Re: Script Debugging Modules?

[Daniel Chetlin]

On Sun, Dec 10, 2000 at 07:26:38PM -0800, Bill Moseley wrote:
 Just how smart is the compiler?
[snip]
 use constant DEBUG_TEMPLATE  = 1;
 use constant DEBUG_SESSION   = 2;
 use constant DEBUG_REQUEST   = 4;
 use constant DEBUG_QUERY = 8;
 use constant DEBUG_QUERY_PARSED  = 16;
 
 my $debug = DEBUG_REQUEST|DEBUG_QUERY;
 
 warn "query = '$query'\n" if $debug  DEBUG_QUERY;

Not quite that smart. It has no idea if `$debug' will have changed by
the time you're asking about it. However, if you make `$debug' into a
constant, it will work (where "work" is defined as "optimize out the
conditional").

  use constant FOO = 1;
  use constant BAR = 2;
  use constant FOOBAR = FOO|BAR;
  warn "baz" if FOOBAR  FOO;

 use constant DEBUG_TEMPLATE  = 0;  # OFF
 use constant DEBUG_SESSION   = 1;  # ON
 use constant DEBUG_REQUEST   = 0;
 use constant DEBUG_QUERY = 1;  # ON
 use constant DEBUG_QUERY_PARSED  = 0;
 
 warn $query if DEBUG_QUERY || DEBUG_QUERY_PARSED;

This will also work, but I like the first approach better. It allows you
to factor out the component you want to debug.

-dlc

Re: Script Debugging Modules?

[Stas Bekman]

On Sun, 10 Dec 2000, Michael A. Nachbaur wrote:

 I'm starting a rather large project right now, and I want to make debugging
 as easy as possible for me.  The only way I know of debugging under mod_perl
 is the typical 'print STDERR foo' technique.  There must be a better way
 then that, whether automating the 'print STDERR', or giving me logs of what
 was called when (doubtful).

You can do the normal -d debug under mod_perl, see:
http://perl.apache.org/guide/debug.html

BTW, has anyone came with a solution for ptkdb to work more than once
under mod_perl? The author has never replied to my inqueries :( 

 Basically, I was thinking of having something like syslog, but for my perl
 modules.  I'd also like to be able to limit the debugging output on a
 per-module basis.  Anyone know of anything like this, before I build one?

package Foo;
use constant DEBUG = 1;
...
warn "foo" if DEBUG;
...

package Bar;
use constant DEBUG = 0;
...
warn "bar" if DEBUG;
...

you get the idea... Only warns in Foo will work...

you can keep the debug statements in the code without having any overhead
of doing if DEBUG, since they are stripped at compile time.


_
Stas Bekman  JAm_pH --   Just Another mod_perl Hacker
http://stason.org/   mod_perl Guide  http://perl.apache.org/guide 
mailto:[EMAIL PROTECTED]   http://apachetoday.com http://logilune.com/
http://singlesheaven.com http://perl.apache.org http://perlmonth.com/  

Script Debugging Modules?

[Michael A. Nachbaur]

I'm starting a rather large project right now, and I want to make debugging
as easy as possible for me.  The only way I know of debugging under mod_perl
is the typical 'print STDERR foo' technique.  There must be a better way
then that, whether automating the 'print STDERR', or giving me logs of what
was called when (doubtful).

Basically, I was thinking of having something like syslog, but for my perl
modules.  I'd also like to be able to limit the debugging output on a
per-module basis.  Anyone know of anything like this, before I build one?

Thanks.

-man
Michael A Nachbaur

Re: Script Debugging Modules?

[Bill Moseley]

At 08:04 PM 12/10/00 +0100, Stas Bekman wrote:
use constant DEBUG = 0;
...
warn "bar" if DEBUG;

you can keep the debug statements in the code without having any overhead
of doing if DEBUG, since they are stripped at compile time.

Just how smart is the compiler?

Maybe all these debugging options indicate there's too much stuff in this
module, but...

use constant DEBUG_TEMPLATE  = 1;
use constant DEBUG_SESSION   = 2;
use constant DEBUG_REQUEST   = 4;
use constant DEBUG_QUERY = 8;
use constant DEBUG_QUERY_PARSED  = 16;

my $debug = DEBUG_REQUEST|DEBUG_QUERY;

...

warn "query = '$query'\n" if $debug  DEBUG_QUERY;

Is the compiler that smart, or is there a better way such as 

use constant DEBUG_TEMPLATE  = 0;  # OFF
use constant DEBUG_SESSION   = 1;  # ON
use constant DEBUG_REQUEST   = 0;
use constant DEBUG_QUERY = 1;  # ON
use constant DEBUG_QUERY_PARSED  = 0;

warn $query if DEBUG_QUERY || DEBUG_QUERY_PARSED;



Bill Moseley
mailto:[EMAIL PROTECTED]