[question] Meson + freetype fail to cross compile

[Slashcash]

Hi, I am having an hard time to cross compile freetype since the recipe has been moved to Meson.

I am cross-compiling with an aarch-64 buildroot-provided toolchain. It is installed into the system with a custom recipe:

class Toolchain(ConanFile):
    name = "toolchain-linux-aarch64-gcc-11.3"
    version = "1.0"

    def source(self):
        get(self, "https://toolchains.bootlin.com/downloads/releases/toolchains/aarch64/tarballs/aarch64--glibc--stable-2022.08-1.tar.bz2",
                  **strip_root=True)

it gets downloaded and relocated within the context of the recipe then since the toolchain provides a cmake toolchain file I just do:

    def package_info(self):
        self.conf_info.append("tools.cmake.cmaketoolchain:user_toolchain", os.path.join(self.package_folder, "share", "buildroot", "toolchainfile.cmake"))

With this setup I have been able to cross-compile pretty much every dependency (without resorting to define variables to relocate compilers/linkers/...)

For this reason my host profile is pretty simple:

{% set os, arch, compiler, compiler_version, type = profile_name.split('-') %}
{% set toolchain = "toolchain-{}-{}-{}-{}/1.0".format(os, arch, compiler, compiler_version) %}

{% if type == "debug" %}
    {% set loglevel = "trace" %}
    {% set btype = "Debug" %}
{% else %}
    {% set loglevel = "info" %}
    {% set btype = "Release" %}
{% endif %}

[settings]
os={{ os.capitalize() }}
arch={{ arch }}
compiler={{ compiler }}
compiler.version={{ compiler_version }}
compiler.libcxx=libstdc++11
build_type={{ btype }}

[tool_requires]
{{ toolchain }}
cmake/3.27.0

[runenv]
SPDLOG_LEVEL={{ loglevel }}

[conf]
tools.system.package_manager:mode=install
tools.system.package_manager:sudo=True

Apart from the jinja noise there is really nothing special.

When cross-compiling freetype with this toolchain/profile I get:

../src/meson.build:26:0: ERROR: 'c' compiler binary not defined in cross or native file

and surely enough the conan-generated _conan_mesoncross.ini have empty definitions for both the c and the cpp compiler:

[properties]
needs_exe_wrapper = true

[constants]
preprocessor_definitions = []

[project options]
wrap_mode = 'nofallback'
bindir = 'bin'
sbindir = 'bin'
libexecdir = 'bin'
includedir = 'include'
libdir = 'lib'
brotli = 'enabled'
bzip2 = 'enabled'
harfbuzz = 'disabled'
png = 'enabled'
tests = 'disabled'
zlib = 'system'

[binaries]
c = ''
cpp = ''
pkgconfig = '/root/.conan2/p/pkgco03f8fb03aa80a/p/bin/pkgconf'
pkg-config = '/root/.conan2/p/pkgco03f8fb03aa80a/p/bin/pkgconf'

[built-in options]
buildtype = 'release'
default_library = 'static'
b_ndebug = 'true'
backend = 'ninja'
pkg_config_path = '/root/.conan2/p/b/freet0516abaf9bd52/b/build-release/conan'
# C/C++ arguments
c_args = [] + preprocessor_definitions
c_link_args = []
cpp_args = [] + preprocessor_definitions
cpp_link_args = []

[build_machine]
system = 'linux'
cpu_family = 'x86_64'
cpu = 'x86_64'
endian = 'little'
[host_machine]
system = 'linux'
cpu_family = 'aarch64'
cpu = 'armv8'
endian = 'little'

Am I doing something really wrong? I am experiencing this with Conan 2.4.1

[Slashcash]

Probably not a bug so changing the title. Probably something related to the fact that I am missing a correctly generated MesonToolchain?

[franramirez688]

Hi @Slashcash - Thanks for opening the issue!

I think that we only need to set the compiler_executables in your profile:

your_host_profile

{% set os, arch, compiler, compiler_version, type = profile_name.split('-') %}
{% set toolchain = "toolchain-{}-{}-{}-{}/1.0".format(os, arch, compiler, compiler_version) %}
# .....

[conf]
tools.build:compiler_executables={'c': '/path/to/aarch64-gcc-11.3', 'cpp': '/path/to/aarch64-g++-11.3'}
tools.system.package_manager:mode=install
tools.system.package_manager:sudo=True

Let me know if setting that solved your issue 😁

[Slashcash]

Hi @Slashcash - Thanks for opening the issue!

I think that we only need to set the compiler_executables in your profile:

your_host_profile

{% set os, arch, compiler, compiler_version, type = profile_name.split('-') %}
{% set toolchain = "toolchain-{}-{}-{}-{}/1.0".format(os, arch, compiler, compiler_version) %}
# .....

[conf]
tools.build:compiler_executables={'c': '/path/to/aarch64-gcc-11.3', 'cpp': '/path/to/aarch64-g++-11.3'}
tools.system.package_manager:mode=install
tools.system.package_manager:sudo=True

Let me know if setting that solved your issue 😁

I couldn't do this because the compiler path is unknown at profile-level (it ends up being deployed by Conan in a non predicible folder everytime)

But putting your suggestion in my toolchain recipe like this:

self.conf_info.define("tools.build:compiler_executables", {"c": os.path.join(compiler_path, compiler_c), "cpp": os.path.join(self.package_folder, compiler_cxx)})

works indeed! Thanks a lot!

Now I am confused a bit because I get why it was working up until now with CMake-based recipe. What I don't get is how it was magically working with make based recipe that I had in my dependencies. It's my understanding that this should have failed in a similar fashion! :D But that's another matter.

[franramirez688]

works indeed! Thanks a lot!

That's great!

Now I am confused a bit because I get why it was working up until now with CMake-based recipe. What I don't get is how it was magically working with make based recipe that I had in my dependencies. It's my understanding that this should have failed in a similar fashion! :D But that's another matter.

It was working because of your toolchain-xxxx/1.0 as tool_requires injection. As the older versions were CMake-based, that toolchain was correctly injecting all the needed variables, but as it's Meson-based now, those variables are not affecting the freetype recipe 😓

[franramirez688]

@Slashcash let me close the issue and put it as resolved.

Anyway, do not hesitate to reopen it if you have any other doubts.