Various changes made as part of trying to run include-what-you-use on the systemd repository (systemd#37112)

I have been trying to run
https://github.com/include-what-you-use/include-what-you-use on the
systemd repository to hopefully get a handle on the rampant numbers of
includes we have in every file with no idea if any of the symbols coming
from that file are used or not.

While I haven't got it fully working yet, these changes still make sense
IMO and can be merged already.

Except the last commit, all other changes are about removing circular
dependencies between headers which trips up include-what-you-use.
Regardless of the tool, circular dependencies between headers are a code
smell and I think we should get rid of them regardless of whether we end
up using the tool or not.

Author: DaanDeMeyer

LICENSES/README.md

@@ -32,23 +32,23 @@ The following exceptions apply:
  * some sources under src/udev/ are licensed under **GPL-2.0-or-later**,
    so all udev programs (`systemd-udevd`, `udevadm`, and the udev builtins
    and test programs) are also distributed under **GPL-2.0-or-later**.
- * the header files contained in src/basic/linux/ and src/shared/linux/ are copied
+ * the header files contained in src/basic/include/linux are copied
    verbatim from the Linux kernel source tree and are licensed under **GPL-2.0 WITH
    Linux-syscall-note** and are used within the scope of the Linux-syscall-note
    exception provisions
  * the following sources are licensed under the **LGPL-2.0-or-later** license:
    - src/basic/utf8.c
    - src/shared/initreq.h
- * the src/shared/linux/bpf_insn.h header is copied from the Linux kernel
+ * the src/basic/include/linux/bpf_insn.h header is copied from the Linux kernel
    source tree and is licensed under either **BSD-2-Clause** or **GPL-2.0-only**,
    and thus is included in the systemd build under the BSD-2-Clause license.
- * The src/basic/linux/wireguard.h header is copied from the Linux kernel
+ * The src/basic/include/linux/wireguard.h header is copied from the Linux kernel
    source tree and is licensed under either **MIT** or **GPL-2.0 WITH Linux-syscall-note**,
    and thus is included in the systemd build under the MIT license.
  * the following sources are licensed under the **MIT** license (in case of our
    scripts, to facilitate copying and reuse of those helpers to other projects):
    - hwdb.d/parse_hwdb.py
-   - src/basic/linux/batman_adv.h
+   - src/basic/include/linux/batman_adv.h
    - src/basic/sparse-endian.h
    - tools/catalog-report.py
  * the following sources are licensed under the **CC0-1.0** license:

coccinelle/run-coccinelle.sh

@@ -5,8 +5,7 @@ set -e
 # Exclude following paths from the Coccinelle transformations
 EXCLUDED_PATHS=(
     "src/boot/efi/*"
-    "src/shared/linux/*"
-    "src/basic/linux/*"
+    "src/basic/include/linux/*"
     # Symlinked to test-bus-vtable-cc.cc, which causes issues with the IN_SET macro
     "src/libsystemd/sd-bus/test-bus-vtable.c"
     "src/libsystemd/sd-journal/lookup3.c"

meson.build

@@ -2053,11 +2053,18 @@ boot_stubs = []
 
 build_dir_include = include_directories('.')
 
-basic_includes = include_directories(
-        'src/basic',
-        'src/fundamental',
-        'src/systemd',
-        '.')
+basic_includes = [
+        include_directories(
+                'src/basic',
+                'src/fundamental',
+                'src/systemd',
+                '.',
+        ),
+        include_directories(
+                'src/basic/include',
+                is_system : true,
+        ),
+]
 
 libsystemd_includes = [basic_includes, include_directories(
         'src/libsystemd/sd-bus',

src/ac-power/ac-power.c

@@ -5,6 +5,7 @@
 #include "ansi-color.h"
 #include "battery-util.h"
 #include "build.h"
+#include "log.h"
 #include "main-func.h"
 #include "pretty-print.h"
 

src/analyze/analyze-compare-versions.c

@@ -4,6 +4,7 @@
 
 #include "analyze-compare-versions.h"
 #include "compare-operator.h"
+#include "log.h"
 #include "macro.h"
 #include "string-util.h"
 #include "strv.h"

src/analyze/analyze-time-data.h

@@ -3,6 +3,7 @@
 
 #include "sd-bus.h"
 
+#include "memory-util.h"
 #include "time-util.h"
 #include "unit-def.h"
 

src/basic/alloc-util.c

@@ -6,7 +6,6 @@
 
 #include "alloc-util.h"
 #include "macro.h"
-#include "memory-util.h"
 
 void* memdup(const void *p, size_t l) {
         void *ret;

src/basic/alloc-util.h

@@ -7,7 +7,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "assert-util.h"
 #include "macro.h"
+#include "memory-util.h"
 
 #if HAS_FEATURE_MEMORY_SANITIZER
 #  include <sanitizer/msan_interface.h>
@@ -266,5 +268,3 @@ _alloc_(2) static inline void *realloc0(void *p, size_t new_size) {
 
         return q;
 }
-
-#include "memory-util.h"

src/basic/argv-util.c

@@ -8,6 +8,7 @@
 #include "argv-util.h"
 #include "capability-util.h"
 #include "errno-util.h"
+#include "log.h"
 #include "missing_sched.h"
 #include "parse-util.h"
 #include "path-util.h"

src/basic/argv-util.h

@@ -3,6 +3,7 @@
 
 #include <stdbool.h>
 
+#include "assert-util.h"
 #include "macro.h"
 
 extern int saved_argc;