
[[libc\.so\..*]] [[libgcc_s\.so\..*]] [[libm\.so\..*]] [[libstdc\+\+\.so\..*]]
POST_EXCLUDE_REGEXES
[[.*/system32/.*\.dll]]
[[^/lib.*]]
[[^/usr/lib.*]]
DIRECTORIES ${CONAN_RUNTIME_LIB_DIRS}
)
absolute_paths¶
By default, CMakeToolchain
will generate relative paths. For example the CMakeUserPresets.json
will have a
relative path to the included CMakePresets.json
(both files generated by CMakeToolchain
), and the
CMakePresets.json
file will have a relative path to the conan_toolchain.cmake
file defined in its toolchainFile
field, that will be relative to the build folder, as specified by the CMake presets documentation.
If for some reason using absolute paths was desired, it is possible to do it with:
def generate(self):
tc = CMakeToolchain(self)
tc.absolute_paths = True
tc.generate()
Using a custom toolchain file¶
There are two ways of providing custom CMake toolchain files:
The
conan_toolchain.cmake
file can be completely skipped and replaced by a user one, defining thetools.cmake.cmaketoolchain:toolchain_file=<filepath>
configuration value.A custom user toolchain file can be added (included from) to the
conan_toolchain.cmake
one, by using theuser_toolchain
block described below, and defining thetools.cmake.cmaketoolchain:user_toolchain=["<filepath>"]
configuration value.The configuration
tools.cmake.cmaketoolchain:user_toolchain=["<filepath>"]
can be defined in theglobal.conf
. but also creating a Conan package for your toolchain and usingself.conf_info
to declare the toolchain file:import os from conan import ConanFile class MyToolchainPackage(ConanFile): ... def package_info(self): f = os.path.join(self.package_folder, "mytoolchain.cmake") self.conf_info.define("tools.cmake.cmaketoolchain:user_toolchain", [f])
If you declare the previous package as a
tool_require
, the toolchain will be automatically applied.If you have more than one
tool_requires
defined, you can easily append all the user toolchain values together using theappend
method in each of them, for instance:import os from conan import ConanFile class MyToolRequire(ConanFile): ... def package_info(self): f = os.path.join(self.package_folder, "mytoolchain.cmake") # Appending the value to any existing one self.conf_info.append("tools.cmake.cmaketoolchain:user_toolchain", f)
So, they’ll be automatically applied by your
CMakeToolchain
generator without writing any extra code:from conan import ConanFile from conan.tools.cmake import CMake class Pkg(ConanFile): settings = "os", "compiler", "arch", "build_type" exports_sources = "CMakeLists.txt" tool_requires = "toolchain1/0.1", "toolchain2/0.1" generators = "CMakeToolchain" def build(self): cmake = CMake(self) cmake.configure()
Extending and advanced customization¶
CMakeToolchain
implements a powerful capability for extending and customizing the resulting toolchain file.
The contents are organized by blocks
that can be customized. The following predefined blocks are available,
and added in this order:
user_toolchain: Allows to include user toolchains from the
conan_toolchain.cmake
file. If the configurationtools.cmake.cmaketoolchain:user_toolchain=["xxxx", "yyyy"]
is defined, its values will beinclude(xxx)\ninclude(yyyy)
as the first lines inconan_toolchain.cmake
.generic_system: Defines
CMAKE_SYSTEM_NAME
,CMAKE_SYSTEM_VERSION
,CMAKE_SYSTEM_PROCESSOR
,CMAKE_GENERATOR_PLATFORM
,CMAKE_GENERATOR_TOOLSET
compilers: Defines
CMAKE_<LANG>_COMPILER
for different languages, as defined bytools.build:compiler_executables
configuration.android_system: Defines
ANDROID_PLATFORM
,ANDROID_STL
,ANDROID_ABI
and includesANDROID_NDK_PATH/build/cmake/android.toolchain.cmake
whereANDROID_NDK_PATH
comes defined intools.android:ndk_path
configuration value.apple_system: Defines
CMAKE_OSX_ARCHITECTURES
(see the universal binaries section),CMAKE_OSX_SYSROOT
for Apple systems.fpic: Defines the
CMAKE_POSITION_INDEPENDENT_CODE
when there is aoptions.fPIC
arch_flags: Defines C/C++ flags like
-m32, -m64
when necessary.linker_scripts: Defines the flags for any provided linker scripts.
