Re: Disabling string evaluation in a logging system

[Gautier write-only <gautier_niouzes@hotmail.com>]

On 18 Mai, 09:48, dhenry <tfc.d...@gmail.com> wrote:

> In a language like C or C++, I would use the preprocessor:
> #define LOG(text, level) if (level > 0) { log.write (text, level) }
>
> I'm wondering how in Ada 95 and/or Ada 2005 I could write such a
> logging system (if it's possible). The goal is that logging should not
> be too intrusive in my code.

Yes. You can get the same in (and within) Ada with the magic of the
Inline pragma.
Gnatchop the following:

--8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<---
package Log is
  procedure Write (Text: String; Level: Natural);
  pragma Inline(Write);
end Log;
--
with Ada.Text_IO;
package body Log is
  procedure Write (Text: String; Level: Natural) is
  begin
    if Level > 0 then
      Ada.Text_IO.Put_Line("Log: " & Text);
    end if;
  end Write;
end Log;
--
with Log;
procedure Test_Opti_inline is
begin
  Log.Write (Text => "Blabla...", Level => 5);
  Log.Write (Text => "No no no!", Level => 0);
end;
--8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<---
Then:
gcc -S -gnatn test_opti_inline.adb
The string "No no no!" doesn't even appear in the assembler
listing :-)
HTH
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