core: Remove circular dependencies between headers

Currently there are various circular dependencies between headers
in core/. Let's get rid of these by making judicious use of forward
declarations and moving includes into implementation files instead of
having them in header files.

Getting rid of circular header includes simplifies the code and makes
various clang based tooling such as iwyu work much better on our code.

The most important change is getting rid of the manager.h include in
unit.h which is possible thanks to the previous commits. We also move
the OOMPolicy and StatusType enums to unit.h to remove the need for
other unit headers to include manager.h to get access to these enums.

src/core/all-units.h

@@ -5,6 +5,7 @@
 
 #include "automount.h"
 #include "device.h"
+#include "mount.h"
 #include "path.h"
 #include "scope.h"
 #include "service.h"

src/core/automount.c

@@ -22,6 +22,7 @@
 #include "io-util.h"
 #include "label-util.h"
 #include "mkdir-label.h"
+#include "manager.h"
 #include "mount-util.h"
 #include "mount.h"
 #include "mountpoint-util.h"

src/core/automount.h

@@ -1,8 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct Automount Automount;
-
 #include "unit.h"
 
 typedef enum AutomountResult {
@@ -15,7 +13,7 @@ typedef enum AutomountResult {
         _AUTOMOUNT_RESULT_INVALID = -EINVAL,
 } AutomountResult;
 
-struct Automount {
+typedef struct Automount {
         Unit meta;
 
         AutomountState state, deserialized_state;
@@ -35,7 +33,7 @@ struct Automount {
         sd_event_source *expire_event_source;
 
         AutomountResult result;
-};
+} Automount;
 
 extern const UnitVTable automount_vtable;
 

src/core/bpf-firewall.c

@@ -20,6 +20,7 @@
 #include "bpf-program.h"
 #include "fd-util.h"
 #include "in-addr-prefix-util.h"
+#include "manager.h"
 #include "memory-util.h"
 #include "missing_syscall.h"
 #include "unit.h"

src/core/bpf-restrict-ifaces.c

@@ -3,6 +3,7 @@
 #include "fd-util.h"
 #include "bpf-restrict-ifaces.h"
 #include "netlink-util.h"
+#include "unit.h"
 
 #if BPF_FRAMEWORK
 /* libbpf, clang and llc compile time dependencies are satisfied */

src/core/bpf-restrict-ifaces.h

@@ -2,7 +2,6 @@
 #pragma once
 
 #include "fdset.h"
-#include "unit.h"
 
 typedef struct Unit Unit;
 

src/core/bpf-socket-bind.c

@@ -6,6 +6,7 @@
 
 #include "fd-util.h"
 #include "bpf-socket-bind.h"
+#include "unit.h"
 
 #if BPF_FRAMEWORK
 /* libbpf, clang, llvm and bpftool compile time dependencies are satisfied */

src/core/bpf-socket-bind.h

@@ -2,7 +2,8 @@
 #pragma once
 
 #include "fdset.h"
-#include "unit.h"
+
+typedef struct Unit Unit;
 
 int bpf_socket_bind_supported(void);
 

src/core/cgroup.c

@@ -27,6 +27,7 @@
 #include "io-util.h"
 #include "ip-protocol-list.h"
 #include "limits-util.h"
+#include "manager.h"
 #include "nulstr-util.h"
 #include "parse-util.h"
 #include "path-util.h"

src/core/core-varlink.c

@@ -3,9 +3,12 @@
 #include "sd-varlink.h"
 
 #include "core-varlink.h"
+#include "dynamic-user.h"
 #include "json-util.h"
+#include "manager.h"
 #include "mkdir-label.h"
 #include "strv.h"
+#include "unit.h"
 #include "user-util.h"
 #include "varlink-internal.h"
 #include "varlink-io.systemd.UserDatabase.h"

src/core/core-varlink.h

@@ -1,7 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include "manager.h"
+typedef struct Manager Manager;
+typedef struct Unit Unit;
 
 int manager_setup_varlink_server(Manager *m);
 

src/core/dbus-cgroup.c

@@ -22,6 +22,7 @@
 #include "in-addr-prefix-util.h"
 #include "ip-protocol-list.h"
 #include "limits-util.h"
+#include "manager.h"
 #include "memstream-util.h"
 #include "parse-util.h"
 #include "path-util.h"

src/core/dbus-execute.h

@@ -5,6 +5,7 @@
 #include "sd-bus-vtable.h"
 
 #include "execute.h"
+#include "unit.h"
 
 #define BUS_EXEC_STATUS_VTABLE(prefix, offset, flags)                   \
         BUS_PROPERTY_DUAL_TIMESTAMP(prefix "StartTimestamp", (offset) + offsetof(ExecStatus, start_timestamp), flags), \

src/core/dbus-job.h

@@ -3,9 +3,10 @@
 
 #include "sd-bus.h"
 
