Correct errors when compiling with GHDL. Add some tests without modif…

…ying the old ones. All test with GHDL passes (in 93 and 2008) for all tests in vunit/vhdl (GHDL 3.0.0-dev (v2.0.0-101-g791ff0c1) [Dunoon edition] Compiled with GNAT Version: 9.3.0. GCC back-end code generator)

vunit/vhdl/data_types/src/codec.vhd

@@ -36,7 +36,7 @@ package codec_pkg is
   --===========================================================================
   -- All data going through the encoding process becomes a string: it
   -- basically becomes a sequence of bytes without any overhead for type
-  -- information. The 'codec' package doesn’t know if four bytes represents an
+  -- information. The 'codec' package does not know if four bytes represents an
   -- integer, four characters or something else. The interpretation of these
   -- bytes takes place when the user decodes the data using a type specific
   -- 'decode' function.

vunit/vhdl/data_types/src/codec_builder.vhd

@@ -1057,8 +1057,6 @@ package body codec_builder_pkg is
   -----------------------------------------------------------------------------
   procedure encode_string(constant data : in string; variable index : inout code_index_t; variable code : inout code_t) is
   begin
-    -- Note: Modelsim sets data'right to 0 which is out of the positive
-    -- index range used by strings.
     encode_range(data'left, data'right, data'ascending, index, code);
     encode_raw_string(data, index, code);
   end procedure;
@@ -1074,12 +1072,13 @@ package body codec_builder_pkg is
   -----------------------------------------------------------------------------
   procedure encode_raw_bit_array(constant data : in bit_array; variable index : inout code_index_t; variable code : inout code_t) is
     constant actual_code_length : natural := code_length_raw_bit_array(data);
-    variable value : ieee.numeric_bit.unsigned(data'length-1 downto 0) := ieee.numeric_bit.unsigned(data);
-    constant BYTE_MASK : ieee.numeric_bit.unsigned(data'length-1 downto 0) := resize(to_unsigned(basic_code_nb_values-1, basic_code_length), data'length);
+    variable value : bit_array(ceil_div(data'length, basic_code_length)*basic_code_length-1 downto 0);
+    variable byte : bit_array(basic_code_length-1 downto 0);
   begin
-    for i in actual_code_length-1 downto 0 loop
-      code(index + i) := character'val(to_integer(value and BYTE_MASK));
-      value := value srl basic_code_length;
+    value(data'length-1 downto 0) := data;
+    for i in 0 to actual_code_length-1 loop
+      byte := value(basic_code_length*(i+1)-1 downto basic_code_length*i);
+      code(index + actual_code_length - i - 1) := character'val(to_integer(ieee.numeric_bit.unsigned(byte)));
     end loop;
     index := index + actual_code_length;
   end procedure;
@@ -1123,8 +1122,12 @@ package body codec_builder_pkg is
   procedure decode_bit_vector(constant code : in code_t; variable index : inout code_index_t; variable result : out bit_vector) is
     variable ret_val : bit_array(result'range);
   begin
-    decode_bit_array(code, index, ret_val);
-    result := bit_vector(ret_val);
+    if ret_val'length /= 0 then -- GHDL work-around (see explanation at the end of the file)
+      decode_bit_array(code, index, ret_val);
+      result := bit_vector(ret_val);
+    else
+      result := "";
+    end if;
   end procedure;
 
   -----------------------------------------------------------------------------
@@ -1138,8 +1141,12 @@ package body codec_builder_pkg is
   procedure decode_numeric_bit_unsigned(constant code : in code_t; variable index : inout code_index_t; variable result : out ieee.numeric_bit.unsigned) is
     variable ret_val : bit_array(result'range);
   begin
-    decode_bit_array(code, index, ret_val);
-    result := ieee.numeric_bit.unsigned(ret_val);
+    if ret_val'length /= 0 then -- GHDL work-around (see explanation at the end of the file)
+      decode_bit_array(code, index, ret_val);
+      result := ieee.numeric_bit.unsigned(ret_val);
+    else
+      result := "";
+    end if;
   end procedure;
 
   -----------------------------------------------------------------------------
@@ -1153,8 +1160,12 @@ package body codec_builder_pkg is
   procedure decode_numeric_bit_signed(constant code : in code_t; variable index : inout code_index_t; variable result : out ieee.numeric_bit.signed) is
     variable ret_val : bit_array(result'range);
   begin
-    decode_bit_array(code, index, ret_val);
-    result := ieee.numeric_bit.signed(ret_val);
+    if ret_val'length /= 0 then -- GHDL work-around (see explanation at the end of the file)
+      decode_bit_array(code, index, ret_val);
+      result := ieee.numeric_bit.signed(ret_val);
+    else
+      result := "";
+    end if;
   end procedure;
 
