From 2a94d6e33faa8fe9b5de4bab7cc0523092c2cafa Mon Sep 17 00:00:00 2001
From: KWSys Upstream <kwrobot@kitware.com>
Date: Thu, 5 Nov 2026 09:26:48 -0500
Subject: [PATCH] KWSys 2026-11-05 (3f6dbdae)

Code extracted from:

    https://gitlab.kitware.com/utils/kwsys.git

at commit 3f6dbdae567f1cfb6a459359825677d106db6362 (master).

Upstream Shortlog
-----------------

Aymeric Wibo (2):
      10b37500 SystemInformation: Fix reading hw.physmem on FreeBSD & DragonFly
      642ccce9 SystemInformation: Implement getting available memory on FreeBSD
---
 SystemInformation.cxx | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/SystemInformation.cxx b/SystemInformation.cxx
index 43c45f72b5..467450658f 100644
--- a/SystemInformation.cxx
+++ b/SystemInformation.cxx
@@ -5395,6 +5395,8 @@ bool SystemInformationImplementation::QueryBSDMemory()
 #  if defined(HW_PHYSMEM64)
   int64_t k;
   ctrl[1] = HW_PHYSMEM64;
+#  elif defined(__FreeBSD__) || defined(__DragonFly__)
+  unsigned long k;
 #  else
   int k;
 #  endif
@@ -5406,6 +5408,21 @@ bool SystemInformationImplementation::QueryBSDMemory()
 
   this->TotalPhysicalMemory = k >> 10 >> 10;
 
+#  if defined(__FreeBSD__)
+  u_int freeCount;
+  u_int pageSize;
+  sz = sizeof(freeCount);
+  if (sysctlbyname("vm.stats.vm.v_free_count", &freeCount, &sz, nullptr, 0) ==
+      0) {
+    sz = sizeof(pageSize);
+    if (sysctlbyname("vm.stats.vm.v_page_size", &pageSize, &sz, nullptr, 0) ==
+        0) {
+      this->AvailablePhysicalMemory =
+        (static_cast<uint64_t>(freeCount) * pageSize) >> 10 >> 10;
+    }
+  }
+#  endif
+
   return true;
 #else
   return false;