-#include "unit.h"
 #include "bus-object.h"
 
+typedef struct Job Job;
+
 extern const sd_bus_vtable bus_job_vtable[];
 extern const BusObjectImplementation job_object;
 

src/core/dbus-manager.c

@@ -25,6 +25,7 @@
 #include "dbus-unit.h"
 #include "dbus-util.h"
 #include "dbus.h"
+#include "dynamic-user.h"
 #include "env-util.h"
 #include "fd-util.h"
 #include "fileio.h"

src/core/dbus-manager.h

@@ -3,7 +3,9 @@
 
 #include "sd-bus-vtable.h"
 
-#include "manager.h"
+#include "time-util.h"
+
+typedef struct Manager Manager;
 
 extern const sd_bus_vtable bus_manager_vtable[];
 extern const sd_bus_vtable bus_manager_log_control_vtable[];

src/core/dbus-scope.h

@@ -4,9 +4,10 @@
 #include "sd-bus.h"
 #include "sd-bus-vtable.h"
 
-#include "scope.h"
 #include "unit.h"
 
+typedef struct Scope Scope;
+
 extern const sd_bus_vtable bus_scope_vtable[];
 
 int bus_scope_set_property(Unit *u, const char *name, sd_bus_message *i, UnitWriteFlags flags, sd_bus_error *error);

src/core/dbus-util.c

@@ -4,6 +4,7 @@
 #include "bus-util.h"
 #include "dbus-util.h"
 #include "escape.h"
+#include "manager.h"
 #include "parse-util.h"
 #include "path-util.h"
 #include "reboot-util.h"

src/core/dbus.h

@@ -3,7 +3,9 @@
 
 #include "sd-bus.h"
 
-#include "manager.h"
+#include "fdset.h"
+
+typedef struct Manager Manager;
 
 void bus_send_pending_reload_message(Manager *m);
 

src/core/device.c

@@ -13,6 +13,7 @@
 #include "device-util.h"
 #include "device.h"
 #include "log.h"
+#include "manager.h"
 #include "parse-util.h"
 #include "path-util.h"
 #include "ratelimit.h"

src/core/device.h

@@ -3,8 +3,6 @@
 
 #include "unit.h"
 
-typedef struct Device Device;
-
 /* A mask specifying where we have seen the device currently. This is a bitmask because the device might show up
  * asynchronously from each other at various places. For example, in very common case a device might already be mounted
  * before udev finished probing it (think: a script setting up a loopback block device, formatting it and mounting it
@@ -17,7 +15,7 @@ typedef enum DeviceFound {
         _DEVICE_FOUND_MASK = DEVICE_FOUND_UDEV|DEVICE_FOUND_MOUNT|DEVICE_FOUND_SWAP,
 } DeviceFound;
 
-struct Device {
+typedef struct Device {
         Unit meta;
 
         char *sysfs, *deserialized_sysfs;
@@ -36,7 +34,7 @@ struct Device {
 
         /* The SYSTEMD_WANTS udev property for this device the last time we saw it */
         char **wants_property;
-};
+} Device;
 
 extern const UnitVTable device_vtable;
 

src/core/dynamic-user.c

@@ -12,6 +12,7 @@
 #include "fs-util.h"
 #include "iovec-util.h"
 #include "lock-util.h"
+#include "manager.h"
 #include "parse-util.h"
 #include "random-util.h"
 #include "serialize.h"

src/core/dynamic-user.h

@@ -1,7 +1,15 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+#include "fdset.h"
+#include "memory-util.h"
+
 typedef struct DynamicUser DynamicUser;
+typedef struct Manager Manager;
 
 typedef struct DynamicCreds {
         /* A combination of a dynamic user and group */
@@ -9,8 +17,6 @@ typedef struct DynamicCreds {
         DynamicUser *group;
 } DynamicCreds;
 
-#include "manager.h"
-
 /* Note that this object always allocates a pair of user and group under the same name, even if one of them isn't
  * used. This means, if you want to allocate a group and user pair, and they might have two different names, then you
  * need to allocated two of these objects. DynamicCreds below makes that easy. */

src/core/emergency-action.c

@@ -6,6 +6,7 @@
 #include "bus-error.h"
 #include "bus-util.h"
 #include "emergency-action.h"
+#include "manager.h"
 #include "raw-reboot.h"
 #include "reboot-util.h"
 #include "special.h"

src/core/emergency-action.h

@@ -3,8 +3,11 @@
 
 #include <errno.h>
 
+#include "macro.h"
 #include "runtime-scope.h"
 