   -----------------------------------------------------------------------------
@@ -1227,8 +1238,12 @@ package body codec_builder_pkg is
 
   procedure decode_std_ulogic_array(constant code : in code_t; variable index : inout code_index_t; variable result : out std_ulogic_array) is
   begin
-    index := index + code_length_integer_range;
-    decode_raw_std_ulogic_array(code, index, result);
+    if result'length /= 0 then -- GHDL work-around (see explanation at the end of the file)
+      index := index + code_length_integer_range;
+      decode_raw_std_ulogic_array(code, index, result);
+    else
+      result := "";
+    end if;
   end procedure;
 
   -----------------------------------------------------------------------------
@@ -1242,8 +1257,12 @@ package body codec_builder_pkg is
   procedure decode_std_ulogic_vector(constant code : in code_t; variable index : inout code_index_t; variable result : out std_ulogic_vector) is
     variable ret_val : std_ulogic_array(result'range);
   begin
-    decode_std_ulogic_array(code, index, ret_val);
-    result := std_ulogic_vector(ret_val);
+    if ret_val'length /= 0 then -- GHDL work-around (see explanation at the end of the file)
+      decode_std_ulogic_array(code, index, ret_val);
+      result := std_ulogic_vector(ret_val);
+    else
+      result := "";
+    end if;
   end procedure;
 
   -----------------------------------------------------------------------------
@@ -1257,8 +1276,12 @@ package body codec_builder_pkg is
   procedure decode_numeric_std_unsigned(constant code : in code_t; variable index : inout code_index_t; variable result : out ieee.numeric_std.unsigned) is
     variable ret_val : std_ulogic_array(result'range);
   begin
-    decode_std_ulogic_array(code, index, ret_val);
-    result := ieee.numeric_std.unsigned(ret_val);
+    if ret_val'length /= 0 then -- GHDL work-around (see explanation at the end of the file)
+      decode_std_ulogic_array(code, index, ret_val);
+      result := ieee.numeric_std.unsigned(ret_val);
+    else
+      result := "";
+    end if;
   end procedure;
 
   -----------------------------------------------------------------------------
@@ -1272,8 +1295,12 @@ package body codec_builder_pkg is
   procedure decode_numeric_std_signed(constant code : in code_t; variable index : inout code_index_t; variable result : out ieee.numeric_std.signed) is
     variable ret_val : std_ulogic_array(result'range);
   begin
-    decode_std_ulogic_array(code, index, ret_val);
-    result := ieee.numeric_std.signed(ret_val);
+    if ret_val'length /= 0 then -- GHDL work-around (see explanation at the end of the file)
+      decode_std_ulogic_array(code, index, ret_val);
+      result := ieee.numeric_std.signed(ret_val);
+    else
+      result := "";
+    end if;
   end procedure;
 
 
@@ -1338,4 +1365,21 @@ package body codec_builder_pkg is
     return bit_vector(ret_val);
   end function;
 
+
+
+  --===========================================================================
+  -- GHDL limitations
+  --===========================================================================
+
+  -- GHDL work-around: GHDL raises an error when casting a null
+  -- range of type bit_array(-1 downto 0) to bit_vector.
+  -- Error: 'bound check failure'
+  -- However:
+  -- LRM VHDL-2008: '5.2.1 General'
+  -- > A constraint is compatible with a subtype if each bound of the
+  --   range belongs to the subtype or if the range constraint defines
+  --   a null range. Otherwise, the range constraint is not compatible
+  --   with the subtype.
+  -- This happens for conversion between array types
+
 end package body;

vunit/vhdl/data_types/test/tb_codec.vhd

@@ -16,6 +16,7 @@ use vunit_lib.path.all;
 use vunit_lib.queue_pkg.all;
 use vunit_lib.integer_vector_ptr_pkg.all;
 use vunit_lib.codec_pkg.all;
+use vunit_lib.codec_builder_pkg.all;
 
 library ieee;
 use ieee.std_logic_1164.all;
@@ -94,7 +95,9 @@ begin
     variable null_string         : string(10 to 9);
     variable t1  : time;
     variable string_15_downto_4 : string(15 downto 4);
+    variable bit_array_m3_downto_m5 : bit_array(-3 downto -5);
     variable bit_vector_5_downto_3 : bit_vector(5 downto 3);
+    variable std_ulogic_array_m3_downto_m5 : std_ulogic_array(-3 downto -5);
     variable std_ulogic_vector_5_downto_3 : std_ulogic_vector(5 downto 3);
     variable numeric_bit_unsigned_5_downto_3 : ieee.numeric_bit.unsigned(5 downto 3);
     variable numeric_bit_signed_5_downto_3 : ieee.numeric_bit.signed(5 downto 3);
@@ -108,12 +111,24 @@ begin
     function get_decoded_range_right ( constant vec: string ) return integer is
     begin return vec'right; end;
 
