# Building with libsoup

## Buildsystem Integration

Like other GNOME libraries, libsoup uses `pkg-config` to provide compiler options. The package name is `libsoup-3.0`. For example if you use Autotools:

    PKG_CHECK_MODULES(LIBSOUP, [libsoup-3.0])
    AC_SUBST(LIBSOUP_CFLAGS)
    AC_SUBST(LIBSOUP_LIBS)

If you use Meson:

    libsoup_dep = dependency('libsoup-3.0')

## API Availability and Deprecation Warnings

If you want to restrict your program to a particular libsoup version or range of versions, you can define `SOUP_VERSION_MIN_REQUIRED` and/or `SOUP_VERSION_MAX_ALLOWED`. For example with Autotools:

    LIBSOUP_CFLAGS="$LIBSOUP_CFLAGS -DSOUP_VERSION_MIN_REQUIRED=SOUP_VERSION_3_0"
    LIBSOUP_CFLAGS="$LIBSOUP_CFLAGS -DSOUP_VERSION_MAX_ALLOWED=SOUP_VERSION_3_2"

Or with Meson:

    add_project_arguments(
      '-DSOUP_VERSION_MIN_REQUIRED=SOUP_VERSION_2_99',
      '-DSOUP_VERSION_MAX_ALLOWED=SOUP_VERSION_3_0',
      language: 'c'
    )

The `SOUP_VERSION_MIN_REQUIRED` declaration states that the code is not expected to compile on versions of libsoup older than the indicated version, and so the compiler should print warnings if the code uses functions that were deprecated as of that release.

The `SOUP_VERSION_MAX_ALLOWED` declaration states that the code is expected to compile on versions of libsoup up to the indicated version, and so, when compiling the program against a newer version than that, the compiler should print warnings if the code uses functions that did not yet exist in the max-allowed release.

You can use `SOUP_CHECK_VERSION()` to check the version of libsoup at compile time, to compile different code for different libsoup versions. (If you are setting `SOUP_VERSION_MIN_REQUIRED` and `SOUP_VERSION_MAX_ALLOWED` to different versions, as in the example above, then you almost certainly need to be doing this.)

## Headers

Code using libsoup should include the header like so:

    #include <libsoup/soup.h>