From ae6d3bfc4e3ac9e74d562689c11c22a87c07c0af Mon Sep 17 00:00:00 2001
From: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Date: Sat, 20 Dec 2025 14:04:35 +0100
Subject: [PATCH] Implement BSD specific sys_ExecutablePathname

This is more reliable than argv[0] which is effectively used via
unix_ExecutablePathname. Also drop the fallback as it effectively is the
same as the generic fallback and blocks making cxxtest optional.

On FreeBSD the procfs is not mounted by default, so use a syscall
instead.

Refs: #8618
Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
---
 source/lib/sysdep/os/bsd/bsd.cpp | 32 +++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/source/lib/sysdep/os/bsd/bsd.cpp b/source/lib/sysdep/os/bsd/bsd.cpp
index 5f8db1886f..3ffec55c38 100644
--- a/source/lib/sysdep/os/bsd/bsd.cpp
+++ b/source/lib/sysdep/os/bsd/bsd.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2014 Wildfire Games.
+/* Copyright (C) 2026 Wildfire Games.
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -23,9 +23,35 @@
 #include "precompiled.h"
 
 #include "lib/sysdep/sysdep.h"
-#include "lib/sysdep/os/unix/unix_executable_pathname.h"
 
+#include <climits>
+
+#if defined(__FreeBSD__)
+#include <sys/param.h>
+#include <sys/sysctl.h>
+#else
+#include <stdlib.h>
+#endif
+
+/**
+ * Get the path to the executable
+ *
+ * In FreeBSD the procfs isn't available by default so use a system call instead.
+ */
 OsPath sys_ExecutablePathname()
 {
-	return unix_ExecutablePathname();
+	char pathBuffer[PATH_MAX];
+
+#if defined(__FreeBSD__)
+	int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
+	size_t length = sizeof(pathBuffer);
+	int error = sysctl(mib, 4, pathBuffer, &length, nullptr, 0);
+	if (error < 0 || length <= 1)
+		return {};
+#else
+	if (realpath("/proc/curproc/file", pathBuffer) == nullptr)
+		return {};
+#endif
+
+	return pathBuffer;
 }