From dfbfecb6baa8190297c0081296ff07949b56815b Mon Sep 17 00:00:00 2001
From: Brad Smith <brad@comstyle.com>
Date: Thu, 24 Sep 2026 14:03:29 -0400
Subject: [PATCH] OpenBSD: use `getexecpath()` (#3379)

Apparently it's more kosher than looking at `/proc`.
---
 CMakeLists.txt               |  6 ++++++
 rts/System/Platform/Misc.cpp | 11 +++++++++++
 2 files changed, 17 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 49e7b0acd8f..da60d1095f1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -344,6 +344,12 @@ if (NOT HAVE_STRNLEN)
 	message(FATAL_ERROR "this compiler/environment isn't supported, the function strnlen is missing!")
 endif()
 
+include (CheckFunctionExists)
+check_symbol_exists(getexecpath unistd.h HAVE_GETEXECPATH)
+if (HAVE_GETEXECPATH)
+	add_definitions(-DHAVE_GETEXECPATH)
+endif()
+
 ### Add Link-Time-Optimization flags, if supported (GCC >= 4.5) and enabled
 option(LTO "Link Time Optimizations (LTO)" FALSE)
 if    (LTO)
diff --git a/rts/System/Platform/Misc.cpp b/rts/System/Platform/Misc.cpp
index e78c15dd399..ab3eb32d63e 100644
--- a/rts/System/Platform/Misc.cpp
+++ b/rts/System/Platform/Misc.cpp
@@ -168,6 +168,7 @@ namespace Platform
 	// Mac OS X:        _NSGetExecutablePath() (man 3 dyld)
 	// Linux:           readlink /proc/self/exe
 	// Solaris:         getexecname()
+	// OpenBSD:         getexecpath()
 	// FreeBSD:         sysctl CTL_KERN KERN_PROC KERN_PROC_PATHNAME -1
 	// BSD with procfs: readlink /proc/curproc/file
 	// Windows:         GetModuleFileName() with hModule = NULL
@@ -212,6 +213,16 @@ namespace Platform
 			procExeFilePath = path;
 
 
+		#elif defined(__OpenBSD__) && defined(HAVE_GETEXECPATH)
+		char path[PATH_MAX];
+
+		if (getexecpath(path, sizeof(path)) == 0) {
+			procExeFilePath = path;
+		} else {
+			error = "[openbsd] execve(2) could not determine the executable pathname";
+		}
+
+
 		#elif defined(__FreeBSD__)
 		const int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
 		const long maxpath = pathconf("/", _PC_PATH_MAX);