Move various files that don't need to be in basic/ to shared/

This doesn't have much effect on the final build, because we link libbasic.a
into libsystemd-shared.so, so in the end, all the object built from basic/
end up in libsystemd-shared. And when the static library is linked into binaries,
any objects that are included in it but are not used are trimmed. Hence, the
size of output artifacts doesn't change:

$ du -sb /var/tmp/inst*
54181861	/var/tmp/inst1    (old)
54207441	/var/tmp/inst1s   (old split-usr)
54182477	/var/tmp/inst2    (new)
54208041	/var/tmp/inst2s   (new split-usr)

(The negligible change in size is because libsystemd-shared.so is bigger
by a few hundred bytes. I guess it's because symbols are named differently
or something like that.)

The effect is on the build process, in particular partial builds. This change
effectively moves the requirements on some build steps toward the leaves of the
dependency tree. Two effects:
- when building items that do not depend on libsystemd-shared, we
  build less stuff for libbasic.a (which wouldn't be used anyway,
  so it's a net win).
- when building items that do depend on libshared, we reduce libbasic.a as a
  synchronization point, possibly allowing better parallelism.

Method:
1. copy list of .h files from src/basic/meson.build to /tmp/basic
2. $ for i in $(grep '.h$' /tmp/basic); do echo $i; git --no-pager grep "include \"$i\"" src/basic/ 'src/lib*' 'src/nss-*' 'src/journal/sd-journal.c' |grep -v "${i%.h}.c";echo ;done | less

1 files changed, 97 insertions, 0 deletions

diff --git a/src/shared/exit-status.h b/src/shared/exit-status.h
new file mode 100644
index 0000000000..c41e8b82c3
--- /dev/null
+++ b/src/shared/exit-status.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "hashmap.h"
+#include "macro.h"
+#include "set.h"
+
+/* This defines pretty names for the LSB 'start' verb exit codes. Note that they shouldn't be confused with the LSB
+ * 'status' verb exit codes which are defined very differently. For details see:
+ *
+ * https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html
+ */
+
+enum {
+        /* EXIT_SUCCESS defined by libc */
+        /* EXIT_FAILURE defined by libc */
+        EXIT_INVALIDARGUMENT = 2,
+        EXIT_NOTIMPLEMENTED = 3,
+        EXIT_NOPERMISSION = 4,
+        EXIT_NOTINSTALLED = 5,
+        EXIT_NOTCONFIGURED = 6,
+        EXIT_NOTRUNNING = 7,
+
+        /* BSD's sysexits.h defines a couple EX_xyz exit codes in the range 64 … 78 */
+
+        /* The LSB suggests that error codes >= 200 are "reserved". We use them here under the assumption that they
+         * hence are unused by init scripts. */
+        EXIT_CHDIR = 200,
+        EXIT_NICE,
+        EXIT_FDS,
+        EXIT_EXEC,
+        EXIT_MEMORY,
+        EXIT_LIMITS,
+        EXIT_OOM_ADJUST,
+        EXIT_SIGNAL_MASK,
+        EXIT_STDIN,
+        EXIT_STDOUT,
+        EXIT_CHROOT,   /* 210 */
+        EXIT_IOPRIO,
+        EXIT_TIMERSLACK,
+        EXIT_SECUREBITS,
+        EXIT_SETSCHEDULER,
+        EXIT_CPUAFFINITY,
+        EXIT_GROUP,
+        EXIT_USER,
+        EXIT_CAPABILITIES,
+        EXIT_CGROUP,
+        EXIT_SETSID,   /* 220 */
+        EXIT_CONFIRM,
+        EXIT_STDERR,
+        _EXIT_RESERVED, /* used to be tcpwrap, don't reuse! */
+        EXIT_PAM,
+        EXIT_NETWORK,
+        EXIT_NAMESPACE,
+        EXIT_NO_NEW_PRIVILEGES,
+        EXIT_SECCOMP,
+        EXIT_SELINUX_CONTEXT,
+        EXIT_PERSONALITY,  /* 230 */
+        EXIT_APPARMOR_PROFILE,
+        EXIT_ADDRESS_FAMILIES,
+        EXIT_RUNTIME_DIRECTORY,
+        _EXIT_RESERVED2, /* used to be used by kdbus, don't reuse */
+        EXIT_CHOWN,
+        EXIT_SMACK_PROCESS_LABEL,
+        EXIT_KEYRING,
+        EXIT_STATE_DIRECTORY,
+        EXIT_CACHE_DIRECTORY,
+        EXIT_LOGS_DIRECTORY, /* 240 */
+        EXIT_CONFIGURATION_DIRECTORY,
+};
+
+typedef enum ExitStatusLevel {
+        EXIT_STATUS_MINIMAL,   /* only cover libc EXIT_STATUS/EXIT_FAILURE */
+        EXIT_STATUS_SYSTEMD,   /* cover libc and systemd's own exit codes */
+        EXIT_STATUS_LSB,       /* cover libc, systemd's own and LSB exit codes */
+        EXIT_STATUS_FULL,      /* cover libc, systemd's own, LSB and BSD (EX_xyz) exit codes */
+} ExitStatusLevel;
+
+typedef struct ExitStatusSet {
+        Set *status;
+        Set *signal;
+} ExitStatusSet;
+
+const char* exit_status_to_string(int status, ExitStatusLevel level) _const_;
+
+typedef enum ExitClean {
+        EXIT_CLEAN_DAEMON,
+        EXIT_CLEAN_COMMAND,
+} ExitClean;
+
+bool is_clean_exit(int code, int status, ExitClean clean, ExitStatusSet *success_status);
+
+void exit_status_set_free(ExitStatusSet *x);
+bool exit_status_set_is_empty(ExitStatusSet *x);
+bool exit_status_set_test(ExitStatusSet *x, int code, int status);