+typedef struct Manager Manager;
+
 typedef enum EmergencyAction {
         EMERGENCY_ACTION_NONE,
         EMERGENCY_ACTION_EXIT,
@@ -34,9 +37,6 @@ typedef enum EmergencyActionFlags {
         _EMERGENCY_ACTION_FLAGS_MAX  = (1 << 3) - 1,
 } EmergencyActionFlags;
 
-#include "macro.h"
-#include "manager.h"
-
 void emergency_action(
                 Manager *m,
                 EmergencyAction action,

src/core/exec-invoke.c

@@ -24,11 +24,13 @@
 #include "bpf-restrict-fs.h"
 #include "btrfs-util.h"
 #include "capability-util.h"
+#include "cgroup.h"
 #include "cgroup-setup.h"
 #include "chase.h"
 #include "chattr-util.h"
 #include "chown-recursive.h"
 #include "copy.h"
+#include "dynamic-user.h"
 #include "env-util.h"
 #include "escape.h"
 #include "exec-credential.h"
@@ -43,10 +45,12 @@
 #include "ioprio-util.h"
 #include "iovec-util.h"
 #include "journal-send.h"
+#include "manager.h"
 #include "memfd-util.h"
 #include "missing_sched.h"
 #include "missing_syscall.h"
 #include "mkdir-label.h"
+#include "mount-util.h"
 #include "osc-context.h"
 #include "proc-cmdline.h"
 #include "process-util.h"

src/core/execute-serialize.c

@@ -2,7 +2,9 @@
 
 #include "af-list.h"
 #include "capability-util.h"
+#include "cgroup.h"
 #include "cgroup-setup.h"
+#include "dynamic-user.h"
 #include "escape.h"
 #include "exec-credential.h"
 #include "execute-serialize.h"

src/core/execute.c

@@ -25,6 +25,7 @@
 #include "cgroup-setup.h"
 #include "constants.h"
 #include "cpu-set-util.h"
+#include "dynamic-user.h"
 #include "env-file.h"
 #include "env-util.h"
 #include "errno-list.h"

src/core/execute.h

@@ -1,19 +1,11 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct ExecStatus ExecStatus;
-typedef struct ExecCommand ExecCommand;
-typedef struct ExecContext ExecContext;
-typedef struct ExecSharedRuntime ExecSharedRuntime;
-typedef struct DynamicCreds DynamicCreds;
-typedef struct ExecRuntime ExecRuntime;
-typedef struct ExecParameters ExecParameters;
-typedef struct Manager Manager;
-
 #include <sched.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <sys/capability.h>
+#include <sys/socket.h>
 
 #include "bus-unit-util.h"
 #include "cgroup-util.h"
@@ -22,6 +14,7 @@ typedef struct Manager Manager;
 #include "exec-util.h"
 #include "fdset.h"
 #include "list.h"
+#include "log-context.h"
 #include "namespace.h"
 #include "nsflags.h"
 #include "numa-util.h"
@@ -34,6 +27,17 @@ typedef struct Manager Manager;
 #include "set.h"
 #include "time-util.h"
 
+typedef struct CGroupContext CGroupContext;
+typedef struct ExecStatus ExecStatus;
+typedef struct ExecCommand ExecCommand;
+typedef struct ExecContext ExecContext;
+typedef struct ExecSharedRuntime ExecSharedRuntime;
+typedef struct DynamicCreds DynamicCreds;
+typedef struct ExecRuntime ExecRuntime;
+typedef struct ExecParameters ExecParameters;
+typedef struct Manager Manager;
+typedef struct Unit Unit;
+
 #define EXEC_STDIN_DATA_MAX (64U*1024U*1024U)
 
 typedef enum ExecUtmpMode {
@@ -494,9 +498,6 @@ struct ExecParameters {
                 .pidref_transport_fd    = -EBADF, \
         }
 
-#include "unit.h"
-#include "dynamic-user.h"
-
 int exec_spawn(
                 Unit *unit,
                 ExecCommand *command,

src/core/executor.c

@@ -9,6 +9,8 @@
 #include "argv-util.h"
 #include "build.h"
 #include "capability-util.h"
+#include "cgroup.h"
+#include "dynamic-user.h"
 #include "exec-invoke.h"
 #include "execute-serialize.h"
 #include "execute.h"

src/core/fuzz-execute-serialize.c

@@ -20,6 +20,7 @@
 #include <stdio.h>
 
 #include "alloc-util.h"
+#include "dynamic-user.h"
 #include "execute-serialize.h"
 #include "fd-util.h"
 #include "fuzz.h"

src/core/fuzz-unit-file.c

@@ -5,6 +5,7 @@
 #include "fuzz.h"
 #include "install.h"
 #include "load-fragment.h"
+#include "manager.h"
 #include "manager-dump.h"
 #include "memstream-util.h"
 #include "string-util.h"

src/core/job.c

@@ -16,6 +16,7 @@
 #include "job.h"
 #include "log.h"
 #include "macro.h"
+#include "manager.h"
 #include "parse-util.h"
 #include "serialize.h"
 #include "set.h"

src/core/job.h

@@ -7,6 +7,8 @@
 #include "sd-event.h"
 
