nvc report output is noisy

[m-kru]

Let us consider this simple testbench:

library ieee;
   use ieee.std_logic_1164.all;

entity test is
end entity;

architecture test of test is

   type foo_t is record
      a : std_logic;
      b : boolean;
      i : integer;
   end record;

   function to_str(f : foo_t) return string is
   begin
      return "('" & to_string(f.a) & "', " & to_string(f.b) & ", " & to_string(f.i) & ")";
   end function;

   function to_dbg(f : foo_t) return string is
   begin
      return "(" & LF &
         "   a => '" & to_string(f.a) & "', " & LF &
         "   b => "& to_string(f.b) & ", " & LF &
         "   i =>  " & to_string(f.i) & LF &
         ")";
   end function;

begin

   main : process is
      variable f : foo_t := ('0', true, 10);
   begin
      report to_str(f);
      report to_dbg(f);

      std.env.finish;
   end process;

end architecture;

The output:

** Note: 0ms+0: Report Note: ('0', true, 10)
	 /home/mkru/workspace/tmp/vhdl-string/test.vhd:34
** Note: 0ms+0: Report Note: (
   a => '0',
   b => true,
   i =>  10
)
	 /home/mkru/workspace/tmp/vhdl-string/test.vhd:35

In my humble opinion it is noisy.

I do not have any particular idea how to improve it, I just would like to open a discussion.

My first question is why do we have Note and Report Note? What does the first Note refer to?

My second question is whether file and line number should be displayed by default? Maybe it should be displayed only if some additional flag is provided when running the simulation?

[nickg]

There is --messages=compact already which changes the output to:

test.vhd:34:7: note: 0ms+0: Report Note: ('0', true, 10)
test.vhd:35:7: note: 0ms+0: Report Note: (
   a => '0',
   b => true,
   i =>  10
)
../lib/std.08/env-body.vhd:40:9: note: 0ms+0: FINISH called

With --std=2019 there is also SetVhdlAssertFormat in the std.env package which allows you to fully customise the assert and report format.

[m-kru]

Ok, when I add --exit-severity=note note becomes fatal, but when I set, for example, --exit-severity=warning. The note is still note, it is not downgraded/upgraded. It looks like the first level is always the same as the second one, except in the last message if the simulator exists because of severity level. In such case, I think we could resign from repeating the level, and only print during the exit that simulation exits because of severity level. A few examples what we would get:

By default:

** 0ms+0: Note: ('0', true, 10)
	 /home/mkru/workspace/tmp/vhdl-string/test.vhd:34
** 0ms+0: Note: (
   a => '0',
   b => true,
   i => 10
)
	 /home/mkru/workspace/tmp/vhdl-string/test.vhd:35

With --messages=compact:

test.vhd:34:7: 0ms+0: Note: ('0', true, 10)
test.vhd:35:7: 0ms+0: Note: (
   a => '0',
   b => true,
   i =>  10
)
../lib/std.08/env-body.vhd:40:9: note: 0ms+0: FINISH called

Example output with --exit-severity=note (the last line is currently not present):

** 0ms+0: Note: ('0', true, 10)
	 /home/mkru/workspace/tmp/vhdl-string/test.vhd:43
nvc: exit with failure because of '--exit-severity=note'

Two more remarks:

1. Personally I do not see any value in adding ** at the beginning in the default mode. The line with file is already indented and stands out.
2. I do not see any value in adding column number after the line number in --messages=compact mode. Adding column number is nice when there are syntax or semantics errors during compilation as it allows to easily locate the problematic token. In the case of report (log) message having file and line number is more than enough.

A few examples what we would get:

By default:

0ms+0: Note: ('0', true, 10)
	 /home/mkru/workspace/tmp/vhdl-string/test.vhd:34
0ms+0: Note: (
   a => '0',
   b => true,
   i => 10
)
	 /home/mkru/workspace/tmp/vhdl-string/test.vhd:35

With --messages=compact:

test.vhd:34: 0ms+0: Note: ('0', true, 10)
test.vhd:35: 0ms+0: Note: (
   a => '0',
   b => true,
   i =>  10
)
../lib/std.08/env-body.vhd:40: note: 0ms+0: FINISH called

Example output with --exit-severity=note (the last line is currently not present):

0ms+0: Note: ('0', true, 10)
	 /home/mkru/workspace/tmp/vhdl-string/test.vhd:43
nvc: exit with failure because of '--exit-severity=note'

[nickg]

It's required by the LRM to include the word "report" at least. From section 10.4:

The report message consists of at least the following:
a) An indication that this message is from a report statement.
...

The column number is there so that an editor can easily parse it and jump to the right location.

Whether you like the ** or not is of course down to personal preference. I think it helps break up the output and it's used consistently in all the diagnostic messages nvc generates.

[m-kru]

The report message consists of at least the following:
a) An indication that this message is from a report statement.

Aren't automatically added words like Note:, Warning: etc. already an indication that this message is from a report statement? There is nothing about adding the report or Report word in the LRM.
Regardless of this, in test.vhd:34:7: note: 0ms+0: Report Note: ('0', true, 10) the info about the level is included twice note, and Report Note. The first level differs only when simulation exists because of --exit-severity. Printing the same information all the time because it might be different in the last message seems redundant. The first level info could be removed, and at the end nvc could simply print something like nvc: exit with failure because of '--exit-severity=note'. Correct me if I am wrong.

In the default mode there is no column number at the end.

[m-kru]

@nickg bump

[nickg]

I am not sure what you are hoping to achieve by "bumping" this. I am quite busy with other things at the moment (such as my day job) and any support is provided on a best effort basis (see the "Reporting bugs" section of the README). This is a purely cosmetic issue which is not blocking you from using the tool.

[m-kru]

I have tried --messages=compact. However, in my case full path to the file is printed, not only file name.

nvc --messages=compact --std=2019 -L. -r tb_prot_funcs --wave
note: writing FST waveform data to tb_prot_funcs.fst
/home/mkru/workspace/vhdl/vhdl-amba/apb/tb/tb-prot-funcs.vhd:15:7: note: 0ms+0: Report Note: ('0', '0', '0')
/home/mkru/workspace/vhdl/vhdl-amba/apb/tb/tb-prot-funcs.vhd:16:7: note: 0ms+0: Report Note: (
   data_instruction => '0',
   secure_non_secure => '0',
   normal_privileged => '0'
)

[nickg]

That's probably because you passed an absolute file name when you analysed the source.

[m-kru]

Can this be changed to print file name only?

[nickg]

That's not very useful if you have multiple files in a project with the same name but different directory.

[m-kru]

Unique paths can be constructed. For example, some/path/a/foo.vhd, some/path/b/foo.vhd. path2/bar.vhd would yield a/foo.vhd, b/foo.vhd, and bar.vhd.