From 5ec65ab5d082616716c94ebff94636daf1f789ac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Wed, 20 Sep 2023 17:23:28 +0200
Subject: [PATCH] Add semantic patch to explicitly cast chars to unsigned for
 ctype.h

Add a semantic patch to catch all the places where we pass 'char' to the
<ctype.h> family of functions (isalpha() and friends, toupper(),
tolower()).  While it generally works because the way how these
functions are constructed in the libc, it's safer to do the explicit
cast.
---
 cocci/ctype.spatch | 105 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 cocci/ctype.spatch

diff --git a/cocci/ctype.spatch b/cocci/ctype.spatch
new file mode 100644
index 0000000000..2b392cb310
--- /dev/null
+++ b/cocci/ctype.spatch
@@ -0,0 +1,105 @@
+@@
+char T;
+@@
+
+- isalnum(T)
++ isalnum((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isalpha(T)
++ isalpha((unsigned char)T)
+
+@@
+char T;
+@@
+
+- iscntrl(T)
++ iscntrl((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isdigit(T)
++ isdigit((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isgraph(T)
++ isgraph((unsigned char)T)
+
+@@
+char T;
+@@
+
+- islower(T)
++ islower((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isprint(T)
++ isprint((unsigned char)T)
+
+@@
+char T;
+@@
+
+- ispunct(T)
++ ispunct((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isspace(T)
++ isspace((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isupper(T)
++ isupper((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isxdigit(T)
++ isxdigit((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isascii(T)
++ isascii((unsigned char)T)
+
+@@
+char T;
+@@
+
+- isblank(T)
++ isblank((unsigned char)T)
+
+@@
+char T;
+@@
+
+- tolower(T)
++ tolower((unsigned char)T)
+
+@@
+char T;
+@@
+
+- toupper(T)
++ toupper((unsigned char)T)
+