Why is this an issue?

Trailing comments should not be used. Comments are far better placed on the previous empty line of code, where they will be more visible and readable.

How to fix it

Code examples

Noncompliant code example

process(clk) is
begin
  if rising_edge(clk) then -- This very long comment is better placed before the line of code.
    xr <= not xr;
  end if;
end process;

Compliant solution

process(clk) is
begin
  -- This very long comment is more visible and readable on its own line.
  if rising_edge(clk) then
    xr <= not xr;
  end if;
end process;