+    function get_decoded_range_left ( constant vec: bit_array ) return integer is
+    begin return vec'left; end;
+
+    function get_decoded_range_right ( constant vec: bit_array ) return integer is
+    begin return vec'right; end;
+
     function get_decoded_range_left ( constant vec: bit_vector ) return integer is
     begin return vec'left; end;
 
     function get_decoded_range_right ( constant vec: bit_vector ) return integer is
     begin return vec'right; end;
 
+    function get_decoded_range_left ( constant vec: std_ulogic_array ) return integer is
+    begin return vec'left; end;
+
+    function get_decoded_range_right ( constant vec: std_ulogic_array ) return integer is
+    begin return vec'right; end;
+
     function get_decoded_range_left ( constant vec: std_ulogic_vector ) return integer is
     begin return vec'left; end;
 
@@ -219,6 +234,14 @@ begin
         check_relation(decode_string(encode_string(string_15_downto_4)) = string'("Hello world!"));
         check_relation(get_decoded_range_left(decode_string(encode_string(string_15_downto_4))) = 15);
         check_relation(get_decoded_range_right(decode_string(encode_string(string_15_downto_4))) = 4);
+      elsif run("Test that bit_array can be encoded and decoded") then
+        bit_array_m3_downto_m5 := "101";
+        check_relation(decode_bit_array(encode_bit_array("101")) = bit_array'("101"));
+        check_relation(decode_bit_array(encode_bit_array("1")) = bit_array'("1"));
+        check_relation(decode_bit_array(encode_bit_array("")) = bit_array'(""));
+        check_relation(decode_bit_array(encode_bit_array(bit_array_m3_downto_m5)) = bit_array'("101"));
+        check_relation(get_decoded_range_left(decode_bit_array(encode_bit_array(bit_array_m3_downto_m5))) = -3);
+        check_relation(get_decoded_range_right(decode_bit_array(encode_bit_array(bit_array_m3_downto_m5))) = -5);
       elsif run("Test that bit_vector can be encoded and decoded") then
         bit_vector_5_downto_3 := "101";
         check_relation(decode_bit_vector(encode_bit_vector("101")) = bit_vector'("101"));
@@ -227,6 +250,14 @@ begin
         check_relation(decode_bit_vector(encode_bit_vector(bit_vector_5_downto_3)) = bit_vector'("101"));
         check_relation(get_decoded_range_left(decode_bit_vector(encode_bit_vector(bit_vector_5_downto_3))) = 5);
         check_relation(get_decoded_range_right(decode_bit_vector(encode_bit_vector(bit_vector_5_downto_3))) = 3);
+      elsif run("Test that std_ulogic_array can be encoded and decoded") then
+        std_ulogic_array_m3_downto_m5 := "XU1";
+        check_relation(decode_std_ulogic_array(encode_std_ulogic_array("XU1")) = std_ulogic_array'("XU1"));
+        check_relation(decode_std_ulogic_array(encode_std_ulogic_array("X")) = std_ulogic_array'("X"));
+        check_relation(decode_std_ulogic_array(encode_std_ulogic_array("")) = std_ulogic_array'(""));
+        check_relation(decode_std_ulogic_array(encode_std_ulogic_array(std_ulogic_array_m3_downto_m5)) = std_ulogic_array'("XU1"));
+        check_relation(get_decoded_range_left(decode_std_ulogic_array(encode_std_ulogic_array(std_ulogic_array_m3_downto_m5))) = -3);
+        check_relation(get_decoded_range_right(decode_std_ulogic_array(encode_std_ulogic_array(std_ulogic_array_m3_downto_m5))) = -5);
       elsif run("Test that std_ulogic_vector can be encoded and decoded") then
         std_ulogic_vector_5_downto_3 := "XU1";
         check_relation(decode_std_ulogic_vector(encode_std_ulogic_vector("XU1")) = std_ulogic_vector'("XU1"));