testsuite/synth: add a test for #1080

1 files changed, 63 insertions, 0 deletions

diff --git a/testsuite/synth/issue1080/repro2_1.vhdl b/testsuite/synth/issue1080/repro2_1.vhdl
new file mode 100644
index 000000000..8a609e9cc
--- /dev/null
+++ b/testsuite/synth/issue1080/repro2_1.vhdl
@@ -0,0 +1,63 @@
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+entity repro2_1 is
+  port (
+    clk : std_logic;
+    rst : std_logic;
+    tx : out std_logic_vector(7 downto 0));
+end repro2_1;
+
+architecture behav of repro2_1 is
+  subtype byte_t is std_logic_vector(7 downto 0);
+
+  -- Define terminal newline characters (CR+LF)
+  constant NEWLINE_CR : byte_t := x"0d";
+  constant NEWLINE_LF : byte_t := x"0a";
+
+  -- Create ROM array with all concatenated messages.
+  type array_t is array(0 to 15) of byte_t;
+
+  impure function get_msg_array return array_t is
+    variable result : array_t := (others => (others => '0'));
+    variable ridx   : integer := 0;
+
+    procedure append(constant msg : string) is
+    begin
+        -- Append the message to the output array.
+        for c in 0 to msg'length-1 loop
+            result(ridx) := x"00";
+            ridx := ridx + 1;
+        end loop;
+        -- Then append the CR+LF characters.
+        result(ridx+0) := NEWLINE_CR;
+        result(ridx+1) := NEWLINE_LF;
+        ridx := ridx + 2;
+    end procedure;
+  begin
+    -- For each fixed message...
+    append("xx");
+    return result;
+  end function;
+
+  constant MESSAGE_ROM : array_t := get_msg_array;
+begin
+  process (clk)
+    variable p : natural;
+  begin
+    if rising_edge(clk) then
+      if rst = '1' then
+        p := 0;
+      else
+        tx <= message_rom (p);
+        if p = message_rom'right then
+          p := message_rom'left;
+        else
+          p := p + 1;
+        end if;
+      end if;
+    end if;
+  end process;
+end behav;
+