From b100e2612fad57a9c0c07d2fbb41b05ffec787d2 Mon Sep 17 00:00:00 2001
From: tmeissner <programming@goodcleanfun.de>
Date: Thu, 18 Feb 2021 12:21:15 +0100
Subject: [PATCH] Add issue code for ghdl/ghdl#1654

---
 issues/issue_1654.vhd | 122 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 issues/issue_1654.vhd

diff --git a/issues/issue_1654.vhd b/issues/issue_1654.vhd
new file mode 100644
index 0000000..57961c2
--- /dev/null
+++ b/issues/issue_1654.vhd
@@ -0,0 +1,122 @@
+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;
+
+
+entity issue is
+  port (
+    clk : in std_logic
+  );
+end entity issue;
+
+
+architecture psl of issue is
+
+  signal a, b, c, d : std_logic;
+
+begin
+
+  -- async reset 100 ps after rising edge in cycle 1
+  d <= '0', '1' after 1100 ps, '0' after 1400 ps;
+
+  --                              0123456789
+  SEQ_A : entity work.sequencer generic map ("-___-_____") port map (clk, a);
+  SEQ_B : entity work.sequencer generic map ("_______-__") port map (clk, b);
+  SEQ_C : entity work.sequencer generic map ("-_________") port map (clk, c);
+  --  D :                                     _|________
+
+  -- All is sensitive to rising edge of clk
+  default clock is rising_edge(clk);
+
+  -- This assertion holds
+  WITH_ABORT_0_a : assert (always a -> next (b before a)) abort c;
+
+  -- This assertion should also hold, but it does not
+  -- GHDL seems to implement abort as sync_abort instead of async_abort
+  -- See 1850-2010 6.2.1.5.1 abort, async_abort, and sync_abort
+  WITH_ABORT_1_a : assert (always a -> next (b before a)) abort d;
+
+
+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 := 29;
+  begin
+    loop
+      wait until rising_edge(clk);
+      index := index - 1;
+      exit when index = 0;
+    end loop;
+    stop(0);
+  end process;
+
+
+end architecture sim;
\ No newline at end of file