https://github.com/eserte/perl-tk/pull/79
https://github.com/eserte/perl-tk/pull/80

From f7565b07f40e0cc3820e8fb0c3d2e7b5abb5eeeb Mon Sep 17 00:00:00 2001
From: Christopher Chavez <chrischavez@gmx.us>
Date: Fri, 12 Mar 2021 07:24:18 -0600
Subject: [PATCH] Fix some implicit function declarations

Hstrdup.c: missing stdlib.h for exit()
Hstrtoul.c: missing string.h for strcmp()
--- a/pTk/config/Hstrdup.c
+++ b/pTk/config/Hstrdup.c
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <string.h>
 
 #define STRING "Whatever"
--- a/pTk/config/Hstrtoul.c
+++ b/pTk/config/Hstrtoul.c
@@ -1,4 +1,5 @@
 #include <stdlib.h>
+#include <string.h>
 
 int main()
 {char *e;

From 47219864d6ef3fe0c5616cada78e3008447a96a1 Mon Sep 17 00:00:00 2001
From: Christopher Chavez <chrischavez@gmx.us>
Date: Fri, 12 Mar 2021 07:28:22 -0600
Subject: [PATCH] signedchar.c: use int main to avoid C99 warning

--- a/config/signedchar.c
+++ b/config/signedchar.c
@@ -1,4 +1,4 @@
-main()
+int main()
 {
  signed char x = 'a';
  return (x - 'a');