libcxx: Defines
-stdlib=libc++
flag when necessary as well as_GLIBCXX_USE_CXX11_ABI
.vs_runtime: Defines the
CMAKE_MSVC_RUNTIME_LIBRARY
variable, as a generator expression for multiple configurations.cppstd: defines
CMAKE_CXX_STANDARD
,CMAKE_CXX_EXTENSIONS
parallel: defines
/MP
parallel build flag for Visual.cmake_flags_init: defines
CMAKE_XXX_FLAGS
variables based on previously defined Conan variables. The blocks above only defineCONAN_XXX
variables, and this block will define CMake ones likeset(CMAKE_CXX_FLAGS_INIT "${CONAN_CXX_FLAGS}" CACHE STRING "" FORCE)`
.try_compile: Stop processing the toolchain, skipping the blocks below this one, if
IN_TRY_COMPILE
CMake property is defined.find_paths: Defines
CMAKE_FIND_PACKAGE_PREFER_CONFIG
,CMAKE_MODULE_PATH
,CMAKE_PREFIX_PATH
so the generated files fromCMakeDeps
are found.rpath: Defines
CMAKE_SKIP_RPATH
. By default it is disabled, and it is needed to defineself.blocks["rpath"].skip_rpath=True
if you want to activateCMAKE_SKIP_RPATH
shared: defines
BUILD_SHARED_LIBS
.output_dirs: Define the
CMAKE_INSTALL_XXX
variables.CMAKE_INSTALL_PREFIX: Is set with the
package_folder
, so if a “cmake install” operation is run, the artifacts go to that location.CMAKE_INSTALL_BINDIR, CMAKE_INSTALL_SBINDIR and CMAKE_INSTALL_LIBEXECDIR: Set by default to
bin
.CMAKE_INSTALL_LIBDIR: Set by default to
lib
.CMAKE_INSTALL_INCLUDEDIR and CMAKE_INSTALL_OLDINCLUDEDIR: Set by default to
include
.CMAKE_INSTALL_DATAROOTDIR: Set by default to
res
.
If you want to change the default values, adjust the
cpp.package
object at thelayout()
method:def layout(self): ... # For CMAKE_INSTALL_BINDIR, CMAKE_INSTALL_SBINDIR and CMAKE_INSTALL_LIBEXECDIR, takes the first value: self.cpp.package.bindirs = ["mybin"] # For CMAKE_INSTALL_LIBDIR, takes the first value: self.cpp.package.libdirs = ["mylib"] # For CMAKE_INSTALL_INCLUDEDIR, CMAKE_INSTALL_OLDINCLUDEDIR, takes the first value: self.cpp.package.includedirs = ["myinclude"] # For CMAKE_INSTALL_DATAROOTDIR, takes the first value: self.cpp.package.resdirs = ["myres"]
Note
It is not valid to change the self.cpp_info at the
package_info()
method.
Customizing the content blocks¶
Every block can be customized in different ways (recall to call tc.generate()
after the customization):
# tc.generate() should be called at the end of every one
# remove an existing block, the generated conan_toolchain.cmake
# will not contain code for that block at all
def generate(self):
tc = CMakeToolchain(self)
tc.blocks.remove("generic_system")
# remove several blocks
def generate(self):
tc = CMakeToolchain(self)
tc.blocks.remove("generic_system", "cmake_flags_init")
# keep one block, remove all the others
# If you want to generate conan_toolchain.cmake with only that
# block
def generate(self):
tc = CMakeToolchain(self)
tc.blocks.select("generic_system")
# keep several blocks, remove the other blocks
def generate(self):
tc = CMakeToolchain(self)
tc.blocks.select("generic_system", "cmake_flags_init")
# iterate blocks
def generate(self):
tc = CMakeToolchain(self)
for block_name in tc.blocks.keys():
# do something with block_name
for block_name, block in tc.blocks.items():
# do something with block_name and block
# modify the template of an existing block
def generate(self):
tc = CMakeToolchain(self)
tmp = tc.blocks["generic_system"].template
new_tmp = tmp.replace(...) # replace, fully replace, append...
tc.blocks["generic_system"].template = new_tmp
# modify one or more variables of the context
def generate(self):
tc = CMakeToolchain(conanfile)
# block.values is the context dictionary
toolset = tc.blocks["generic_system"].values["toolset"]
tc.blocks["generic_system"].values["toolset"] = "other_toolset"
# modify the whole context values
def generate(self):
tc = CMakeToolchain(conanfile)
tc.blocks["generic_system"].values = {"toolset": "other_toolset"}
# modify the context method of an existing block
import types
def generate(self):
tc = CMakeToolchain(self)
generic_block = toolchain.blocks["generic_system"]
def context(self):
assert self # Your own custom logic here
return {"toolset": "other_toolset"}
generic_block.context = types.MethodType(context, generic_block)
# completely replace existing block
from conan.tools.cmake import CMakeToolchain
def generate(self):
tc = CMakeToolchain(self)
# this could go to a python_requires
class MyGenericBlock:
template = "HelloWorld"
def context(self):
return {}
tc.blocks["generic_system"] = MyGenericBlock
# add a completely new block
from conan.tools.cmake import CMakeToolchain
def generate(self):
tc = CMakeToolchain(self)
# this could go to a python_requires
class MyBlock:
template = "Hello {{myvar}}!!!"
