2 files changed, 67 insertions, 0 deletions
diff --git a/testsuite/issues/issue154/keep.vhdl b/testsuite/issues/issue154/keep.vhdl
new file mode 100644
index 0000000..7be4966
--- /dev/null
+++ b/testsuite/issues/issue154/keep.vhdl
@@ -0,0 +1,55 @@
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+--  Led positions
+--
+--  I         D3
+--  r
+--  D     D2  D5  D4
+--  A
+--            D1
+--
+entity leds is
+  port (clk : in std_logic;
+        led1, led2, led3, led4, led5 : out std_logic);
+end leds;
+architecture blink of leds is
+
+signal clk_4hz: std_logic := '0';
+constant gates: integer := 3 - 1;
+signal max: integer := 3e6;
+signal A: std_logic_vector(0 to gates) := ( others => '0');
+
+attribute keep: boolean;
+attribute keep of A: signal is true;  
+
+signal B: std_logic := '1';
+signal C: std_logic := '1';
+signal val: std_logic := '0';
+signal data: std_logic := '0';
+
+begin 
+  process (clk)
+    variable counter : unsigned (23 downto 0) := (others => '0');
+  begin
+    if rising_edge(clk) then
+      if counter >= max then
+        counter := x"000000";
+        clk_4hz <= not clk_4hz;
+      else
+        counter := counter + 1;
+      end if;
+    end if;
+  end process;
+
+GEN:
+    for i in 0 to gates generate
+        A(i) <= not A(gates - i);    
+    end generate GEN;
+
+  led2 <= clk_4hz;
+  led3 <= clk_4hz;
+  led4 <= clk_4hz;
+  led5 <= clk_4hz;
+end;
diff --git a/testsuite/issues/issue154/testsuite.sh b/testsuite/issues/issue154/testsuite.sh
new file mode 100755
index 0000000..8ed5a44
--- /dev/null
+++ b/testsuite/issues/issue154/testsuite.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+
+topdir=../..
+. $topdir/testenv.sh
+
+run_yosys -Q -q -p "ghdl keep.vhdl -e; write_verilog keep.v"
+
+# Check the signal still exists
+fgrep -q "wire [2:0] a" keep.v
+
+rm -f *.v
+echo OK