Correct build for C23
Wrong type for size variable, missing parameters in decls
Missing include and wrong types in bundled libusb library
https://bugs.gentoo.org/944433
https://bugs.gentoo.org/883101
--- a/src/parsedate.c
+++ b/src/parsedate.c
@@ -175,8 +175,8 @@
 static time_t	yyRelSeconds;
 
 
-extern struct tm	*localtime();
-static void		date_error();
+extern struct tm	*localtime(const time_t *timep);
+static void		date_error(char *s);
 
 
 /* Enabling traces.  */
--- a/src/parsedate.y
+++ b/src/parsedate.y
@@ -94,8 +94,8 @@
 static time_t	yyRelSeconds;
 
 
-extern struct tm	*localtime();
-static void		date_error();
+extern struct tm	*localtime(const time_t *timep);
+static void		date_error(char *s);
 %}
 
 %union {
--- a/src/pilot-read-todos.c
+++ b/src/pilot-read-todos.c
@@ -202,8 +202,8 @@
 
 	for (i = 0;; i++) {
 		int 	attr,
-			category,
-			len;
+			category;
+		ssize_t	len;
 
 		struct 	ToDo todo;
 
--- a/libpisock/linuxusb.c
+++ b/libpisock/linuxusb.c
@@ -27,6 +27,7 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/socket.h>
 
 #include "pi-debug.h"
 #include "pi-source.h"
@@ -48,8 +49,8 @@
 
 static int u_open(pi_socket_t *ps, struct pi_sockaddr *addr, size_t addrlen);
 static int u_close(pi_socket_t *ps);
-static int u_write(pi_socket_t *ps, unsigned char *buf, size_t len, int flags);
-static int u_read(pi_socket_t *ps, pi_buffer_t *buf, size_t len, int flags);
+static ssize_t u_write(pi_socket_t *ps, const unsigned char *buf, size_t len, int flags);
+static ssize_t u_read(pi_socket_t *ps, pi_buffer_t *buf, size_t len, int flags);
 static int u_poll(pi_socket_t *ps, int timeout);
 static int u_flush(pi_socket_t *ps, int flags);
 
@@ -188,8 +189,8 @@
  * Returns:     Nothing
  *
  ***********************************************************************/
-static int
-u_write(pi_socket_t *ps, unsigned char *buf, size_t len, int flags)
+static ssize_t
+u_write(pi_socket_t *ps, const unsigned char *buf, size_t len, int flags)
 {
 	int 	total,
 		nwrote;
@@ -281,7 +282,7 @@
  * Returns:     number of bytes read or negative otherwise
  *
  ***********************************************************************/
-static int
+static ssize_t
 u_read(pi_socket_t *ps, pi_buffer_t *buf, size_t len, int flags)
 {
 	ssize_t rbuf = 0,