 #include "list.h"
+#include "memory-util.h"
+#include "time-util.h"
 #include "unit-dependency-atom.h"
 
 typedef struct ActivationDetails ActivationDetails;

src/core/kill.h

@@ -1,8 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct KillContext KillContext;
-
 #include <stdbool.h>
 #include <stdio.h>
 
@@ -18,7 +16,7 @@ typedef enum KillMode {
         _KILL_MODE_INVALID = -EINVAL,
 } KillMode;
 
-struct KillContext {
+typedef struct KillContext {
         KillMode kill_mode;
         int kill_signal;
         int restart_kill_signal;
@@ -26,7 +24,7 @@ struct KillContext {
         int watchdog_signal;
         bool send_sigkill;
         bool send_sighup;
-};
+} KillContext;
 
 typedef enum KillWhom {
         /* Kill whom is a property of an operation */

src/core/load-dropin.c

@@ -1,16 +1,29 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include "conf-parser.h"
+#include "dropin.h"
 #include "fs-util.h"
 #include "load-dropin.h"
 #include "load-fragment.h"
 #include "log.h"
+#include "manager.h"
 #include "stat-util.h"
 #include "string-util.h"
 #include "strv.h"
 #include "unit-name.h"
 #include "unit.h"
 
+int unit_find_dropin_paths(Unit *u, bool use_unit_path_cache, char ***paths) {
+        assert(u);
+
+        return unit_file_find_dropin_paths(NULL,
+                                           u->manager->lookup_paths.search_path,
+                                           use_unit_path_cache ? u->manager->unit_path_cache : NULL,
+                                           ".d", ".conf",
+                                           u->id, u->aliases,
+                                           paths);
+}
+
 static int process_deps(Unit *u, UnitDependency dependency, const char *dir_suffix) {
         _cleanup_strv_free_ char **paths = NULL;
         int r;

src/core/load-dropin.h

@@ -1,20 +1,12 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include "dropin.h"
-#include "unit.h"
+#include <stdbool.h>
+
+typedef struct Unit Unit;
 
 /* Read service data supplementary drop-in directories */
 
-static inline int unit_find_dropin_paths(Unit *u, bool use_unit_path_cache, char ***paths) {
-        assert(u);
-
-        return unit_file_find_dropin_paths(NULL,
-                                           u->manager->lookup_paths.search_path,
-                                           use_unit_path_cache ? u->manager->unit_path_cache : NULL,
-                                           ".d", ".conf",
-                                           u->id, u->aliases,
-                                           paths);
-}
+int unit_find_dropin_paths(Unit *u, bool use_unit_path_cache, char ***paths);
 
 int unit_load_dropin(Unit *u);

src/core/load-fragment.h

@@ -2,7 +2,8 @@
 #pragma once
 
 #include "conf-parser.h"
-#include "unit.h"
+
+typedef struct Unit Unit;
 
 /* These functions are declared in the header to make them accessible to unit tests. */
 bool contains_instance_specifier_superset(const char *s);

src/core/manager-dump.c

@@ -4,6 +4,7 @@
 #include "fd-util.h"
 #include "fileio.h"
 #include "hashmap.h"
+#include "manager.h"
 #include "manager-dump.h"
 #include "memstream-util.h"
 #include "unit-serialize.h"

src/core/manager-dump.h

@@ -3,7 +3,7 @@
 
 #include <stdio.h>
 
-#include "manager.h"
+typedef struct Manager Manager;
 
 void manager_dump_jobs(Manager *s, FILE *f, char **patterns, const char *prefix);
 int manager_get_dump_jobs_string(Manager *m, char **patterns, const char *prefix, char **ret);

src/core/manager-serialize.c

@@ -5,6 +5,7 @@
 #include "clean-ipc.h"
 #include "core-varlink.h"
 #include "dbus.h"
+#include "dynamic-user.h"
 #include "fd-util.h"
 #include "fileio.h"
 #include "format-util.h"

src/core/manager-serialize.h

@@ -2,10 +2,12 @@
 #pragma once
 
 #include <stdbool.h>
+#include <stdio.h>
 
-#include "manager.h"
 #include "fdset.h"
 
