Bug 1954903 - Allow to use system PipeWire libs instead of bundled r=stransky,mjf

Introduce "--with-system-pipewire" option, allowing to build Firefox
against system PipeWire library and to find system PipeWire header
files.

Differential Revision: https://phabricator.services.mozilla.com/D242100

config/make-system-wrappers.py

@@ -20,11 +20,12 @@ def gen_wrappers(unused, outdir, *header_list):
     for header in header_list:
         with FileAvoidWrite(os.path.join(outdir, header)) as f:
             includes = include_next_template.format(header=header)
-            if header == "wayland-util.h":
-                # wayland-util.h in Wayland < 1.12 includes math.h inside an
-                # extern "C" block, which breaks including the header from C++.
-                # This was fixed in Wayland 1.12, but for versions earlier than
-                # that, we work around that by force-including math.h first.
+            if header == "wayland-util.h" or header == "pipewire/pipewire.h":
+                # wayland-util.h in Wayland < 1.12 and pipewire.h > 1.4 include
+                # math.h inside an extern "C" block, which breaks including the
+                # header from C++. This was fixed in Wayland 1.12, but for versions
+                # earlier than that, we work around that by force-including math.h
+                # first.
                 includes = "#include <math.h>\n" + includes
             elif header == "wayland-client.h":
                 # The system wayland-client.h uses quote includes for

config/system-headers.mozbuild

@@ -1267,6 +1267,11 @@ if CONFIG["MOZ_SYSTEM_LIBDRM"]:
         "xf86drm.h",
     ]
 
+if CONFIG["MOZ_SYSTEM_PIPEWIRE"]:
+    system_headers += [
+        "pipewire/pipewire.h",
+    ]
+
 if CONFIG["MOZ_JACK"]:
     system_headers += [
         "jack/jack.h",