Build a simple Meson project using Conan¶

In this example, we are going to create a string compressor application that uses one of the most popular C++ libraries: Zlib.

Note

This example is based on the main Build a simple CMake project using Conan tutorial. So we highly recommend reading it before trying out this one.

We’ll use Meson as build system and pkg-config as helper tool in this case, so you should get them installed before going forward with this example.

Please, first clone the sources to recreate this project. You can find them in the examples2 repository in GitHub:

$ git clone https://github.com/conan-io/examples2.git
$ cd examples2/examples/tools/meson/mesontoolchain/simple_meson_project

We start from a very simple C language project with this structure:

.
├── meson.build
└── src
    └── main.c

This project contains a basic meson.build including the zlib dependency and the source code for the string compressor program in main.c.

Let’s have a look at the main.c file:

main.c¶

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <zlib.h>

int main(void) {
    char buffer_in [256] = {"Conan is a MIT-licensed, Open Source package manager for C and C++ development "
                            "for C and C++ development, allowing development teams to easily and efficiently "
                            "manage their packages and dependencies across platforms and build systems."};
    char buffer_out [256] = {0};

    z_stream defstream;
    defstream.zalloc = Z_NULL;
    defstream.zfree = Z_NULL;
    defstream.opaque = Z_NULL;
    defstream.avail_in = (uInt) strlen(buffer_in);
    defstream.next_in = (Bytef *) buffer_in;
    defstream.avail_out = (uInt) sizeof(buffer_out);
    defstream.next_out = (Bytef *) buffer_out;

    deflateInit(&defstream, Z_BEST_COMPRESSION);
    deflate(&defstream, Z_FINISH);
    deflateEnd(&defstream);

    printf("Uncompressed size is: %lu\n", strlen(buffer_in));
    printf("Compressed size is: %lu\n", strlen(buffer_out));

    printf("ZLIB VERSION: %s\n", zlibVersion());

    return EXIT_SUCCESS;
}

Also, the contents of meson.build are:

meson.build¶

project('tutorial', 'c')
zlib = dependency('zlib', version : '1.2.11')
executable('compressor', 'src/main.c', dependencies: zlib)

Let’s create a conanfile.txt with the following content to install Zlib:

conanfile.txt¶

[requires]
zlib/1.2.11

[generators]
PkgConfigDeps
MesonToolchain

In this case, we will use PkgConfigDeps to generate information about where the Zlib library files are installed thanks to the *.pc files and MesonToolchain to pass build information to Meson using a conan_meson_[native|cross].ini file that describes the native/cross compilation environment, which in this case is a conan_meson_native.ini one.

We will use Conan to install Zlib and generate the files that Meson needs to find this library and build our project. We will generate those files in the folder build. To do that, run:

$ conan install . --output-folder=build --build=missing

Now we are ready to build and run our compressor app:

Windows¶

$ cd build
$ meson setup --native-file conan_meson_native.ini .. meson-src
$ meson compile -C meson-src
$ meson-src\compressor.exe
Uncompressed size is: 233
Compressed size is: 147
ZLIB VERSION: 1.2.11

Linux, macOS¶

$ cd build
$ meson setup --native-file conan_meson_native.ini .. meson-src
$ meson compile -C meson-src
$ ./meson-src/compressor
Uncompressed size is: 233
Compressed size is: 147
ZLIB VERSION: 1.2.11