def context(self):
return {"myvar": "World"}
tc.blocks["mynewblock"] = MyBlock
For more information about these blocks, please have a look at the source code.
Cross building¶
The generic_system
block contains some basic cross-building capabilities. In the general
case, the user would want to provide their own user toolchain defining all the specifics,
which can be done with the configuration tools.cmake.cmaketoolchain:user_toolchain
. If
this conf value is defined, the generic_system
block will include the provided file or files, but
no further define any CMake variable for cross-building.
If user_toolchain
is not defined and Conan detects it is cross-building, because the build
and host profiles contain different OS or architecture, it will try to define the following
variables:
CMAKE_SYSTEM_NAME
:tools.cmake.cmaketoolchain:system_name
configuration if defined, otherwise, it will try to autodetect it. This block will consider cross-building if Android systems (that is managed by other blocks), and not 64bits to 32bits builds in x86_64, sparc and ppc systems.CMAKE_SYSTEM_VERSION
:tools.cmake.cmaketoolchain:system_version
conf if defined, otherwiseos.version
subsetting (host) when defined. On Apple systems, thisos.version
is converted to the corresponding Darwin version.CMAKE_SYSTEM_PROCESSOR
:tools.cmake.cmaketoolchain:system_processor
conf if defined, otherwisearch
setting (host) if defined
Support for Universal Binaries in macOS¶
Warning
This feature is experimental and subject to breaking changes. See the Conan stability section for more information.
Starting in Conan 2.2.0, there’s preliminary support for building universal binaries on macOS using CMakeToolchain. To specify multiple architectures for a universal binary in Conan, use the | separator when defining the architecture in the settings. This approach enables passing a list of architectures. For example, running:
conan create . --name=mylibrary --version=1.0 -s="arch=armv8|x86_64"
will create a universal binary for mylibrary containing both armv8
and x86_64
architectures, by setting CMAKE_OSX_ARCHITECTURES
with a value of arm64;x86_64
in
the conan_toolchain.cmake file.
Warning
It is important to note that this method is not applicable to build systems other than CMake.
Be aware that this feature is primarily beneficial for building final univeral binaries for release purposes. The default Conan behavior of managing one binary per architecture generally provides a more reliable and trouble-free experience. Users should be cautious and not overly rely on this feature for broader use cases.
Reference¶
- class CMakeToolchain(conanfile, generator=None)¶
- generate()¶
This method will save the generated files to the conanfile.generators_folder
conf¶
CMakeToolchain is affected by these [conf]
variables:
tools.cmake.cmaketoolchain:toolchain_file user toolchain file to replace the
conan_toolchain.cmake
one.tools.cmake.cmaketoolchain:user_toolchain list of user toolchains to be included from the
conan_toolchain.cmake
file.tools.android:ndk_path value for
ANDROID_NDK_PATH
.tools.android:cmake_legacy_toolchain: boolean value for
ANDROID_USE_LEGACY_TOOLCHAIN_FILE
. It will only be defined inconan_toolchain.cmake
if given a value. This is taken into account by the CMake toolchain inside the Android NDK specified in thetools.android:ndk_path
config, for versionsr23c
and above. It may be useful to set this toFalse
if compiler flags are defined viatools.build:cflags
ortools.build:cxxflags
to prevent Android’s legacy CMake toolchain from overriding the values. If setting this toFalse
, please ensure you are using CMake 3.21 or above.tools.cmake.cmaketoolchain:system_name is not necessary in most cases and is only used to force-define
CMAKE_SYSTEM_NAME
.tools.cmake.cmaketoolchain:system_version is not necessary in most cases and is only used to force-define
CMAKE_SYSTEM_VERSION
.tools.cmake.cmaketoolchain:system_processor is not necessary in most cases and is only used to force-define
CMAKE_SYSTEM_PROCESSOR
.tools.cmake.cmaketoolchain:extra_variables: dict-like python object which specifies the CMake variable name and value. Value can be a plain string, number or a dict-like python object which must specifies
value
(string/number) ,cache
(boolean),type
(CMake cache type) and optionally,docstring
(string: defaulted to variable name). Potential override of CMakeToolchain defined variables, users are at their own risk. E.g.
