Create your first Conan package with Meson¶
In the Create your first Conan package tutorial
CMake was used as the build system. If you haven’t read that section, read it first to familiarize
yourself with the conanfile.py
and test_package
concepts, then come back to read
about the specifics of the Meson
package creation.
Use the conan new command to create a “Hello World” C++ library example project:
$ conan new meson_lib -d name=hello -d version=1.0
This will create a Conan package project with the following structure.
├── conanfile.py
├── meson.build
├── hello.vcxproj
├── src
│ ├── hello.h
│ └── hello.cpp
└── test_package
├── conanfile.py
├── meson.build
└── src
└── example.cpp
The structure and files are very similar to the previous CMake example:
conanfile.py: On the root folder, there is a conanfile.py which is the main recipe file, responsible for defining how the package is built and consumed.
meson.build: A Meson build script. This script doesn’t need to contain anything Conan-specific, it is completely agnostic of Conan, because the integration is transparent.
src folder: the folder that contains the simple C++ “hello” library.
test_package folder: contains an example application that will require and link with the created package. In this case the
test_package
also contains ameson.build
, but it is possible to have thetest_package
using other build system as CMake if desired. It is not mandatory that the test_package is using the same build system as the package.
Let’s have a look at the package recipe conanfile.py (only the relevant new parts):
exports_sources = "meson.build", "src/*"
def layout(self):
basic_layout(self)
def generate(self):
tc = MesonToolchain(self)
tc.generate()
def build(self):
meson = Meson(self)
meson.configure()
meson.build()
def package(self):
meson = Meson(self)
meson.install()
Let’s explain the different sections of the recipe briefly:
The
layout()
defines abasic_layout()
, this is less flexible than a CMake one, so it doesn’t allow any parametrization.The
generate()
method callsMesonToolchain
that can generateconan_meson_native.ini
andconan_meson_cross.ini
Meson toolchain files for cross builds. If the project had dependencies with Conanrequires
, it should addPkgConfigDeps
tooThe
build()
method uses theMeson()
helper to drive the buildThe
package()
method uses theMeson
install functionality to define and copy to the package folder the final artifacts.
The test_package folder also contains a meson.build
file that declares a dependency to
the tested package, and links an application, to verify the package was correctly created and contains
that library:
project('Testhello', 'cpp')
hello = dependency('hello', version : '>=0.1')
executable('example', 'src/example.cpp', dependencies: hello)
Note the test_package/conanfile.py
contains also a generators = "PkgConfigDeps", "MesonToolchain"
,
because the test_package
has the “hello” package as dependency, and PkgConfigDeps
is necessary to
locate it.
Note
This example assumes Meson, Ninja and PkgConfig are installed in the system, which might not always be the case.
If they are not, you can create a profile myprofile
with:
include(default)
[tool_requires]
meson/[*]
pkgconf/[*]
We added Meson and pkg-config as tool requirements to the profile. By executing conan create . -pr=myprofile
, those tools will be installed and made available during the package’s build process.
Let’s build the package from sources with the current default configuration, and then let
the test_package
folder test the package:
$ conan create .
...
======== Testing the package: Executing test ========
hello/1.0 (test package): Running test()
hello/1.0 (test package): RUN: .\example
hello/1.0: Hello World Release!
hello/1.0: _M_X64 defined
hello/1.0: MSVC runtime: MultiThreadedDLL
hello/1.0: _MSC_VER1939
hello/1.0: _MSVC_LANG201402
hello/1.0: __cplusplus201402
hello/1.0 test_package
We can now validate that the recipe and the package binary are in the cache:
$ conan list "hello/1.0:*"
Local Cache:
hello
hello/1.0
revisions
856c535669f78da11502a119b7d8a6c9 (2024-03-04 17:52:39 UTC)
packages
c13a22a41ecd72caf9e556f68b406569547e0861
info
settings
arch: x86_64
build_type: Release
compiler: msvc
compiler.cppstd: 14
compiler.runtime: dynamic
compiler.runtime_type: Release
compiler.version: 193
os: Windows