+typedef struct Manager Manager;
+
 #define DESTROY_IPC_FLAG (UINT32_C(1) << 31)
 
 int manager_open_serialization(Manager *m, FILE **ret_f);

src/core/manager.c

@@ -42,6 +42,7 @@
 #include "dbus-unit.h"
 #include "dbus.h"
 #include "dirent-util.h"
+#include "dynamic-user.h"
 #include "env-util.h"
 #include "escape.h"
 #include "event-util.h"
@@ -5182,11 +5183,3 @@ static const char* const manager_timestamp_table[_MANAGER_TIMESTAMP_MAX] = {
 };
 
 DEFINE_STRING_TABLE_LOOKUP(manager_timestamp, ManagerTimestamp);
-
-static const char* const oom_policy_table[_OOM_POLICY_MAX] = {
-        [OOM_CONTINUE] = "continue",
-        [OOM_STOP]     = "stop",
-        [OOM_KILL]     = "kill",
-};
-
-DEFINE_STRING_TABLE_LOOKUP(oom_policy, OOMPolicy);

src/core/manager.h

@@ -9,14 +9,22 @@
 #include "sd-event.h"
 #include "sd-varlink.h"
 
-#include "common-signal.h"
 #include "cgroup-util.h"
 #include "cgroup.h"
+#include "common-signal.h"
+#include "emergency-action.h"
+#include "execute.h"
 #include "fdset.h"
 #include "hashmap.h"
+#include "job.h"
 #include "list.h"
+#include "path-lookup.h"
 #include "prioq.h"
 #include "ratelimit.h"
+#include "show-status.h"
+#include "transaction.h"
+#include "unit-name.h"
+#include "unit.h"
 
 struct libmnt_monitor;
 typedef struct Unit Unit;
@@ -62,21 +70,6 @@ typedef enum ManagerObjective {
         _MANAGER_OBJECTIVE_INVALID = -EINVAL,
 } ManagerObjective;
 
-typedef enum StatusType {
-        STATUS_TYPE_EPHEMERAL,
-        STATUS_TYPE_NORMAL,
-        STATUS_TYPE_NOTICE,
-        STATUS_TYPE_EMERGENCY,
-} StatusType;
-
-typedef enum OOMPolicy {
-        OOM_CONTINUE,          /* The kernel or systemd-oomd kills the process it wants to kill, and that's it */
-        OOM_STOP,              /* The kernel or systemd-oomd kills the process it wants to kill, and we stop the unit */
-        OOM_KILL,              /* The kernel or systemd-oomd kills the process it wants to kill, and all others in the unit, and we stop the unit */
-        _OOM_POLICY_MAX,
-        _OOM_POLICY_INVALID = -EINVAL,
-} OOMPolicy;
-
 /* Notes:
  * 1. TIMESTAMP_FIRMWARE, TIMESTAMP_LOADER, TIMESTAMP_KERNEL, TIMESTAMP_INITRD,
  *    TIMESTAMP_SECURITY_START, and TIMESTAMP_SECURITY_FINISH are set only when
@@ -135,14 +128,6 @@ typedef enum WatchdogType {
         _WATCHDOG_TYPE_MAX,
 } WatchdogType;
 
-#include "execute.h"
-#include "job.h"
-#include "path-lookup.h"
-#include "show-status.h"
-#include "transaction.h"
-#include "unit-name.h"
-#include "unit.h"
-
 typedef enum ManagerTestRunFlags {
         MANAGER_TEST_NORMAL                  = 0,       /* run normally */
         MANAGER_TEST_RUN_MINIMAL             = 1 << 0,  /* create basic data structures */
@@ -670,9 +655,6 @@ LogTarget manager_get_executor_log_target(Manager *m);
 
 int manager_allocate_idle_pipe(Manager *m);
 
-const char* oom_policy_to_string(OOMPolicy i) _const_;
-OOMPolicy oom_policy_from_string(const char *s) _pure_;
-
 void unit_defaults_init(UnitDefaults *defaults, RuntimeScope scope);
 void unit_defaults_done(UnitDefaults *defaults);
 

src/core/mount.h

@@ -1,9 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct Mount Mount;
-
-#include "dynamic-user.h"
 #include "kill.h"
 #include "pidref.h"
 #include "unit.h"
@@ -42,7 +39,7 @@ typedef enum MountProcFlags {
         MOUNT_PROC_JUST_CHANGED = 1 << 2,
 } MountProcFlags;
 
