From a80493d221eea6393fc919008d752063fa02b7a3 Mon Sep 17 00:00:00 2001
From: Andrew Kaster <akaster@serenityos.org>
Date: Sun, 26 Jun 2022 19:11:09 -0600
Subject: [PATCH] LibC: Align _ctype_ to newlib's implementation

newlib has an extra character slot at the beginning to enable some
macro tricks that cause a warning when someone passes a type that's not
"int" into a ctype function. Our deviation from this causes issues for
LLVM.
---
 Userland/Libraries/LibC/ctype.cpp |  3 ++-
 Userland/Libraries/LibC/ctype.h   | 35 +++++++++++++++++++------------
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/Userland/Libraries/LibC/ctype.cpp b/Userland/Libraries/LibC/ctype.cpp
index 81a69a8bce0b43..c866ed6aaf93f5 100644
--- a/Userland/Libraries/LibC/ctype.cpp
+++ b/Userland/Libraries/LibC/ctype.cpp
@@ -8,7 +8,8 @@
 
 extern "C" {
 
-char const _ctype_[256] = {
+char const _ctype_[1 + 256] = {
+    0,
     _C, _C, _C, _C, _C, _C, _C, _C,
     _C, _C | _S, _C | _S, _C | _S, _C | _S, _C | _S, _C, _C,
     _C, _C, _C, _C, _C, _C, _C, _C,
diff --git a/Userland/Libraries/LibC/ctype.h b/Userland/Libraries/LibC/ctype.h
index 62bbbbb866a967..1947f3416b9c58 100644
--- a/Userland/Libraries/LibC/ctype.h
+++ b/Userland/Libraries/LibC/ctype.h
@@ -10,6 +10,10 @@
 
 __BEGIN_DECLS
 
+#ifndef EOF
+#    define EOF (-1)
+#endif
+
 /* Do what newlib does to appease GCC's --with-newlib option. */
 #define _U 01
 #define _L 02
@@ -20,16 +24,21 @@ __BEGIN_DECLS
 #define _X 0100
 #define _B 0200
 
-extern char const _ctype_[256] __attribute__((visibility("default")));
+/**
+ * newlib has a 257 byte _ctype_ array to enable compiler tricks to catch
+ * people passing char instead of int. We don't engage in those tricks,
+ * but still claim to be newlib to the toolchains
+ */
+extern char const _ctype_[1 + 256] __attribute__((visibility("default")));
 
 static inline int __inline_isalnum(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_U | _L | _N);
+    return _ctype_[(unsigned char)(c) + 1] & (_U | _L | _N);
 }
 
 static inline int __inline_isalpha(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_U | _L);
+    return _ctype_[(unsigned char)(c) + 1] & (_U | _L);
 }
 
 static inline int __inline_isascii(int c)
@@ -39,52 +48,52 @@ static inline int __inline_isascii(int c)
 
 static inline int __inline_iscntrl(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_C);
+    return _ctype_[(unsigned char)(c) + 1] & (_C);
 }
 
 static inline int __inline_isdigit(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_N);
+    return _ctype_[(unsigned char)(c) + 1] & (_N);
 }
 
 static inline int __inline_isxdigit(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_N | _X);
+    return _ctype_[(unsigned char)(c) + 1] & (_N | _X);
 }
 
 static inline int __inline_isspace(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_S);
+    return _ctype_[(unsigned char)(c) + 1] & (_S);
 }
 
 static inline int __inline_ispunct(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_P);
+    return _ctype_[(unsigned char)(c) + 1] & (_P);
 }
 
 static inline int __inline_isprint(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_P | _U | _L | _N | _B);
+    return _ctype_[(unsigned char)(c) + 1] & (_P | _U | _L | _N | _B);
 }
 
 static inline int __inline_isgraph(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_P | _U | _L | _N);
+    return _ctype_[(unsigned char)(c) + 1] & (_P | _U | _L | _N);
 }
 
 static inline int __inline_islower(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_L);
+    return _ctype_[(unsigned char)(c) + 1] & (_L);
 }
 
 static inline int __inline_isupper(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_U);
+    return _ctype_[(unsigned char)(c) + 1] & (_U);
 }
 
 static inline int __inline_isblank(int c)
 {
-    return _ctype_[(unsigned char)(c)] & (_B) || (c == '\t');
+    return _ctype_[(unsigned char)(c) + 1] & (_B) || (c == '\t');
 }
 
 static inline int __inline_toascii(int c)