upstream: import some hacked systemd headers

This brings journal-file data structures and byte swapping
helpers I may as well just reuse.

I've had to do some minor messing about to make things workable in
isolation out of the systemd tree without pulling in too much.

I've also added a new HashedObjectHeader type to encompass the
slightly larger common header components of FieldObject and
DataObject to facilitate a generic hash table iterator that can
operate on just loading HashedObjectHeader when nothing more
than the object size is needed for accounting.  Basically the
HashedObjectHeader is ObjectHeader+hash+next_hash_offset.

1 files changed, 102 insertions, 0 deletions

diff --git a/src/upstream/_sd-common.h b/src/upstream/_sd-common.h
new file mode 100644
index 0000000..1055b00
--- /dev/null
+++ b/src/upstream/_sd-common.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#ifndef foosdcommonhfoo
+#define foosdcommonhfoo
+
+/***
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+/* This is a private header; never even think of including this directly! */
+
+#if defined(__INCLUDE_LEVEL__) && __INCLUDE_LEVEL__ <= 1 && !defined(__COVERITY__)
+#  error "Do not include _sd-common.h directly; it is a private header."
+#endif
+
+typedef void (*_sd_destroy_t)(void *userdata);
+
+#ifndef _sd_printf_
+#  if __GNUC__ >= 4
+#    define _sd_printf_(a,b) __attribute__((__format__(printf, a, b)))
+#  else
+#    define _sd_printf_(a,b)
+#  endif
+#endif
+
+#ifndef _sd_sentinel_
+#  define _sd_sentinel_ __attribute__((__sentinel__))
+#endif
+
+#ifndef _sd_packed_
+#  define _sd_packed_ __attribute__((__packed__))
+#endif
+
+#ifndef _sd_pure_
+#  define _sd_pure_ __attribute__((__pure__))
+#endif
+
+/* Note that strictly speaking __deprecated__ has been available before GCC 6. However, starting with GCC 6
+ * it also works on enum values, which we are interested in. Since this is a developer-facing feature anyway
+ * (as opposed to build engineer-facing), let's hence conditionalize this to gcc 6, given that the developers
+ * are probably going to use something newer anyway. */
+#ifndef _sd_deprecated_
+#  if __GNUC__ >= 6
+#    define _sd_deprecated_ __attribute__((__deprecated__))
+#  else
+#    define _sd_deprecated_
+#  endif
+#endif
+
+#ifndef _SD_STRINGIFY
+#  define _SD_XSTRINGIFY(x) #x
+#  define _SD_STRINGIFY(x) _SD_XSTRINGIFY(x)
+#endif
+
+#ifndef _SD_BEGIN_DECLARATIONS
+#  ifdef __cplusplus
+#    define _SD_BEGIN_DECLARATIONS                              \
+        extern "C" {                                            \
+        struct _sd_useless_struct_to_allow_trailing_semicolon_
+#  else
+#    define _SD_BEGIN_DECLARATIONS                              \
+        struct _sd_useless_struct_to_allow_trailing_semicolon_
+#  endif
+#endif
+
+#ifndef _SD_END_DECLARATIONS
+#  ifdef __cplusplus
+#    define _SD_END_DECLARATIONS                                \
+        }                                                       \
+        struct _sd_useless_cpp_struct_to_allow_trailing_semicolon_
+#  else
+#    define _SD_END_DECLARATIONS                                \
+        struct _sd_useless_struct_to_allow_trailing_semicolon_
+#  endif
+#endif
+
+#ifndef _SD_ARRAY_STATIC
+#  if __STDC_VERSION__ >= 199901L
+#    define _SD_ARRAY_STATIC static
+#  else
+#    define _SD_ARRAY_STATIC
+#  endif
+#endif
+
+#define _SD_DEFINE_POINTER_CLEANUP_FUNC(type, func)             \
+        static __inline__ void func##p(type **p) {              \
+                if (*p)                                         \
+                        func(*p);                               \
+        }                                                       \
+        struct _sd_useless_struct_to_allow_trailing_semicolon_
+
+#endif