-struct Mount {
+typedef struct Mount {
         Unit meta;
 
         char *where;
@@ -88,7 +85,7 @@ struct Mount {
         sd_event_source *timer_event_source;
 
         unsigned n_retry_umount;
-};
+} Mount;
 
 extern const UnitVTable mount_vtable;
 

src/core/path.c

@@ -16,6 +16,7 @@
 #include "glob-util.h"
 #include "inotify-util.h"
 #include "macro.h"
+#include "manager.h"
 #include "mkdir-label.h"
 #include "path.h"
 #include "path-util.h"

src/core/path.h

@@ -1,10 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct Path Path;
-typedef struct PathSpec PathSpec;
-typedef struct ActivationDetailsPath ActivationDetailsPath;
-
 #include "unit.h"
 
 typedef enum PathType {
@@ -52,7 +48,7 @@ typedef enum PathResult {
         _PATH_RESULT_INVALID = -EINVAL,
 } PathResult;
 
-struct Path {
+typedef struct Path {
         Unit meta;
 
         LIST_HEAD(PathSpec, specs);
@@ -67,12 +63,12 @@ struct Path {
         RateLimit trigger_limit;
 
         sd_event_source *trigger_notify_event_source;
-};
+} Path;
 
-struct ActivationDetailsPath {
+typedef struct ActivationDetailsPath {
         ActivationDetails meta;
         char *trigger_path_filename;
-};
+} ActivationDetailsPath;
 
 void path_free_specs(Path *p);
 

src/core/scope.c

@@ -10,6 +10,7 @@
 #include "exit-status.h"
 #include "load-dropin.h"
 #include "log.h"
+#include "manager.h"
 #include "process-util.h"
 #include "random-util.h"
 #include "scope.h"

src/core/scope.h

@@ -1,8 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct Scope Scope;
-
 #include "cgroup.h"
 #include "kill.h"
 #include "unit.h"
@@ -16,7 +14,7 @@ typedef enum ScopeResult {
         _SCOPE_RESULT_INVALID = -EINVAL,
 } ScopeResult;
 
-struct Scope {
+typedef struct Scope {
         Unit meta;
 
         CGroupContext cgroup_context;
@@ -41,7 +39,7 @@ struct Scope {
         char *group;
 
         OOMPolicy oom_policy;
-};
+} Scope;
 
 extern const UnitVTable scope_vtable;
 

src/core/service.h

@@ -1,12 +1,9 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct Service Service;
-typedef struct ServiceFDStore ServiceFDStore;
-typedef struct ServiceExtraFD ServiceExtraFD;
-
 #include "exit-status.h"
 #include "kill.h"
+#include "manager.h"
 #include "open-file.h"
 #include "path.h"
 #include "pidref.h"
@@ -14,6 +11,8 @@ typedef struct ServiceExtraFD ServiceExtraFD;
 #include "socket.h"
 #include "unit.h"
 
+typedef struct Service Service;
+
 typedef enum ServiceRestart {
         SERVICE_RESTART_NO,
         SERVICE_RESTART_ON_SUCCESS,
@@ -101,7 +100,7 @@ typedef enum ServiceRestartMode {
         _SERVICE_RESTART_MODE_INVALID = -EINVAL,
 } ServiceRestartMode;
 
-struct ServiceFDStore {
+typedef struct ServiceFDStore {
         Service *service;
 
         int fd;
@@ -109,13 +108,13 @@ struct ServiceFDStore {
         sd_event_source *event_source;
         bool do_poll;
 
-        LIST_FIELDS(ServiceFDStore, fd_store);
-};
+        LIST_FIELDS(struct ServiceFDStore, fd_store);
+} ServiceFDStore;
 
-struct ServiceExtraFD {
+typedef struct ServiceExtraFD {
         int fd;
         char *fdname;
-};
+} ServiceExtraFD;
 
 struct Service {
         Unit meta;

src/core/slice.c

@@ -7,6 +7,7 @@
 #include "dbus-unit.h"
 #include "fd-util.h"
 #include "log.h"
+#include "manager.h"
 #include "serialize.h"
 #include "slice.h"
 #include "special.h"

src/core/slice.h

@@ -3,9 +3,7 @@
 
 #include "unit.h"
 
-typedef struct Slice Slice;
-
-struct Slice {
+typedef struct Slice {
         Unit meta;
 
         SliceState state, deserialized_state;
@@ -16,7 +14,7 @@ struct Slice {
         CGroupContext cgroup_context;
 
         CGroupRuntime *cgroup_runtime;
-};
+} Slice;
 
 extern const UnitVTable slice_vtable;
 

src/core/socket.c

@@ -28,6 +28,7 @@
 #include "ip-protocol-list.h"
 #include "label-util.h"
 #include "log.h"
+#include "manager.h"
 #include "mkdir-label.h"
 #include "parse-util.h"
 #include "path-util.h"

src/core/socket.h

@@ -1,14 +1,13 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct Socket Socket;
-typedef struct SocketPeer SocketPeer;
-
-#include "mount.h"
 #include "pidref.h"
 #include "socket-util.h"
 #include "unit.h"
 
