Add a dummy uhdm plugin It shows a deprecation warning and automatically loads the systemverilog plugin. Signed-off-by: Tomasz Gorochowik <tgorochowik@antmicro.com>

diff --git a/Makefile b/Makefile
index 5f3503f..91b0ba9 100644
--- a/Makefile
+++ b/Makefile

@@ -6,7 +6,7 @@
 #
 # SPDX-License-Identifier:ISC
 
-PLUGIN_LIST := fasm xdc params sdc ql-iob design_introspection integrateinv ql-qlf systemverilog dsp-ff
+PLUGIN_LIST := fasm xdc params sdc ql-iob design_introspection integrateinv ql-qlf systemverilog uhdm dsp-ff
 PLUGINS := $(foreach plugin,$(PLUGIN_LIST),$(plugin).so)
 PLUGINS_INSTALL := $(foreach plugin,$(PLUGIN_LIST),install_$(plugin))
 PLUGINS_CLEAN := $(foreach plugin,$(PLUGIN_LIST),clean_$(plugin))

diff --git a/uhdm-plugin/Makefile b/uhdm-plugin/Makefile
new file mode 100644
index 0000000..8018d76
--- /dev/null
+++ b/uhdm-plugin/Makefile

@@ -0,0 +1,11 @@
+# Copyright (C) 2022  The SymbiFlow Authors.
+#
+# Use of this source code is governed by a ISC-style
+# license that can be found in the LICENSE file or at
+# https://opensource.org/licenses/ISC
+#
+# SPDX-License-Identifier:ISC
+
+NAME = uhdm
+SOURCES = uhdm.cc
+include ../Makefile_plugin.common

diff --git a/uhdm-plugin/tests/Makefile b/uhdm-plugin/tests/Makefile
new file mode 100644
index 0000000..66d5a63
--- /dev/null
+++ b/uhdm-plugin/tests/Makefile

@@ -0,0 +1,9 @@
+# Copyright (C) 2020-2021  The SymbiFlow Authors.
+#
+# Use of this source code is governed by a ISC-style
+# license that can be found in the LICENSE file or at
+# https://opensource.org/licenses/ISC
+#
+# SPDX-License-Identifier:ISC
+
+include $(shell pwd)/../../Makefile_test.common

diff --git a/uhdm-plugin/uhdm.cc b/uhdm-plugin/uhdm.cc
new file mode 100644
index 0000000..2babb21
--- /dev/null
+++ b/uhdm-plugin/uhdm.cc

@@ -0,0 +1,38 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2022 Antmicro
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include "kernel/log.h"
+
+USING_YOSYS_NAMESPACE
+
+PRIVATE_NAMESPACE_BEGIN
+
+struct UhdmDummy {
+    UhdmDummy()
+    {
+        log("\n");
+        log("!! DEPRECATION WARNING !!\n");
+        log("\n");
+        log("The uhdm plugin has been renamed to systemverilog.\n");
+        log("Loading the systemverilog plugin...\n");
+
+        std::vector<std::string> plugin_aliases;
+        load_plugin("systemverilog", plugin_aliases);
+    }
+} UhdmDummy;
+
+PRIVATE_NAMESPACE_END