main: Move away debug flag management to util.c

The rest of debug flag details are in util.c and util.h, make things
less scattered by moving the rest to util.c too.

While at it, put the coredump:ability setting needed for being suid
there too, so we have a common place for initializing "debug utils".

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1833>

src/core/main.c

@@ -71,10 +71,6 @@
 #include <systemd/sd-login.h>
 #endif /* HAVE_WAYLAND && HAVE_NATIVE_BACKEND */
 
-#ifdef HAVE_SYS_PRCTL
-#include <sys/prctl.h>
-#endif
-
 #include "backends/meta-backend-private.h"
 #include "backends/meta-monitor-manager-private.h"
 #include "backends/meta-virtual-monitor.h"
@@ -101,32 +97,6 @@
 #include "backends/native/meta-backend-native.h"
 #endif
 
-static const GDebugKey meta_debug_keys[] = {
-  { "focus", META_DEBUG_FOCUS },
-  { "workarea", META_DEBUG_WORKAREA },
-  { "stack", META_DEBUG_STACK },
-  { "sm", META_DEBUG_SM },
-  { "events", META_DEBUG_EVENTS },
-  { "window-state", META_DEBUG_WINDOW_STATE },
-  { "window-ops", META_DEBUG_WINDOW_OPS },
-  { "geometry", META_DEBUG_GEOMETRY },
-  { "placement", META_DEBUG_PLACEMENT },
-  { "ping", META_DEBUG_PING },
-  { "keybindings", META_DEBUG_KEYBINDINGS },
-  { "sync", META_DEBUG_SYNC },
-  { "startup", META_DEBUG_STARTUP },
-  { "prefs", META_DEBUG_PREFS },
-  { "groups", META_DEBUG_GROUPS },
-  { "resizing", META_DEBUG_RESIZING },
-  { "shapes", META_DEBUG_SHAPES },
-  { "edge-resistance", META_DEBUG_EDGE_RESISTANCE },
-  { "dbus", META_DEBUG_DBUS },
-  { "input", META_DEBUG_INPUT },
-  { "wayland", META_DEBUG_WAYLAND },
-  { "kms", META_DEBUG_KMS },
-  { "screen-cast", META_DEBUG_SCREEN_CAST },
-  { "remote-desktop", META_DEBUG_REMOTE_DESKTOP },
-};
 
 /*
  * The exit code we'll return to our parent process when we eventually die.
@@ -762,7 +732,6 @@ meta_init (void)
 {
   struct sigaction act;
   sigset_t empty_mask;
-  const char *debug_env;
   MetaCompositorType compositor_type;
   GType backend_gtype;
   unsigned int n_properties;
@@ -770,10 +739,6 @@ meta_init (void)
   GValue *prop_values;
   int i;
 
-#ifdef HAVE_SYS_PRCTL
-  prctl (PR_SET_DUMPABLE, 1);
-#endif
-
   sigemptyset (&empty_mask);
   act.sa_handler = SIG_IGN;
   act.sa_mask    = empty_mask;
@@ -789,19 +754,7 @@ meta_init (void)
 
   g_unix_signal_add (SIGTERM, on_sigterm, NULL);
 
-  if (g_getenv ("MUTTER_VERBOSE"))
+  meta_init_debug_utils ();
-    meta_set_verbose (TRUE);
-
-  debug_env = g_getenv ("MUTTER_DEBUG");
-  if (debug_env)
-    {
-      MetaDebugTopic topics;
-
-      topics = g_parse_debug_string (debug_env,
-                                     meta_debug_keys,
-                                     G_N_ELEMENTS (meta_debug_keys));
-      meta_add_verbose_topic (topics);
-    }
 
   if (_compositor_configuration_overridden)
     {

src/core/util-private.h

@@ -43,4 +43,6 @@ void     meta_set_is_wayland_compositor (gboolean setting);
 char *   meta_generate_random_id (GRand *rand,
                                   int    length);
 
+void meta_init_debug_utils (void);
+
 #endif

src/core/util.c

@@ -36,11 +36,42 @@
 #include <X11/Xlib.h>   /* must explicitly be included for Solaris; #326746 */
 #include <X11/Xutil.h>  /* Just for the definition of the various gravities */
 
+#ifdef HAVE_SYS_PRCTL
+#include <sys/prctl.h>
+#endif
+
 #include "clutter/clutter.h"
 #include "cogl/cogl.h"
 #include "meta/common.h"
 #include "meta/main.h"
 
+static const GDebugKey meta_debug_keys[] = {
+  { "focus", META_DEBUG_FOCUS },
+  { "workarea", META_DEBUG_WORKAREA },
+  { "stack", META_DEBUG_STACK },
+  { "sm", META_DEBUG_SM },
+  { "events", META_DEBUG_EVENTS },
+  { "window-state", META_DEBUG_WINDOW_STATE },
+  { "window-ops", META_DEBUG_WINDOW_OPS },
+  { "geometry", META_DEBUG_GEOMETRY },
+  { "placement", META_DEBUG_PLACEMENT },
+  { "ping", META_DEBUG_PING },
+  { "keybindings", META_DEBUG_KEYBINDINGS },
+  { "sync", META_DEBUG_SYNC },
+  { "startup", META_DEBUG_STARTUP },
+  { "prefs", META_DEBUG_PREFS },
+  { "groups", META_DEBUG_GROUPS },
+  { "resizing", META_DEBUG_RESIZING },
+  { "shapes", META_DEBUG_SHAPES },
+  { "edge-resistance", META_DEBUG_EDGE_RESISTANCE },
+  { "dbus", META_DEBUG_DBUS },
+  { "input", META_DEBUG_INPUT },
+  { "wayland", META_DEBUG_WAYLAND },
+  { "kms", META_DEBUG_KMS },
+  { "screen-cast", META_DEBUG_SCREEN_CAST },
+  { "remote-desktop", META_DEBUG_REMOTE_DESKTOP },
+};
+
 #ifdef WITH_VERBOSE_MODE
 static void
 meta_topic_real_valist (MetaDebugTopic topic,
@@ -163,6 +194,30 @@ meta_remove_verbose_topic (MetaDebugTopic topic)
     verbose_topics &= ~topic;
 }
 
+void
+meta_init_debug_utils (void)
+{
+  const char *debug_env;
+
+#ifdef HAVE_SYS_PRCTL
+  prctl (PR_SET_DUMPABLE, 1);
+#endif
+
+  if (g_getenv ("MUTTER_VERBOSE"))
+    meta_set_verbose (TRUE);
+
+  debug_env = g_getenv ("MUTTER_DEBUG");
+  if (debug_env)
+    {
+      MetaDebugTopic topics;
+
+      topics = g_parse_debug_string (debug_env,
+                                     meta_debug_keys,
+                                     G_N_ELEMENTS (meta_debug_keys));
+      meta_add_verbose_topic (topics);
+    }
+}
+
 gboolean
 meta_get_replace_current_wm (void)
 {