[conf]
tools.cmake.cmaketoolchain:extra_variables={'MY_CMAKE_VAR': 'MyValue'}
Resulting in:
set(MY_CMAKE_VAR "MyValue")
Which will be injected later so it can override default Conan variables.
Another advanced usage:
tools.cmake.cmaketoolchain:extra_variables={'MyIntegerVariable': 42, 'CMAKE_GENERATOR_INSTANCE': '${ENV}/buildTools/'}
tools.cmake.cmaketoolchain:extra_variables*={'CACHED_VAR': {'value': '/var/run', 'cache': True, 'type': 'PATH', 'docstring': 'test cache var'}}
Resulting in:
set(MyIntegerVariable 42)
set(CMAKE_GENERATOR_INSTANCE "${ENV}/buildTools/")
set(CACHED_VAR "/var/run" CACHE BOOL "test cache var")
This block injects $
which will be expanded later. It also defines a cache variable of type PATH
.
Tip
Use the configuration data operator *=
to update (instead of redefining) conf variables already set in profiles or the global configuration.
tools.cmake.cmaketoolchain:toolset_arch: Will add the
,host=xxx
specifier in theCMAKE_GENERATOR_TOOLSET
variable ofconan_toolchain.cmake
file.tools.cmake.cmaketoolchain:toolset_cuda: (Experimental) Will add the
,cuda=xxx
specifier in theCMAKE_GENERATOR_TOOLSET
variable ofconan_toolchain.cmake
file.tools.cmake.cmake_layout:build_folder_vars: Settings, Options, and/or
self.name
andself.version
that will produce a different build folder and different CMake presets names.tools.cmake.cmaketoolchain:presets_environment: Set to
'disabled'
to prevent the addition of the environment section to the generated CMake presets.tools.build:cxxflags list of extra C++ flags that will be appended to
CMAKE_CXX_FLAGS_INIT
.tools.build:cflags list of extra of pure C flags that will be appended to
CMAKE_C_FLAGS_INIT
.tools.build:sharedlinkflags list of extra linker flags that will be appended to
CMAKE_SHARED_LINKER_FLAGS_INIT
.tools.build:exelinkflags list of extra linker flags that will be appended to
CMAKE_EXE_LINKER_FLAGS_INIT
.tools.build:defines list of preprocessor definitions that will be used by
add_definitions()
.tools.apple:sdk_path value for
CMAKE_OSX_SYSROOT
. In the general case it’s not needed and will be passed to CMake by the settings values.tools.apple:enable_bitcode boolean value to enable/disable Bitcode Apple Clang flags, e.g.,
CMAKE_XCODE_ATTRIBUTE_ENABLE_BITCODE
.tools.apple:enable_arc boolean value to enable/disable ARC Apple Clang flags, e.g.,
CMAKE_XCODE_ATTRIBUTE_CLANG_ENABLE_OBJC_ARC
.tools.apple:enable_visibility boolean value to enable/disable Visibility Apple Clang flags, e.g.,
CMAKE_XCODE_ATTRIBUTE_GCC_SYMBOLS_PRIVATE_EXTERN
.tools.build:sysroot defines the value of
CMAKE_SYSROOT
.tools.microsoft:winsdk_version Defines the
CMAKE_SYSTEM_VERSION
or theCMAKE_GENERATOR_PLATFORM
according to CMake policyCMP0149
.tools.build:compiler_executables dict-like Python object which specifies the compiler as key and the compiler executable path as value. Those keys will be mapped as follows:
c
: will setCMAKE_C_COMPILER
in conan_toolchain.cmake.cpp
: will setCMAKE_CXX_COMPILER
in conan_toolchain.cmake.RC
: will setCMAKE_RC_COMPILER
in conan_toolchain.cmake.objc
: will setCMAKE_OBJC_COMPILER
in conan_toolchain.cmake.objcpp
: will setCMAKE_OBJCXX_COMPILER
in conan_toolchain.cmake.cuda
: will setCMAKE_CUDA_COMPILER
in conan_toolchain.cmake.fortran
: will setCMAKE_Fortran_COMPILER
in conan_toolchain.cmake.asm
: will setCMAKE_ASM_COMPILER
in conan_toolchain.cmake.hip
: will setCMAKE_HIP_COMPILER
in conan_toolchain.cmake.ispc
: will setCMAKE_ISPC_COMPILER
in conan_toolchain.cmake.