Add UUID generation support for OpenBSD

2 files changed, 81 insertions, 0 deletions

diff --git a/libbutl/buildfile b/libbutl/buildfile
index a7b20f3..4dd952c 100644
--- a/libbutl/buildfile
+++ b/libbutl/buildfile
@@ -39,6 +39,7 @@ lib{butl}: cxx{uuid-linux}:   include = ($tclass == 'linux')
 lib{butl}: cxx{uuid-macos}:   include = ($tclass == 'macos')
 lib{butl}: cxx{uuid-windows}: include = $windows
 lib{butl}: cxx{uuid-freebsd}: include = ($tsys == 'freebsd' || $tsys == 'netbsd')
+lib{butl}: cxx{uuid-openbsd}: include = ($tsys == 'openbsd')
 
 # GCC prior to version 6 has flaky `#pragma GCC diagnostic` so we have to
 # disable certain warnings outright.
diff --git a/libbutl/uuid-openbsd.cxx b/libbutl/uuid-openbsd.cxx
new file mode 100644
index 0000000..b64436b
--- /dev/null
+++ b/libbutl/uuid-openbsd.cxx
@@ -0,0 +1,80 @@
+// file      : libbutl/uuid-openbsd.cxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BUILD2_BOOTSTRAP
+
+#include <libbutl/uuid.hxx>
+
+#include <uuid.h>
+
+#include <errno.h>
+
+#include <cassert>
+#include <cstring>      // memcpy()
+#include <system_error>
+
+using namespace std;
+
+namespace butl
+{
+  void
+  uuid_throw_weak (); // uuid.cxx
+
+  uuid uuid_system_generator::
+  generate (bool strong)
+  {
+    // The OpenBSD uuid_*() (<uuid.h>, uuid_compare(3)) API generates version
+    // 4 UUIDs (i.e. randomly generated) at least from version 6.4. For now we
+    // will assume that only random ones are strong.
+    //
+    // Here we assume uuid_t has the same definition as in FreeBSD/NetBSD (it
+    // is defined in <sys/uuid.h>).
+    //
+    uuid_t d;
+    uint32_t s;
+    uuid_create (&d, &s);
+
+    // None of the uuid_s_* errors seem plausible for this function so let's
+    // return the generic "not supported" error code.
+    //
+    if (s != uuid_s_ok)
+      throw system_error (ENOSYS, system_category ());
+
+    uuid r;
+
+    // This is effectively just memcpy() but let's reference the member names
+    // in case anything changes on either side.
+    //
+    r.time_low = d.time_low;
+    r.time_mid = d.time_mid;
+    r.time_hiv = d.time_hi_and_version;
+    r.clock_seq_hir = d.clock_seq_hi_and_reserved;
+    r.clock_seq_low = d.clock_seq_low;
+    memcpy (r.node, d.node, 6);
+
+    assert (r.variant () == uuid_variant::dce); // Sanity check.
+
+    if (strong)
+    {
+      switch (r.version ())
+      {
+      case uuid_version::random: break;
+      default:                   uuid_throw_weak ();
+      }
+    }
+
+    return r;
+  }
+
+  void uuid_system_generator::
+  initialize ()
+  {
+  }
+
+  void uuid_system_generator::
+  terminate ()
+  {
+  }
+}
+
+#endif // BUILD2_BOOTSTRAP