basic: Remove circular dependency between process-util.h and pidref.h

src/basic/capability-util.c

@@ -20,6 +20,7 @@
 #include "macro.h"
 #include "parse-util.h"
 #include "pidref.h"
+#include "process-util.h"
 #include "stat-util.h"
 #include "user-util.h"
 

src/basic/pidref.h

@@ -1,10 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-typedef struct PidRef PidRef;
-
 #include "macro.h"
-#include "process-util.h"
+#include "memory-util.h"
 
 /* An embeddable structure carrying a reference to a process. Supposed to be used when tracking processes
  * continuously. This combines a PID, a modern Linux pidfd and the 64bit inode number of the pidfd into one
@@ -29,22 +27,22 @@ typedef struct PidRef PidRef;
  *    process. Moreover, most operations will fail with -EREMOTE. Only PidRef structures that are not marked
  *    *unset* can be marked *remote*.
  */
-struct PidRef {
-        pid_t pid;      /* > 0 if the PidRef is set, otherwise set to PID_AUTOMATIC if automatic mode is
-                         * desired, or 0 otherwise. */
+typedef struct PidRef {
+        pid_t pid;      /* > 0 if the PidRef is set, otherwise set to INT_MIN (PID_AUTOMATIC) if automatic
+                         * mode is desired, or 0 otherwise. */
         int fd;         /* only valid if pidfd are available in the kernel, and we manage to get an fd. If we
                          * know that the PID is not from the local machine we set this to -EREMOTE, otherwise
                          * we use -EBADF as indicator the fd is invalid. */
         uint64_t fd_id; /* the inode number of pidfd. only useful in kernel 6.9+ where pidfds live in
                            their own pidfs and each process comes with a unique inode number */
-};
+} PidRef;
 
 #define PIDREF_NULL (PidRef) { .fd = -EBADF }
 
 /* A special pidref value that we are using when a PID shall be automatically acquired from some surrounding
  * context, for example connection peer. Much like PIDREF_NULL it will be considered unset by
  * pidref_is_set(). */
-#define PIDREF_AUTOMATIC (const PidRef) { .pid = PID_AUTOMATIC, .fd = -EBADF }
+#define PIDREF_AUTOMATIC (const PidRef) { .pid = (pid_t) INT_MIN, .fd = -EBADF }
 
 /* Turns a pid_t into a PidRef structure on-the-fly *without* acquiring a pidfd for it. (As opposed to
  * pidref_set_pid() which does so *with* acquiring one, see below) */