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

build/gn_processor.py

@@ -584,6 +584,16 @@ def write_mozbuild(
                     )
             except KeyError:
                 pass
+            try:
+                if (
+                    relsrcdir
+                    in write_mozbuild_variables["INCLUDE_SYSTEM_PIPEWIRE_HANDLING"]
+                ):
+                    mb.write('CXXFLAGS += CONFIG["MOZ_PIPEWIRE_CFLAGS"]\n')
+                    mb.write('if not CONFIG["MOZ_SYSTEM_PIPEWIRE"]:\n')
+                    mb.write('    LOCAL_INCLUDES += [ "/third_party/pipewire/" ]\n')
+            except KeyError:
+                pass
             try:
                 if (
                     relsrcdir

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",

dom/media/webrtc/third_party_build/gn-configs/webrtc.json

@@ -25,6 +25,11 @@
       "third_party/libwebrtc/modules/desktop_capture/desktop_capture_gn",
       "third_party/libwebrtc/modules/portal/portal_gn"
     ],
+    "INCLUDE_SYSTEM_PIPEWIRE_HANDLING": [
+      "third_party/libwebrtc/modules/desktop_capture/desktop_capture_gn",
+      "third_party/libwebrtc/modules/portal/portal_gn",
+      "third_party/libwebrtc/modules/video_capture/video_capture_internal_impl_gn"
+    ],
     "INCLUDE_SYSTEM_DAV1D_HANDLING": [
       "third_party/libwebrtc/modules/video_coding/codecs/av1/dav1d_decoder_gn",
       "third_party/libwebrtc/modules/video_coding/codecs/av1/libaom_av1_encoder_gn"

third_party/pipewire/libpipewire/moz.build

@@ -4,13 +4,13 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-SOURCES += [
-    'mozpipewire.cpp',
-]
-
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
     CXXFLAGS += CONFIG['MOZ_GTK3_CFLAGS']
 
-LOCAL_INCLUDES += ['/third_party/pipewire']
+if CONFIG["MOZ_SYSTEM_PIPEWIRE"]:
+    OS_LIBS += CONFIG["MOZ_PIPEWIRE_LIBS"]
+else:
+    SOURCES += ['mozpipewire.cpp']
+    LOCAL_INCLUDES += ['/third_party/pipewire']
 
 FINAL_LIBRARY = 'xul'

toolkit/moz.configure

@@ -678,6 +678,24 @@ def v4l2(target, toolkit_gtk):
 set_config("MOZ_ENABLE_V4L2", True, when=v4l2)
 set_define("MOZ_ENABLE_V4L2", True, when=v4l2)
 
+# System PipeWire support
+# =============================================================
+with only_when(compile_environment):
+    system_lib_option(
+        "--with-system-pipewire",
+        nargs="?",
+        help="Use system PipeWire",
+        when=use_pkg_config,
+    )
+
+    pipewire_headers = pkg_check_modules(
+        "MOZ_PIPEWIRE",
+        "libpipewire-0.3 libspa-0.2",
+        when="--with-system-pipewire",
+    )
+
+    set_config("MOZ_SYSTEM_PIPEWIRE", True, when="--with-system-pipewire")
+
 # System gbm support (for screencast support using PipeWire)
 # =============================================================
 with only_when(compile_environment):