ghdl: fix llvm backend, add passthru.tests

pkgs/development/compilers/ghdl/default.nix

···
-{ stdenv, fetchFromGitHub, gnat, zlib, llvm, lib
+{ stdenv, fetchFromGitHub, callPackage, gnat, zlib, llvm, lib
 , backend ? "mcode" }:
 
 assert backend == "mcode" || backend == "llvm";
···
   LIBRARY_PATH = "${stdenv.cc.libc}/lib";
 
   buildInputs = [ gnat zlib ] ++ lib.optional (backend == "llvm") [ llvm ];
+  propagatedBuildInputs = lib.optionals (backend == "llvm") [ zlib ];
 
   preConfigure = ''
     # If llvm 7.0 works, 7.x releases should work too.
···
   hardeningDisable = [ "format" ];
 
   enableParallelBuilding = true;
+
+  passthru = {
+    # run with either of
+    # nix-build -A ghdl-mcode.passthru.tests
+    # nix-build -A ghdl-llvm.passthru.tests
+    tests = {
+      simple = callPackage ./test-simple.nix { inherit backend; };
+    };
+  };
 
   meta = with lib; {
     homepage = "https://github.com/ghdl/ghdl";

pkgs/development/compilers/ghdl/expected-output.txt

···
+simple-tb.vhd:71:5:@700ms:(report note): 32
+simple-tb.vhd:71:5:@900ms:(report note): 78
+simple-tb.vhd:71:5:@1100ms:(report note): 105
+simple-tb.vhd:71:5:@1300ms:(report note): 120
+simple-tb.vhd:71:5:@1500ms:(report note): 79
+simple-tb.vhd:71:5:@1700ms:(report note): 83
+simple-tb.vhd:71:5:@1900ms:(report note): 32
+simple-tb.vhd:75:1:@2100ms:(report note): All tests passed.

pkgs/development/compilers/ghdl/simple-tb.vhd

···
+library ieee;
+use IEEE.STD_LOGIC_1164.all;
+use ieee.numeric_std.all;
+
+library STD;
+use STD.textio.all;
+
+entity tb is
+end tb;
+
+architecture beh of tb is
+
+component simple
+port (
+    CLK, RESET : in std_ulogic;
+    DATA_OUT : out std_ulogic_vector(7 downto 0);
+    DONE_OUT : out std_ulogic
+);
+end component;
+
+signal data : std_ulogic_vector(7 downto 0) := "00100000";
+signal clk : std_ulogic;
+signal RESET : std_ulogic := '0';
+signal done : std_ulogic := '0';
+signal cyclecount : integer := 0;
+
+constant cycle_time_c : time := 200 ms;
+constant maxcycles : integer := 100;
+
+begin
+
+simple1 : simple
+port map (
+    CLK => clk,
+    RESET => RESET,
+    DATA_OUT => data,
+    DONE_OUT => done
+);
+
+clk_process : process
+begin
+    clk <= '0';
+    wait for cycle_time_c/2;
+    clk <= '1';
+    wait for cycle_time_c/2;
+end process;
+
+count_process : process(CLK)
+begin
+    if (CLK'event and CLK ='1') then
+    if (RESET = '1') then
+        cyclecount <= 0;
+    else
+        cyclecount <= cyclecount + 1;
+    end if;
+    end if;
+end process;
+
+test : process
+
+begin
+
+RESET <= '1';
+wait until (clk'event and clk='1');
+wait until (clk'event and clk='1');
+RESET <= '0';
+wait until (clk'event and clk='1');
+for cyclecnt in 1 to maxcycles loop
+    exit when done = '1';
+    wait until (clk'event and clk='1');
+    report integer'image(to_integer(unsigned(data)));
+end loop;
+wait until (clk'event and clk='1');
+
+report "All tests passed." severity NOTE;
+wait;
+end process;
+end beh;

pkgs/development/compilers/ghdl/simple.vhd

···
+library IEEE;
+use IEEE.STD_LOGIC_1164.all;
+use IEEE.NUMERIC_STD.ALL;
+use IEEE.STD_LOGIC_MISC.or_reduce;
+
+entity simple is
+
+port (
+    CLK, RESET : in std_ulogic;
+    DATA_OUT : out std_ulogic_vector(7 downto 0);
+    DONE_OUT : out std_ulogic
+);
+end simple;
+
+architecture beh of simple is
+
+signal data : std_ulogic_vector(7 downto 0);
+signal done: std_ulogic;
+
+begin
+
+proc_ctr : process(CLK)
+begin
+if (CLK = '1' and CLK'event) then
+    if (RESET = '1') then
+        data <= "01011111";
+        done <= '0';
+    else
+    case data is
+        when "00100000" =>  data <= "01001110";
+        when "01001110" =>  data <= "01101001";
+        when "01101001" =>  data <= "01111000";
+        when "01111000" =>  data <= "01001111";
+        when "01001111" =>  data <= "01010011";
+        when others =>  data <= "00100000";
+    end case;
+    done <= not or_reduce(data xor "01010011");
+    end if;
+end if;
+end process;
+
+DATA_OUT <= data;
+DONE_OUT <= done;
+
+end beh;

pkgs/development/compilers/ghdl/test-simple.nix

···
+{ stdenv, ghdl-llvm, ghdl-mcode, backend }:
+
+let
+  ghdl = if backend == "llvm" then ghdl-llvm else ghdl-mcode;
+in
+stdenv.mkDerivation {
+  name = "ghdl-test-simple";
+  meta.timeout = 300;
+  nativeBuildInputs = [ ghdl ];
+  buildCommand = ''
+    cp ${./simple.vhd} simple.vhd
+    cp ${./simple-tb.vhd} simple-tb.vhd
+    mkdir -p ghdlwork
+    ghdl -a --workdir=ghdlwork --ieee=synopsys simple.vhd simple-tb.vhd
+    ghdl -e --workdir=ghdlwork --ieee=synopsys -o sim-simple tb
+  '' + (if backend == "llvm" then ''
+    ./sim-simple --assert-level=warning > output.txt
+  '' else ''
+    ghdl -r --workdir=ghdlwork --ieee=synopsys tb > output.txt
+  '') + ''
+    diff output.txt ${./expected-output.txt} && touch $out
+  '';
+}