## Meson and external wraps

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Ok, last time I mentioned how to include wraps from the wrapdb into a meson build and it was all happy! But what if the dependency we need is not in the wrap database?

Well, as many other things in engineering, it depends, the most simplest case (what I am going to document today) is when the dependency is “somewhere” and is using Meson too. Let’s take a simple case, there is a test library for C, Criterion, in the repository we can see they are using Meson (see that meson.build file?) so is perfect for our case!

#include <criterion/criterion.h>

Test(simple, test) {
cr_assert(0, "Hello world");
}


Ok, time for the simplest build file (ignore the default_options part, that is just to make clang happy in macOS):

project('test_criterion', 'c', default_options: ['cpp_std=c++17'])
criterion = dependency('criterion')
executable('test_criterion', 'test.c', dependencies: [criterion])


Ok, we will create our own wrap file to define Criterion as a dependency, we will grab the version 2.4.1 from the repository using Git, use a recursive cloning (Criterion uses Git submodules) with a simple depth of 1 (we don’t need the whole history).

[wrap-git]
url = https://github.com/Snaipe/Criterion.git
revision = v2.4.1
depth = 1
clone-recursive = true

[provide]
criterion = criterion


Where that last part comes from? well, if we look at the file src/meson.build we will see this fragment:

criterion = declare_dependency(
include_directories: [criterion_api],
dependencies: deps,

Telling us this build exports a dependency named criterion, we just say this library provides a dependency named criterion and we will use it under the name criterion (my_dep = proj_dep).
Done! on meson build it will grab Criterion and all its dependencies (including any wraps defined by Criterion) and with meson compile -C build we should see our test_criterion executable.