Add issue code for ghdl/ghdl#2336

issues/issue_2336.vhd

@@ -0,0 +1,136 @@
+library ieee;
+  use ieee.std_logic_1164.all;
+
+entity sequencer is
+  generic (
+    seq : string
+  );
+  port (
+    clk  : in  std_logic;
+    data : out std_logic
+  );
+end entity sequencer;
+
+architecture rtl of sequencer is
+
+  signal index : natural := seq'low;
+
+  function to_bit (a : in character) return std_logic is
+    variable ret : std_logic;
+  begin
+    case a is
+      when '0' | '_' => ret := '0';
+      when '1' | '-' => ret := '1';
+      when others    => ret := 'X';
+    end case;
+    return ret;
+  end function to_bit;
+
+begin
+
+  process (clk) is
+  begin
+    if rising_edge(clk) then
+      if (index < seq'high) then
+        index <= index + 1;
+      end if;
+    end if;
+  end process;
+
+  data <= to_bit(seq(index));
+
+end architecture rtl;
+
+
+library ieee;
+  use ieee.std_logic_1164.all;
+  use ieee.numeric_std.all;
+
+entity issue is
+  port (
+    clk : in std_logic
+  );
+end entity issue;
+
+architecture psl of issue is
+
+  signal a, b, c, d, e, f : std_logic;
+
+begin
+
+
+  --                                          012345678901
+  SEQ_A : entity work.sequencer generic map ("__-_________") port map (clk, a);
+
+  -- Next 3 sequences should hold with next[3:5]
+  --                                          012345678901
+  SEQ_B : entity work.sequencer generic map ("_____-______") port map (clk, b);
+  SEQ_C : entity work.sequencer generic map ("______-_____") port map (clk, c);
+  SEQ_D : entity work.sequencer generic map ("_______-____") port map (clk, d);
+
+  -- Next two sequences should not hold with next[3:5]
+  --                                          012345678901
+  SEQ_E : entity work.sequencer generic map ("____-_______") port map (clk, e);
+  SEQ_F : entity work.sequencer generic map ("________-___") port map (clk, f);
+
+
+  -- All is sensitive to rising edge of clk
+  default clock is rising_edge(clk);
+
+   -- This assertion should hold, but doesn't (GHDL BUG)
+  NEXT_0_a : assert always (a -> next_e[3 to 5] (b))
+    report "NEXT_0_a failed";
+
+  -- This assertion should hold, but doesn't (GHDL BUG)
+  NEXT_1_a : assert always (a -> next_e[3 to 5] (c))
+    report "NEXT_1_a failed";
+
+  -- This assertion holds (CORRECT)
+  NEXT_2_a : assert always (a -> next_e[3 to 5] (d))
+    report "NEXT_2_a failed";
+
+  -- This assertion doesn't hold (CORRECT)
+  NEXT_3_a : assert always (a -> next_e[3 to 5] (e))
+    report "NEXT_3_a failed";
+
+  -- This assertion doesn't hold (CORRECT)
+  NEXT_4_a : assert always (a -> next_e[3 to 5] (f))
+    report "NEXT_4_a failed";
+
+end architecture psl;
+
+library ieee;
+  use ieee.std_logic_1164.all;
+
+use std.env.all;
+
+
+entity test_issue is
+end entity test_issue;
+
+
+architecture sim of test_issue is
+
+  signal clk   : std_logic := '1';
+
+begin
+
+
+  clk <= not clk after 500 ps;
+
+  DUT : entity work.issue(psl) port map (clk);
+
+  -- stop simulation after 30 cycles
+  process
+    variable index : natural := 10;
+  begin
+    loop
+      wait until rising_edge(clk);
+      index := index - 1;
+      exit when index = 0;
+    end loop;
+    stop(0);
+  end process;
+
+
+end architecture sim;