From 637c4d5d302d7405fc7e85bce4cacdd4bb19edf8 Mon Sep 17 00:00:00 2001
From: Emil Williams <emilemilemil@cock.li>
Date: Sat, 20 Jul 2024 17:17:05 +0000
Subject: [PATCH] Define At Beginning Header Guard

---
 .gitignore                       |  6 ++++++
 chad.tex                         |  8 +++++---
 reasoning/header-guard/README.md |  8 ++++++++
 reasoning/header-guard/a.h       | 10 ++++++++++
 reasoning/header-guard/ac.h      | 10 ++++++++++
 reasoning/header-guard/b.h       | 10 ++++++++++
 reasoning/header-guard/bc.h      | 10 ++++++++++
 reasoning/header-guard/main.c    | 19 +++++++++++++++++++
 8 files changed, 78 insertions(+), 3 deletions(-)
 create mode 100644 .gitignore
 create mode 100644 reasoning/header-guard/README.md
 create mode 100644 reasoning/header-guard/a.h
 create mode 100644 reasoning/header-guard/ac.h
 create mode 100644 reasoning/header-guard/b.h
 create mode 100644 reasoning/header-guard/bc.h
 create mode 100644 reasoning/header-guard/main.c

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..f126ada
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,6 @@
+auto
+chad.pdf
+chad.log
+chad.aux
+*.out
+*.o
diff --git a/chad.tex b/chad.tex
index 3112654..c655fda 100644
--- a/chad.tex
+++ b/chad.tex
@@ -82,16 +82,18 @@ type a = {
 Do not use relative pathing in headers, instead use compiler flags
 or full paths to enable your compilation.
 
-\bitem{Define At End Header Guard} \\
+\bitem{Define At Beginning Header Guard} \\
 Use this kind of header guard:
 
 \begin{verbatim}
 #if HEADER_H
-...
 #define HEADER_H
-#endif
+...
+#endif // HEADER_H
 \end{verbatim}
 
+\bitem{No Double Blank Line} Shortens code and removes blank redundancy, use Single Blank Lines as much you want.
+
 \bitem{Namespacing For Externally Exposed Headers \& Variables}
 Add a namespace suffix for headers \& variables meant to be used
 outside your project.
diff --git a/reasoning/header-guard/README.md b/reasoning/header-guard/README.md
new file mode 100644
index 0000000..909ea03
--- /dev/null
+++ b/reasoning/header-guard/README.md
@@ -0,0 +1,8 @@
+## Justification for Define At End Header Guard -> Define At Beginning Header Guard.
+
+Define At End Header Guard is a very pretty style for Header Guards, however is nonviable due to:
+
+Define At End Header Guard fail to properly handle circular dependence as the define comes after the dependency,
+hence using Define At Beginning Header Guard is always preferable.
+
+This was brought to light by an long-term Anonymous contributor, and is responsible for this change and justification.
diff --git a/reasoning/header-guard/a.h b/reasoning/header-guard/a.h
new file mode 100644
index 0000000..179fd6c
--- /dev/null
+++ b/reasoning/header-guard/a.h
@@ -0,0 +1,10 @@
+#ifndef A_H
+
+#include "b.h"
+
+struct a {
+	int i;
+};
+
+#define A_H
+#endif
diff --git a/reasoning/header-guard/ac.h b/reasoning/header-guard/ac.h
new file mode 100644
index 0000000..304fdda
--- /dev/null
+++ b/reasoning/header-guard/ac.h
@@ -0,0 +1,10 @@
+#ifndef A_H
+#define A_H
+
+#include "bc.h"
+
+struct a {
+	int i;
+};
+
+#endif
diff --git a/reasoning/header-guard/b.h b/reasoning/header-guard/b.h
new file mode 100644
index 0000000..8c75f68
--- /dev/null
+++ b/reasoning/header-guard/b.h
@@ -0,0 +1,10 @@
+#ifndef B_H
+
+#include "a.h"
+
+struct b {
+	int i;
+};
+
+#define B_H
+#endif
diff --git a/reasoning/header-guard/bc.h b/reasoning/header-guard/bc.h
new file mode 100644
index 0000000..a1b2e23
--- /dev/null
+++ b/reasoning/header-guard/bc.h
@@ -0,0 +1,10 @@
+#ifndef B_H
+#define B_H
+
+#include "ac.h"
+
+struct b {
+	int i;
+};
+
+#endif
diff --git a/reasoning/header-guard/main.c b/reasoning/header-guard/main.c
new file mode 100644
index 0000000..d468a94
--- /dev/null
+++ b/reasoning/header-guard/main.c
@@ -0,0 +1,19 @@
+// @BAKE gcc $@ -o $*.out $+
+
+#ifndef CIRCULAR
+# define CIRCULAR 0
+#endif
+
+#if CIRCULAR
+// Define At End Header Guard
+# include "a.h"
+# include "b.h"
+#else
+// Define At Beginning Header Guard
+# include "ac.h"
+# include "bc.h"
+#endif
+
+signed main () {
+	return(0);
+}