From 236556ba05cffa042c58f11d3d6a75e2954231f4 Mon Sep 17 00:00:00 2001
From: Mahmoud Al-Qudsi <mqudsi@neosmart.net>
Date: Tue, 9 Oct 2018 19:47:49 -0500
Subject: [PATCH] Update `get_executable_path()` for FreeBSD
Remove dependency on the Linux compatibility layer's procfs being
installed and mounted when running under FreeBSD by directly querying
the MIB for the path to the running fish executable
(KERN_PROC_PATHNAME). Tested under FreeBSD 11.2-RELEASE.
---
src/fish.cpp | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/src/fish.cpp b/src/fish.cpp
index 0ca626425..bed624932 100644
--- a/src/fish.cpp
+++ b/src/fish.cpp
@@ -54,6 +54,10 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
#include "signal.h"
#include "wutil.h" // IWYU pragma: keep
+#ifdef __FreeBSD__
+#include <sys/sysctl.h>
+#endif
+
// PATH_MAX may not exist.
#ifndef PATH_MAX
#define PATH_MAX 4096
@@ -104,12 +108,25 @@ static std::string get_executable_path(const char *argv0) {
// https://opensource.apple.com/source/adv_cmds/adv_cmds-163/ps/print.c
uint32_t buffSize = sizeof buff;
if (_NSGetExecutablePath(buff, &buffSize) == 0) return std::string(buff);
+#elif __FreeBSD__
+ // FreeBSD does not have /proc by default, but it can be mounted as procfs via the
+ // Linux compatibility layer. Per sysctl(3), passing in a process ID of -1 returns
+ // the value for the current process.
+ size_t buff_size = sizeof buff;
+ int name[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
+ int result = sysctl(name, sizeof(name) / sizeof(int), buff, &buff_size, nullptr, 0);
+ if (result != 0) {
+ wperror(L"sysctl KERN_PROC_PATHNAME");
+ }
+ else {
+ return std::string(buff);
+ }
#else
- // On non-OS X UNIXes, try /proc directory.
+ // On other unixes, fall back to the Linux-ish /proc/ directory
ssize_t len;
len = readlink("/proc/self/exe", buff, sizeof buff - 1); // Linux
if (len == -1) {
- len = readlink("/proc/curproc/file", buff, sizeof buff - 1); // BSD
+ len = readlink("/proc/curproc/file", buff, sizeof buff - 1); // other BSDs
if (len == -1) {
len = readlink("/proc/self/path/a.out", buff, sizeof buff - 1); // Solaris
}