cmake_find_package
generator
This generator is especially useful if you are using CMake
using the find_package
feature to locate the dependencies.
The cmake_find_package
generator creates a file for each requirement specified in the conanfile.
The name of the files follows the pattern Find<package_name>.cmake
. So for the zlib/1.2.11@conan/stable
package,
a Findzlib.cmake
file will be generated.
In a conanfile.py
from conans import ConanFile, tools
class LibConan(ConanFile):
...
requires = "zlib/1.2.11@conan/stable"
generators = "cmake_find_package"
def build(self):
cmake = CMake(self) # it will find the packages by using our auto-generated FindXXX.cmake files
cmake.configure()
cmake.build()
In the previous example, the CMake
build helper will adjust automatically the CMAKE_MODULE_PATH
to the
conanfile.install_folder
, where the generated Find<package_name>.cmake
are.
In the CMakeList.txt
you do not need to specify or include anything related with Conan at all, just
rely on the find_package
feature:
cmake_minimum_required(VERSION 3.0)
project(helloworld)
add_executable(helloworld hello.c)
find_package(Zlib)
# Global approach
if(ZLIB_FOUND)
include_directories(${ZLIB_INCLUDE_DIRS})
target_link_libraries (helloworld ${ZLIB_LIBRARIES})
endif()
# Modern CMake targets approach
if(TARGET zlib::zlib)
target_link_libraries(helloworld zlib::zlib)
endif()
$ conan create . user/channel
lib/1.0@user/channel: Calling build()
-- The C compiler identification is AppleClang 9.1.0.9020039
...
-- Conan: Using autogenerated Findzlib.cmake
-- Found: /Users/user/.conan/data/zlib/1.2.11/conan/stable/package/0eaf3bfbc94fb6d2c8f230d052d75c6c1a57a4ce/lib/libz.a
lib/1.0@user/channel: Package '72bce3af445a371b892525bc8701d96c568ead8b' created
In a conanfile.txt
If you are using a conanfile.txt
file in your project, instead of a conanfile.py
, this generator
can be used together with the cmake_paths generator to adjust the CMAKE_MODULE_PATH
variable automatically
and let CMake to locate the generated Find<package_name>.cmake
files.
With cmake_paths:
[requires]
zlib/1.2.11@conan/stable
...
[generators]
cmake_find_package
cmake_paths
cmake_minimum_required(VERSION 3.0)
project(helloworld)
include(${CMAKE_BINARY_DIR}/conan_paths.cmake)
add_executable(helloworld hello.c)
find_package(Zlib)
# Global approach
if(ZLIB_FOUND)
include_directories(${ZLIB_INCLUDE_DIRS})
target_link_libraries (helloworld ${ZLIB_LIBRARIES})
endif()
# Modern CMake targets approach
if(TARGET zlib::zlib)
target_link_libraries(helloworld zlib::zlib)
endif()
$ mkdir build && cd build
$ conan install ..
$ cmake .. -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release
-- Conan: Using autogenerated Findzlib.cmake
-- Found: /Users/user/.conan/data/zlib/1.2.11/conan/stable/package/0eaf3bfbc94fb6d2c8f230d052d75c6c1a57a4ce/lib/libz.a
...
$ cmake --build .
Or you can also adjust CMAKE_MODULE_PATH
manually.
Without cmake_paths, adjusting CMAKE_MODULE_PATH
manually:
[requires]
zlib/1.2.11@conan/stable
...
[generators]
cmake_find_package
cmake_minimum_required(VERSION 3.0)
project(helloworld)
set(CMAKE_MODULE_PATH ${CMAKE_BINARY_DIR} ${CMAKE_MODULE_PATH})
add_executable(helloworld hello.c)
find_package(Zlib)
# Global approach
if(ZLIB_FOUND)
include_directories(${ZLIB_INCLUDE_DIRS})
target_link_libraries (helloworld ${ZLIB_LIBRARIES})
endif()
# Modern CMake targets approach
if(TARGET zlib::zlib)
target_link_libraries(helloworld zlib::zlib)
endif()
See also
Check the section Reference/Generators/cmake_find_package to read more about this generator and the adjusted CMake variables/targets.