cleanup: fix warnings

fnv1a.c

@@ -1,6 +1,8 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+#include "fnv1a.h"
+
 static const uint32_t fnv1a32_prime = 16777619;
 static const uint32_t fnv1a32_offset = 2166136261U;
 

limit_process.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2019, Michael Santos <michael.santos@gmail.com>
+/* Copyright (c) 2019-2021, Michael Santos <michael.santos@gmail.com>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -16,6 +16,8 @@
 #include <sys/resource.h>
 #include <time.h>
 
+#include "limit_process.h"
+
 int limit_process(runcron_t *rp) {
   struct rlimit rl = {0};
 

runcron.c

@@ -22,6 +22,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdnoreturn.h>
 #include <string.h>
 #include <sys/file.h>
 #include <sys/param.h>
@@ -65,7 +66,7 @@ static int set_env(char *key, int val);
 static void print_argv(int argc, char *argv[]);
 static int randinit(char *tag);
 static char *join(char **arg, size_t n);
-static void usage(void);
+static noreturn void usage(void);
 
 static const struct option long_options[] = {
     {"file", required_argument, NULL, 'f'},
@@ -88,11 +89,11 @@ static const struct option long_options[] = {
     {NULL, 0, NULL, 0},
 };
 
-pid_t pid;
+static pid_t pid;
 static int fdp = -1;
-int default_signal = SIGTERM;
-volatile sig_atomic_t runnow = 0;
-volatile sig_atomic_t remaining = 0;
+static int default_signal = SIGTERM;
+static volatile sig_atomic_t runnow = 0;
+static volatile sig_atomic_t remaining = 0;
 
 int main(int argc, char *argv[]) {
   runcron_t *rp;
@@ -606,7 +607,7 @@ static char *join(char **arg, size_t n) {
   return NULL;
 }
 
-static void usage() {
+static noreturn void usage() {
   errx(EXIT_FAILURE,
        "[OPTION] <CRONTAB EXPRESSION> <command> <arg> <...>\n"
        "version: %s (using %s mode process restriction)\n\n"

strtonum.c

@@ -24,6 +24,8 @@
 #include <limits.h>
 #include <stdlib.h>
 
+#include "strtonum.h"
+
 #define INVALID 1
 #define TOOSMALL 2
 #define TOOLARGE 3