(mozconfig)=

# mozconfig Files

mozconfig files are used to configure how a build works.

mozconfig files are actually shell scripts. They are executed in a
special context with specific variables and functions exposed to them.

## API

### Functions

The following special functions are available to a mozconfig script.

#### ac_add_options

This function is used to declare extra options/arguments to pass into
configure.

e.g.:

```
ac_add_options --disable-tests
ac_add_options --enable-optimize
```

#### mk_add_options

This function is used to inject statements into client.mk for execution.
It is typically used to define variables, notably the object directory.

e.g.:

```
mk_add_options AUTOCLOBBER=1
```

### Special mk_add_options Variables

For historical reasons, the method for communicating certain
well-defined variables is via mk_add_options(). In this section, we
document what those special variables are.

#### MOZ_OBJDIR

This variable is used to define the {term}`object directory` for the current
build.

## Finding the active mozconfig

Multiple mozconfig files can exist to provide different configuration
options for different tasks. The rules for finding the active mozconfig
are defined in the
{py:func}`mozboot.mozconfig.find_mozconfig` method.

```{eval-rst}
.. automodule:: mozboot.mozconfig
   :members: find_mozconfig
```

### Loading the active mozconfig

```{eval-rst}
.. autoclass:: mozbuild.mozconfig.MozconfigLoader
   :members: read_mozconfig
```