+typedef struct Socket Socket;
+typedef struct SocketPeer SocketPeer;
+
 typedef enum SocketExecCommand {
         SOCKET_EXEC_START_PRE,
         SOCKET_EXEC_START_CHOWN,

src/core/swap.c

@@ -17,6 +17,7 @@
 #include "fd-util.h"
 #include "format-util.h"
 #include "fstab-util.h"
+#include "manager.h"
 #include "parse-util.h"
 #include "path-util.h"
 #include "process-util.h"

src/core/swap.h

@@ -10,8 +10,6 @@
 #include "pidref.h"
 #include "unit.h"
 
-typedef struct Swap Swap;
-
 typedef enum SwapExecCommand {
         SWAP_EXEC_ACTIVATE,
         SWAP_EXEC_DEACTIVATE,
@@ -38,7 +36,7 @@ typedef struct SwapParameters {
         bool priority_set;
 } SwapParameters;
 
-struct Swap {
+typedef struct Swap {
         Unit meta;
 
         char *what;
@@ -85,7 +83,7 @@ struct Swap {
         devices for the same swap. We chain them up here. */
 
         LIST_FIELDS(struct Swap, same_devnode);
-};
+} Swap;
 
 extern const UnitVTable swap_vtable;
 

src/core/target.h

@@ -3,13 +3,11 @@
 
 #include "unit.h"
 
-typedef struct Target Target;
-
-struct Target {
+typedef struct Target {
         Unit meta;
 
         TargetState state, deserialized_state;
-};
+} Target;
 
 extern const UnitVTable target_vtable;
 

src/core/timer.c

@@ -12,6 +12,7 @@
 #include "dbus-timer.h"
 #include "dbus-unit.h"
 #include "fs-util.h"
+#include "manager.h"
 #include "parse-util.h"
 #include "random-util.h"
 #include "serialize.h"

src/core/timer.h

@@ -1,9 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct Timer Timer;
-typedef struct ActivationDetailsTimer ActivationDetailsTimer;
-
 #include "calendarspec.h"
 #include "unit.h"
 
@@ -37,7 +34,7 @@ typedef enum TimerResult {
         _TIMER_RESULT_INVALID = -EINVAL,
 } TimerResult;
 
-struct Timer {
+typedef struct Timer {
         Unit meta;
 
         usec_t accuracy_usec;
@@ -64,12 +61,12 @@ struct Timer {
         bool defer_reactivation;
 
         char *stamp_path;
-};
+} Timer;
 
-struct ActivationDetailsTimer {
+typedef struct ActivationDetailsTimer {
         ActivationDetails meta;
         dual_timestamp last_trigger;
-};
+} ActivationDetailsTimer;
 
 #define TIMER_MONOTONIC_CLOCK(t) ((t)->wake_system ? CLOCK_BOOTTIME_ALARM : CLOCK_MONOTONIC)
 

src/core/transaction.c

@@ -8,6 +8,7 @@
 #include "bus-common-errors.h"
 #include "bus-error.h"
 #include "dbus-unit.h"
+#include "manager.h"
 #include "slice.h"
 #include "strv.h"
 #include "terminal-util.h"

src/core/transaction.h

@@ -1,20 +1,15 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct Transaction Transaction;
-typedef enum TransactionAddFlags TransactionAddFlags;
-
 #include "hashmap.h"
 #include "job.h"
-#include "manager.h"
-#include "unit.h"
 
-struct Transaction {
+typedef struct Transaction {
         /* Jobs to be added */
         Hashmap *jobs;        /* Unit object => Job object list 1:1 */
         Job *anchor_job;      /* The job the user asked for */
         bool irreversible;
-};
+} Transaction;
 
 Transaction* transaction_new(bool irreversible);
 Transaction* transaction_free(Transaction *tr);

src/core/unit-printf.c

@@ -4,6 +4,7 @@
 #include "cgroup-util.h"
 #include "format-util.h"
 #include "macro.h"
+#include "manager.h"
 #include "sd-path.h"
 #include "specifier.h"
 #include "string-util.h"

src/core/unit-serialize.c

@@ -10,6 +10,7 @@
 #include "parse-util.h"
 #include "serialize.h"
 #include "string-table.h"
+#include "unit.h"
 #include "unit-serialize.h"
 #include "user-util.h"
 

src/core/unit-serialize.h

@@ -1,11 +1,13 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
+#include <stdbool.h>
 #include <stdio.h>
 
-#include "unit.h"
 #include "fdset.h"
 
+typedef struct Unit Unit;
+
 /* These functions serialize state for our own usage, i.e.: across a reload/reexec, rather than for being
  * passed to a child process. */
 

src/core/unit.c

@@ -24,6 +24,7 @@
 #include "dbus-unit.h"
 #include "dbus.h"
 #include "dropin.h"
+#include "dynamic-user.h"
 #include "env-util.h"
 #include "escape.h"
 #include "exec-credential.h"
@@ -6810,6 +6811,14 @@ static const char* const unit_mount_dependency_type_table[_UNIT_MOUNT_DEPENDENCY
 
 DEFINE_STRING_TABLE_LOOKUP(unit_mount_dependency_type, UnitMountDependencyType);
 
+static const char* const oom_policy_table[_OOM_POLICY_MAX] = {
+        [OOM_CONTINUE] = "continue",
+        [OOM_STOP]     = "stop",
+        [OOM_KILL]     = "kill",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(oom_policy, OOMPolicy);
+
 UnitDependency unit_mount_dependency_type_to_dependency_type(UnitMountDependencyType t) {
         switch (t) {
 

src/core/unit.h

@@ -9,7 +9,21 @@
 
 #include "sd-id128.h"
 
-/* Circular dependency with manager.h, needs to be defined before local includes */
+#include "cgroup.h"
+#include "condition.h"
+#include "emergency-action.h"
+#include "execute.h"
+#include "install.h"
+#include "job.h"
+#include "list.h"
+#include "log-context.h"
+#include "mount-util.h"
+#include "pidref.h"
+#include "ratelimit.h"
+#include "unit-file.h"
+
+typedef struct UnitRef UnitRef;
+
 typedef enum UnitMountDependencyType {
         UNIT_MOUNT_WANTS,
         UNIT_MOUNT_REQUIRES,
@@ -17,18 +31,6 @@ typedef enum UnitMountDependencyType {
         _UNIT_MOUNT_DEPENDENCY_TYPE_INVALID = -EINVAL,
 } UnitMountDependencyType;
 
-#include "cgroup.h"
-#include "condition.h"
-#include "emergency-action.h"
-#include "install.h"
-#include "list.h"
-#include "log-context.h"
-#include "mount-util.h"
-#include "pidref.h"
-#include "unit-file.h"
-
-typedef struct UnitRef UnitRef;
-
 typedef enum KillOperation {
         KILL_TERMINATE,
         KILL_TERMINATE_AND_LOG,
@@ -46,6 +48,21 @@ typedef enum CollectMode {
         _COLLECT_MODE_INVALID = -EINVAL,
 } CollectMode;
 
+typedef enum OOMPolicy {
+        OOM_CONTINUE,          /* The kernel or systemd-oomd kills the process it wants to kill, and that's it */
+        OOM_STOP,              /* The kernel or systemd-oomd kills the process it wants to kill, and we stop the unit */
+        OOM_KILL,              /* The kernel or systemd-oomd kills the process it wants to kill, and all others in the unit, and we stop the unit */
+        _OOM_POLICY_MAX,
+        _OOM_POLICY_INVALID = -EINVAL,
+} OOMPolicy;
+
+typedef enum StatusType {
+        STATUS_TYPE_EPHEMERAL,
+        STATUS_TYPE_NORMAL,
+        STATUS_TYPE_NOTICE,
+        STATUS_TYPE_EMERGENCY,
+} StatusType;
+
 static inline bool UNIT_IS_ACTIVE_OR_RELOADING(UnitActiveState t) {
         return IN_SET(t, UNIT_ACTIVE, UNIT_RELOADING, UNIT_REFRESHING);
 }
@@ -200,8 +217,6 @@ static inline void* UNIT_DEPENDENCY_TO_PTR(UnitDependency d) {
         return INT_TO_PTR(d);
 }
 
-#include "job.h"
-
 struct UnitRef {
         /* Keeps tracks of references to a unit. This is useful so
          * that we can merge two units if necessary and correct all
@@ -1061,6 +1076,9 @@ UnitMountDependencyType unit_mount_dependency_type_from_string(const char *s) _c
 const char* unit_mount_dependency_type_to_string(UnitMountDependencyType t) _const_;
 UnitDependency unit_mount_dependency_type_to_dependency_type(UnitMountDependencyType t) _pure_;
 
+const char* oom_policy_to_string(OOMPolicy i) _const_;
+OOMPolicy oom_policy_from_string(const char *s) _pure_;
+
 /* Macros which append UNIT= or USER_UNIT= to the message */
 
 #define log_unit_full_errno_zerook(unit, level, error, ...)             \